title: Effects of metal ions on growth, β-oxidation system, and thioesterase activity of Lactococcus lactis.
abstract: The effects of divalent metal ions (Ca(2+), Mg(2+), Fe(2+), and Cu(2+)) on the growth, β-oxidation system, and thioesterase activity of Lactococcus lactis were investigated. Different metal ions significantly influenced the growth of L. lactis: Ca(2+) and Fe(2+) accelerated growth, whereas Cu(2+) inhibited growth. Furthermore, Mg(2+) inhibited growth of L. lactis at a low concentration but stimulated growth of L. lactis at a high concentration. The divalent metal ions had significant effects on activity of the 4 key enzymes of the β-oxidation system (acyl-CoA dehydrogenase, enoyl-CoA hydratase, L-3-hydroxyacyl-CoA dehydrogenase, and thiolase) and thioesterase of L. lactis. The activity of acyl-CoA dehydrogenases increased markedly in the presence of Ca(2+) and Mg(2+), whereas it decreased with 1 mmol/L Fe(2+) or 12 mmol/L Mg(2+). All the metal ions could induce activity of enoyl-CoA hydratase. In addition, 12 mmol/L Mg(2+) significantly stimulated activity of L-3-hydroxyacyl-CoA dehydrogenase, and all metal ions could induce activity of thiolase, although thiolase activity decreased significantly when 0.05 mmol/L Cu(2+) was added into M17 broth. Inhibition of thioesterase activity by all 4 metal ions could be reversed by 2 mmol/L Ca(2+). These results help us understand the effect of metal ions on the β-oxidation system and thioesterase activity of Lactococcus lactis.
authors: School of Food Science and Engineering, Harbin Institute of Technology, 202 Haihe Road, Harbin, Heilongjiang 150090, China; College of Food Science, Northeast Agricultural University, 59 Gongbin Road, Harbin, Heilongjiang 150030, China.
authors: Liang
authors: L
authors: Li
authors: School of Food Science and Engineering, Harbin Institute of Technology, 202 Haihe Road, Harbin, Heilongjiang 150090, China. Electronic address: maying@hit.edu.cn.
authors: Ying
authors: Y
authors: Ma
mesh_terms: D002118:Calcium / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D005227:Fatty Acids / Q000378:metabolism; D007477:Ions / Q000494:pharmacology; D007659:Ketones / Q000378:metabolism; D013294:Lactococcus lactis / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism; D019216:Metals, Heavy / Q000494:pharmacology*; D010084:Oxidation-Reduction / Q000187:drug effects; D013869:Thiolester Hydrolases / Q000378:metabolism*
chemical_list: D005227:Fatty Acids; D007477:Ions; D007659:Ketones; D019216:Metals, Heavy; D013869:Thiolester Hydrolases; D002118:Calcium
keywords: Lactococcus lactis; metal ion; thioesterase; β-oxidation system