Affiliation:
1. Kemerovo State University
Abstract
Growth-stimulating properties of Bacillus amyloliquefaciens B-11265 and Bacillus aryabhattai B-13192 strains were studied, and the possibility of their co-cultivation for activity intensification was evaluated. The strains under study were found to be able to synthesize indolyl-3-acetic and gibberellic acids, siderophores: B. amyloliquefaciens B-11265 in the amount of 5.23 µg/ml, 1.05 mg/ml, 46.15%; B. aryabhattai B-13192 – 3.07 µg/ml, 0.84 mg/ml, 35.50%, respectively. The research results showed that the strains were biocompatible and did not inhibit each other's development, allowing them to be included in the same consortium. Joint cultivation of the strains showed that the ratio of microorganisms in the nutrient substrate has a significant effect on the yield of the target substances. At the ratio of B. amyloliquefacien and B. aryabhattai 1 : 1, inhibition of indolyl-3-acetic acid synthesis was observed; ratios of 2 : 3 and 3 : 2 led to a decrease in gibberellic acid production. It was found that three (B. amyloliquefacien) to one (B. aryabhattai) was the optimal ratio to increase the yield of the target substances compared to the average values characteristic of individual strains. In this variant, the synthesis of growth-stimulating substances by the consortium was: indolyl-3-acetic acid – 5.31 μg/ml, gibberellic acid – 1.23 mg/ml, siderophores – 51.27%. The results obtained indicate the high potential of the engineered consortium for agricultural applications. However, in order to develop a growth-stimulating preparation based on it, it is necessary to conduct a number of additional studies aimed at investigating the effect of the strain on agricultural crops in laboratory and field experiments.