Optimization of L-Asparaginage production by Bacillus subtilis isolated from honey of west Iran

Abstract

Bacillus subtilis can be found in extreme physicochemical environments and many sources, such as honey. The bacteria can produce hydrolytic enzymes, including L-asparaginase, which breaks the amino acid L-asparagine into two components, Aspartic acid and Ammonia. This enzyme has various applications in industry such as food industries and medical purposes, especially in the treatment of cancer. Objective:In this study, optimization of L-Asparaginage production by Bacillus subtilis strain KP6, which was isolated from the west Iran natural honey, was investigated and the effect of growth conditions such as media and other factors on bacterial growth and L- asparginase enzyme production by the bacteria was studied.Materials and methods: First, the KP6 strain was screened for the production of L-asparaginase. Different factors of culturing condition and physical environment such as inoculum size, cultivation duration, nitrogen source, and aeriation condition for L-asparaginase production was evaluated using one factor at time method. To evaluation of bacterial growth, dry weight method (Biomass) and photometry by spectrophotometer method are used and production of L-asp arginase enzyme is measured by qualitative and quantitative methods such as bacterial culture in solid medium containing color indicator and specifically, nesslerization method.Results:The results showed that the KP6 sttrain capable of producing L-aspaginase enzymes, and the factors that were most effective in optimizing its production was aeriation cultivation for 84h in Casein-lectin containing media.Conclusion:The results showed that Bacillus subtilis isolated from honey is capable of producing L-asparaginase the continuous aeriation, 84h of cultivation and casein hydrolyzed as the nitrogen source has most effect on Asparaginase production.