Abstract
Nitrogen fixation of the Methanosarcina barkeri strains “Fusaro” (DSM 804) and “227” (DSM 1538) was found to be dependent on the presence of vanadium or molybdenum whereby molybdenum (added as Na2-molybdate) was preferred to vanadium (added as VCl3). Strain “227” showed less pronounced effects on diazotrophic growth with respect to vanadium and molybdenum. Rhenium (ReCl3) or tungsten (Na2-tungstate) could not replace vanadium or molybdenum. The optimum concentrations were found to be 2μM for vanadium and 5μM for molybdenum (strain “Fusaro”). This Mo optimum of methanogenesis was 10-fold higher with N2 than with NH4Cl as nitrogen source. A vanadium requirement with NH4Cl could not be detected. No interferences were observed if molybdenum and vanadium were added simultaneously under diazotrophic conditions. Growth yields were smallest for strain “227” grown diazotrophically (\(Y_{CH_3 OH}\)=0.6g dw/mol in the presence of vanadium and \(Y_{CH_3 OH}\)=0.9g dw/mol in the presence of molybdenum), obviously higher for strain “Fusaro” grown diazotrophically (\(Y_{CH_3 OH}\)=1.15g dw/mol in the presence of V and \(Y_{CH_3 OH}\)=1.4g dw/mol with Mo) and highest if M. barkeri was grown on NH4Cl as N-source (\(Y_{CH_3 OH}\)=3.4g dw/mol with Mo, strain “Fusaro”).
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.