Mechanism controlling the extended lag period associated with vinyl chloride starvation in Nocardioides sp. strain JS614.

Abstract

The extended lag period associated with vinyl chloride (VC) starvation in VC- and ethene-assimilating Nocardioides sp. strain JS614 was examined. The extended lag periods were variable (3-7 days), only associated with growth on VC or ethene, and were observed in VC- or ethene-grown cultures following 24 h carbon starvation and mid-exponential phase cultures grown on non-alkene carbon sources (e.g. acetate). Alkene monooxygenase (AkMO) and epoxyalkane:coenzyme M transferase (EaCoMT) are the initial enzymes of VC and ethene biodegradation in strain JS614. Reverse-transcription PCR confirmed that the AkMO gene etnC was expressed in response to epoxyethane, a metabolic intermediate of ethene biodegradation. Epoxyethane (0.5 mM) eliminated the extended lag period in both starved and mid-exponential phase cultures, suggesting that epoxyethane accumulation activates AkMO expression in strain JS614. AkMO activity in ethene-grown cultures was not detected after 6.7 h of carbon starvation, while 40% of the initial EaCoMT activity remained after 24 h. Acetate eliminated the extended lag period in starved cultures but not in mid-exponential phase cultures suggesting that acetate reactivates extant AkMO in starved VC- or ethene-grown cultures. The imbalance between AkMO and EaCoMT activities during starvation likely contributes to the extended lag period by delaying epoxide accumulation and subsequent AkMO induction.

• Authors: Timothy E Mattes, Nicholas V Coleman, Adina S Chuang, Andrea J Rogers, Jim C Spain, James M Gossett
• Journal: Archives of microbiology (Arch Microbiol) Vol. 187 Issue 3 Pg. 217-26 (Mar 2007) ISSN: 0302-8933 [Print] Germany
• PMID: 17308936 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.)

Chemical References

• Ethylenes
• Vinyl Chloride

Topics

• Adaptation, Physiological
• Biodegradation, Environmental
• Ethylenes (metabolism)
• Nocardiaceae (genetics, growth & development, metabolism)
• Oxidative Stress (physiology)
• Vinyl Chloride (metabolism)