title: Nitrite reduction in Veillonella alcalescens.
abstract: Nitrite reduction was examined in Veillonella alcalescens C-1, and obligate anaerobe with an ATP-yielding nitrate-reducing system. Hydrogen donors for nitrite reduction included hydrosulfite, hydrogen gas, and pyruvate, but not pyridine nucleotides, in the presnece or absence of flavins. Pyruvate-linked nitrite reduction was not inhibited by 4,4,4-trifluoro-1-(2-thienyl) 1,3-butanedione, dicoumarol, or 2-heptyl-4-hydroxy-quinoline-N-oxide. The noninvolvement of membrane-bound factors was supported by the fact that 100% of pyruvate-linked activity remained in the soluble fraction after fractionation of crude extracts by ultracentrifugation. Using DEAE-cellulose column chromatography, however, the participation of ferredoxin in nitrite reduction was demonstrated. The product of nitrite reduction appeared to be ammonia, as determined from H2-to-NO2- ratios. Nitrite reductase was induced by nitrate or nitrite and was repressed by increased levels of reduced nitrogenous compounds.
mesh_terms: D000693:Anaerobiosis; D002474:Cell-Free System; D005288:Ferredoxins / Q000378:metabolism; D009572:Nitrite Reductases / Q000037:antagonists & inhibitors / Q000378:metabolism; D009573:Nitrites / Q000378:metabolism*; D010084:Oxidation-Reduction; D010269:Paraquat / Q000378:metabolism; D011773:Pyruvates / Q000378:metabolism; D013447:Sulfites / Q000378:metabolism; D014678:Veillonella / Q000378:metabolism*
chemical_list: D005288:Ferredoxins; D009573:Nitrites; D011773:Pyruvates; D013447:Sulfites; D009572:Nitrite Reductases; D010269:Paraquat