1.
Production Of Polyhydroxybutyrate From Azotobacter Vinelandii Using Molasses And Whey As Substrates
by Samia Saeed | Ms. Asma Waris | Dr. Muhammad Tayyab | Ms. Sehrish.
Material type: ; Format:
print
; Literary form:
not fiction
Publisher: 2014Dissertation note: Polyhydroxybutyrate (PHB) is biodegradable polyester produced in nature by microbial fermentation and it is used as thermoplastic. Azotobacter vinelandii is a bacterium that accumulates PHB as intracellular granules in response to physiological stress such as excess of carbohydrate sources and limitation of nutrients e.g. nitrogen, oxygen and phosphorus etc. PHB produced in this work have great potential be used in various industries like pharmaceutics and food industry for packaging purposes and medical field. Recent research work was conducted to produce PHB form cheap agro industrial wastes like Molasses and Whey by fermentation. Different parameters such as substrate water ratio, incubation period, volume of inoculums and pH were optimized for maximum yield of PHB.
In this study fermentation media containing whey and molasses as substrates was used to check the production of PHB from the Azotobacter vinelandii. 0.5ml of inoculum media was taken in fermentation media and then kept for incubation for 24-72 hours. After incubation, culture media was centrifuged and then sediment was used for extraction, determination and identification of PHB.
It was found that Azotobacter vinelandii in molasses contained medium gives maximum yield of PHB (mg/100mL) at 4% substrate water ratio after 48 hours of incubation period (140 mg/100mL), at 2.5 mL of volume of inoculum (204 mg/100mL), at pH 8.0 (220 mg/100mL), at 0.2% of peptone (252 mg/100mL) and 0.25% (234 mg/100mL) of yeast extract. While 4% of substrate water ratio after 60 hours of incubation (128 mg/100mL), 2.0 mL of volume of inoculum (176 mg/100mL), pH 7.0 (192 mg/100mL), 0.25% of peptone (248 mg/100mL) and 0.25% of yeast extract (240 mg/100mL) were observed to be optimum parameters for maximum production of PHB from Azotobacter vinelandii in whey based medium. Data was analyzed by means of linear regression analysis to determine R (regression coefficient), which was used to find significant differences (P?0.05) in each experiment.
Conclusion: The results of present study show that molasses and whey are economically good substrates for production of polyhydroxybutyrate (biodegradable polymer) from Azotobacter vinelandii. The results also suggest that Azotobacter vinelandii is a good potential strain for production of PHB under optimized conditions.
Availability: Items available for loan: UVAS Library [Call number: 1810,T] (1).
2.
Production Purification And Characterization Of Alkaline Proteasefrom Aspergillus Flavus Using Agricultural
by Naheed ishrat | Miss Asma waris | Dr Waseem | Dr. Muhammad tayyab.
Material type: ; Format:
print
; Literary form:
drama
Publisher: 2014Dissertation note: Abstract Availability: Items available for loan: UVAS Library [Call number: 1872,T] (1).
3.
Optimization For The Production Of Amylase By Geobacillus Sbs-4S
by Nasreen abdul jabbar | Dr. Muhammad Tayyab | Dr. Ali Raza awan | Ms. Asma waris.
Material type: ; Format:
print
; Literary form:
not fiction
Publisher: 2014Dissertation note: Abstract Availability: Items available for loan: UVAS Library [Call number: 1905,T] (1).
4.
Effect of Ginger and Turmeric Against Cadmium Induced Hepato-Renal Toxicity in Albino Rats
by Hafiza Sajda Ashraf (2012-VA-578) | Ms.Asma Waris | Dr. Muhammad Tayyab | Dr. Sehrish Firyal.
Material type: ; Literary form:
not fiction
Publisher: 2014Dissertation note: Metal compounds and metal is natural elements of all ecosystems, moving between biosphere, hydrosphere, atmosphere and lithosphere. Metal complexes are increasingly introduced in the environment and could finally accumulate in a/biotic systems (Florea et al. 2005).
Contact to heavy metals is potentially damaging particularly for those metal compounds, which do not contain any physiological function in the metabolism of cells. A heavy metal is a part of an ill-defined subset of constituents that show metallic properties, which would mostly include the some metalliods, actinides, lanthanides and transition metals. Heavy metals have a high density and atomic weight much greater at least 5 times than water. Anthropogenic basis of heavy metals, i.e. contamination, have been introduced to the ecosystem waste-derived fuels are particularly prone to have heavy metals. More than 20 heavy metals, but inorganic arsenic, lead and cadmium are of particular concern (Gornal 1949).
Although, carcinogenic and toxic effects of metals have been observed in animals and humans, and that these metals form a key part in the normal functioning of biological cells. Some necessary transition metals like manganese, iron, zinc and copper contribute in controlling a variety of signaling and metabolic pathways. On the other hand their redox properties and coordination chemistry gave them an additional advantage that these metals might escape from the control mechanism such that homeostasis, partitioning, transport and binding to the designated cell elements and they interrelate with protein sites other than those which are tailor- made for them by displacing other metals from their natural binding sites. While, this process does not take place regularly, but the toxicity of metals can lead to impairment and dysfunctioning of cells (Leonard et al. 2004).
Oxidative stress is one of the main mechanisms of heavy metal toxicity. These metals are able to interact with DNA causing oxidative worsening of biological macromolecules and nuclear protein (Chen et al. 2001).
Metals like mercury, iron, cadmium, lead, copper and nickel, have the capability to produce reactive radicals, leading to cell damage like damage to lipid bilayer, depletion of enzyme activities and DNA (Stohs 1995). Moreover, these reactive radical species comprise a broad diversity of sulfur-, oxygen, nitrogen- and carbon radicals, initiating not only from lipid peroxides, hydrogen peroxide and superoxide radical but also in chelates of proteins complex peptide and amino acid, with the toxic metals. Metals produce reactive species, which in turn can cause nephrotoxicity, hepatotoxicity and neurotoxicity in humans and animals (Chen and Sthos 1995).
