Al-Jawasim Mohammed, Yu Kewei, Park Joong-Wook
Department of Biological and Environmental Sciences, Troy University, Troy, AL 36082, USA.
Department of Biological and Environmental Sciences, Troy University, Troy, AL 36082, USA
FEMS Microbiol Lett. 2015 Sep;362(17):fnv144. doi: 10.1093/femsle/fnv144. Epub 2015 Aug 26.
A combined effect of crude oil plus dispersant (Corexit 9500A) significantly altered indigenous bacterial communities in a Louisiana salt marsh sediment after 30 days of incubation; the crude oil and/or Corexit 9500A treatments triggered shifts in bacterial communities and the shifted bacterial structure by crude oil plus Corexit 9500A was considerably different from those by either crude oil or Corexit 9500A. However, the synergistic effect of crude oil plus Corexit 9500A was not observed after 7 days of incubation; the bacterial community was slightly shifted by Corexit 9500A and the crude oil did not trigger any bacterial community shift after 7 days of incubation. DNA sequencing data indicated that Chromobacterium species was enriched in the Corexit 9500A microcosms after 7 days of incubation, while Pseudomonas, Advenella, Acidocella and Dyella spp. were enriched after 30 days of incubation. Parvibaculum was a dominant species in the crude oil microcosms after 30 days of incubation. Rhodanobacter, Dyella and Frateuria spp. were dominant in crude oil plus Corexit 9500A microcosms after 30 days of incubation. Our data show that the effect of crude oil plus Corexit 9500A on bacterial community is synergistic, and thus the dispersant effect should be considered with the spilled oil to correctly evaluate the environmental impact.
原油与分散剂（Corexit 9500A）的联合作用在路易斯安那盐沼沉积物培养30天后显著改变了本地细菌群落；原油和/或Corexit 9500A处理引发了细菌群落的变化，且原油加Corexit 9500A导致的细菌结构变化与单独使用原油或Corexit 9500A时的变化有很大不同。然而，在培养7天后未观察到原油加Corexit 9500A的协同效应；培养7天后，Corexit 9500A使细菌群落略有变化，而原油未引发任何细菌群落变化。DNA测序数据表明，培养7天后，色杆菌属在Corexit 9500A微宇宙中富集，而假单胞菌属、食酸菌属、嗜油菌属和迪茨氏菌属在培养30天后富集。培养30天后，微小杆菌属是原油微宇宙中的优势物种。培养30天后，红杆菌属、迪茨氏菌属和富氏菌属在原油加Corexit 9500A微宇宙中占主导地位。我们的数据表明，原油加Corexit 9500A对细菌群落的影响具有协同性，因此在评估环境影响时应将分散剂的作用与泄漏的原油一并考虑。
