The main objective of this study was production of ethanol from three lignocellulosic biomasses like sugarcane bagasse, rice straw and wheat straw by Sacchromyces cervisae. All the three substrates were ground to powder form (2 mm) and pretreated with 3%H2O2 + 2% NaOH followed by steaming at 130 °C for 60 min. These substrates were hydrolyzed by commercial cellulase enzyme. The whole fermentation process was carried out in 500 mL Erlenmeyer flask under anaerobic conditions in submerged fermentation at 30 °C for three days of incubation period. FTIR analysis of the substrates indicated significant changes in the alteration of the structure occurred after pretreatment which leads to efficient saccharification. After pretreatment the substrates were hydrolyzed by commercial cellulase enzyme and maximum hydrolysis was observed in sugarcane bagasse (64%) followed by rice straw (40%) and wheat straw (34%). Among all these tested substrates, sugarcane bagasse (77 g/L) produced more ethanol as compared to rice straw (62 g/L) and wheat straw (44 g/L) using medium composition of (%) 0.25 (NH4)2SO4, 0.1 KH2PO4, 0.05 MgSO4, 0.25 Yeast extract by S. cervisae.

Present study dealt with the production, purification and characterization of xylanase from Bacillus subtilis- BS05 grown in submerged fermentation at 37(o)C for 48h using sugarcane bagasse as a substrate. Xylanase enzyme was purified to homogeneity by ammonium sulphate fractionation followed by sephadex G-100 chromatography. The molecular mass of xylanase enzyme was found to be 23kDa by SDS-PAGE. The optimum pH and temperature of xylanase enzyme was 5 and 50°C with stability range of 5-6 and 30°C -50°C respectively. The enzyme had half life of 1386-1155 minutes at 30°C -50°C respectively. Metal profile of the enzyme showed that Mn(2+) (127.4 %) and Fe(2+) (115%) were the activators while Hg(2+) (14%) and EDTA (19%) were the inhibitors. Kinetic parameters revealed that the enzyme is specific to birchwood xylan with Km , Kcat , Vmax and Kcat/Km value of 1.15 mg/ml, 850 s(-1), 117.64 U/mg and 739.13 s(-1)mg(-1).mL respectively.

BACKGROUND The deactivation of cellulases by phenolics is considered to be the main bottleneck in the saccharification of agricultural by‐products for efficient bioethanol production on a large scale. The removal of these phenolic inhibitors, produced as a result of pretreatment, is essential for an efficient saccharification process. One such process is overliming that has been mostly studied for hydrolysates of agricultural by‐products. In the present study however, solid biomass was used whereby the detection of phenolic compounds and their effect on saccharification was studied. RESULTS The pretreated wheat straw showed 19% saccharification and total phenolic content (TPC) of 188 mg gallic acid equivalent g‐1 biomass dry weight. Detoxification of pretreated wheat straw applying different alkalis, i.e. NaOH, NH4OH and Ca(OH)2 was conducted. Overliming using Ca(OH)2 solution of pH 12, for 2 h at 80°C showed significant removal of 60% of phenolic compounds, which in turn enhanced the saccharification by 2.4‐fold. Scanning electron microscopy of pretreated and overlimed substrates also showed considerable change in structure, making it more accessible for enzymatic hydrolysis. CONCLUSION The elimination of phenolic compounds due to overliming has facilitated increased saccharification that in turn will help in substrate efficient biofuel production. © 2018 Society of Chemical Industry

Two different strains of Rhizopus sp. i.e. R. oligosporus-M30 and R. arrhizus-M26 were employed for the production of acid protease using different agro-residues such as rice husk, rice bran, wheat bran, defatted soybean meal and sunflower meal as a sole carbon source. R. oligosporus-M30 gave maximum enzyme level with soybean meal (15.6 U/gds) while R. arrhizus-M26 with sunflower meal (13.6 U/gds) respectively. The optimal conditions for the enzyme production by R .oligosporus-M30 were initial pH of 5.5, temperature 30 o C with 10% of inoculum size for 72hr of fermentation period. When R. arrhizus-M26 was cultivated that exhibit the best enzyme production with the fermentation period of 72h, initial pH 5.0, temperature 33 o C with 5% of inoculum size

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