Cadmium is a natural metal located in the Periodic Table of the elements between mercury and zinc and the chemical behavior of cadmium is like a Zn. There is usually a divalent cation, complexd through other constituents (e.g CdCl2). Cadmium in the soil crust around 0.1ppm (Hans 1995) frequently being found as a contaminant in Pb or Zn deposits. In Zn or Pb smelting cadmium produced as a by product. Commercially, Cd is used in batteries, galvanizing steel, lasers, ink color, television screens, cosmetics and was used as an obstacle in nuclear fission and zinc to weld seals in water pipes made of lead before 1960. In the United States, approximately 600 metric tons are produced annually and about 150 tons are imported (US 2012).
Contact of Cd in human occurs mainly through ingestion or inhalation. Absorption through the skin contact is negligible. Intestinal absorption of cadmium is greater in individuals with zinc, calcium or iron deficiency (Nordberg et al. 2007).
The main source of cadmium exposure in human is considered to be the cigarette smoking (Friberg et al. 1983). Cd levels in blood and kidney are consistently elevated in smokers than nonsmokers. Inhalation exposure due to industry can be major occupational settings for example, soldering or welding and can cause a severe chemical pneumonitis (Nordberg et al 2007).
Exposure to cadmium from getting unhygienic food (eg, shellfish, leafy vegetables, rice regions of Japan and China and organ meats,) or water (either the old tap closed Zn / CD or a long-term industrial pollution) and can produce long-term effects on health (Abernethy et al. 2010).
After absorption, Cd is transported all over the body, often linked to a sulfhydryl group of protein such as metallothionein and about 30% deposits in the kidneys and 30% in the livers, and the rest scattered throughout the body (Argonne et al 2001). Half life of cadmium in the blood was estimated 75 to 128 days. (Jarup et al 1983). As a result urine, blood and hair Cd levels are poor substitutes for body burden and primarily reflect current contact; it is also true with the other heavy metals. Urine provocation test will require the estimation of cadmium in the body (Bernhoft et al. 2012).
The toxicity of cadmium has been shown in parts of body, cadmium induces tissue damage by creation of oxidative stress (Matovic et al. 2011; Patra et al. 2011; Cuypers et al. 2010) epigenetic changes in DNA expression (Wang et al. 2012; Martinez et al. 2011; Luparello 2012) mainly in the proximal segment of the renal tubule S1 (Vesay et al. 2010) inhibition or up regulation of transport routes (Therenod et al. 2012; Wan et al. 2012; Vankerkhove 2012).
Other pathologic mechanisms comprise competition disruption of the physiologic effects of Mg or Zn (Abdulla et al. 1989; Moulis et al. 2010; Shukla et al. 1984), destruction of mitochondrial function and inhibition of heme synthesis (Schauder et al. 2010), and potentially inducing apoptosis (Cannino et al. 2009). Glutathione reduction is observed, as structural deformation of proteins due sulfhydryl groups bind to the cadmium (Valko et al. 2005). Moreover, these effects are amplified by contact with other toxic metals such as As and Pb (Whittaker et al. 2011) and may be ameliorated by Se or Zn and by factors increasing levels of Nrf2 (Wang et al. 2012; Kcwill 2012).
Medicinal plants are plants having inherent active components used to treat disease or relieve pain (Okigboet et al. 2008). In most developing countries traditional medicines and medicinal plants are used as healing agents for the maintenance of good physical condition (UNESCO 1996) and in developing countries 80% of the peoples relies on traditional medicines, usually herbal remedies, for their prime health care needs (Schmincke et al. 2003). Plants extracts and their products are used in medicines as herbal remedies and they are being used to cure diverse infections (Arekemase et al. 2011). Moreover, there has been an increased concern in the beneficial potential of medicinal plants or plant products containing antioxidant properties in plummeting free radical induced tissue injury (Gupta & Flora 2005). Plants make a vital contribution to health care. The medicinal properties of plants could be based on the antimicrobial, antipyretic, antioxidant, effects of the phytochemicals in them (Cowman 1999; Adesokan et al. 2008).
Natural antioxidants also in the form of crude extracts or their chemical ingredient are very efficient in retarding the devastating processes create by oxidative stress (Zengin et al. 2011) and the toxicity analysis of the majority of the medicinal plants are not yet fully appreciated it is usually accepted that drugs which are derivative of plant products are safer than their imitative counterparts (Oluyemi 2007).
Ginger (Zingiber officinale), is a part of the Zingiberaceae family, is a eminent spice used in your daily diet (Demin et al. 2010) and also utilized for the traditional treatment of several infirmities (Afzal et al 2001). Major components of ginger like shogaol, gingerol, diarylheptanoids and volatile oil, work as antioxidant, anti-diabetic, analgesic, antipyretic, anti-inflammatory, anti-lipid and anti-tumor (Penna et al. 2003; Kadnur et al. 2005; Islamr et al. 2008; Shim et al. 2011; Kim 2008; Wangw et al. 2009). Latest scientific research has exposed that ginger has many therapeutic such as anti-oxidant effects, a capability to restrain the formation of inflammatory complexs and direct anti-inflammatory effects (Thomson et al. 2002). Ginger extract have antioxidative features, since it can scavenge hydroxyl radicals and superoxide anion. Z. officinale was found to slow down the activity of peroxidation and lipoxygenase (Topic et al. 2002).
Another, frequently used spice of Zingiberaceae: ‘curcuma longa’ (turmeric) has shown its strong intrinsic activity as a healing agent for several ailments. The active ingerdient of turmeric is the Curcumin that (Curcuma langalinn) shows antioxidant property. It is a yellow coloured phenolic pigment yield from the turmeric rhizomes (family Zingiberaceae).The most significant characteristic of curcumin is that it has no side consequences, regardless of the therapeutic agent in a number of useful purposes. It acts as a scavenger of free radicals (Khanna et al. 1999). Curcumin is considered to be an efficient antioxidant against oxidative tissue damage. It can considerably restrain the generation of reactive oxygen species (Joe et al. 1994) Moreover, curcumin is considered to be a powerful inhibitor tumour cells proliferation (Joe et al. 2004) a powerful cancer chemopreventive agent (Duvoix et al. 2005; Aggarwal et al. 2005) an dexhibits anti carcinogenic, anti-infective and anti viral properties (Araujo et al. 2001).
