Utilization of corn straw as a sole nitrogen and energy source in the production of biomass protein by some microorganisms

The utilization of corn straw hydrolysate [CSH] as a sole carbon and nitrogen source for the production of biomass protein by three different strains of microorganisms was studied. Aspergillus niger, Saccharomyces carlsbergensis and Candida utilis proved to grow well on media containing low and moderate concentrations of CSH with considerable amounts of cellular protein [SCP]. S. carlsbergensis produced the largest amount of SCP [37.9%] followed by C. utilis [34.6%] and A. niger [32.8%]. The presence of CSH in the fermentation media in a concentration containing 1.0% sugar supported the highest growth accompanied with the highest SCP production of all the tested strains. The obtained protein contained 17, 18 or 18 amino acids for A. niger, S. carlsbergensis and C. utilis, respectively

Production of fats and lipids by yeast utilizing whey

The yeast Candida utilis was grown on media containing different concentrations of whey as a substituent of carbon and N sources. With incubation, vigor growth and maximum intracellular accumulation of lipids occurred in 25% whey after 6 days incubation. Addition of 0.4 g/l yeast extract to the whey medium led to excellent growth of the yeast with a high amount of lipids accumulated within the cells

Bioconversion of wheat straw by yeasts into single- cell protein

Dried wheat straw was homogenised and carefully ground, hydrolysed with 0.5 N H2SO4 at 121 for 20 min. Amount of reducing sugars obtained after hydrolysis was 31.8% of the straw dry weight. Straw hydrolysate was used as sole carbon source in five concentrations for preparation of fermentation media on which two strains of yeasts, Saccharomyces cerevisiae and Candida utilis were grown. The increase in wheat straw hydrolysate concentration enhanced the biomass yield and the protein formation within the yeast cells. Lower carbon utilization by the two yeast strains occurred in the waste-containing media, as compared to control, increasing the economic value of the waste usage. Maximum biomass yield and protein production were obtained after 7-day fermentation

Whey utilization by saccharomyces cerevisiae for production of biomass protein

Fayoum cheese whey from buffalo milk at different concentrations was used for growth and protein production by Saccharomyces cerevisiae. Analysis of whey sample indicated that it contained 88.7 percent water 11.3 percent total solids, 2.6 percent ash. The total reducing sugars, total nitrogen and total soluble salts constituted 18.3 percent, 16.2 percent and 3.9 percent respectively. The protein content represented 31.6 percent of the whey sample. Media containing whey, at all concentrations, recorded higher growth with better fermentation yield than control medium. Among the different concentration tested, 5 percent whey containing medium was the most favorable for production of maximum biomass protein. The suitable fermentation period was 4 days. Analysis of the harvested yeast cells on the tested media indicated also that the yeast grown on 5 percent whey containing medium has the highest percentage of protein [55.6 percent of the dry biomass] and promising amount of total sterols. The protein conversion coefficient revealed that 50.5 percent of the utilized sugar by S. cerevisiae was converted into protein