Isolation and identification of contamination microorganisms in ε-poly-L-lysine fermentation process

Abstract:

[Objective] To solve the problem of contamination during ε-poly-L-lysine (ε-PL) fermentation, contamination microorganisms were screened and identified in this study. [Methods] Many strategies, like dilution coated plate, streak plate method, environmental stress method and liquid nutrient enrichment method, were performed to screen microorganisms from contaminated sample. Then the phylogenetic position of the isolate was determined through colony and microscopic morphology observation and 16S rRNA gene sequence analysis. Subsequently, the ε-PL tolerance of the isolate had evaluated. [Results] Contamination microorganisms were screened using liquid nutrient enrichment method isolated and identified as Acinetobacter bereziniae by 16S rRNA gene sequence analysis. Meanwhile, this isolate could tolerant high concentration of ε-PL. [Conclusion] Acinetobacter bereziniae was identified as the dominate contamination microorganism in ε-PL fermentation. And this find is helpful for the treatment of contamination microorganism in the process of ε-PL fermentation.