The Diplomonad Fish Parasite Spironucleus vortens Produces Hydrogen

摘要: The diplomonad fish parasite Spironucleus vortens causes major problems in aquaculture of ornamental fish, resulting severe economic losses the farming industry. strain S. studied here was isolated from an angelfish and grown Keister's modified TY-I-S33 medium. A membrane-inlet mass spectrometer employed to monitor, a closed system, O2, CO2, H2. When introduced into air-saturated buffer, rapidly consumed O2 at average rate 62±4 nmol/min/107 cells CO2 produced 75±11 cells. Hydrogen production began under microaerophilic conditions ([O2]=33.±15 μM) 77±7 inhibited by 62% immediately after adding 150 μM KCN reaction vessel, 50% 0.24 CO, suggesting that Fe-only hydrogenase is responsible for H2 production. Metronidazole (1 mM) 50%, while not affected. This suggests metronidazole may be reduced enzyme pathway, thus competing electrons with H+.