Genomic information of Kocuria isolates from sake brewing process

Area of Science:

• Microbiology
• Genomics
• Food Science

Background:

• Kocuria bacteria are common in various environments, including food production.
• Specific Kocuria strains were identified as unique to a sake brewery in Toyama, Japan.

Purpose of the Study:

• To investigate the genomic characteristics of Kocuria isolates from a sake brewery.
• To understand the potential for genetic exchange between these isolates.

Main Methods:

• 16S rRNA gene sequencing to differentiate Kocuria isolates.
• Whole-genome sequencing of two distinct Kocuria isolates (TGY1120_3 and TGY1127_2).
• Comparative genomic analysis to identify shared and unique genetic elements.

Main Results:

• Two Kocuria groups were identified, resembling Kocuria koreensis (Kk type) and Kocuria uropygioeca (Ku type).
• Isolate TGY1120_3 (Kk type) possessed one chromosome and three plasmids, with a shared transposon region across chromosomal and plasmid DNA.
• Isolate TGY1127_2 (Ku type) had one chromosome and one plasmid, also containing an identical transposase coding region, suggesting inter-isolate transfer.
• All four plasmids shared a highly similar region, indicating a common ancestor and potential for horizontal gene transfer.

Conclusions:

• The two Kocuria isolates represent distinct species with unique genomic features.
• Evidence suggests a community of Kocuria in the sake brewery capable of exchanging genetic information via plasmids.
• This genetic exchange may play a role in the sake brewing process.