Lech Kiara L, Sundaravadivelu Devi, Grosser Robert J, Trutschel Leah R, Brinkman Nichole E, Conmy Robyn N
Office of Research and Development, Environmental Protection Agency, Cincinnati, Ohio, USA.
Pegasus Technical Services, Inc., Cincinnati, Ohio, USA.
Appl Environ Microbiol. 2025 May 21;91(5):e0233424. doi: 10.1128/aem.02334-24. Epub 2025 Apr 22.
Spill treating agents (STAs) may be authorized for use during an oil spill response; however, the impact of certain classes of agents on oil biodegradation is poorly understood. Microcosms comprising an oil-degrading microbial consortium were amended with weathered crude oil and treated with two STAs: a surface washing agent or chemical herder, alongside single-agent treatments. The microbial community readily degraded the STAs, evidenced by microbial growth and respiration. Carbon dioxide production was higher than expected in treatments containing oil and STA together, suggesting synergistic co-metabolism of otherwise recalcitrant compounds or dead-end metabolites. Within 14 days, n-alkanes and polycyclic aromatic hydrocarbons were biodegraded in oil-containing treatments by 90% and 57%, respectively. However, over the 40-day study, a fraction of higher molecular weight n-alkanes persisted in the oil treatment amended with the surface washing agent. The chemical herder initially confined the oil, limiting its bioavailability, but within 72 hours, the chemical herder was degraded, releasing oil hydrocarbons for subsequent biodegradation. Pronounced shifts in the microbial community were observed in all treatments with distinct differences between the total and active populations. Known contaminant-degrading families and were well represented in crude oil treatments, while groups such as , , and flourished in treatments containing STA. These findings demonstrate the outsized impact STAs have in shaping the activity and structure of the oil-degrading microbial community under laboratory conditions. However, uncertainty remains regarding the influence of these agents on oil biodegradation in real-world applications.
Spill treating agents offer oil spill responders alternative measures to reduce the overall impact of oil in the environment. Although the environmental implications of chemical dispersant use have been exhaustively studied under various conditions, this study aims to close knowledge gaps regarding lesser-known spill treating agents that may inhibit oil biodegradation. Results of this study demonstrated an impact on hydrocarbon degradation, highlighting significant differences in microbial community structure among the treatments. However, these agents were also readily biodegraded, potentially yielding limited influence on oil biodegradation in the environment. These findings broaden current understanding of how oil-degrading microbial communities may be affected by the use of spill treating agents, beyond chemical dispersants, ultimately aiding personnel tasked with operational decision-making during the critical stages of an oil spill response.
溢油处理剂（STAs）可能被批准用于应对溢油事故；然而，某些类型的处理剂对石油生物降解的影响却知之甚少。用风化原油对包含石油降解微生物群落的微观世界进行修正，并使用两种溢油处理剂进行处理：一种表面清洗剂或化学围油剂，同时进行单剂处理。微生物群落很容易降解溢油处理剂，这从微生物的生长和呼吸中得到了证明。在同时含有石油和溢油处理剂的处理中，二氧化碳的产生量高于预期，这表明原本难降解的化合物或最终代谢产物存在协同共代谢作用。在14天内，含油处理中的正构烷烃和多环芳烃分别被生物降解了90%和57%。然而，在为期40天的研究中，一部分高分子量的正构烷烃在添加了表面清洗剂的石油处理中持续存在。化学围油剂最初限制了石油的扩散，限制了其生物可利用性，但在72小时内，化学围油剂被降解，释放出石油烃以供后续生物降解。在所有处理中都观察到微生物群落发生了显著变化，总菌群和活性菌群之间存在明显差异。已知的污染物降解菌属在原油处理中占比很大，而诸如[具体菌属1]、[具体菌属2]和[具体菌属3]等菌群在含有溢油处理剂的处理中大量繁殖。这些发现表明，在实验室条件下，溢油处理剂对石油降解微生物群落的活性和结构具有巨大影响。然而，这些处理剂在实际应用中对石油生物降解的影响仍存在不确定性。
溢油处理剂为溢油事故应对人员提供了减少石油对环境总体影响的替代措施。尽管在各种条件下对化学分散剂的环境影响已经进行了详尽研究，但本研究旨在填补关于可能抑制石油生物降解的鲜为人知的溢油处理剂的知识空白。本研究结果表明对烃类降解有影响，突出了各处理之间微生物群落结构的显著差异。然而，这些处理剂也很容易被生物降解，可能对环境中石油的生物降解影响有限。这些发现拓宽了目前对石油降解微生物群落如何受到溢油处理剂（除化学分散剂外）使用影响的理解，最终有助于在溢油事故应对关键阶段负责操作决策的人员。
