Acetobacter bacteria are found in Zhenjiang vinegar grains

Area of Science:

• Microbiology
• Food Science
• Biotechnology

Background:

• Zhenjiang vinegar is a renowned traditional Chinese vinegar characterized by its unique microbial flora within its grains.
• Understanding the microbial composition of Zhenjiang vinegar grains is crucial for preserving its quality and traditional production methods.

Purpose of the Study:

• To isolate and characterize acetic acid bacteria (AAB) from Zhenjiang vinegar grains.
• To evaluate the acid production and acetate decomposition capabilities of isolated AAB strains.
• To identify high-performing AAB strains using molecular methods for potential application in vinegar fermentation.

Main Methods:

• Isolation of unique acetic acid bacteria from Zhenjiang vinegar grains.
• Qualitative analysis of acetate decomposition and acid production capacities of isolated strains.
• Identification of high-yield AAB strains using 16S rDNA sequencing and Basic Local Alignment Search Tool (BLAST) comparison.
• Physiological and biochemical evaluation of selected strains.

Main Results:

• Six significant strains of acetic acid bacteria were successfully isolated from Zhenjiang vinegar grains.
• All isolated strains demonstrated the capacity for acetate decomposition and did not produce brown precipitate.
• Strain W1 was identified as Acetobacter aceti and strain W6 as Acetobacter pasteurianus based on sequencing and biochemical analysis, exhibiting the highest acid yield.

Conclusions:

• The study successfully identified key acetic acid bacteria, Acetobacter aceti and Acetobacter pasteurianus, within Zhenjiang vinegar grains.
• These identified strains possess desirable characteristics for acid production and acetate decomposition, vital for Zhenjiang vinegar fermentation.
• The findings contribute to the understanding and potential optimization of Zhenjiang vinegar production through microbial characterization.