Availability: Items available for loan: UVAS Library [Call number: 2199,T] (1).
5.
Production Of Laccase By Immobilized White Rot Fungi And Its Application For The Decolorization Of Textile Effluent Dyes
by Iqra Ghulam Rasool (2012-VA-579) | Ms. Faiza Masood | Dr. Muhammad Tayyab | Prof. Dr. Tahir Yaqub.
Material type: ; Literary form:
not fiction
Publisher: 2014Dissertation note: Textile wastewater effluent contains several types of dyes that are toxic, carcinogenic, and dangerous for environment (Nyanhongo et al. 2002). More than 10,000 different kinds of dyes and pigments are used in dyeing and textile industries. Approximately 8, 00, 000 tons colorant is produced annually and 10% of used dyes are enters the environment in the form of wastes. There are different types of textile dyes such as direct dyes, disperse dyes, reactive dyes, acid dyes, and basic dyes. Wastewater effluents discharge from textile industries contain more than 10-15% of these dyes (Kunamneni et al. 2007). Such wastewater effluents are being discharged into water stream without or after only partial treatments, causing water pollution and negatively affecting the aquatic life. The treatment of textile wastewater effluents are of major environment concerns (Nyanhongo et al. 2002).
White rot fungi (WRF) is a wide class of fungi and it is mostly comprised of basidiomycetes, ascomycetes and lignin-decomposing fungi (Wesenberg et al. 2003). WRF are the most abundant wood degraders, and are so named because they leave a bleached appearance of the wood fibers following their attack. WRF has the ability to degrade contaminants by virtue of the nonspecific nature of its extracellular ligninolytic enzyme system (Nyanhongo et al. 2002)
The white rot fungus is also known as lignin degraders because it degrades lignin effectively due to some enzymes present in it. The important enzymes involves in degradation of lignin are following: (i) lignin peroxidase: It oxidizes both phenolics and non pheolics compounds, (ii) manganese-dependent peroxidase, (iii) laccase: It oxidises phenolic compounds and produce phenoxy radicals and quinones; (iv) glucose oxidase and glyoxal oxidase used for H2O2 production, and (v) celloulobiose quinone oxidoreductase for quinone reduction (Kunamneni et al. 2007).
Laccase (oxidoreductase, EC 1.10.3.2) belongs to polyphenol oxidases group of enzymes. Copper atoms are present in the catalytic center of enzyme so it is also known as multicopper oxidases (Baldrain et al. 2006). The molecular mass of laccase is 50–100 kDa (Couto and Toca 2006). According to the mechanism of laccase, it carries out the reduction of oxygen to water along with the oxidation of its substrate. Laccases oxidize wide range of compounds such as polyphenols, methoxy substituted phenols, aromatic diamines, and other compounds (Baldrain et al. 2006).
The substrate specificity of laccase is very wide and broad. In ortho and para substituted mono and polyphenolics substrate, it carries out reduction by removing hydrogen atom from hydroxyl group. In aromatic amines, it removes one electron and produces free radicals. These radical are able of many other reactions such as depolymerization, repolymerization, demethylation, or quinone formation. During lignin degradation, oxidation of methoxyhydroquinones followed by auto-oxidation of the methoxysemiquinones. Furthermore, formation of superoxide anion radicals undergoes more chemical reactions. The activity of laccase may be increased by using different kind of activators, such as ABTS (2, 2-azinobis (3-ethylbenzthiazoline- sulfonic acid), 1-hydroxybenzotriazole, or compounds secreted by fungi (Abadulla et al. 2000). In the presence of ABTS, the decolorization efficiency increases up to 45% (Tong et al. 2007).
Laccases have been produced from different kind of sources such as some species of fungus like white rot fungi, different kinds of bacteria, and some insects (Heinzkill et al. 1998; Diamantidis et al. 2000; Dittmer and Kanost 2010). This enzyme is widely distributed in Ascomycetes, Deuteromycetes, and Basidiomycetes, WRF is the major source for the production of laccase enzyme because this fungi is involved in metabolism of lignin (Bourbonnais et al. 1995).
There are many applications of fugal laccases such as effluent decolorization discharged from industries, degradation of pulp released from paper and pulp industries, removal of phenolics compounds from alcohols, synthesis of organic compounds, biosensors, pharmaceutical sector (Yaver et al. 2001). This enzyme can also improve animal performance, increase nutrient digestibility when added to animal feed (Sharma et al. 2013). Fungal laccases have higher redox potential of +800mV as compared to plants or bacterial laccases that’s why there are several applications of laccase in biotechnology field especially in the decolorization of dyes. Enzymes can be produce in larger amount so that laccase based decolorization techniques are advantageous to bioremediation technologies (Devi et al. 2012).
Pleurotus is a species of WRF and few laccases have been isolated, purified and cloned from Pleurotus species. However, the physiological significance of laccase produced by the white rot fungi is not known. Literature reports that mycelia culture of Pleurotus florida produces at least two laccases (L1 and L2), one of which appears to be linked with the mycelia growth of the fungus (Das et al. 1997). The L1 isoenzyme is dominantly involved in the dye decolorization process.
Submerged fermentation (SmF) is a type of fermentation in which microorganism is grow in liquid broth and enzymes and other compounds are released in the broth. This technique used free liquid substrates such as nutrients etc. The substrates are utilized quite rapidly and constantly supplemented with nutrients. In fermentation broth, microorganisms are provided with appropriate nutrients and conditions such as high oxygen concentration for the production of microorganism in order to get desired products. In this technique, mycelium formation is takes place. Mycelium formation can lead to pellet formation which hinders the diffusion of oxygen and nutrients in the medium.
