Modulating the production of xylanase by Bacillus pumilus BS131 through optimization using waste fiber sludge / Modulando a produção de xilanase por Bacillus pumilus BS131 por meio da otimização usando lodo de fibra residual

Abstract In recent days, cheapest alternative carbon source for fermentation purpose is desirable to minimize production cost. Xylanases have become attractive enzymes as their potential in bio-bleaching of pulp and paper industry. The objective of the present study was to identify the potential ability on the xylanase production by locally isolated Bacillus pumilus BS131 by using waste fiber sludge and wheat bran media under submerged fermentation. Culture growth conditions were optimized to obtain significant amount of xylanase. Maximum xylanase production was recorded after 72 hours of incubation at 30 °C and 7 pH with 4.0% substrate concentration. In the nutshell, the production of xylanase using inexpensive waste fiber sludge and wheat-bran as an alternative in place of expensive xylan substrate was more cost effective and environment friendly.

Resumo Nos últimos dias, a fonte alternativa de carbono mais barata para fins de fermentação é desejável para minimizar o custo de produção. As xilanases têm se tornado enzimas atraentes como seu potencial no biobranqueamento da indústria de papel e celulose. O objetivo do presente estudo foi identificar a capacidade potencial na produção de xilanase por Bacillus pumilus BS131 isolado localmente usando lodo de fibra residual e farelo de trigo em meio de fermentação submersa. As condições de crescimento da cultura foram otimizadas para obter uma quantidade significativa de xilanase. A produção máxima de xilanase foi registrada após 72 horas de incubação a 30 °C e pH 7 com concentração de substrato de 4,0%. Resumindo, a produção de xilanase usando lodo de fibra residual de baixo custo e farelo de trigo como uma alternativa no lugar do substrato de xilano caro foi mais econômica e ecológica.

Production, purification, characterization and over-expression of xylanases from actinomycetes.

Xylanases are a group of depolymerizing enzymes often used for the hydrolysis of xylan (present in hemicellulose) to monomeric sugars and comprise endo-xylanases (EC 3.2.1.8) and β-xylosidases (EC 3.2.1.37). They often act in synergy with other enzymes for complete hydrolysis of hemicellulose. Xylanases find several industrial applications, for example in food and feed industries, paper and pulp industries and more recently have acquired a great role in biomass to biofuels program. Bacteria and fungi can best produce xylanases. Recent developments in rDNA technology have resulted in molecular cloning and expression of xylanases in heterologous and homologous hosts. In view of significance of the actinomycetes for the production of biotechnological products, attempts have been made in recent years to explore them for the production of industrial enzymes, including xylanses, aiming to find the enzyme with novel features. This review provides the state-of-art information and developments on the xylanases from actinomycetes, presenting the production, purification, characterization and over-expression from various actinomycetes cultures.

Enzymatic hydrolysis of water hyacinth biomass for the production of ethanol: Optimization of driving parameters.

An efficient conversion of lignocellulose into fermentable sugars is a key step in producing bioethanol in a cost effective and eco-friendly manner. Alternative source like water hyacinth biomass (WHB) (Eichhornia crassipes) may be used as a supplement for the routine feedstocks. The enzyme loading for optimum yield of total reducing sugar was investigated and the enzyme-substrate interaction optimised. The maximal reducing sugar and xylose yield was obtained using cellulase and xylanase loading of 46.12 and 289.98 U/g and 2.26% (w/v) substrate loading. The efficiencies of ethanol production from the WHB hydrolysate are very less and the maximal ethanol yield was 3.4969 g/L when Pichia stiptis was used, followed by 3.4496 and 3.1349 g/L for Candida shehatae and Saccharomyces cerevisiae.