关键词: 解淀粉芽孢杆菌, 鉴定, 发酵条件优化

Abstract: Heavy metals are highly toxic, nondegradable, sustainable in the environment and can accumulate in the soil through food chain which result in a serious threat to the health of organisms. Although the microbial remediation has advantages of low economic cost, high efficiency and no secondary pollution, there are several disadvantages including exogenous microorganisms not easy to survive and reproduce in soil. Therefore, this study identified the strain of HNU1, an enriched copper ion bacterium, which was isolated and preserved in  previous study. The strain HNU1 was identified as Bacillus amyloliquefaciens through morphological observation, physiological and biochemical test and the analysis of 16S rDNA. Based on single factor experiment and orthogonal experimental, the optimum fermentation conditions were designed: the optimal medium contained 2 g·L-1 sucrose, 4 g·L-1 yeast extract, 6 g·L-1 tryptone, and 5 g·L-1 MgSO4. The optimum condition was pH 8.0, temperature 37 °C, inoculation quantity of 0.1%, rotation speed of 180 r·min-1, liquid volume of 25 mL and a 50 mL shake flask. In this study, the strain HNU1 was identified as Bacillus amyloliquefaciens with good properties of copper ions adsorption. Therefore, the strain HNU1 could be further developed into microbial fertilizer for the remediation of copper contaminated soil, which was of great significance for the remediation of heavy metal contaminated soil.

Key words: Bacillus amyloliquefaciens, identification, optimization of fermentation conditions