The bacterial diversity of ripened Guang'yuan Suancai and in vitro evaluation of potential probiotic lactic acid bacteria isolated from Suancai

- Bacterial community in Guang'yuan Suancai was studied by 16S rRNA gene clone libraries.
- L. fermentum from Guang'yuan Suancai was firstly reported as potential probiotic LAB.
- L. fermentum (isolate SC_21) had the highest DPPH radical-scavenging activity.

The bacterial diversity of ripened Guang'yuan Suancai (SC) was investigated by using the 16S rRNA gene clone libraries, and lactic acid bacteria (LAB) strains isolated from SC were evaluated for potential probiotic application by in vitro screening assays. A total of 100 clones were recovered from the 16S rRNA gene clone libraries, and Lactobacillus (74%), Acinetobacter (9%), and Wautersiella (7%) were found to be the dominant genera. Fifty-seven presumptive LAB isolates were collected, four of which showed an excellent tolerance to low pH values and high concentrations of bile salt. All four of the isolates were identified as Lactobacillus fermentum. These four isolates showed aggregation capacity and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (in the range of 29.09-39.63%). This study enhances our knowledge about bacterial diversity in Guang'yuan SC and provides a foundation for the application of isolated LAB as probiotic preparations for fermented foods or other products.