Shifts in a Phenanthrene-Degrading Microbial Community are Driven by Carbohydrate Metabolism Selection in a Ryegrass Rhizosphere

• DOI: 10.1021/acs.est.0c04951
• Publication Date: 2020-12-29T05:50:25Z
• Authors: Longfei Jiang; Chunling Luo; Dayi Zhang; Mengke Song; Weiping Mei; Yingtao Sun; Gan Zhang
• Keywords: Stable-isotope probing; Exudate

Plants usually promote pollutant bioremediation by several mechanisms including modifying the diversity of functional microbial species. However, conflicting results are reported that root exudates have no effects or negative on organic degradation. In this study, we investigated roles ryegrass in phenanthrene degradation soils using DNA stable isotope probing (SIP) and metagenomics to reveal a potential explanation for among phytoremediation studies. Phenanthrene biodegradation efficiency was improved 8% after 14 days cultivation. Twelve ten operational taxonomic units (OTUs) were identified as active degraders non-rhizosphere rhizosphere soils, respectively. The exhibited higher average phylogenetic distances (0.33) than (0.26). Ka/Ks values (the ratio nonsynonymous synonymous substitutions) about 10.37% treatment >90% all key carbohydrate metabolism-related genes, implying may be an important driver community variation relieving metabolism pressure improving survival ability r-strategy microbes. Most root-exudate-related genes little change, except fumarate hydratase increased 13-fold compared treatment. less 50% phenanthrene-degradation-related affected, 30% which 70% behaved oppositely. Genes with altered had low percentage followed inconsistent changing tendency, indicating its metabolites not major factors influencing degraders. These suggested importance metabolism, especially fumaric acid, shift, hinted at new hypothesis effect depends existence competitive advantages acid metabolism.