巴氏醋杆菌高酸度醋发酵过程的能量代谢分析

Analysis of energetic metabolism of Acetobacter pasteurianus during high acidic vinegar fermentation

摘要:

【目的】初步分析了Acetobacter pasteurianus CICIM B7003-02在醋酸发酵过程中的能量代谢状况, 通过强化细胞能量代谢水平以提升菌株高酸发酵的产酸强度。【方法】探明A. pasteurianus CICIM B7003-02在高酸度醋发酵的不同阶段中三羧酸循环底物含量、乙醇呼吸链酶活及能量代谢酶基因的转录水平等代谢特点, 分析用于醋酸发酵的产能代谢途径及其作用。【结果】发现A. pasteurianus CICIM B7003-02在醋酸发酵初期, 主要通过苹果酸/琥珀酸回补偶联有氧呼吸途径产能。进入醋酸快速积累阶段, 乙醇呼吸链为主要供能代谢途径。发酵后期苹果酸/琥珀酸回补途径配合乙醇呼吸链供能。基于上述研究, 采取添加琥珀酸和苹果酸强化细胞产能, 促进高酸度醋发酵强度。【结论】能量供给影响醋杆菌耐酸能力和醋酸生产能力。确定乙醇呼吸链为醋酸发酵的主要供能系统。强化细胞产能手段可达到提高醋酸发酵强度的目的。

Abstract:

[Objective] We are aiming to analyze the energy metabolism of A. pasteurianus CICIM B7003-02 during high acidic vinegar fermentation so that we can identify the targets to enhance the energy metabolism for vinegar productivity improvement. [Methods] Tricarboxylic acid cycle metabolism, alcohol respiratory chain enzyme activity and relative transcriptional level of enzyme-coding genes in energy metabolism pathways were investigated during the high acidic vinegar fermentation by B7003-02. [Results] We have characterized the bacterial energy metabolism during high acidic vinegar fermentation. Malic/succinic acid feedback pathway is the major route for energy supply at the beginning of fermentation, and alcohol respiratory chain plays the major role in providing energy to cells during the major acetification phase. Both malic/succinic acid feedback pathway and the alcohol respiratory chain supply energy when fermentation approaches its final stage. [Conclusion] Energy supply influences vinegar productivity, the supplementation of malic acid and succinic acid can strength the malic/succinic acid feedback pathway and improve vinegar productivity.