Liang Jibei, Cheng Tao, Huang Yi, Liu Jianhua
Ocean College, Zhejiang University, Marine Science Building #379, Zhoushan Campus, 1 Zheda Road, Dinghai District, Zhoushan, 316000, ZJ, China.
Ocean Research Center of Zhoushan, Zhejiang University, Zhoushan, 316021, ZJ, China.
AMB Express. 2018 May 28;8(1):88. doi: 10.1186/s13568-018-0620-5.
Enhanced bioremediation is a favorable approach for petroleum pollutant cleanup, which depends on the growth of oil-eating microorganisms. In this study, we show that, by using the modified T-RFLP (mT-RFLP) methodology, one of the four major microbial populations derived from oil sludge has failed to propagate in MS medium supplemented with 2% yeast extract (YE). rDNA sequence-based analysis indicated that the four populations were Donghicola sp. CT5, Bacillus sp. CT6, Alcaligenes sp. CT10, and Pseudomonas sp. ZS1. Four purified strains grow well individually in MS medium supplemented with 2% YE, suggesting that ZS1 growth is antagonized by other strains. Co-growth analysis using mT-RFLP methodology and plate inhibitory assay indicated that ZS1 exhibited antagonistic effect against CT5 and CT6. On the other hand, co-growth analysis and plate inhibition assay showed that CT10 antagonized against ZS1. To investigate the potential compounds responsible for the antagonism, supernatant of CT10 culture was subjected to GC-MS analysis. Analysis indicated that CT10 produced a number of antimicrobial compounds including cyclodipeptide c-(L-Pro-L-Phe), which was known to inhibit the growth of Pseudomonas sp. Growth test using the purified c-(L-Pro-L-Phe) from CT10 confirmed its inhibitory activity. We further showed that, using both gravimetric and GC analysis, CT10 antagonism against the oil-eating ZS1 led to the diminishing of crude oil degradation. Together, our results indicate that bioremediation can be affected by environmental antagonists.
强化生物修复是一种用于清理石油污染物的有利方法，它依赖于食油微生物的生长。在本研究中，我们表明，通过使用改良的末端限制性片段长度多态性（mT-RFLP）方法，从油泥中分离出的四个主要微生物种群之一在添加了2%酵母提取物（YE）的MS培养基中未能繁殖。基于rDNA序列的分析表明，这四个种群分别是东海icola菌属CT5、芽孢杆菌属CT6、产碱菌属CT10和假单胞菌属ZS1。四种纯化菌株在添加了2% YE的MS培养基中单独生长良好，这表明ZS1的生长受到其他菌株的拮抗。使用mT-RFLP方法和平板抑制试验进行的共生长分析表明，ZS1对CT5和CT6表现出拮抗作用。另一方面，共生长分析和平板抑制试验表明，CT10对ZS1具有拮抗作用。为了研究导致拮抗作用的潜在化合物，对CT10培养物的上清液进行了气相色谱-质谱（GC-MS）分析。分析表明，CT10产生了多种抗菌化合物，包括环二肽c-（L-脯氨酸-L-苯丙氨酸），已知该化合物可抑制假单胞菌属的生长。使用从CT10中纯化的c-（L-脯氨酸-L-苯丙氨酸）进行的生长试验证实了其抑制活性。我们进一步表明，使用重量法和气相色谱分析，CT10对食油ZS1的拮抗作用导致原油降解减少。总之，我们的结果表明生物修复可能会受到环境拮抗剂的影响。
