Influence of metals on oxygen uptake, carbon dioxide fixation, and cytochrome reduction in Nitrobacter Agilis

Abstract

Oxygen uptake coupled with nitrite oxidation by washed cell suspensions of Nitrobacter ugilis was tested in the presence of copper, nickel, aluminum, uranyl, and molybdate ions. Copper ion was slightly stimulatory at low concentrations and strongly inhibitory at 17 mM. Molybdate ion showed either slight enhancement or no inhibition at all test concentrations. With the other test ions, inhibition of oxygen uptake was observed. Carbon dioxide fixation was generally more sensitive to metal ions than was oxygen uptake. Cytochrome reduction in washed cells of N. ugilis was demonstrated in the presence and absence of metal ions. Cytochrome uu3 and cytochrome ul (a-peak at 590 nm) were sensitive to aluminum, uranyl, and molybdate ions, whereas cytochrome c (/?-peak at 520 nm) was insensitive to test ions. All metal ions inhibited the reduction of cytochrome al (y-peak a t 438 nm). This inhibition decreased when the concentration of copper and molybdate was increased to 1.7 mM. Only aluminum and nickel ions demonstrated a concentration-dependent inhibition of cytochrome al (438 nm). The test ions blocked the activity of cytochrome c (a-peak at 550 nm). The inhibition of cytochrome c at 415 nm (7-peak) was also apparent.

Light-induced absorbance changes associated with photoinhibition and pigments in nitrifying bacteria

“…It is safe to assume that the fluences used in this work did not lead to photobleaching since dark recovery of nitrifying activity occurred previously (Guerrero & Jones 1996a, b) when using identical light doses. Prior to this study soluble and membrane-bound cytochrome-c had been characterized among nitrifiers (Miller & Wood 1982, Tanaka et al 1983, DiSpirito et al 1985, firstein et al 1986, Tsai & Tuovinen 1989, Hooper et al 1991. The cell-free extract system used in this work showed properties very similar to the above cited purified oxidized or reduced cyt-c fraction (Dispirit0 et al 1985;Fig.…”

Influence of combined chemicals on prodigiosin Synthesis of Serratia marcescens

“…These observations could be due t o possible chemical interactions such as redox couples even by using binary metal ion pairs and complex samples. Cu2+, for example, effects 0 2 uptake, C02 fixation, and redox properties of cytochromes (Tsai and Tuovinen, 1989). Since it is known that respiration activity in S .…”

Influence of sulfooxyanions on oxygen uptake, carbon dioxide fixation, and cytochrome reduction in Nitrobacter Agilis

“…The growth condition of N . agilis and preparation of cells were carried out as described in the preceding paper (Tsai and Tuovinen, 1989).…”

“…Cytochrome spectra of washed cells of N. agilis were determined as described in the preceding paper (Tsai and Tuovinen, 1989).…”

“…(Tsai and Tuovinen, 1985). In the present work, several test compounds of sulfur were studied using the same techniques as described in the preceding paper (Tsai and Tuovinen, 1989) in which the physiological response by Nitrobacter agilis to metal ions was evaluated.…”