Optimization of Alkaline Protease Production by Solibacillus silvestris, Isolated from Gir Region of Gujarat

Abstract

Objectives: Microbes from Mangrove ecosystem have the ability to produce useful primary and secondary metabolites of biotechnological significance and hence the objective of this study is to optimize the production of bacterial alkaline protease from a Mangrove isolate Solibacillus silvestris. Methodology: The bacterium (named as Madhwad 10−3 Summer Zobell) used in the present study was isolated from the soil collected from Madhwad, Gir, India in summer season and was identified using MALDI-TOF (Mass spectrometry). It had shown the highest alkaline protease enzyme activity amongst the other isolates and hence was further analyzed using different physical and chemical factors. Selected parameters i.e. Sucrose, Peptone, and Salinity were further used for the optimization using Response Surface Methodology (RSM). Findings: The bacterium (named as Madhwad 10−3 Summer Zobell) was identified as Solibacillus silvestris. Among the physical parameters, the results proved that highest enzyme production can be obtained at pH 8.5, 40 °C of temperature, 48 h of incubation period, and agitation speed of 120 rpm while in the chemical parameters, Sucrose and Peptone with 0% salinity were found to give highest enzyme activity i.e. 221.7 U/ml and 246.7 U/ml, respectively. In the statistical analysis done using RSM, all the parameters found to be significant and gave the highest result of 258.750 U/ml at 2.5% Sucrose, 10% Peptone, and 0% Salinity level. Applications/improvements: The enzyme produced due to its efficiency in working at alkaline pH can be utilized in industries such as detergent and textile or in Bioremediation. Keywords: Mangroves, Alkaline Protease, Response Surface Methodology, Solibacillus silvestris.