Production of xylanase by Aspergillus niger GIO and Bacillus megaterium through solid-state fermentation

Abstract

Xylanase breaks xylan down to xylose, which is used in industries such as pulp and paper, food and feed, among others. The utilization of wastes for xylanase production is economical, hence this work aimed at producing xylanase through solid-state fermentation and characterizing the enzyme. Xylanase-producing strains of Bacillus megaterium and Aspergillus niger GIO were inoculated separately in a 5 and 10 day solid fermentation study on maize straw, rice straw, sawdust, corn cob, sugarcane bagasse, conifer litters, alkaline-pretreated maize straw (APM) and combined alkaline and biological-pretreated maize straw, respectively. The best substrate was selected for xylanase production. The crude enzyme was extracted from the fermentation medium and xylanase activity was characterized using parameters such as temperature, cations, pH and surfactants. Among different substrates, the highest xylanase activity of 3.18 U ml−1 was recorded when A. niger GIO was grown on APM. The xylanase produced by A. niger GIO and B. megaterium had the highest activities (3.67 U ml−1 and 3.36 U ml−1) at 40 °C after 30 and 45 min of incubation, respectively. Optimal xylanase activities (4.58 and 3.58 U ml−1) of A. niger GIO and B. megaterium , respectively, were observed at pH 5.0 and 6.2. All cations used enhanced xylanase activities except magnesium ion. Sodium dodecyl sulfate supported the highest xylanase activity of 6.13 and 6.90 U ml−1 for A. niger GIO and B. megaterium , respectively. High yields of xylanase were obtained from A. niger GIO and B. megaterium cultivated on APM. The xylanase activities were affected by pH, temperature, surfactants and cations.

Enzyme cocktail with hyperactive lipase through solid-state fermentation by the novel strain Penicillium sp. Y-21

“…Lipase and proteinase production were significantly higher in the tray bioreactor, and their production yields are 75 and 35% higher in the tray bioreactor than in the flask bioreactor. The results were in accordance with previous reports that filamentous fungi had better performance for enzyme production in static bed 28 – 32 .…”