In recent times, wide variety of secondary metabolites has been produced commercially by fungal fermentation. Fungi are complex microorganism that is different morphologically and structurally at different phases of their life cycles form others. It is also differ in form between surface and submerged growth in fermentation media. Nature of liquid media also effect on the growth of fungi. Different culture conditions such as temperature, pH and mechanical forces are important for fungi growth but these parameters are different for different fungi (Kossen et al. 2000).
Enzymes act like catalyst and they speed up any chemical reaction without being used up in the reaction. The uses of enzymes are advantageous due to its several characteristics and features as compared to conventional chemical catalyst. However, there are some problems that can reduce the operational life time of any enzymes. These problems includes; non-reusability of enzyme, the instability of their structure, high cost of isolation, purification and characterization and their sensitivity to harsh condition of reaction.
These objectionable limitations of enzymes may be reduced by the use of immobilized enzymes. There are mainly four procedures present for immobilization of any cell (Kunamneni et al. 2007). These procedures are following: adsorption, gels entrapment or polymer entrapment, covalent coupling, and cross-linking to insoluble matrices (Brouers et al. 1989). For immobilization different kinds of matrices, such as agar, calcium alginate beads, polyacrylamide gel, etc have been used. In order to select suitable matrix and immobilization procedure, type of the cell, type of the substrate, medium conditions and products are major factors (Prasad et al. 2005).
During immobilization, enzyme is fixed to or within solid matrix in order to get heterogeneous immobilized enzyme system. Naturally enzymes are bounded to cellular membrane in living cells for most cases so in order to get the natural form of enzyme, immobilization of the cell is done. This immobilized system stabilized the structure and activity of the enzyme for longer period of time. When enzymes are immobilized, they are stronger and more challenging to harsh environment changes. Immobilization also allows easy recovery of enzyme and also it’s multiple re-use in processes. The Michaelis constant of immobilized enzymes increased and their activity usually lowered when compared to free enzyme. When immobilization procedure applied, different structural changes introduced to an enzyme which leads to these alterations. Immobilization helps to maintain the structure, stability and activity of enzyme for longer time without being de-activated (Kunamneni et al. 2007).
Immobilization represents an attractive option to obtain enzymatic catalyst for dyes treatment. This technique provides different advantages: (i) it prevents enzyme leakage even under harsh conditions; (ii) it facilitates enzyme use in different types of reactors like packed bed, stirred tank and continuous bed; (iii) it causes stabilization of the enzyme tertiary structure, usually as a consequence of multipoint attachment of the enzyme to the support, providing enzyme rigidity. The stabilization provided by covalent bonding is usually counter balanced by partial enzyme deactivation. This negative effect can be mitigated by carefully optimizing the immobilization conditions in order to maximize the ratio between immobilized enzyme activity and activity of the primary enzyme solution (Pezzella et al. 2014).
Immobilization of laccase was extensively investigated with broad range of different techniques and substrates. Inactivation of enzyme occurs when oxidized products are absorbed on the surface of the immobilization matrix support (Kunamneni et al. 2007).
Textile industries discharged wastewater effluents comprised of toxic dyes are dangerous for aquatic life and have harmful impacts on the environment. There are different methods including physical and chemical methods which are use previously to decolorized dyes. These physical and chemical methods are quite costly, prolonged, ineffective and insecure (Shang and Chi 1996; Mechichi et al. 2006). In comparison to these methods, biological processes are quite suitable and helpful. Biological processes are less expensive, safe and take less time and effective. Biological processes used microorganisms to decolorize dyes. Laccase as an extracellular oxidative enzyme produced by white rot fungi are eco-friendly and cheap. In order to decolorize dye, three day old fermentation media is used and dyes is added in the broth. To get 70-75% decolorization in fungal culture, more than 48 hours are required. Pleurotus Species produced laccase efficiently and this laccase could decolorize malachite green dye upto 70% within 24 hours (Yan et al. 2009).
Laccases can degrade several dye structures such as phenol, polyphenols and diamines (Abadulla. et al. 2000) to degrade harmful compounds into less toxic compounds and may be helpful to reduce environmental pollution (Gianfreda et al. 1999). The specific features and mechanism of laccase helps to make it a versatile biocatalyst. Due to its versatility, it is suitable for several applications such as biopulping, biobleaching, and industrial wastewater treatment. Due to the severe environment legislation, the textile industry is trying to introduce new innovative technologies for the treatment of wastewater effluents discharged from textile industries. Laccase has potential to degrade dyes of various chemical structures so that development of techniques based on laccase seems an attractive and suitable solution in decolorizing dyes (Madhavi and Lele 2009). The decolorization and detoxification of the wastewater effluent would help to use it again and again in dying process in textile wet processing.
The major purpose of this research is to decolorize the textile effluents dyes discharged by industries after partial treatment and cause water pollution and have negative effect on aquatic life and ecosystem. It is necessary to established most effective and efficient method to produce sufficient amount of laccase enzyme through immobilized white rot fungus and then utilized it in the process of bioremediation.
Availability: Items available for loan: UVAS Library [Call number: 2208,T] (1).
6.
Bioconversion Of Molasses To Glucose Oxidase Through Solid State Fermentation With Aspergillus Niger
by Wajeeha Zafar (2012-VA-574) | Dr.Abu Saeed Hashmi | Dr. Muhammad Tayyab | Dr. Muhammad Wasim.
Material type: ; Literary form:
not fiction
Publisher: 2014Dissertation note: Enzymes can be defined as soluble colloidal organic catalysts which are produced by living cells and are capableof acting independently of the cells. Glucose oxidase belongs to oxidoreductaseand is also called as glucose dehydrogenase. The glucose oxidase enzyme (GOX) oxidizes glucose to gluconic acid. In cells, it aids in breaking the sugar down into its metabolites. Glucose oxidasehas found several commercial applications including glucose removal from dried egg; improvement of color, flavor, and shelf life of food materials; oxygen removal from fruit juices, canned beverages. It has also been used in an automatic glucose assay kit in conjunction with catalase and chiefly in biosensorsfor the detection and estimation of glucose in industrial solutions and in body fluids such as blood and urine. It is often extracted from Aspergillusniger. GOX is a dimeric protein. The active site where glucose binds is in a deep pocket. This enzyme acts outside of cells, is covered with carbohydrate chains (Raba and Horacio 1995).
