Phosphate and carbon source regulation of alkaline phosphatase and phospholipase in Vibrio vulnificus.
In this study, the effects of phosphate concentration and carbon source on the patterns of alkaline phosphatase (APase) and phospholipase (PLase) expression in Vibrio vulnificus ATCC 29307 were assessed under various conditions. The activities of these enzymes were repressed by excess phosphate (4 mM) in the culture medium, but this repression was reversed upon the onset of phosphate starvation in low phosphate defined medium (LPDM) containing 0.2 mM of phosphate at approximately the end of the exponential growth phase. The expressions of the two enzymes were also influenced by different carbon sources, including glucose, fructose, maltose, glycerol, and sodium acetate at different levels. The APase activity was derepressed most profoundly in LPDM containing fructose as a sole carbon source. However, the repression/derepression of the enzyme by phosphate was not observed in media containing glycerol or sodium acetate. In LPDM-glycerol or sodium acetate, the growth rate was quite low. The highest levels of PLase activity were detected in LPDMsodium acetate, followed by LPDM-fructose. PLase was not fully repressed by high phosphate concentrations when sodium acetate was utilized as the sole carbon source. These results showed that multiple regulatory systems, including the phosphate regulon, may perform a function in the expression of both or either APase and PLC, in the broader context of the survival of V. vulnificus.
Oh
Wan-Seok
WS
Department of Biology, University of Incheon, Incheon 402-749, Republic of Korea.
Im
Young-Sun
YS
Yeon
Kyu-Young
KY
Yoon
Young-Jun
YJ
Kim
Jung-Wan
JW
D000469:Alkaline Phosphatase / Q000378:metabolism*; D002244:Carbon / Q000494:pharmacology*; D002384:Catalysis / Q000187:drug effects; D003470:Culture Media / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D005632:Fructose / Q000494:pharmacology; D005947:Glucose / Q000494:pharmacology; D005990:Glycerol / Q000494:pharmacology; D008320:Maltose / Q000494:pharmacology; D010710:Phosphates / Q000494:pharmacology*; D010740:Phospholipases / Q000378:metabolism*; D019346:Sodium Acetate / Q000494:pharmacology; D013379:Substrate Specificity; D013997:Time Factors; D041261:Vibrio vulnificus / Q000187:drug effects* / Q000201:enzymology
D003470:Culture Media; D010710:Phosphates; D005632:Fructose; D019346:Sodium Acetate; D008320:Maltose; D002244:Carbon; D010740:Phospholipases; D000469:Alkaline Phosphatase; D005947:Glucose; D005990:Glycerol