Journal
WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY
Volume 29, Issue 9, Pages 1625-1633Publisher
SPRINGER
DOI: 10.1007/s11274-013-1325-1
Keywords
Alkalotolerant and thermostable RNase; Streptomyces; Optimization; Central composite design; Response surface methodology
Categories
Funding
- Ege University [09.MUH.078]
Ask authors/readers for more resources
Total of 171 alkaliphilic actinomycetes were evaluated for extracellular RNase production and Streptomyces sp. M49-1 was selected for further experiments. Fermentation optimization for RNase production was implemented in two steps using response surface methodology with central composite design. In the first step, the effect of independent fermentation variables including temperature, initial pH and process time were investigated. After identification of carbon and nitrogen sources affecting the production by one variable at a time method, concentrations of glucose and yeast extract and also inoculum size were chosen for the second central composite design. A maximum RNase activity was obtained under optimal conditions of 4.14 % glucose concentration, 4.63 % yeast extract concentration, 6.7 x 10(6) spores as inoculum size for 50 ml medium, 42.9 A degrees C, 91.2 h process time and medium initial pH 9.0. Optimum activity of the enzyme is achieved at pH 11 and temperature 60 A degrees C. The enzyme is highly stable at pH range 9.0-12.0 and at 90 A degrees C after 2 h. Statistical optimization experiments provide 2.25 fold increases in the activity of alkalotolerant and thermostable RNase and shortened the fermentation time compared to that of unoptimized condition. The members of Streptomyces can be promising qualified RNase producer for pharmaceutical industries.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available