Strain Improvement by UV Mutagenesis for Protease Overproduction from Bacillus subtilis E6-5 and Nutritional Optimization
Abstract
The purpose of the present study was to enhance the protease production of the parental type Bacillus subtilis E6-5 by UV irradiation. The parental type was subjected to UV irradiation at different distances (5-15 cm) for different time intervals ( 1-120 min). After each treatment, total 400 mutants were obtained. The mutants were screened on skim milk agar plates for the selection of best proteolytic mutant. Among mutants, the mutant MET39, which obtained at 15 cm distance and irradiation time 5 min of exposure, was selected as best mutant produced 1.5 fold more enzyme over the parent strain. The effects of nutritional factors (various carbon, nitrogen sources and metal ions) on the protease production from MET39 mutant strain were studied. The best carbon source was found as glycerol. Among the inorganic nitrogen sources, the highest enzyme production was obtained in the presence of tryptone. The metal ions did not indicate significant effect on enzyme production. In order to enhance the yield, new modified medium was obtained by combining the best carbon and nitrogen sources. In this medium, enzyme yield was enhanced 88% compared to basal medium. MET39 mutant strain might have a great potential for protease production at industrial scale.
Keywords
Protease, Bacillus, UV, Mutant, Nutritional Factors, Optimization
References
- Auther C, Helal M, and Amer H (2012). Physiological and microbiological studies on production of alkaline protease from locally isolated Bacillus subtilis. Aust. J. Basic Appl. Sci., 6: 193-203.
- Bach E, Sant’Anna V, and Daroit DJ (2012). Production, one-step purification, and characterization of a keratinolytic protease from Serratia marcescens P3. Process Biochem., 47: 2455–2462.
- Basavaraju S, Kathera C, and Jasti PK (2014). Induction of Alkaline Protease Production by Bacillus Mutants Through U.V. Irradiation Int. J. Pharm. Sci. Rev. Res., 26(1): 78-83.
- Belmessikh A, Boukhalfa H, and Mechakra-Maza A (2013). Statistical optimization of culture medium for neutral protease production by Aspergillus oryzae. Comparative study between solid and submerged fermentations on tomato pomace. J. Taiwan Inst. Chem. Eng., 44: 377-385.
- Boominadhan, U., Rajakumar, R., Sivakumaar, P. K. V., & Joe, M. M. (2009). Optimization of protease enzyme production using Bacillus sp. isolated from different wastes. Bot. Res. Int, 2(2), 83-87.
- Chellappan S, Jasmin C, Basheer SM, Elyas KK, and Bhat SG (2006). Production, purification and partial characterization of a novel protease from marine Engyodontium album BTMFS10 under solid state fermentation. Proc. Biochem., 41: 956-961.
- Chi Z, Ma C, and Wang P (2007). Optimization of medium and cultivation conditions for alkaline protease production by the marine yeast Aureobasidium pullulans. Bioresour Technol., 98: 534-538.
- Contesini FJ, Melo RR, and Sato HH (2018). An overview of Bacillus proteases: from production to application. Critical Reviews in Biotechnology, 38(3): 321-334.
- Dutta JR, and Banerjee R (2006). Isolation and characterization of a newly isolated Pseudomonas mutant for protease production. Braz. arch. biol. technol., Vol. 49, Curitiba.
- Dutta JR, and Rintu B (2006). Isolation and characterization of a newly isolated Pseudomonas mutant for protease production. Brazilian archives of biology and technology, 49(1): 37-47.