Bacterial community characterization and dynamics of indigo fermentation

Area of Science:

• Microbiology
• Industrial Biotechnology
• Textile Chemistry

Background:

• Traditional indigo fermentation for textile dyeing in Japan lacks detailed understanding of microbial involvement.
• Succession patterns of bacterial communities during indigo reduction remain largely uncharacterized.

Purpose of the Study:

• To investigate the bacterial community structure and succession during the early stages of indigo fermentation.
• To identify key bacterial genera involved in maintaining the reduced state of indigo.

Main Methods:

• Utilized denaturing gradient gel electrophoresis (DGGE) and clone library analysis of 16S rRNA genes.
• Employed culture-dependent and culture-independent analyses for microbial identification.

Main Results:

• Observed a significant shift from Halomonas spp. to Amphibacillus spp. during early fermentation, correlating with indigo reduction.
• Alkalibacterium spp., previously identified indigo reducers, were predominant in aged (10-month) fermentation liquor.
• Isolated novel indigo-reducing strains: Amphibacillus spp. strain C40 and Oceanobacillus spp. strain A21.

Conclusions:

• Bacterial succession, particularly the roles of Amphibacillus and Oceanobacillus genera, is crucial for indigo reduction in traditional fermentation.
• These genera, alongside Alkalibacterium, are vital for sustaining the reduced indigo state necessary for dyeing.