Aspergillus niger is the potential source for the production of glucose oxidase and is preferreddue to its high production ration of extracellular enzyme. The ability of Aspergillus niger toutilize a wide range of waste products as nutrition source makes it more economical source of the enzyme (Rajesh et al .2002).
The glucose oxidase fromA. nigerisalso an intracellularenzyme present in the mycelium of the organism. Aspergillus nigeris a filamentous fungus belonging to phylum Ascomycota. It Produces microscopic conidia on conidiophores that are produced asexually. Hyphae possess septa and are hyaline. They are supported at their base by foot cells from which conidiophores originate. It possesses long, double-walled, smooth and colorless to brown conidiophores.It is commonly foundin mesophilic environments such as soil, plants and enclosed air environments. It is capable of surviving in various environments, it is not only a xerophilic fungus, but is also a thermo tolerant organism. It is because of this property that it exhibits a high tolerance to freezing temperature(Schuster 2002).
Glucose oxidase was first isolated from mycelia ofA. nigerandPenicilliumglaucumby Müller.
A large number of microbes including bacteria and filamentous fungi have been used for the production of glucose oxidase. Glucose oxidase is produced at large scale using A. nigerand P. amagasakiense. Many bacteria are also involved in the production of this enzyme; some of these are Zymomonasmobilis, Micrococcus and Enterobacte(Yogananth et al. 2012).
Glucose oxidase (GOX) from Aspergillus niger is a well-characterised glycoprotein consisting of two identical 80-kDa subunits with two FAD co-enzymes bound. Both the DNA sequence and protein structure at 1.9 A have been determined that these identical subunits size vary from 70 to 80 KDa. It catalyzes the oxidation of D-glucose (C6H12O6) to D -gluconolactone (C6H10O6) and hydrogen peroxide. It is produced naturally in some fungi and insects where its catalytic product, hydrogen peroxide, acts as an anti-bacterial and anti-fungal agent (Ikram et al . 2014).
Glucose oxidase has a molecular weight of 160,000 a.m.u. (Tsugeet al .1975) and consists of two identical polypeptide chain subunits having nearly equal molecular weights linked by disulphide bonds (O'Malley and Weaver 1972) and it is highly specific for β-D-glucose (Bentley 1963). Each subunit of the glucose oxidase contains one mole of Fe and one mole of FAD (Flavin adenine dinucleotides) and it contains 74% protein, 16% natural sugar and 2% amino sugars (Tsugeet al. 1975). The Glucose oxidase enzyme in its purest form is pale-yellow powder. The molecular weight of GOX ranges from approximately 130 kDa to 175 KDa (Kalisz et al. 1997).
Gluconic acid, the oxidation product of glucose, is a mild neithercaustic nor corrosive, non-toxic and readily biodegradable organic acid of great interest for many applications. As a multifunctional carbonic acid belonging to the bulk chemicals and due to its physiological and chemical characteristics, gluconic acid itself, its salts (e.g. alkali metal salts, in especially sodium gluconate) and the gluconolactone form have found extensively versatile uses in the chemical, pharmaceutical, food, construction and other industries (Anastassiadis and Morgunov 2007 ).
This enzyme is present in all aerobic organisms and normally functions in conjunction with catalase (Coxon and Schaffer 1971). This enzyme is also used as an antioxidant (Berg et al. 1992). It is mainly available from microbial sources and is normally produced by aerobic fermentation of Aspergillus nigerand Penicillium species (Fiedurak1996; Lu et al. 1996; Plush et al .1996; Rando et al. 1997). It has high specificity for D-glucose (Kuly and Cenas 1983).
This enzymeis also widely used to produce gluconicacidthatGOXtogether with Horse Reddish peroxidase has a range of applications in the food industry for glucose determination. GOX is being used in the textile industry producing hydrogen peroxide for bleaching process. This enzyme is also used to determine capillary glucose in screening of gestational diabetes (Mesiggi et al. 1988). This enzyme is utilized to extend the shelf life of fish(Field et al.1986) andproduction of calcium gluconate, gluconic acid and its derivatives (Khurshid2009).
Solid state fermentation [SSF] has been recently considered as the most cheapest and more environmentally friendly relative to submergedliquid fermentation [SLF] in the production of value added industrial based products such as enzymes, bio fuels.Advantages of Solid State Fermentation over Submerged Fermentation isHigher volumetric productivity, usually simpler with lower energy requirements, Might be easier to meet aeration requirements, Resembles the natural habitat of some fungi and bacteria and Easier downstream processing (Mienda et al. 2011).
Molasses is a dark brown, almost black, moist granular sugar. Its distinctive molasses taste is due to its high content of minerals. Nutritively, it has high iron content (Draycott and Philip 2008).
Aspergillus niger is a fungus, one of the most common species of the genus Aspergillus.The genus Aspergillus isimportant economically, ecologically and medically (Nizamuddinet al.2008).
Glucose oxidase enzymewas producedthrough the microbial fermentation. For that purpose solid state fermentation wasdevelopedwithA.niger. Solid state fermentation was applied to utilize agricultural residue such as Molasses as substrate.
The current research work was focused on production ofextracellular Glucose Oxidase (GOX) fromAspergillusniger using industrial waste such as molasses as substrate by Solid state ( static ) fermentation.
Availability: Items available for loan: UVAS Library [Call number: 2219-T] (1).
7.
DNA Based Characterization Of Protease Gene From Geobacillussp.Sbs-4s
by Anam Shabbir (2012-VA-608) | Dr. Muhammad Tayyab | Ms. Huma Mujahid | Prof. Dr. Tahir Yaqub.
Material type: ; Literary form:
not fiction
Publisher: 2014Dissertation note: Proteases are hydrolytic enzymes responsible for the hydrolysis of proteins(Qadar et al.2004).These enzymes contribute major role in textile and leather industry,accounting 60% of the world wide enzyme market(Nascimento et al.2004).These enzymes are also being used in food ,pharmaceutical ,detergent, brewage sweet industry and as digestive additives in human and animal feed (Wilson, 2012).
