1.
Delignification Of Rice Husk By Organic Solvent Treatment To Increase It’s In Vitro Digestibility
by Awais Alam (2012-VA-604) | Dr. AbuSaeed Hashmi | Miss Huma Mujahid | Dr. Asif Nadeem.
Material type: ; Literary form:
not fiction
Publisher: 2014Dissertation note: The major constituent of plant cell wall is lignocellulose. Plant biomass mostly consist of cellulose, hemicellulose and lignin alongside little measures of pectin, protein, extractives (dissolvable nonstructural materials, for example, sugars, nitrogenous material, chlorophyll, waxes) and ash. Lignocellulosic biomass is the most abundant organic material in nature. There is an expected yearly overall production of 10–50 billion dry tons representing about 50% of the worldwide biomass yield (Parveen et al. 2009).
Numerous physicochemical, structural and compositional variables decrease the digestibility of cellulose present in lignocellulosic material. So a treatment is required to increase the digestibility of lignocellulose biomass by exposing the cellulose present in plant fibers. Different techniques have been utilized for treatment, including chemical treatment, ammonia fiber explosion, biological treatment and steam explosion to modify the cellulosic structure to increase the availability of cellulose for digestion (Haoran et al. 2013). At that point, acids, bases and enzymes might be utilized to break down the cellulose into its respective sugars. Cellulolytic enzymesare broadly used to break down cellulose into its constituent sugars.
Among various agricultural wastes a broadly available waste is Rice husk (RH) which is rich in lignocellulosic material. Internationally, roughly 600 million tons of rice paddy is delivered every year. By and large 20% of the rice paddy is husk, giving a yearly aggregate generation of 120 million tons (Abbas et al. 2010). Pakistan is a rice producing country a great part of the husk produced from processing of rice is either blazed or dumped as waste. Rice husk yield in Pakistan is more than 1780 thousand tons every year (Asif et al. 2013).
Rice husk produced during rice refining, makes disposal issue because of less business interest. Additionally, handling and transportation of RH is hazardous because of its low density. Rice husk ash (RHA) is an incredible environmental risk bringing about harm to land and encompassing range here it is dumped. Thus, business utilization of rice husk and its ash is the option answer for disposal problem (Dilip et al. 2014).
RH are essentially made up of lignocellulose (60wt. %) and silica (11wt. %). The greater part of past investigations concentrated on the preparation of silica or other silicon based materials from RH, while the lignocellulose in RH was mostly glazed and then wasted. Thus, a methodology for comprehensive usage of RH has been produced to expand its digestibility by the breakdown of lignocellulosic mass. (Ajay et al. 2012)
Numerous techniques have been adopted for treating lignocellulosic feedstocks. However just a few of them appear to be encouraging. These treatment techniques include dilute acid treatment, steam blast (CO2 blast), pH controlled water treatment, ammonia fiber expension, ammonia recycle percolation (ARP) and lime treatment. Some survey articles have been appeared for microbial biomass treatment. But the present study gave presentations on organosolv treatment process. Despite the fact that organosolv treatment is more expensive at present than the leading treatment forms, it can give some significant side products. It appears that organosolv treatment is more practical for biorefinery of lignocellulosic biomass which considers the usage of every bit of biomass parts. An essential streamlining and usage of side products may lead the organosolv treatment to be a guaranteeing one for bio refining lignocellulosic feedstock in future. Organosolv treatment yields three different parts: dry lignin, a watery hemicellulose stream and a moderately pure cellulose division (Xuebing et al. 2009).
Availability: Items available for loan: UVAS Library [Call number: 2230-T] (1).
2.
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).
3.
Biochemical And Homology Analysis Of Jak2 Gene In Canines And Hominidae
by Marya Saadullah Khan (2014-VA-324) | Ms. Huma Mujahid | Dr. Abu Saeed Hashmi | Dr. Muhammad Yasir Zahoor.
Material type: ; Literary form:
not fiction
Publisher: 2016Dissertation note: Cancers are considered to be the most lethal of all diseases known out of which myeloproliferative neoplasms comprise of a very little percentage.The frequency of these disorders is known in human beings and a lot of work has been done on humans. But there is a lot of scope for research on this area in canines. As dogs were found to have strong homology with human beings, we compared canine cJAK2 exon 13 sequence with the humanhJAK2 exon 13 and found 96 % homology. Mutations in JAK2 gene are well known to cause three types of disorders i.e. polycythemia vera caused by a well-known point mutation in exon 14 causing substitution of valine for phenylalanine in JH2 domain of the protein.Essential thrombocythemia and idiopathic myelofibrosis may also be caused by this mutation but similar clinical conditions arise without the presence of this mutation. Studies have revealed that other point mutations such as deletion, addition or substitution are also responsible for these disorders.
JAK2 is an intracellular protein which performs phosphorylation of STAT molecules upon their activation. Although the whole protein in its good state is important for its function but the two domains JH1 and JH2 are vital. JH1 domain acts as a tyrosine kinase enzyme and its activity is controlled by JH2 domain also known as pseudo tyrosine kinase domain. Any mutation in these domains leads to protein conformation defect and thus prevents its performance. Besides V617F mutation, other mutations are being discovered in this part of gene. Researchers have found mutations in exon 12, 13 and 15 that have been found to be involved in development of myeloproliferative neoplasms in different cases of patients.
Blood picture do not reveal any direct clue except for increased erythrocytes alone or along with other cells like increased platelets. Therefore blood indices are not reliable parameter to indicate the type of mutation involved in these disorders. Also LDH and EPO levels are not correlated with the disorder. Although EPO test must be done to exclude the possibility of secondary PV and erythropoiesis.
Availability: Items available for loan: UVAS Library [Call number: 2544-T] (1).
