RESUMEN
Petroleum hydrocarbons (PHCs) can be biodegraded into CO2, and PHC-contaminated aquifers are always deemed as carbon sources. Fortunately, some carbon fixation microorganisms have been found in PHC-contaminated sites. However, most of the studies are related to volatile short-chain PHC, and few studies focus on long-chain PHC-contaminated sites. To reveal the carbon fixation microorganisms in these sites, in the study, a long-chain PHC polluted site in North China was selected. Through hydrochemical and metagenomics analysis, the structure and capacity of carbon fixing microorganisms in the site were revealed. Results showed that there were many kinds of carbon fixed microorganisms that were identified such as Flavobacterium, Pseudomonas. HP/4HB, rTCA, and DC/4HB cycles were dominated carbon fixation pathways. The long-chain PHC were weakly correlated with carbon fixation microorganisms, but it may stimulate the growth of some carbon fixation microorganisms, such as microorganisms involved in rTCA cycle. PRACTITIONER POINTS: The microorganisms with carbon fixation gene exist in the aquifer contaminated by long-chain petroleum hydrocarbon. Microorganisms that have the ability to degrade petroleum also have the ability to carbon fixation. Long-chain petroleum hydrocarbon may promote the growth of carbon fixation microorganisms.
Asunto(s)
Ciclo del Carbono , Agua Subterránea , Hidrocarburos , Petróleo , Contaminantes Químicos del Agua , Petróleo/metabolismo , Hidrocarburos/metabolismo , Agua Subterránea/microbiología , Agua Subterránea/química , Contaminantes Químicos del Agua/metabolismo , Contaminantes Químicos del Agua/química , Bacterias/metabolismo , Bacterias/clasificación , Bacterias/genética , Biodegradación Ambiental , ChinaRESUMEN
Microorganisms in groundwater at petroleum hydrocarbon (PHC)-contaminated sites are crucial for PHC natural attenuation. Studies mainly focused on the microbial communities and functions in groundwater contaminated by PHC only. However, due to diverse raw and auxiliary materials and the complex production processes, in some petrochemical sites, groundwater suffered multi-component contamination, but the microbial structure remains unclear. To solve the problem, in the study, a petrochemical enterprise site, where the groundwater suffered multi-component pollution by PHC and sulfates, was selected. Using hydrochemistry, 16S rRNA gene, and metagenomic sequencing analyses, the relationships among electron acceptors, microbial diversity, functional genes, and their interactions were investigated. Results showed that different production processes led to different microbial structures. Overall, pollution reduced species richness but increased the abundance of specific species. The multi-component contamination multiplied a considerable number of hydrocarbon-degrading and sulfate-reducing microorganisms, and the introduced sulfates might have promoted the biodegradation of PHC. PRACTITIONER POINTS: The compound pollution of the site changed the microbial community structure. Sulfate can promote the degradation of petroleum hydrocarbons by hydrocarbon-degrading microorganisms. The combined contamination of petroleum hydrocarbons and sulfates will decrease the species richness but increase the abundance of endemic species.