Screening and identification of high-acetic-acid-producing strain for sugarcane vinegar production

To screen out high-acetic-acid-producing bacteria suitable for producing sugarcane vinegar, screening work was developed and inoculum originated from the natural fermentation process of bagasse. By enrichment culture and plate isolation, 116 strains were obtained.And then a series of experiments was carried out including acetic acid production, test of ethanol endurance and genetic stability.Using HPLC to test acetic acid production of fermentation broth, strain C22 with excellent characteristics was isolated owing to its high yield of acetic acid, strong ethanol endurance, and stable hereditary character. Even if under alcohol content of 12% ( v /v) , C22 remained to have strong fermentation capability and its acetic acid production were 41.8g /L and 62.2g /L when the initial alcohol content were 6% ( v /v) and 12% ( v /v) respectively. C22 was identified as Acetobacter pasteurium based on the survey on morphology, physiological characteristics and 16S rDNA detection.