Statistical evaluation of fermentation conditions and nutritional factors by Plackett-Burman two-level factorial design followed by optimization of significant parameters using response surface methodology for lipase production by Bacillus brevis was performed in submerged batch fermentation. Temperature, glucose, and olive oil were found to be the significant factors affecting lipase production. Maximum lipase activity of 5.

The objective of this work is to enhance the production of lovastatin using Monascus purpureus MTCC 369 in mixed substrate solid state fermentation using various solid substrates and to optimize the combination of the solid substrates by response surface methodology. Solid state fermentation was conducted in a 250 mL Erlenmeyer flask at 30°C for 14 days with initial moisture content of 40% and inoculum size of 10% active culture. Barley, long grain rice and sago starch were found to be the suitable substrates producing maximum lovastatin of 193.7 mg, 190.2 mg and 180.9 mg/g of dry solids. These substrates were further used in various combinations as designed by the central composite design for enhancing the lovastatin production using Monascus purpureus. To the best of our knowledge this is the first report on the production of lovastatin using a mixed substrate solid state fermentation using Monascus purpureus.

Xylanases are hydrolytic enzymes which randomly cleave the β-1, 4 backbone of the complex plant cell wall polysaccharide xylan. Diverse forms of these enzymes exist, displaying varying folds, mechanisms of action, substrate specificities, hydrolytic activities, and physicochemical characteristics. This article focuses on the fermentative production of xylanase from Arthrobacter sp. and the factors affecting the production. The batchsubmerged fermentation was carried out in a 250-ml Erlenmeyer flask. The inoculum size of 5% v/v, initial pH of 7.0, and shaking speed of 150 rpm at 32 • C were maintained for the optimization of medium components. The cell growth, xylanase activity, cellulase activity, protein, and pH were determined at regular time intervals. Plackett-Burman statistical methodology was adopted to study the effect of media components on xylanase production. The effect of temperature and pH was studied using optimized medium composition determined by Plackett-Burman experimental design. The maximum xylanase activity of 4.0 U ml −1 at 84 h at the optimum temperature of 35 • C and pH of 7.0 was obtained. 