School of Life Sciences, University of Warwick, Warwick, UK.
Unidad de investigación-HUC, La Laguna-Tenerife, Spain.
Environ Microbiol. 2020 Apr;22(4):1356-1369. doi: 10.1111/1462-2920.14947. Epub 2020 Feb 27.
Pristine marine environments are highly oligotrophic ecosystems populated by well-established specialized microbial communities. Nevertheless, during oil spills, low-abundant hydrocarbonoclastic bacteria bloom and rapidly prevail over the marine microbiota. The genus Alcanivorax is one of the most abundant and well-studied organisms for oil degradation. While highly successful under polluted conditions due to its specialized oil-degrading metabolism, it is unknown how they persist in these environments during pristine conditions. Here, we show that part of the Alcanivorax genus, as well as oils, has an enormous potential for biodegrading aliphatic polyesters thanks to a unique and abundantly secreted alpha/beta hydrolase. The heterologous overexpression of this esterase proved a remarkable ability to hydrolyse both natural and synthetic polyesters. Our findings contribute to (i) better understand the ecology of Alcanivorax in its natural environment, where natural polyesters such as polyhydroxyalkanoates (PHA) are produced by a large fraction of the community and, hence, an accessible source of carbon and energy used by the organism in order to persist, (ii) highlight the potential of Alcanivorax to clear marine environments from polyester materials of anthropogenic origin as well as oils, and (iii) the discovery of a new versatile esterase with a high biotechnological potential.
原始海洋环境是高度贫营养的生态系统，其中存在着成熟的特殊微生物群落。然而，在石油泄漏期间，低丰度的烃类降解细菌会大量繁殖并迅速占据海洋微生物群。产碱杆菌属是研究最多的用于石油降解的最丰富的生物之一。尽管由于其特殊的石油降解代谢作用，在污染环境中非常成功，但在原始条件下它们如何在这些环境中持续存在尚不清楚。在这里，我们表明，部分产碱杆菌属以及石油本身具有巨大的潜力，可以通过一种独特且大量分泌的α/β水解酶来生物降解脂肪族聚酯。该酯酶的异源过表达证明了其水解天然和合成聚酯的显著能力。我们的研究结果有助于：(i) 更好地了解产碱杆菌属在其自然环境中的生态，在这种环境中，社区的很大一部分会产生天然聚酯，如聚羟基烷酸酯（PHA），这是生物体用来维持生存的可利用碳源和能源；(ii) 强调产碱杆菌属清除海洋环境中源自人为的聚酯材料和石油的潜力；(iii) 发现了一种具有高生物技术潜力的新型多功能酯酶。
