Ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) is essential for growth of the methanotroph < em > Methylococcus capsulatus < /em > Bath

This study expands the known capacity of methanotrophs to fix CO2 via RubisCO, which may play a more pivotal role in the Earth's biogeochemical carbon cycling and greenhouse gas regulation than previously recognized. Further, M. capsulatus Bath and other CO2-assimilating methanotrophs represent excellent candidates for use in the bioconversion of biogas waste streams that consist of both CH4 and CO2. Importance The importance of RubisCO and CO2 in M. capsulatus Bath metabolism is unclear. In this study, we demonstrated that both CO2 and RubisCO are essential for M. capsulatus Bath growth. 13CO2 tracing experiments supported that RubisCO mediates CO2 fixation and a non-canonical Calvin cycle is active in this organism. Our study provides insights into the expanding knowledge of methanotroph metabolism and implicates dual CH4/CO2-utilizing bacteria as more important players in the biogeochemical carbon cycle than previously appreciated. In addition, M. capsulatusand other methanotrophs with CO2 assimilation capacity represent candidate organisms for the development of biotechnologies to mitigate the two most abundant greenhouse gases CH4 and CO2.PMID:34288705 | DOI:10.1128/AEM.00881-21
Source: Applied and Environmental Microbiology - Category: Microbiology Authors: Source Type: research