Studies on Commercial Aspects of Xylanase from <i>Chainia </i>Species

Abstract

878-882Production of xylanase from Chainia species in a fermenter was standardized to a one litre scale. The substrate, wheat bran, was varied  from 3 per cent to 5 per cent and the pH profile monitored. When 3 per cent and 4 per cent wheat bran was used the major portion of the xylan was utilized for biomass production. With 5 per cent substrate a maximum activity of 29.78 IU/ml, in 72h was achieved .The conditions were easily scaled up to 101. Many commercial organic nitrogen sources were studied, at shake flask level, 2 per cent soybean meal supplemented with 0.2 per cent yeast extract, gave activities comparable to when 2 per cent yeast extract was used in the media. Separation of enzyme from fermentation broth was tried by two methods, ultrafiltration and solvent precipitation. Ultra filtration was carried out using cellulose acetate membrane cut off 5000. However, a three-old concentration of fermentation broth gave only a little over 50 per cent of the original xylanase activity. The solvents used for precipitation of xylanase from fermentation broth were ethanol and acetone. Three volumes of ethanol gave 99 per cent xylanase recovery with a 20-fold increase in specific activity. Whereas two volumes of acetone gave 93.5 per cent recovery with 10-fold increase in specific activity. Xylanase activity in a clarified fermentation broth, stored at 10oC, retained 90 per cent of the original activity, it reduced to half its value only after three months