TY - JOUR

T1 - Selective Enrichment of Methylococcaceae versus Methylocystaceae Methanotrophs via Control of Methane Feeding Schemes

AU - Lee, Ju Yong

AU - Choi, Munjeong

AU - Song, Min Joon

AU - Kim, Daehyun Daniel

AU - Yun, Taeho

AU - Chang, Jin

AU - Ho, Adrian

AU - Myung, Jaewook

AU - Yoon, Sukhwan

N1 - Publisher Copyright: © 2024 American Chemical Society.

PY - 2024/8/13

Y1 - 2024/8/13

N2 - Methanotrophs are crucial in keeping environmental CH4 emissions in check. However, the contributions of different groups of methanotrophs at terrestrial CH4-oxidation hotspots, such as the oxic-anoxic interface of rice paddies, have shown considerable inconsistency across observations. To address the knowledge gap regarding this inconsistency, methanotrophic microbiomes were enriched from paddy soils in well-mixed CH4-fed batch reactors under six different incubation conditions, prepared as combinations of two CH4 mixing ratios (0.5 and 10%) and three supplemented Cu2+ concentrations (0, 2, and 10 μM). Monitoring of temporal community shifts in these cultures revealed a dominance of Methylocystis spp. in all 0.5%-CH4 cultures, while methanotrophs affiliated to Gammaproteobacteria dominated the 10%-CH4 cultures that were less consistent both temporally and across conditions. The shotgun metagenome analyses of the 0.5%-CH4 cultures corroborated the Methylocystis dominance and, interestingly, showed that copper deficiency did not select for mmoXYZ-possessing methanotrophs. Instead, a mbn cluster, accounting for approximately 5% of the Methylocystis population, was identified, suggesting the ecological significance of methanobactin in Cu-deficient methanotrophy. These findings underscore the important role of Methylocystis spp. in mitigating emissions from terrestrial CH4 hotspots and suggest the feasibility of directed enrichment and/or isolation of Methylocystis spp. for utilization in, for example, methanobactin and polyhydroxybutyrate production.

AB - Methanotrophs are crucial in keeping environmental CH4 emissions in check. However, the contributions of different groups of methanotrophs at terrestrial CH4-oxidation hotspots, such as the oxic-anoxic interface of rice paddies, have shown considerable inconsistency across observations. To address the knowledge gap regarding this inconsistency, methanotrophic microbiomes were enriched from paddy soils in well-mixed CH4-fed batch reactors under six different incubation conditions, prepared as combinations of two CH4 mixing ratios (0.5 and 10%) and three supplemented Cu2+ concentrations (0, 2, and 10 μM). Monitoring of temporal community shifts in these cultures revealed a dominance of Methylocystis spp. in all 0.5%-CH4 cultures, while methanotrophs affiliated to Gammaproteobacteria dominated the 10%-CH4 cultures that were less consistent both temporally and across conditions. The shotgun metagenome analyses of the 0.5%-CH4 cultures corroborated the Methylocystis dominance and, interestingly, showed that copper deficiency did not select for mmoXYZ-possessing methanotrophs. Instead, a mbn cluster, accounting for approximately 5% of the Methylocystis population, was identified, suggesting the ecological significance of methanobactin in Cu-deficient methanotrophy. These findings underscore the important role of Methylocystis spp. in mitigating emissions from terrestrial CH4 hotspots and suggest the feasibility of directed enrichment and/or isolation of Methylocystis spp. for utilization in, for example, methanobactin and polyhydroxybutyrate production.

KW - copper

KW - directed enrichment

KW - methane

KW - methane monooxygenases

KW - methanotrophs

KW - microbiome

UR - http://www.scopus.com/inward/record.url?scp=85200202176&partnerID=8YFLogxK

U2 - 10.1021/acs.est.4c02655

DO - 10.1021/acs.est.4c02655

M3 - Article

C2 - 39080826

AN - SCOPUS:85200202176

VL - 58

SP - 14237

EP - 14248

JO - Environmental Science and Technology

JF - Environmental Science and Technology

SN - 0013-936X

IS - 32

ER -