Nanoporous Materials for Biological Application Research Group (NAMBAR), Sustainability Research Alliance, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia.
Bioresour Technol. 2012 Feb;105:48-59. doi: 10.1016/j.biortech.2011.11.094. Epub 2011 Dec 1.
A novel bacterial consortium, NAR-2 which consists of Citrobacter freundii A1, Enterococcus casseliflavus C1 and Enterobacter cloacae L17 was investigated for biodegradation of Amaranth azo dye under sequential microaerophilic-aerobic condition. The NAR-2 bacterial consortium with E. casseliflavus C1 as the dominant strain enhanced the decolorization process resulting in reduction of Amaranth in 30 min. Further aerobic biodegradation, which was dominated by C. freundii A1 and E. cloacae L17, allowed biotransformation of azo reduction intermediates and mineralization via metabolic pathways including benzoyl-CoA, protocatechuate, salicylate, gentisate, catechol and cinnamic acid. The presence of autoxidation products which could be metabolized to 2-oxopentenoate was elucidated. The biodegradation mechanism of Amaranth by NAR-2 bacterial consortium was predicted to follow the steps of azo reduction, deamination, desulfonation and aromatic ring cleavage. This is for the first time the comprehensive microaerophilic-aerobic biotransformation pathways of Amaranth dye intermediates by bacterial consortium are being proposed.
一种新型细菌共生体 NAR-2，由弗氏柠檬酸杆菌 A1、屎肠球菌 C1 和阴沟肠杆菌 L17 组成，在序批微需氧-好氧条件下研究了其对偶氮染料苋菜红的生物降解作用。以屎肠球菌 C1 为优势菌的 NAR-2 细菌共生体增强了脱色过程，使苋菜红在 30 分钟内减少。进一步的好氧生物降解，由弗氏柠檬酸杆菌 A1 和阴沟肠杆菌 L17 主导，通过包括苯甲酰辅酶 A、原儿茶酸、水杨酸、龙胆酸、儿茶酚和肉桂酸在内的代谢途径，允许偶氮还原中间产物的生物转化和矿化。阐明了可以代谢为 2-氧戊烯酸的自氧化产物的存在。NAR-2 细菌共生体对苋菜红的生物降解机制预计遵循偶氮还原、脱氨、脱硫和芳环裂解的步骤。这是首次提出细菌共生体对偶氮染料苋菜红中间产物的综合微需氧-好氧生物转化途径。
