优势醋酸菌株的筛选鉴定及乙醇脱氢酶活性研究

为满足苹果醋液态深层发酵的需要，从果渣、泥土中选育出生长良好、遗传稳定的较优醋酸菌株，实现高效率、高产量的苹果醋中试生产。经初筛、复筛、产酸试验、遗传稳定性试验、生理生化试验和16S rDNA序列分析鉴定，优选菌株Y010鉴定为巴氏醋酸杆菌（Acetobacter pasteurianus）。进一步研究该菌株在苹果醋发酵过程中乙醇脱氢酶（ADH）活性与产酸量、产酸速率的关系。结果表明：该菌株在醋酸发酵48 h时酶活较高，达到4.62 U/mL，产酸速率最大达到0.51 g/（L·h），发酵120 h总酸含量最高达到53.12 g/L，其ADH酶活与产酸速率变化趋势一致。

Screening and identification of dominate Acetobacter sp. and alcohol dehydrogenase activity research

To meet the needs of apple vinegar submerged fermentation, a growing well and genetically stable Acetobacteria sp. was selected from the pomace and soil achieving high efficiency and high yield pilot production of apple vinegar. The selected strain Y010 was identified as Acetobacter pasteurianus by primary screening, secondary screening, acid-production experiments, physiology biochemistry experiments, genetic stabitliy experiments and 16S rDNA sequence analysis. The relationship between alcohol dehydrogenase (ADH) activity with acid production and acid production rate during the process of fermentation of apple vinegar was further studied. The results showed that the ADH activity and acid production rate of strain Y010 was the highest of 4.62 U/ml and 0.51 g/(L·h) at 48 h, and the total acid content reached the maximum of 53.12 g/L at 120 h. The variation trend of ADH activity and acid production rate showed high consistency.