Flocculation and Re-growth of Mycobacterium avium after ozone exposure

Authors: Dow, Sarahann M.; Amy, Gary; Hernandez, Mark

Source: Proceedings of the Water Environment Federation, Disinfection 2007 , pp. 74-84(11)

Publisher: Water Environment Federation

Buy & download fulltext article:

Price: $17.50 plus tax (Refund Policy)

Abstract:

In bench scale reactors dispersed Mycobacterium avium (M. avium) cells rapidly flocculated into aggregates containing hundreds of cells when exposed to ozone in phosphate buffered waters containing 3 mM carbonate alkalinity at pH 6.6 and 7°C. The flocculation response of M. avium cells after ozone exposure was identified using phase contrast and epi-flourescent microscopy. Batch reactors were inoculated with 10⁷ colony forming units per milliliter (CFU/ml) of M. avium and after complete mixing dosed with initial ozone concentrations of 1 and 2 mg/L. M. avium could not be recovered from ozone quenched samples taken from the reactors on Middlebrooks 7H11 agar plates after a CT of 2 mg min L⁻¹. Reactors placed in incubators at 22°C for 5 days after greater than 2 mg min L⁻¹ ozone exposure demonstrated re-growth of M. avium at concentrations of 10⁴ CFU/ml on Middlebrooks 7H11 agar plates. Re-growth of M. avium was confirmed by epi-flourescent microscopy. Nutrient media was not added to the batch reactors after ozone disinfection. The flocculation response observed using epi-flourescent microscopy may provide a protective mechanism against ozone disinfection allowing M. avium to re-grow in what appeared to be completely disinfected batch reactors.

Document Type: Research article

DOI: http://dx.doi.org/10.2175/193864707787932234

Publication date: 2007-01-01

More about this publication?

Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed.

WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access.
Subscribe to this Title
Membership Information
About WEF Proceedings
WEFTEC Conference Information
ingentaconnect is not responsible for the content or availability of external websites

Flocculation and Re-growth of Mycobacterium avium after ozone exposure

Buy & download fulltext article:

Tools

Key

Text size:

Useful pages