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The hyper-production potential of a cellulase complex from a local strain of Aspergillus tubingensis S2, indigenously isolated from rotten tomato, was investigated. A total of nine fungal species of Aspergillus and Trichoderma were isolated and confirmed through triple-phase screening via 18S ribosomal DNA sequencing and construction of a phylogenetic tree. Congo red testing and the zone of clearance method were used to confirm the cellulase production from A. tubingenesis S2 isolate. A. tubingenesis S2 revealed maximum cellulase production (78 µg/mL/min) and was selected for further study. The optimum fermentative conditions, including the incubation period, pH, and temperature values, were determined to be 96 h, pH 4.8, and 40 °C, respectively, for obtaining the cellulase activity of 86.4±2.1 µg/mL/min. The cellulase was 5.14-fold purified by ammonium sulfate fractionation and gel permeation chromatography. Characterization revealed that maximum activity (130.5 µg/mL/min and 133.5 µg/mL/min) was achieved at 4.5 pH and 40 °C, respectively. A monomeric protein with an apparent molecular weight of 76 kDa was evident after sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Cellulase revealed maximal activity with 40-mesh size corn stover as compared with 20-mesh size corn stover and 80-mesh size corn stover after 36 h of incubation at 40 °C.

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SynopsisThe cellulosic wastes, bagasse and sawdust, were treated with different acidified solvents; chloroform, dioxan, ethanol, ethylacetate, dimethyl sulfoxide and dimethyl formamide; for increasing periods up to 36 h. The treated materials were delignified, dried and introduced in the fermentation media as inducing carbon source for Rchoderma reesei. The untreated materials and pure cellulose powder were used individually in control and reference media, respectively. The fermentation media containing bagasse treated for 8 h in chloroform or dioxan gave a promising cellulase activity, nearly the same as that from the reference medium. The untreated bagasse gave a markedly low cellulase activity.The media with treated sawdust gave a relatively higher enzyme activity but far below the reference medium. The sawdust treatment with the solvents mentioned resulted in a very mild effect because of its high content of admixtures, lighin and hemicellulose bonding cellulose.

In the first experiment, diets containing 14, 16, 18, 20, 22 or 24% protein with no methionine supplementation were tested, while in the second experiment diets containing 16, 18 and 20% supplemented with methionine to give 90, 100 or 110% of the recommended N.R.C. levels were compared with an unsupplemented 24% protein diet. 2. Methionine supplementation of the low protein diets stimulated faster gains than the unsupplemented diets but not enough to surpass the response to the 24% protein control diet. 3. It was concluded that a high protein diet unsupplemented with methionine was more economical to feed to broilers than supplemented low protein diets.