Davidov Keren, Itzahri Sheli, Kartha Aiswarya, Orr Gilad, Lang Ziv, Navon-Venezia Shiri, Oren Matan
Molecular Biology Department, Ariel University, Ariel, Israel.
Physics Department, Crystal Physics Laboratory, Ariel University, Ariel, Israel.
Environ Microbiol. 2025 May;27(5):e70102. doi: 10.1111/1462-2920.70102.
Marine plastic debris provides stable surfaces for microbial colonisation, forming a unique ecosystem known as the plastisphere. Among the early colonisers are Alcanivorax bacteria, hydrocarbon degraders commonly found in oil-polluted seawater and on marine plastic surfaces. This study examined factors influencing the adhesion and colonisation dynamics of six Alcanivorax species. Flagellated species-A. balearicus, A. dieselolei and A. xenomutans-rapidly colonised plastics, particularly polyethylene and polypropylene, while non-flagellated species did not. Notably, plastic photo-weathering treatments led to the elongation of A. dieselolei cells, secretion of extracellular polymeric substance in some cases, and increased colonisation on UVB-treated polyethylene terephthalate. These changes may be linked to the reduced plastic surface hydrophobicity recorded following photo-weathering. To confirm the role of flagella in Alcanivorax adhesion, we disrupted flagellar activity using sub-concentrations of polymyxin B sulfate, resulting in inhibition of swarming motility and complete disruption of colonisation. These results contribute to our understanding of the interactions between hydrocarbon-degrading Alcanivorax bacteria and their plastic substrate, which in turn contributes to the understanding of the ecological impact of plastic pollution in marine environments.
海洋塑料碎片为微生物定殖提供了稳定的表面，形成了一个独特的生态系统，即塑料圈。早期定殖者中有食烷菌属细菌，这是一种常见于受油污染海水和海洋塑料表面的烃类降解菌。本研究考察了影响六种食烷菌属细菌黏附及定殖动态的因素。有鞭毛的物种——巴利阿里食烷菌、柴油食烷菌和奇异食烷菌——能迅速在塑料上定殖，尤其是聚乙烯和聚丙烯，而无鞭毛的物种则不能。值得注意的是，塑料光老化处理导致柴油食烷菌细胞伸长，在某些情况下还会分泌胞外聚合物，并增加了在经紫外线B处理的聚对苯二甲酸乙二酯上的定殖。这些变化可能与光老化后记录到的塑料表面疏水性降低有关。为了证实鞭毛在食烷菌黏附中的作用，我们使用亚浓度的硫酸多粘菌素B破坏鞭毛活性，导致群体运动受到抑制，定殖完全被破坏。这些结果有助于我们理解烃类降解食烷菌属细菌与其塑料底物之间的相互作用，进而有助于理解海洋环境中塑料污染的生态影响。
