“PRODUCTION OF SINGLE-CELL PROTEIN By Aspergillus niger FROM PULSE HUSK” Rajeshwari H.S* Parameswara Naik T Department of Botany and Environmental Science Sahyadri Science College (Autonomous) Kuvempu University.Shivamogga- 577203-Karnataka, India. Abstract The growth of Aspergillus niger biomass on pulse husk broth (PHB) was studied. Using standard methods for determination of dry mass, final pH values and protein content was determined by Lowry’s method using Carbonate-bicarbonate buffer at pH 10. Among the three pulse husk v.i.z, A: Cajanus cajan, B: Cicer aeritinum, C: Dolichus lablab. The medium supplemented with Glucose, (NH4)2SO4, KH2PO4, MgSO4.7H20 and ZnSO4.7H20 resulted in maximum yield. The effect of various nitrogen sources was compared. Ammonium Sulphate gave the highest biomass yield. The mean total protein content of the biomass was 880 mg/g for culture medium A, 880mg/g for B, 840mg/g for C. The total amount of trace elements and major elements were determined by atomic absorption spectrophotometer GBC932AA, as the presence or absence of mineral elements has significance on yield of biomass. Glucose and Nitrogen supplements increased the yield. Since PHB was successfully utilized for the enrichment of protein in product, there is a possibility of converting agro residues to proteinacous feed and food. A: Cajanus cajan B: Cicer aeritinum C: Dolichus lab lab Key words: Aspergillus niger, biomass, pulse husk, protein, pulse husk broth
In onclusion, higher yield of single cell protein production from Aspergillus niger was possible by fermentation of pulse husk broth. Supplementation of pulse husk broth with minerals enhanced fungal utilization of the substrate as well as biomass yield. Glucose supplemented pulse husk medium resulted in the highest yield than the supplement pulse husk (PHB1) medium. Pulse husk was used as a potential source for product with higher protein content. Over all results indicated that Aspergillus niger can be used as a potential strain for SCP production. Since pulse husk broth was successfully utilized for the enrichment of protein in product, there is a possibility of converting agro residues waste materials to proteinaceous feed and food. More over, the result confirmed that enrichment of broth with various nitrogen sources enhanced product yield. The biomass yield was best with the medium with Ammonium sulphate as nitrogen source for single cells proteins. Present investigation also showed that fungi have relatively low growth rates and process control is more difficult than in the case of yeast or bacteria. It has been reported that bacteria have more rapid growth and metabolic rates than yeasts; they have simpler nutritional requirements and their use should eliminate the contamination which often occurs in yeast propagations. However, there are several advantages in using fungal cells, their amino acid profile is better, the recovery of biomass from the culture broth is much easier, their filamentous structure facilitates production of texturized food stuffs without extraction and spinning and they are as yeasts, already accepted as foods in many parts of the world. It should be pointed out that the cell cytotoxicity tests, especially with fungi and some bacteria must be performed in order to use micro-organisms as feed.