Culture conditions for the production of thermostable amylase by Bacillus sp

Abstract

Studies on the α-amylase production were carried out with a bacterial strain isolated from a soil sample. The cells were cultivated in a mineral medium containing soluble starch as sole carbon source. The addition of calcium (10 mM) or peptone (1%) and yeast extract (0.5%) to the mineral medium shortened the lag period and improved the growth and α-amylase synthesis. The addition of glucose to the culture diminished greatly the synthesis of α-amylase, demonstrating that a classical glucose effect is operative in this organism. The optimum temperature and initial medium pH for amylase synthesis by the organism were 50°C and 7.0 respectively. The optimal pH and temperature for activity were 6.0 and 50°C respectively. The enzyme extract retained 100% activity when incubated for one hour at 90°C and 40% at 60°C for 24 h. The addition of glucose to the culture diminished greatly the synthesis of α-amylase.

Agro-industrial residues and starch for growth and co-production of polyhydroxyalkanoate copolymer and α-amylase by Bacillus sp. CFR-67

“…). This finding on lowering of enzyme yield under excess nitrogen supplementation is in agreement with earlier reported work (10,15,27,35). Corn starch was used at 30 g L -1 , other parameters are as indicated in Table 1.…”

Application of Amylolytic Lactobacillus fermentum 04BBA19 in Fermentation for Simultaneous Production of Thermostable Alpha-Amylase and Lactic Acid

“…In the presence of glucose and fructose, amylase production was almost nil; and that was a proof that glucose and fructose repressed amylase synthesis by L. fermentum 04BBA19. This observation is in agreement with the reports of Theodoro and Martin [64] showing that synthesis of carbohydrate degrading enzymes in some microbial species leads to catabolic repression by substrate such as glucose and fructose. Similar results were observed by Halsetine et al [65] for the production of amylase by the hyperthemophilic archeon Sulfolobus solfataricus.…”

Production and properties of alpha-amylase from Citrobacter species

“…The crude α-amylase of the Citrobacter sp. has a comparable temperature activity range with that of Bacillus sp reported by Teodoro and Martins (2000) but was however less stable. The pH activity and stability profiles of the organism showed that at a pH range of 3 -6, there was no appreciable difference in amylase activity.…”