Proteases are produced by microbes,animal and plants but microbial proteases are preferred due to ease in production and cheaper cost (Ningthoujam et al.2010).Microbes produce a variety of proteases according to their requirement that are specific in their function (Neurath 1999).Microbes might be involved in the production of intra or extracellular proteases.Extracellular proteases help the organism to absorb and utilize hydrolytic products from proteinious substrates in order to get energy by catabolism or to synthesize the biomolecules through anabolism reactions(Ningthoujamet al.2010).
Proteases can be classified in different ways.On the basis of cutting preferences these can be divided in to two groups:endopeptidases and exopeptidases (Barret and Mcdonald 1985).Exopeptidases are involved in hydrolysis of the peptide bond near N or C terminal whereas endopeptidases are responsible for the hydrolysis of peptide bond, with the chain, distant from the peptide ends(Motyan et al .2013).On the basis of catalytic residues in active site the proteases can be divided into six groups including glutamate,serine, therionine cysteine,aspartate and metalloproteases(Li et al.2013).
Microorganisms occupy all possible environments including habitats that provides appropriate conditions for growth(Sharma et al.2009).Thermophiles have ability to grow at highertemperature whereas other microbes fail to survive.There has been increasing interest in thermophilic bacteria because of their thermostable enzyme(Obeidat et al.2012).Hyperthermophiles can survive in extremely hot environment. Hyperthermophiles occupy the most basal positions of the phylogenetic tree of life(Bouzas et al. 2006). About 70 species of hyperthermophilic bacteria and archea has been isolated from different terrestrial, marine and thermal areas in the world.Hyperthermophiles are very divergent in their phylogeny and physiological properties.Proteolytic enzymes from hyperthermophiles are catalytically active at high temperature and they can alsoretain their catalytic activity in the presence of detergent and other denaturing substances (Stetter et al.1993).
Geobacillusis widely distributed thermophiles isolated from geothermal areas (Chalopagorn et al.2014).On the basis of16SrRNA gene sequences, Geobacillus belongs to Bacillus genetic group 5. It is phenotypically and phylogeneticallyconsistent group of thermophilicbacilli (Rahman et al. 2007).Bacillus and Geobacillus species are the dominant workhorses in industrial biotechnology. These bacteria produce a variety of extracellular enzymes, such as amylases, xylanases, proteases, phytases, carbonic anhydrases, catalases, pectinases. Bacillus and Geobacillus species hasability to grow at acidic, alkaline, neutral pH and at elevated temperature has positioned them among the most important industrial enzyme producers(Satyanarayana et al. 2012).
Geobacillus are gram-positive, rod-shaped, aerobic,endospore-forming obligate thermophiles.The growth temperature for various Geobacillus species ranges from 37 to 75 °C and pH range of 6.0 to 8.5.The members of Geobacillusare homologus to each other and share homology 99% among them(Tayyab et al.2011). The genus Geobacillusthermophilicstrains, produce a variety of thermostable hydrolytic extracellular enzymes, such as proteases, amylases, and lipases used in various industrial applications (Wiegand et al. 2013)
GeobacillusSBS-4S was isolated from a hot spring located in Gilgit, Northern areas of Pakistan.Geobacillus SBS-4S strain is Gram positive, rod-shaped bacteria and occurs in chains. That could grow at a wide range of temperature (45 to 75˚C) and pH ranging 5.5 to 9.5.Geobacillus SBS-4S produced several extracellular enzymes including amylase, protease and lipase.The comparison of the strain SBS-4S with the already reported species of genus Geobacillus showed that SBS-4S is resistant to antibiotics such as streptomycine, spectinomycin and rifampicin(Tayyab et al.2011).
Availability: Items available for loan: UVAS Library [Call number: 2242-T] (1).
8.
DNA Based Characterization of Xylanase Gene From Hyperthermophilic Archeon
by Saima Zulfiqar (2012-VA-539) | Dr. Muhammad Tayyab | Dr. Faiza Masood | Dr.Sehrish Firyal.
Material type: ; Literary form:
not fiction
Publisher: 2014Dissertation note: Blank CD Availability: Items available for loan: UVAS Library [Call number: 2233-T] (1).
9.
Sequence Analysis Of Mitochondrial Atpase 8/6 Gene Variants In Equine
by Kashif Hameed Anjum (2012-VA-905) | Dr. Asif Nadeem | Mr.Maryam Javed | Dr. Muhammad Tayyab.
Material type: ; Literary form:
not fiction
Publisher: 2014Dissertation note: Human has been using horses for doing different jobs like transportation, hunts, carrying loads, warfare and sports (Zhang et al. 2012). In Pakistan, horses and donkeys are mostly used for transportation whilehorses are also used for racing and playing games like polo.There are two main types of horses:Equuscaballusare domesticated horses and Equusferus are the wild horses. There are more than 300 breeds of horses in the world today (Barbara and Dafydd, 2007). The horse population is estimated as 0.32 million and has been decreasing over the years in Pakistan. Main breeds of horses that are found all over the Pakistan are Kajlan, Kakka, Balochi, Morna, Shien, Anmol, Makra, Pak-thoroughbred,Heerzaiand Waziri (Khan, 2004).
Seventy percent of the population earns living from the land. Agriculture contributes nearly 21% to gross domestic product and generates 43% of all jobs. Over 30 million people in rural areas derive their livelihood from livestock production. The number of impoverished communities moving from the country to find work in Pakistan’s towns and cities is rising. Many of these people rely on working equine animals to earn a living.
Nuclear and mitochondrial genomes are frequently used in animal genetic research. Nuclear genomeis generally a huge and complicated molecule and is not well studied in many species. However mitochondrial DNA being small sized and having high mutation rate is used frequently for the purpose of genetic research (Stanley et al. 1994). Characteristic of having fast evolution rate as compared to nuclear DNA makes mitochondrial genes a good tool for genetic studies (Avise, 1994).
