Kamalanathan Manoj, Schwehr Kathleen A, Labonté Jessica M, Taylor Christian, Bergen Charles, Patterson Nicole, Claflin Noah, Santschi Peter H, Quigg Antonietta
Department of Marine Biology, Texas A&M University at Galveston, Galveston, TX, United States.
Department of Marine and Coastal Environmental Science, Texas A&M University at Galveston, Galveston, TX, United States.
Front Microbiol. 2021 Aug 2;12:675328. doi: 10.3389/fmicb.2021.675328. eCollection 2021.
Microbial interactions influence nearly one-half of the global biogeochemical flux of major elements of the marine ecosystem. Despite their ecological importance, microbial interactions remain poorly understood and even less is known regarding the effects of anthropogenic perturbations on these microbial interactions. The Deepwater Horizon oil spill exposed the Gulf of Mexico to ∼4.9 million barrels of crude oil over 87 days. We determined the effects of oil exposure on microbial interactions using short- and long-term microcosm experiments with and without Macondo surrogate oil. Microbial activity determined using radiotracers revealed that oil exposure negatively affected substrate uptake by prokaryotes within 8 h and by eukaryotes over 72 h. Eukaryotic uptake of heterotrophic exopolymeric substances (EPS) was more severely affected than prokaryotic uptake of phototrophic EPS. In addition, our long-term exposure study showed severe effects on photosynthetic activity. Lastly, changes in microbial relative abundances and fewer co-occurrences among microbial species were mostly driven by photosynthetic activity, treatment (control vs. oil), and prokaryotic heterotrophic metabolism. Overall, oil exposure affected microbial co-occurrence and/or interactions possibly by direct reduction in abundance of one of the interacting community members and/or indirect by reduction in metabolism (substrate uptake or photosynthesis) of interacting members.
微生物相互作用影响着海洋生态系统主要元素近一半的全球生物地球化学通量。尽管它们具有生态重要性，但人们对微生物相互作用的了解仍然很少，对于人为扰动对这些微生物相互作用的影响更是知之甚少。“深水地平线”漏油事件在87天内使墨西哥湾暴露于约490万桶原油中。我们通过使用含有和不含有马孔多替代油的短期和长期微观实验，确定了油暴露对微生物相互作用的影响。使用放射性示踪剂测定的微生物活性表明，油暴露在8小时内对原核生物的底物摄取产生负面影响，在72小时内对真核生物产生负面影响。真核生物对异养胞外聚合物（EPS）的摄取比原核生物对光合EPS的摄取受到的影响更严重。此外，我们的长期暴露研究表明对光合活性有严重影响。最后，微生物相对丰度的变化以及微生物物种间共现的减少主要由光合活性、处理（对照与油）和原核生物异养代谢驱动。总体而言，油暴露可能通过直接减少相互作用群落成员之一的丰度和/或通过减少相互作用成员的代谢（底物摄取或光合作用）间接影响微生物共现和/或相互作用。
