Vitamin B6 production by some local fungi

The potential of twenty-eight fungal species belonging to 13 genera isolated and identified from Egyptian soils to release vitamin B6 in their culture filtrates were tested. It was found that nearly 60% of the tested fungi showed positive results as the production of vitamin B6. Aspergilli particularly Aspergillus tomarii Kita was distinguished by its capacity to produce vitamin B6 when grown on a selected medium. The maximum viamin B6 yields were achieved after on 8 days incubation at 30°C. An initial pH value of 6 was found to be the optimum for growth of A. tamarii and vitamin B6 production. The influence of aeration as well as the amount and age of inoculum upon biosynthesis of the vitamin B6 and biomass yield were also discussed briefly. The present paper gives an account of observation made on the production of vitamin B6 and biomass in relation to the carbon and nitrogen compounds supplied in the medium. Glucose followed by fructose then sucrose were more initiative for the growth and vitamin B6 production than cellulosic compounds. Sugar cane molasses represented the most favorable waste substrate than other sources invesigatored. Yeast extract followed by ammonium nitrate then casein were the best nitrogen sources for biomass and vitamin B6 production by tested fungus. In addition, the impact of the levels of selected carbon and nitrogen sources on both experimental parameters were also examined

Studies on pectin-degrading fungi in compost

The variation in temperature recorded during the composting process of garbage led to corresponding changes in the distribution of pectin decomposing fungi in the compost. It was found that total population and the spectrum of fungal species were sharply declined during the maximum temperature phase [68-70C] inside the pile. At 28C [mesophillic], 22 species belonging to 12 genera were isolated throughout the composting periods. The most common pectinophytic species were Aspergillus niger, Aspergillus flavus, Aspergillus terreus, Penicillium chrysogenum, Fusarium moniliforme, Alternaria alternata, Cladosporium cladosporioids and Trichoderma viride. At 45C, the total population declined sharply during the first two days of composting, then gradually increased till reaching the highest counts at the 35th day and decreased, thereafter. Aspergillus fumigatus, Aspergillus terreus, Aspergillus nidulans and Mucor pusillus were the most common species recovered on pectin plates at 45C. The relative pectinolytic activities of the isolated fungi at 28C revealed that, Aspergillus niger and Aspergillus flavus showed very strong polygalacturonase [PG] and pectin-methyl-esterase [PME] activities when grown on pectin containing medium. On the other hand, Aspergillus fumigatus and Aspergillus terreus were the strongest pectinolytic [PG and PME] fungal isolates at 45C