具有自絮凝特性的乙酸降解菌的筛选及其降解特性  

Screening of a flocculent acetic acid degrading bacterium and its degradative characteristics

作　　者：邹彩连 赵国成[2] 蒋翊宸 林栋青[1] 顾向阳[1] 

机构地区：[1]南京农业大学生命科学学院/农业部农业环境微生物工程重点开放实验室,江苏南京210095 [2]建湖县农业技术推广服务中心,江苏盐城224700

出　　处：《南京农业大学学报》2015年第5期830-837,共8页Journal of Nanjing Agricultural University

基　　金：国家自然科学基金项目(50778089);国际科学基金项目(W4260-1)

摘　　要：[目的]探索利用耐盐絮凝细菌降解硫胶废水中的乙酸，解除乙酸对自养型硫细菌的抑制作用，提高硫胶废水中硫代硫酸盐的降解速率的可行性。[方法]从盐碱土中富集分离耐盐或嗜盐的乙酸降解菌，采用摇瓶培养试验筛选出具有絮凝功能的菌株，通过生理生化特性测定和16SrDNA序列的分析，将所得菌株鉴定至相应的属或种。通过摇瓶试验研究温度、pH、盐度和底物浓度等因素对分离菌株降解性能的影响，获得最佳的降解条件。在硫胶废水中接种絮凝细菌置于最适条件下培养，待乙酸完全降解后将培养液用滤纸过滤除去细菌絮体，然后在滤液中接人适量硫杆菌，并以含有乙酸的硫胶废水原水作对照，比较硫代硫酸盐的降解速率。[结果]从盐碱土中成功分离到1株具有絮凝功能的乙酸降解细菌SSl，以乙酸为碳源生长时絮凝指数达86．41％，根据生理生化特性和16SrDNA序列比对结果，菌株SS1被鉴定为Pseudomonas sp．。菌株SS1是1株中度嗜盐菌，最高可耐受NaCl的质量浓度为75g·L^-1，其降解乙酸的最适条件为30～35℃、pH8．5、NaCl5～30g·L^-1和乙酸1—4g·L^-1。接种SSl絮体质量浓度为1．6g·L^-1时，硫胶废水中的乙酸降解速率可达200mg·L^-1·h^-1，乙酸可在6h内完全降解，硫代硫酸盐完全氧化所需的时间可缩短至48h。[结论]Pseudomonassp．SSl是1株中度嗜盐且具有良好絮凝功能的乙酸降解细菌，该菌株可解除乙酸对盐生硫杆菌的抑制作用，加快硫代硫酸盐的降解，因而在硫胶废水的生物处理中具有较好的应用潜力。[ Objectives ] The present study was aimed to explore the feasibility of accelerating thiosulfate oxidation during the treatment of liquid polysulfide wastewater（LPW） through removing acetic acid by using flocculent bacterium. [ Methods ] Halotolerant or halophilic acetic acid-degrading bacteria were enriched and isolated from alkaline salty soil. Flocculent strain was screened and its physicochemical properties were determined. Bacterial identification was accomplished through analysis of 16S rDNA gene homology. A series of shake-flask experiments were carried out to investigate the effects of temperature, initial medium pH, salinity and substrate concentration on acetate degradation by the isolate. Then the isolated flocculent bacterium was inoculated to LPW and incubated under the optimized conditions. Once acetate was consumed, the LPW was filtered to remove the bacterial flocs and the filtrate was transferred to a 500 mL flask, to which thiosulfate-oxidizing bacterium was inoculated and thiosulfate degradation efficiency was compared with the results from the control flask containing raw LPW and inoculum of thiosulfate-oxidizing bacterium. [ Results ] A flocculent acetic acid-degrading bacterium SS1 was isolated from alkaline salty soil. It was identified as Pseudomonas sp.. Strain SS1 was a moderately halophilic bacterium,which can tolerate high salinity of 75 g·L^-1 of NaC1. Optimal conditions for acetic acid degradation was 30-35 ℃ ,pH 8.5,NaCl 5-30 g·L^-1 and acetic acid 1-4 g·L^-1. When it was introduced into LPW at an inoculum size of 1.6 g·L^-1 ,a high degradation rate of 200 mg·L^-1·h^-1 could be achieved and acetic acid could be consumed within 6 h. As a result complete thiosuffate oxidation could be achieved within 48 h. [ Conclusions ] Pseudomonas sp. SS1 is a moderately halophilic floceulent acetic acid-degrading bacterium. It could be potentially applied in the treatment of LPW due to its strong capability of eliminating inhibitory effect on Halothiobacillus sp. caused by acetic acid

关 键 词：硫胶废水 硫代硫酸盐 盐生硫杆菌 絮凝细菌 

分 类 号：X505[环境科学与工程—环境工程]