AGRO-INDUSTRIAL RESIDUES AND STARCH FOR GROWTH AND CO-PRODUCTION OF POLYHYDROXYALKANOATE COPOLYMER AND alpha-AMYLASE BY BACILLUS SP CFR-67

作者：Shamala T R^*; Vijayendra S V N; Joshi G J

来源：Brazilian Journal of Microbiology, 2012, 43(3): 1094-1102.

• alpha-amylase
• Bacillus sp.
• Corn starch
• Polyhydroxyalkanoate
• Rice bran hydrolysate
• Wheat bran hydrolysate

Polyhydroxyalkanoates (PHA) and alpha-amylase (alpha-1,4 glucan-4-glucanohydrolase, E.C. 3.2.1.1) were co-produced by Bacillus sp. CFR-67 using unhydrolysed corn starch as a substrate. Bacterial growth and polymer production were enhanced with the supplementation of hydrolysates of wheat bran (WBH) or rice bran (RBH) individually or in combination (5-20 g L-1, based on weight of soluble substrates-SS). In batch cultivation, a mixture of WBH and RBH (1:1, 10 g L-1 of SS) along with ammonium acetate (1.75 g L-1) and corn starch (30 g L-1) produced maximum quantity of biomass (10 g L-1) and PHA (5.9 g L-1). The polymer thus produced was a copolymer of polyhydroxybutyrate-co-hydroxyvalerate of 95:5 to 90:10 mol%. Presence of WBH and corn starch (10-50 g L-1) in the medium enhanced fermentative yield of alpha-amylase (2-40 U mL(-1) min(-1)). The enzyme was active in a wide range of pH (4-9) and temperature (40-60 degrees C). This is the first report on simultaneous production of copolymer of bacterial PHA and alpha-amylase from unhydrolysed corn starch and agro-industrial residues as substrates.

• 出版日期2012-9