南大洋罗斯海近海沉积物烷烃与塑料降解微生物多样性

Microbial diversity of alkane-and plastic-degrading microbiome in offshore sediments of Ross Sea,Southern Ocean

石油污染以及塑料垃圾对海洋生态安全具有严重威胁,甚至在南大洋的罗斯海地区也发现石油污染和微塑料的存在。本研究为了获得该地区的低温烷烃降解菌和塑料降解菌,通过采集自南大洋罗斯海地区的12个沉积物样品用于富集分离南大洋低温烷烃降解菌株,结果表明十四烷富集菌群优势属主要包括假单胞菌属(Pseudomonas)、食烷菌属(Alcanivorax)、海单胞菌属(Marinomonas)、假交替单胞菌属(Pseudoalteromonas)等。进一步利用分离获得的烃类富集菌对聚对苯二甲酸乙二醇酯(PET)和聚乙烯(PE)进行降解验证,扫描电子显微镜(SEM)以及傅里叶变换红外光谱技术(ATR-FTIR)证明了Pseudomonas pelagia R1-05-CR3、Pseudomonas taeanensis A11-04-CA4、Halomonas titanicae A11-02-7C2和Rhodococcus cerastii R1-05-7C3这4株细菌对PE可进行有效降解。高效液相色谱质谱技术(UPLC-MS)和SEM结果表明R.cerastii R1-05-7C3、Microbacterium maritypicum RA1-00-CA1、H.titanicae A11-02-7C2对PET塑料具有降解能力。研究结果表明南大洋罗斯海近海沉积物中存在多样性的低温烃类及塑料降解菌,在原位环境污染中发挥自净作用,同时也为低温下烃与塑料污染生物降解提供了菌种资源。

Oil and plastic pollutants are a serious threat to marine ecosystems and have even been found in the Ross Sea of the Southern Ocean.In order to obtain low-temperature alkane degrading bacteria and plastic-degrading bacteria in the region,a total of twelve sediment samples were collected in the Ross Sea area for enrichment and isolation of alkane-degrading bacteria at low-temperature,and the diversity analyses of the tetradecane-enriched communities showed that the most dominant genera were Pseudomonas,Alcanivorax,Marinomonas,Pseudoalteromonas.The polyethylene terephthalate(PET)and polyethylene(PE)was further validated using the dominant alkane-degrading bacteria.Scanning electron microscopy(SEM) and Fourier transform infrared spectroscopy(ATR-FTIR)demonstrated that the four pure cultures of Pseudomonas pelagia R1-05-CR3,Pseudomonas taeanensis A11-04-CA4,Halomonas titanicae A11-02-7C2 and Rhodococcus cerastii R1-05-7C3 could degrade PE effectively.The results of UPLC-MS and SEM confirmed the PET degradation by isolates of R.cerastii R1-05-7C3,Microbacterium maritypicum RA1-00-CA1,and H.titanicae A11-02-7C2.In conclusion,this study reports the diversity of the tetradecane-enriched consortia at low-temperature and plastic degrading bacteria in the offshore sediments of the Ross Sea in the Southern Ocean,which play a selfpurifying role in in-situ environmental contamination,and also provided strain resources for the biodegradation of hydrocarbon and plastic contaminants at low temperature.