Application of statistical experimental design for optimisation of bioinsecticides production by sporeless Bacillus thuringiensis strain on cheap medium

Abstract

In order to overproduce bioinsecticides production by a sporeless Bacillus thuringiensis strain, an optimal composition of a cheap medium was defined using a response surface methodology. In a first step, a Plackett-Burman design used to evaluate the effects of eight medium components on delta-endotoxin production showed that starch, soya bean and sodium chloride exhibited significant effects on bioinsecticides production. In a second step, these parameters were selected for further optimisation by central composite design. The obtained results revealed that the optimum culture medium for delta-endotoxin production consists of 30 g L−1 starch, 30 g L−1 soya bean and 9 g L−1 sodium chloride. When compared to the basal production medium, an improvement in delta-endotoxin production up to 50% was noted. Moreover, relative toxin yield of sporeless Bacillus thuringiensis S22 was improved markedly by using optimised cheap medium (148.5 mg delta-endotoxins per g starch) when compared to the yield obtained in the basal medium (94.46 mg delta-endotoxins per g starch). Therefore, the use of optimised culture cheap medium appeared to be a good alternative for a low cost production of sporeless Bacillus thuringiensis bioinsecticides at industrial scale which is of great importance in practical point of view.

Statistical Analysis of Cultural Parameters Influencing Delta-Endotoxins and Proteases Productions by Bacillus thuringiensis kurstaki

“…Factorial design technique was widely used to improve delta-endotoxin production [17,18]. A factorial experimental design was used to study the delta-endotoxin and proteolytic enzymes produced by B. thuringiensis subsp.…”

Entomopathogenic activity of bacterial and viral strains from the bioresource collection “State Collection of Entomoacariphages and Microorganisms”

“…Bacillus thuringiensis, B. popilliae, Lysinibacillus sphaericus, Paenibacillus larva, etc.) and viruses of nuclear polyhedrosis and granulosis are actively used as active substances [3][4][5][6][7]. The advantage of viral and bacterial insecticides is their environmental friendliness and cumulative effect in agrocenoses [8][9].…”