Several studies have investigated the genetic relationship among horse and donkey breeds using mitochondrial sequences as a marker for breed characterization and phylogenetic. Each mitochondrion contains its own circular DNA, replication, transcription and translation machinery and serves as semi-autonomous organelle. Mitochondria perform so many important functions in our body like metabolism(oxidative phosphorylation), apoptosis and aging(Weinberg, 2007).
The advent ofpolymerase chain reaction and direct sequencing techniques with the use of mtDNA as a phylogenetic marker has been extended to much greater levels of phylogenetic inclusiveness (Zardoya and Meyer,1996). The special features of mtDNAi-e,lack of introns, maternal inheritance, absence of recombination events and haploidy have made it the most common type of sequence information used to estimate phylogenies among both closely and distantly related texa(Meyer, 1993).
Four of the five mitochondrial respiratory chain complexes, namely C1, C3, C4 and C5 (ATP synthase) contain subunits encoded by mitochondrial DNA (Kadenbach, 2012). ATP synthase (Complex5) functions to make ATP that is used by the cell (Von et al. 2009). ATP synthasecomprisesan integral membrane cylindrical, the F0 particle and a peripheral matrix-facing F1 particle, the catalytic ATP synthase domain (Boyer, 1997). All aerobically respiring organisms possess ATP synthase enzymes and are located inthe cell membrane in prokaryotes, the mitochondrial inner membrane in eukaryotes and the chloroplast thylakoid membrane (Ackerman and Tzagoloff, 2005). This enzyme is responsible for the final step of oxidative phosphorylation. The protons move down their concentration gradient from inter membrane space to matrix through F0 particle while F1particleuses the energy provided by influx of these protons and converts ADP molecule into ATP. ATPase 6 and ATPase 8 proteins are components of F0 particle where they play direct role in maintaining the structure and function of ATP synthase (complex 5). All five subunits of F1 and most of the F0 subunits are nuclear encoded(Collinson et al. 1996). Only two proteins i-e, ATPase 6 and ATPase 8 are encoded by mtDNA (Boyer, 1993).
The present study is designed to investigate the diversity and phylogenetic analysis of Thoroughbred Pakistani horse and donkey breeds on the basis of ATPase 6 and ATPase 8 genes.
Availability: Items available for loan: UVAS Library [Call number: 2236-T] (1).
10.
Detoxification Of Aflatoxins Using Different Organic Acids
by Sana Ejaz (2013-VA-14) | Dr. Mateen Abbas | Dr. Muhammad Tayyab | Dr. Sehrish Firyal.
Material type: ; Literary form:
not fiction
Publisher: 2015Dissertation note: From global prospective of food safety and food security, mycotoxin contamination of foods has gained much attention as potential health hazards for humans and animals. Cereals and other crops are exposed to fungal attack in the field or during storage and this attack may result in mycotoxin contamination of crops. Animal feed is basic necessity for all the live stock, poultry and other animals. AF is the most important for human and animal health perspective and in developing countries such as Pakistan where climate conditions favor the formation of these toxic metabolites. Governments and private organizations of international level have established maximum residue levels (MRIs) which usually guide to control AF in feed. Therefore, the current study was planned to detoxify AF by using different organic acid treatments in animal feed collected from different dairy farms of Punjab.
The samples of cotton seed cake, maize oil cake and animal feed were collected and checked the presence of AFB1 qualitatively by TLC and quantitatively by HPLC. The samples which gave positive results were treated with different acidic treatments applied on it. Firstly checked the results of citric acid, acetic acid and lactic acid on feed sample qualitatively by TLC. TLC plates were checked under UV box and the samples which showed the detoxification of AF were quantitatively analyzed by HPLC in Toxicology Laboratory, QOL, UVAS, Lahore, Pakistan.
The average concentration of AFB1 found in the cotton seed cake, maize oil cake and mixed feed were 279.8 ppb, 34.2 ppb and 25.5 ppb, respectively much greater than permissible levels proposed by European Union. Treatments of varying concentration of citric acid, acetic acid and lactic acid were applied on positive samples (≥20 ppb) and checked their effect on rate of detoxification.
All the above mention treatments applied on the feed samples in order to obtained in vitro detoxification of AFB1. Sprayed different concentration of acetic acid, citric acid and lactic on positive samples by varying volumes and placed them over night then extracted and analyzed.
It has been observed that 1N concentration of citric acid, acetic acid and lactic acid showed complete detoxification. However, when these samples were treated with 0.5N solution of organic acids then variation was seen in rate of detoxification.
Statistically these results were analyzed by ANOVA which showed that effect of these treatments on rate of detoxification was highly significant (P<0.05). In vitro detoxification of AF by these organic acids was proved beneficial in order to reduce the animal and human health risks. However, in vivo detoxification of aflatoxin by using these organic acids should be studied in future.
Availability: Items available for loan: UVAS Library [Call number: 2283-T] (1).
11.
Production Of Single Cell Protein By Using Banana Peels As Substrate And Its Biological Evaluation In Broiler Chicks
by Muhammad Sheraz Yasin (2012-VA-603) | Miss Shagufta Saeed | Dr. Muhammad Tayyab | Prof. Dr. Aftab Ahmed Anjum.
Material type: ; Literary form:
not fiction
Publisher: 2015Dissertation note: The term single cell protein (SCP) refers to dead, dry microbial cells or total proteins extracted from pure microbial cell culture and is produced using a number of different microorganisms including bacterium, fungus and algae. It can also be called biomass, bioprotein or microbial protein.
Besides high protein content (about 60-82% of dry cell weight), SCP also contains fats, carbohydrates, nucleic acids, vitamins and minerals.
Fermentation media containing grinded banana peel as substrate was used to check the production of single cell protein for the selected Arachniotus sp. Different parameters were optimized for higher production of SCP e.g: Incubation period, pH, volume of inoculum, carbohydrate source, concentration of corn steep liquor and ionic salts concentration.
