Thermostable, salt-tolerant α-amylase from Bacillus sp. MD 124
✍ Scribed by M. Jana; Dr. B. Pati
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 173 KB
- Volume
- 37
- Category
- Article
- ISSN
- 0233-111X
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✦ Synopsis
A bacterial strain (MD 124) isolated from municipal garbage and identified as Bacillus sp. was found to be capable of producing salt tolerant and thermostable a-amylase. Rhamnose and peptone were found to be the best carbon and nitrogen source for the production of enzyme. The pH and temperature optima for the enzyme activity were found to be at 6 and 90 "C. Seventy five per cent enzyme activity was retained in 5 M NaCl over 24 hrs.
Modification of starch by enzymatic means is documented in industrial processes and a number of evidences have been established in bacteria, molds and yeasts by several workers (DHANWANT et al. 1987, LINARDI and MACHADO 1990, BROWN and KELLY 1995, FOGARTY et al. 1994). Thermostable amylase is now extensively used in high temperature industry for starch hydrolysis to reduce the viscosity of starch paste (SAITO 1973, EMANUILOVA 1984, BAJPAI and BAJPAI 1989).
This communication deals with the isolation and identification of a thermostable and salt tolerant a-amylase producing bacteria along with some properties of the enzyme.
Methods
Strains were isolated from different garbage samples using a selective medium of the following composition: bactopeptone, 0.5%; beef extract, 0.3%; MgS04, 7 H20, 0.05%; CaC12, 2 H20, 0.002%; KHZP04, 0.3%; starch, 0.5%; agar, 2%.
The pH of the medium was adjusted to 7.