Solibacillus daqui sp. nov., isolated from high-temperature Daqu

Area of Science:

• Microbiology
• Bacterial Taxonomy
• Fermentation Science

Background:

• Daqu is a crucial starter culture for Chinese Baijiu production, particularly Jiang-flavour Baijiu.
• High-temperature Daqu harbors diverse microbial communities essential for fermentation.
• Understanding the specific microorganisms involved is key to optimizing fermentation processes.

Purpose of the Study:

• To isolate and characterize a novel bacterial strain from high-temperature Daqu.
• To determine the taxonomic and phylogenetic placement of the novel strain.
• To propose a new species within the genus Solibacillus.

Main Methods:

• Polyphasic taxonomy was employed for characterization.
• 16S rRNA gene sequencing was used for phylogenetic analysis.
• Chemotaxonomic and physiological properties were analyzed.

Main Results:

• A Gram-positive, rod-shaped, endospore-forming, aerobic bacterium, strain ZS111008^T, was isolated.
• Strain ZS111008^T exhibited tolerance to varying NaCl concentrations, pH, and temperatures.
• Phylogenetic analysis indicated its closest relatives are Solibacillus silvestris, S. cecembensis, and S. isronensis, with 16S rRNA gene similarity below the species threshold.

Conclusions:

• Strain ZS111008^T represents a novel species of the genus Solibacillus.
• The proposed name for this new species is Solibacillus daqui sp. nov.
• The type strain is ZS111008^T, with proposed accession numbers CGMCC 1.19455^T and JCM 35214^T.