The biomass yield was estimated for total protein content by Lowrymethod. Biomass produced from fermentation was used for biological evaluation in feed trials of broiler chicks.
It is found that Arachniotus sp gave maximum single cell protein 7.49 g/L using 10 g banana peels at 72 hours incubation period. And protein concentration increased 7.58 g/L by optimizing volume of inoculum 2ml. It is observed in present study carbohydrate source also increases the protein concentration 8.41 g/L when carbohydrate source was optimized (glucose 3%).
Later on it was found that nitrogen source also enhance the protein production upto 12.61 g/L by using 2% corn steep liquor. Results also revealed that ionic salt concentration also play important role in the production of biomass protein, addition of 0.075% CaCl2.H2O produced 14.45 g/L single cell protein using above mentioned optimized conditions. 0.050 %
K2HPO4 produced 15.06 g/L. Addition of 0.050% MgSO4.7H2O produced maximum protein 15.86 g/L.
Biological evaluation in broiler chicks of this biomass protein shown there is no deleterious effects on weight gain, feed conversion ratio, protein efficiency ratio and net protein utilization. Maximum weight gain observed 215.6 grams in the group (C) in which 50% sunflower meal was replaced with biomass protein.
Feed conversion ratio in group (C) was 2.64 in which 50% sunflower meal was replaced by biomass protein and in group (B) was 2.51 in which 25% sunflower meal was replaced. And in control group (A) feed conversion ratio was 2.41.
Protein efficiency ratio was observed with non-significant value. And same results were shown by Chaves et al (1988) who reported non-significant differences among the standard and test diet when Chaetominumcellulolyticum biomass was fed to chicks. Net protein utilization observed in present study gave significant P value among the groups.
So it is concluded that single cell protein produced by this method is cheap and can be used in the food industry as food supplements and can also be included in poultry feed. The study findings suggested that microbial biomass produced by Arachniotus sp using banana peels as substrate can be replaced upto 50% of the protein supply by sunflower meal without any deleterious effects on growing broiler chicks. Moreover, it will also help in the reduction of pollution by using waste i.e. banana peel for useful purpose.
Availability: Items available for loan: UVAS Library [Call number: 2347-T] (1).
12.
Production Oflaccase From White Rot Fungususing Rice Bran As A Substrate By Solidstate Fermentation
by Muhammad Tanweer Muneer (2013-VA-06) | Mr.Shahid Abbas | Dr. Muhammad Tayyab | Prof. Dr.TahirYaqub.
Material type: ; Literary form:
not fiction
Publisher: 2015Dissertation note: Laccase are copper oxidases and are found in large quantities in several white rot fungi that are involved in lignin metabolism. Fungal laccases have boundless biotechnological functions across the globe like the decolouration and detoxification of industrial effluent, bleaching of pulp, phenolic elimination from wines, in preparation of biosensors in detergents blocking dye transfer- functions. Laccase showed vast variety of substrates due to this ability they can enhance different types of industrial mechanism such as methylation, demethylation, polymerization, mineralization of pollutants like hydrocarbons. White rot fungus is efficient for the production of laccase using agro-waste as substrate.
In this research white rot fungus was isolated from stock cultures of Department of Microbiology, University of Veterinary and Animal Sciences, Lahore, Pakistan and the organism was maintained on Tien& Kirk media slants and petri plates. Solid state fermentation technique was used using basal fermentation medium and agro waste rice bran was used as substrate for the production of laccase.Proximate analysis was performed of the substrate rice bran to analyse crude protein, fat, ash, moisture and fibre content. The fermentation was performed at room temperature and flasks were placed on orbital shaker at 100 rpm and 30˚C.
Enzyme activity was checked using (ABTS) as substrate at 420nm, for every 24 hour to observe the maximum enzyme production. Fermentation parameters like substrate concentration, incubation period, pH, temperature and nitrogen source (corn steep liquor and ammonium sulphate) were optimized. The concentration of substrate optimized for rice bran was 7.5g/100ml and optimum production of 6.11 IU/ml of enzyme was observed. The optimum day for the production of enzyme was day 7 and the amount of enzyme produced was 6.91 IU/ml. The optimum pH and temperature were 4 and 40˚C respectively, and the amounts of enzyme produced were 7.48 IU/ml and 7.96 IU/ml respectively. Two nitrogen sources optimized were maize steep liquor 1ml and ammonium sulphate 0.2 g, and the enzyme produced was recorded 7.67 IU/ml and 9.41 IU/ml respectively. Large scale fermentation batch of one litter was carried out under the optimized conditions and the enzyme produced was 9730 IU/L. Triplicates of each parameter were prepared.
The enzyme was purified using the purification techniques like ammonium sulphate precipitation, then by dialysis excess salt was removed, and then gel filtration was performed to collect different fractions on the basis of size of molecules and molecular mass of the laccase was analysed by SDS-PAGE. The size of the protein was found to be 70kDa. Characterization of laccase was performed in terms of optimum pH, temperature and in response to inducers and inhibitors. The optimum pH and temperature of the purified enzyme was 6 and 40˚C respectively. The inducer copper sulphate enhanced the activity of enzyme up to 9.7 U/ml and then inhibitors EDTA and 2-merceptoethanol reduced the activity level up to 4.17IU/ml and 3.98 IU/ml respectively. To study and analyse the effects of optimization parameters Pearson correlation, descriptive statistics and one way Anova were used.
The optimum production of laccase was achieved using agro waste rice bran. The enzyme produced was economical and it can provide effective solutions for bioremediation of hazardous compounds and pollutants.
Availability: Items available for loan: UVAS Library [Call number: 2377-T] (1).
13.
Physical, Chemical and Biological Treatment of Rice Husk to Improve Its Nutrative Value
by Rahat Naseer (2003-VA-196) | Dr. Abu Saeed Hashmi | Dr. Muhammad Tayyab | Prof. Dr. Habib ur Rehman.
Material type: ; Literary form:
not fiction
Publisher: 2015Dissertation note: Thesis submitted without CD. Availability: Items available for loan: UVAS Library [Call number: 2450-T] (1).
