This paper reports the purification and characterization of kinetic parameters of cellulase produced from Trichoderma viride under still culture solid state fermentation technique using cheap and an easily available agricultural waste material, wheat straw as growth supported substrate. Trichoderma viride was cultured in fermentation medium of wheat straw under some previously optimized growth conditions and maximum activity of 398 ± 2.43 U/mL obtained after stipulated fermentation time period. Cellulase was purified 2.33 fold with specific activity of 105 U/mg in comparison to crude enzyme extract using ammonium sulfate precipitation, dialysis and Sephadex-G-100 column chromatography. The enzyme was shown to have a relative low molecular weight of 58 kDa by sodium dodecyl sulphate poly-acrylamide gel electrophoresis. The purified enzyme displayed 6.5 and 55˚C as an optimum pH and temperature respectively. Using carboxymethyl cellulose as substrate, the enzyme showed maximum activity (V max ) of 148 U/mL with its corresponding K M value of 68 µM. Among activators/inhibitors SDS, EDTA, and Hg 2+ showed inhibitory effect on purified cellulase whereas, the enzyme activated by Co 2+ and Mn 2+ at a concentration of 1 mM. The purified cellulase was compatible with four local detergent brands with up to 20 days of shelf life at room temperature suggesting its potential as a detergent additive for improved washing therefore, it is concluded that it may be potentially useful for industrial purposes especially for detergent and laundry industry.

Streptomyces strain KX852460 having antifungal activity against Rhizoctonia solani AG-3 KX852461 that is the causal agent of target spot disease in tobacco leaf. The aim of the study was to determine the antifungal activity of Streptomyces strain KX852460 extract against R. solani AG-3 and to identify bioactive antifungal compounds produced by strain KX852460. Crude substance was produced by submerged fermentation process from Streptomyces strain KX852460. Various solvent was used to extract the culture filtrate. Among all, ethyl acetate extracted supernatant showed great potency against R. solani AG-3 KX852461. The active fractions were purified by silica gel column chromatography having 52 mm zone of inhibition against R. solani AG-3 KX852461. The purified fractions were identified by gas chromatography–mass spectrometry technique. Twenty-seven compounds were identified and most of the compounds were the derivatives of aromatic compounds. Eicosane (C20H42) and dibutyl phthalate (C16H22O4) were found antifungal compounds in this study. While morphinan, 7,8-didehydro-4,5-epoxy-17-methyl-3,6-bis[(trimethylsilyl)oxy]-, (5.Alpha. 6.Alpha)—(C23H35NO3Si2), cyclononasiloxane, octadecamethyl—(C18H54O9Si9) and benzoic acid, 2,5-bis(trimethylsiloxy) (C16H30O4Si3) were the major compounds with highest peak number. These results suggested that Streptomyces strain KX852460 had good general antifungal activity and might have potential biocontrol antagonist against R. solani AG-3 KX852461 to cure the target spot in tobacco leaf.

In this study an attempt was made to optimize the cultural and nutritional conditions for xylanase production by Bacillus species in submerge fermentation process. Whole fermentation process was carried out in 250 ml Erlenmeyer flask with agitation speed of 140 rpm. Bacillus subtilis exhibit maximum xylanase production at initial medium pH of 8, substrate concentration of 2% with inoculum size of 2% at 35 C for 48 h of fermentation period. Further supplementation of sucrose, (NH 4) 2 SO 4 and peptone as a carbon and nitrogen sources favored enzyme production. The other strain Bacillus megaterium showed its peak xylanase production at initial medium pH of 8, inoculum size of 1.5% with substrate concentration of 1.5% at incubation temperature of 40 C for 72 h of fermentation period. The best carbon and nitrogen sources are xylose, KNO 3 and malt extract. Both strains can also utilize molasses at 0.5% concentration for xylanase production can grow in medium containing 0.2% NaCl (B. subtilis BS04) and 0.8% NaCl (B. megaterium BM07) respectively. The optimum temperature of xylanase was 50 C and pH was 5 and 5.5 by B. subtilis BS04 and B. megaterium BM07 respectively.