. 2011 Jul 21;6(2):440–450. doi: 10.1038/ismej.2011.97

Table 2. Nitrogenase activity based on C₂H₂ reduction to C₂H₄ by the magnetotactic gammaproteobacterial strains BW-2 and SS-5 grown autotrophically in semisolid (O₂)-gradient medium with thiosulfate as the electron donor.

Organism	Fixed N source	Total cell protein per culture (μg)	Rate of C₂H₂ reductiona	Duration of assay (hour)
MV-1	None	85.5±8.0	2.0±0.7	5.5
BW-2	None	21.2±1.2	0.7±0.1	17.5
	NH₄Cl (4 mm)	59.1±9.8	None detected	17.5
	NaNO₃ (4 mm)	18.4±4.4	None detected	17.5
SS-5	None	Not determined	None detected	22

Abbreviations: C₂H₂, acetylene; C₂H₄, ethylene.

Cultures of Candidatus Magnetovibrio blakemorei strain MV-1 were used as a positive control (Bazylinski and Williams, 2007). Experiments were performed in triplicate for each growth condition, and results are reported as the mean±s.d.

nmol C₂H₄ produced min⁻¹ mg⁻¹ cell protein. Rates were determined from linear regression calculations. For Candidatus Magnetovibrio blakemorei strain MV-1, r⩾0.9826 (n=5); for strain BW-2, r⩾0.9830 (n=5).

Table 2. Nitrogenase activity based on C2H2 reduction to C2H4 by the magnetotactic gammaproteobacterial strains BW-2 and SS-5 grown autotrophically in semisolid (O2)-gradient medium with thiosulfate as the electron donor.

Table 2. Nitrogenase activity based on C₂H₂ reduction to C₂H₄ by the magnetotactic gammaproteobacterial strains BW-2 and SS-5 grown autotrophically in semisolid (O₂)-gradient medium with thiosulfate as the electron donor.