Browsing by Author "Kebede Amaha"

Now showing 1 - 1 of 1
  • No Thumbnail Available
    Item
    Lignocellulosics for Cellulase and Fungal Biomass Production
    (Addis Ababa University, 1994-06) Kebede Amaha; A.Gashe Berhanu (PhD)
    The effects of teff straw (Eragrostis tett) or corn stalk (Zea mays) on cellulase and biomass production by Trichoderma sp. BDCC-1, Penicillium sp. BDCC-2 and Cladosporium sp. BDCC-3 were studied and compared with those of cellulosic substrates. In Trichoderma sp. both teff straw and corn stalk were found to be superior to filter paper for inducing B-GDase as well as for improving fungal biomass production. CMCase and FPase productions were, however, lower on these substrates than they were on filter paper. In Cladosporium sp. teff straw and corn stalk were found to be better than CMC for inducing both CMCase and FPase. However, no B-GDase activity was detected when only these lignocellulosics were used in the media. It's biomass production was also relatively lower on these substrates as compared to that it produced on 1% CMC. Penicillium sp. produced relatively large amounts of biomass, CMCase, FPase and B-GDase on 2% corn stalk as compared to those it produced on 2% CMC. Lye- and 2% NaOH-pretreatments were generally effective in improving biomass production in the test fungi. But their effect on CMCase, FPase and B-GDase production was not similar for the three fungi. There was, however, no significant difference between Lye- and 2% NaOH-pretreatment in their performance on biomass and cellulase production. 65-80% of the polysaccharides of alkali-treated teff straw and corn stalk were hydrolysed to reducing sugars in 72 hours using culture filtrate of Trichoderma sp. BDCC-1 which consisted of 1.7 IU/ml of FPase. The hydrolysates were found to support good growth of Candida utilis BDCC-25 (16.7-24.8mg dry wt./100ml) and Saccharomyces cerevisiae BDCC-24 (14.6-15.6mg dry wt./100ml). The yields of yeast biomass produced on these hydrolysates were higher than those produced on D-glucose (0.02%). It was, therefore, concluded that teff straw and corn stalk could provide cheap substrates for mold biomass production as well as for single-cell protein production if they are pretreated with Lye.