Song Zhi, Edwards Suzanne R, Burns Richard G
Research School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, UK.
Biodegradation. 2005 Jun;16(3):237-52. doi: 10.1007/s10532-004-0889-8.
Two bacterial strains, 2AC and 4BC, both capable of utilizing naphthalene-2-sulfonic acid (2-NSA) as a sole source of carbon, were isolated from activated sludges previously exposed to tannery wastewater. Enrichments were carried out in mineral salt medium (MSM) with 2-NSA as the sole carbon source. 16S rDNA sequencing analysis indicated that 2AC is an Arthrobacter sp. and 4BC is a Comamonas sp. Within 33 h, both isolates degraded 100% of 2-NSA in MSM and also 2-NSA in non-sterile tannery wastewater. The yield coefficient was 0.33 g biomass dry weight per gram of 2-NSA. A conceptual model, which describes the aerobic transformation of organic matter, was used for interpreting the biodegradation kinetics of 2-NSA. The half-lives for 2-NSA, at initial concentrations of 100 and 500 mg/l in MSM, ranged from 20 h (2AC) to 26 h (4BC) with lag-phases of 8 h (2AC) and 12 h (4BC). The carbon balance indicates that 75-90% of the initial TOC (total organic carbon) was mineralized, 5-20% remained as DOC (dissolved organic carbon) and 3-10% was biomass carbon. The principal metabolite of 2-NSA biodegradation (in both MSM and tannery wastewater) produced by Comamonas sp. 4BC had a MW of 174 and accounted for the residual DOC (7.0-19.0% of the initial TOC and 66% of the remaining TOC). Three to ten percent of the initial TOC (33% of the remaining TOC) was associated with biomass. The metabolite was not detected when Arthrobacter sp. 2AC was used, and a lower residual DOC and biomass carbon were recorded. This suggests that the two strains may use different catabolic pathways for 2-NSA degradation. The rapid biodegradation of 2-NSA (100 mg/l) added to non-sterile tannery wastewater (total 2-NSA, 105 mg/l) when inoculated with either Arthrobacter 2AC or Comamonas 4BC showed that both strains were able to compete with the indigenous microorganisms and degrade 2-NSA even in the presence of alternate carbon sources (DOC in tannery wastewater = 91 mg/l). The results provide information useful for the rational design of bioreactors for tannery wastewater treatment.
从先前接触过制革废水的活性污泥中分离出两种细菌菌株，2AC和4BC，它们都能够将萘-2-磺酸（2-NSA）作为唯一碳源利用。在以2-NSA作为唯一碳源的矿物盐培养基（MSM）中进行富集培养。16S rDNA测序分析表明，2AC是节杆菌属（Arthrobacter sp.）的一种，4BC是丛毛单胞菌属（Comamonas sp.）的一种。在33小时内，两种菌株在MSM中以及在非无菌制革废水中都降解了100%的2-NSA。产率系数为每克2-NSA产生0.33克生物量干重。一个描述有机物好氧转化的概念模型被用于解释2-NSA的生物降解动力学。在MSM中，2-NSA初始浓度为100和500 mg/l时，其半衰期范围为20小时（2AC）至26小时（4BC），延迟期分别为8小时（2AC）和12小时（4BC）。碳平衡表明，初始总有机碳（TOC）的75 - 90%被矿化，5 - 20%以溶解有机碳（DOC）形式残留，3 - 10%为生物量碳。丛毛单胞菌属4BC在MSM和制革废水中对2-NSA进行生物降解产生的主要代谢产物分子量为174，占残留DOC的比例为（初始TOC的7.0 - 19.0%以及剩余TOC的66%）。初始TOC的3 - 10%（剩余TOC的33%）与生物量相关。当使用节杆菌属2AC时未检测到该代谢产物，且记录到较低的残留DOC和生物量碳。这表明两种菌株可能使用不同的分解代谢途径来降解2-NSA。当向非无菌制革废水（总2-NSA为105 mg/l）中添加100 mg/l 的2-NSA并接种节杆菌2AC或丛毛单胞菌4BC时，2-NSA的快速生物降解表明，即使存在替代碳源（制革废水中的DOC = 91 mg/l），两种菌株都能够与本地微生物竞争并降解2-NSA。这些结果为合理设计用于制革废水处理的生物反应器提供了有用信息。
