Production of High Cell Mass of Bacillus firmus Using Statistical Medium Optimization

Abstract

Growing concern over agricultural losses due to nematodes infection had drawn huge interest in using biological control of <em>Bacillus firmus</em> as an agent to reduce the damages and increase crop yield. <em>Bacillus firmus</em> strains are well known for their ability to terminate nematode <em>Meloidogyne incognita</em> activity. They are also able to secrete beneficial enzyme for use in food, animal feed and industrial sector. Therefore, production of high cell mass for this microbeis required. Extensive study for the development of a suitable medium composition and cultivation strategy is needed. The aim of this study is to increase the biomass production of <em>Bacillus firmus</em> through optimization of medium composition using statistical approach. Different production media from previous literatures were screened to supports high cells growth. The best medium was found to yield the highest cell mass of about 6.27 g L^-1. The composition of the medium was screened for significant factors and further being optimized using statistical method which employed Box Behnken design. The optimized mediumwas found to efficiently increased the cell mass of about 10.22 g L^-1. This value is 49.85% higher compared to the unoptimized medium.