Biological Science Program and Centre of Excellence for Innovation in Chemistry, Faculty of Science, Burapha University, Bangsaen, Chonburi, Thailand.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2012;47(11):1491-9. doi: 10.1080/10934529.2012.680312.
Worldwide contamination by acrylamide, a neurotoxicant and carcinogen in animals, is becoming a significant problem. We isolated three novel acrylamide-degrading bacteria from domestic wastewater in Chonburi, Thailand. Using biochemical characteristics and 16S rRNA gene sequencing, the strains were identified as Klebsiella pneumoniae, Kluyvera georgiana and Enterococcus faecalis. K. georgiana strain No. 2 was selected for further characterization due to its degradation potential of high concentrations of acrylamide at the mesophilic temperatures. The strain grew well in the presence of acrylamide at concentrations to 0.5 % (w/v), pH 5.0 to 7.0 and 37°C. Degradation of acrylamide to acrylic acid began after 30 min of cultivation as a biomass-dependent manner. Mass balance analysis revealed 92.3 % conversion of acrylamide to acrylic acid and two lower polarity compounds. Strain No. 2 degraded many aliphatic amides but not iodoacetamide and thioacetamide. High degradation level (>80 %) was found with propionamide, cyanoacetamide and acetamide. Moderate degradation was obtained in the order of formamide > butyramide > lactamide > urea while sodium azide provided 34 % degradation. These findings render this novel bacterium attractive for biodegradation of acrylamide and other aliphatic amides in the environment.
世界范围内的丙烯酰胺污染，一种动物神经毒素和致癌物质，正在成为一个重大问题。我们从泰国春武里的生活污水中分离到三种新型的丙烯酰胺降解细菌。通过生化特征和 16S rRNA 基因测序，这些菌株被鉴定为肺炎克雷伯氏菌、乔治亚克吕沃尔氏菌和粪肠球菌。由于其在中温下对高浓度丙烯酰胺的降解潜力，选择克吕沃尔氏菌菌株 2 号进行进一步表征。该菌株在丙烯酰胺浓度高达 0.5%（w/v）、pH 值 5.0 至 7.0 和 37°C 的条件下生长良好。培养 30 分钟后，以生物量依赖的方式开始将丙烯酰胺降解为丙烯酸。质量平衡分析显示，丙烯酰胺转化率为 92.3%，生成两种低极性化合物。菌株 2 号降解许多脂肪族酰胺，但不降解碘乙酰胺和硫代乙酰胺。高降解水平（>80%）见于丙酰胺、氰基乙酰胺和乙酰胺。在以下顺序中获得中等降解水平：甲酰胺>丁酰胺>乳酰胺>尿素，而叠氮化钠提供 34%的降解。这些发现使这种新型细菌在环境中生物降解丙烯酰胺和其他脂肪族酰胺方面具有吸引力。
