The influence of mercury on the antioxidant enzyme activity of rumen bacteria Streptococcus bovis and Selenomonas ruminantium

• Published in: FEMS microbiology ecology Vol. 27; no. 4; pp. 319 - 325
• Main Authors: Lenartova, V, Holovska, K, Javorsky, P
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier B.V 01-12-1998; Blackwell
• Subjects: Action of physical and chemical agents on bacteria; animal physiology; Animal, plant and microbial ecology; Antioxidant enzyme; Bacteriology; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Mercury; Microbial ecology; Microbiology; Normal microflora of man and animals. Rumen; Selenomonas ruminantium; Streptococcus bovis; Selenomonas ruminantium; Antioxidant enzyme; Mercury; Streptococcus bovis; Glutathione peroxidase; Stomach; Digestive system; Enzyme; Glutathione reductase (NADPH); Toxicity; Environmental factor; Rumen; Superoxide dismutase; Antioxidant; Mercury(II) reductase; Bacteroidaceae; Heavy metal; Resistance; Streptococcaceae; Peroxidases; Enzymatic activity; Bacteria; Micrococcales; Oxidoreductases
• ISSN: 0168-6496; 1574-6941
• DOI: 10.1016/S0168-6496(98)00077-4

Studies were undertaken to investigate the activity response of the antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GSHPx), glutathione reductase (GR) and mercury reductase (MR) of rumen bacteria
Streptococcus bovis and
Selenomonas ruminantium following exposure to HgCl
2. SOD activity of
S. bovis which was considered as Mn-SOD increased when incubated with 5 μg Hg
2+ ml
−1 in anaerobic or aerobic conditions. A significant increase in the aerobic activities of GSHPx, GR and MR was observed in the presence of Hg
2+. The anaerobic activities of these enzymes were unchanged and increased production of thiobarbituric acid reactive substances was observed.
S. ruminantium was tolerant to 10 times higher concentrations of Hg
2+ than
S. bovis. As a reduction of GSHPx, GR and MR activities after exposure to Hg
2+ was observed, we assume that the production of sulfides prevented the toxic effect of mercury on this bacterium.