Proceedings Volume 2010 (format .pdf) - SimpBTH

include xylanase, endoxylanase, 1,4-β-D-xylan-xylanohydrolase, endo-1,4-β-Dxylanase,β-1,4-xylanase and β –xylanase [2].Xylanases have been extensively studied and could potentially beemployed in the production of hydrolysates from agro-industrial wastes, nutritionalimprovements of lignocellulosic feeds, processing of food [1]and increasing animalfeed digestibility, biobleaching of paper pulp [8]. Microbial xylanases enhanceddough rheological properties as increase in loaf volume that improves its bakingperformance and so have great importance in cereal industry [5]. Other potentialapplications include the clarification of fruit juices and wine, the extraction of plantoil, coffee and starch, the production of oligosaccharides and improvement of thenutritional value of feed [4].Biodiesel have drawn attention in the last decade as a renewable,biodegradable, and non-toxic fuel. Raw glycerol can become an importantfeedstock when biodiesel is applied on a large commercial scale.With theproduction of 10 kg of biodiesel from rapeseed oil, 1 kg of glycerol becomesavailable. Few microorganisms can be used for direct glycerol biovalorization.MATERIALS AND METHODSIn this study, Taguchi method [6] was applied to test the relativeimportance of medium components (glycerol, wheat bran, corn steep liquor,ammonium sulfate ) in xylanase production by Bacillus brevis.We considered Taguchi methodology as a good positive option for theoptimization of biotechnological processes of microbial enzymes production . Theexperimental design proposed by Taguchi involves using orthogonal arrays toorganize the parameters affecting the process and the levels at which they shouldbe varies. Instead of having to test all possible combinations like the factorialdesign, the Taguchi method tests pairs of combinations [6,3,7]. This allows thecollection of the necessary data to determine which factors most affect processperformance with a minimum amount of experimentation, thus saving time andresources.Table 1. Medium components and levelsFACTORSLEVELS %Level I Level II Level III• A. Glycerol 1 1,5 2• B. Wheat bran 3 5 7• C. Corn steep liquor 0,5 1 2• D. Ammonium sulfate 0,2 0,3 0,4Selection of medium components and their levels are made on the basis ofsome preliminary trial experiments conducted in the laboratory.225