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.