Recovery of nitrification in marine bacteria following exposure to carbon monoxide or light

Abstract

Recovery of activity by 2 marine nitrifying bacteria, Nitrosomonas cryotolerans and Nitrobacter sp. Nb297, was monitored after exposure to light and/or carbon monoxide. N. cryotolerans recovered more rapidly after exposure to artificial light (25 W m-') than CO (11.4 PM). The adhtion of 100 yM NH,+ during the time of light or CO exposure allowed the cells to recover faster and decreased the difference observed between the inhibitory effects of light and CO. Cells exposed to sunlight recovered much illore slowly than cells exposed to either CO or artificial hght. The ammonium oxidizer N. cryotolerans when exposed to sunlight (2 h) recovered up to 35 "/o of its original ammonium oxidizing activity. Recovery increased to 57 % in the presence of additional substrate (100 pM NH,'). The nitrite oxidizer Nitrobactersp. Nb297 did not show a noticeable recovery from sunlight whether substrate was added or not.

Variability of nitrifying communities in surface coastal waters of the Eastern South Pacific (∼36° S)

“…New strains of N. maritimus (PS0 and HCA) show high tolerance to light, in contrast to previous studies (Qin et al ., ). Also, the recovery of nitrifying metabolic capacities after photoinhibition varies with substrate availability (Yoshioka and Saijo, ; Vanzella et al ., ; Guerrero and Jones, ; Qin et al ., ). Thus, if present, photoinhibition of nitrification (defined as the drop in metabolic capacity induced by the light exposure) may result from either direct damage and/or by indirect effects associated to substrate availability in surface waters.…”

Nitrification in the euphotic zone as a source for nitrite, nitrate, and nitrous oxide at Station ALOHA

“…However, it is possible that nitrifying bacteria may show some recovery from photoinhibition over the course of a 24-h incubation. In laboratory studies with pure nitrifier cultures, ammonium oxidizers rccovered 35% of their activity and nitrite oxidizers recovered 3% 24 h after exposure to sunlight (Vanzella et al 1990). Olson (198 la) made simultaneous 24-h light and dark measurements of ammonium oxidation on two samples from the PNM in the North Pacific subtropical gyre with 15N tracer methodology and found that the light incu- On one cruise (HOT-50) we performed an in situ incubation and used the chemiluminescent method to measure changes in nitrite and nitrate in the incubated samples.…”

The Dark Side of Microbial Processes: Accumulation of Nitrate During Storage of Surface Water in the Dark and the Underlying Mechanism

“…Our results are consistent with previous reports on the inhibition of Nitrosomonas activity by light ( 23 , 24 ). In addition, previous studies have reported that Nitrobacter activity is inhibited by light as well ( 25 , 26 ). On the contrary, our observation suggested that light had no effect on the activity of nitrite to nitrate conversion by Nitrobacter .…”