1株阿魏酸降解菌的筛选与降解特征研究

Ferulic Acid Degradation Bacterium AWS4B Screening and Its Degradation Characteristics

阿魏酸是导致很多作物产生连作障碍的自毒物质。筛选出1株高效降解阿魏酸的细菌,初步鉴定为葡萄球菌属,命名为AWS4B,研究了AWS4B对阿魏酸的降解特征,探讨了其降解途径。结果表明,当无机盐培养基中阿魏酸的浓度为100 mg/L时,菌株AWS4B72h可降解99.97%。降解过程符合一级动力学模型,反应的活化能Ea为19.88kJ/mol,降解方程常数k0为3.26×10-4,得出了菌株AWS4B降解阿魏酸的预测模型方程。AWS4B降解阿魏酸的底物来源比较广泛。菌株AWS4B对阿魏酸降解的可能途径是非氧化脱羧形成香草醛,再氧化形成香草酸,脱甲基后形成原儿茶酸,最后原儿茶酸苯环裂解后分解为水和二氧化碳,最终实现阿魏酸的降解。

Ferulic acid （FA ） was one of important auto‐toxic chemicals leading to continuous cropping obstacle for many crops. A bacterium strain AWS4B was screened out and identified preliminarily as Staphylococcus sp. ,named as AWS4B. The degradation characteristics was studied and the pathway of the degradation was discussed. The results showed that the degradation rate reached 99.97% in 72 h when the initial FA concentration in the inorganic salt urbane liquor was 100 mg/L. The degradation of FA followed first‐order reaction kinetics model and the thermal degradation activation energy was 19.88 kJ/molThe rate constant（k0 ）was 3.26 ＆#215; 10-4 and equation for strain AWS4B prediction model was proposed in this paper. Many compounds provide strain AWS4B with carbon and enery. The influence of different nutrient substrates added in the degradation experiments was also investigated. Degradation pathway was likely to be that FA was degraded into Vanillin , Vanillic acid and protocatechuic acid through non‐oxidative decarboxylation ,oxidation and demethylation. The protocatechuic acid was depredated through benzene ring cleavage and water and carbon dioxide were produced finally and FA was degraded by strain AWS 4B.