Application and Research Center for Advanced Studies, Istanbul Aydin University, Sefakoy Kucukcekmece, 34295, Istanbul, Turkey.
Health Services Vocational School of Higher Education, Istanbul Aydin University, Sefakoy Kucukcekmece, 34295, Istanbul, Turkey.
Environ Res. 2024 May 1;248:118349. doi: 10.1016/j.envres.2024.118349. Epub 2024 Feb 1.
Climate change and plastic pollution are the big environmental problems that the environment and humanity have faced in the past and will face in many decades to come. Sediments are affected by many pollutants and conditions, and the behaviors of microorganisms in environment may be influenced due to changes in sediments. Therefore, the current study aimed to explore the differential effects of various microplastics and temperature on different sediments through the metabolic and oxidative responses of gram-negative Pseudomonas aeruginosa. The sediments collected from various fields including beaches, deep-sea discharge, and marine industrial areas. Each sediment was extracted and then treated with various microplastics under different temperature (-18, +4, +20 and 35 °C) for seven days. Then microplastics were removed from the suspension and microplastic-exposed sediment samples were incubated with Pseudomonas aeruginosa to test bacterial activity, biofilm, and oxidative characteristics. The results showed that both the activity and the biofilm formation of Pseudomonas aeruginosa increased with the temperature of microplastic treatment in the experimental setups at the rates between an average of 2-39 % and 5-27 %, respectively. The highest levels of bacterial activity and biofilm formation were mainly observed in the beach area (average rate +25 %) and marine industrial (average rate +19 %) sediments with microplastic contamination, respectively. Moreover, oxidative characteristics significantly linked the bacterial activities and biofilm formation. The oxidative indicators of Pseudomonas aeruginosa showed that catalase and glutathione reductase were more influenced by microplastic contamination of various sediments than superoxide dismutase activities. For instance, catalase and glutathione reductase activities were changed between -37 and +169 % and +137 to +144 %, respectively; however, the superoxide dismutase increased at a rate between +1 and + 21 %. This study confirmed that global warming as a consequence of climate change might influence the effect of microplastic on sediments regarding bacterial biochemical responses and oxidation characteristics.
气候变化和塑料污染是环境和人类在过去和未来几十年中面临的重大环境问题。沉积物受到许多污染物和条件的影响，而环境中微生物的行为可能会因沉积物的变化而受到影响。因此，本研究旨在通过革兰氏阴性假单胞菌的代谢和氧化反应，探索不同微塑料和温度对不同沉积物的差异影响。采集了来自海滩、深海排放和海洋工业区等不同领域的沉积物。从每个沉积物中提取，然后在不同温度（-18、+4、+20 和 35°C）下用不同的微塑料处理 7 天。然后将微塑料从悬浮液中去除，并将微塑料暴露的沉积物样品与假单胞菌一起孵育，以测试细菌活性、生物膜和氧化特性。结果表明，在实验装置中，微塑料处理温度下，假单胞菌的活性和生物膜形成均随温度升高而增加，平均分别为 2-39%和 5-27%。在海滩地区（平均+25%）和海洋工业区（平均+19%）沉积物中，微塑料污染的沉积物中，假单胞菌的活性和生物膜形成水平最高。此外，氧化特性与细菌活性和生物膜形成密切相关。假单胞菌的氧化指标表明，过氧化氢酶和谷胱甘肽还原酶受各种沉积物中微塑料污染的影响比超氧化物歧化酶活性更大。例如，过氧化氢酶和谷胱甘肽还原酶活性分别变化了-37%至+169%和+137%至+144%；然而，超氧化物歧化酶的活性增加了 1%至+21%。本研究证实，气候变化导致的全球变暖可能会影响微塑料对沉积物的影响，从而影响细菌生化反应和氧化特性。
