Ribosomal RNA gene operon copy number, a functional trait indicating the hydrocarbon degradation level of bacterial communities

• Published in: Journal of hazardous materials 2023-10, Vol.459, p.132100-132100, Article 132100
• Main Authors: Lin, Renzhang, Wu, Hao, Kong, Xiangyu, Ren, Hao, Lu, Zhenmei
• Format: Article
• Language: English
• Subjects: Hydrocarbon; Microbial bioremediation; Resuscitation-promoting factor; rRNA operon copy number
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2023.132100

The lack of universal indicators for predicting microbial biodegradation potential and assessing remediation effects limits the generalization of bioremediation. The community-level ribosomal RNA gene operon (rrn) copy number, an important functional trait, has the potential to serve as a key indicator of the bioremediation of organic pollutants. A meta-analysis based on 1275 samples from 26 hydrocarbon-related studies revealed a positive relationship between the microbial hydrocarbon biodegradation level and the community-level rrn copy number in soil, seawater and culture. Subsequently, a microcosm experiment was performed to decipher the community-level rrn copy number response mechanism during total petroleum hydrocarbon (TPH) biodegradation. The treatment combining straw with resuscitation-promoting factor (Rpf) exhibited the highest community-level rrn copy number and the most effective biodegradation compared with other treatments, and the initial TPH content (20,000 mg kg-1) was reduced by 67.67% after 77 days of incubation. TPH biodegradation rate was positively correlated with the average community-level rrn copy number (p = 0.001, R2 = 0.5781). Both meta and community analyses showed that rrn copy number may reflect the potential of hydrocarbon degradation and microbial dormancy. Our findings provide insight into the applicability of the community-level rrn copy number to assess bacterial biodegradation for pollution remediation. [Display omitted] •Meta-analysis showed the community-level rRNA gene operon copy number difference.•Resuscitation-promoting factor combined with straw stimulated hydrocarbon degradation.•The community-level rRNA gene operon copy number can indicate degradation level.•The relationship between degradation ability and genomic trait was revealed.