|Nadathur, Govind - UNIVERSITY OF PUERTO RICO|
Submitted to: Society of Industrial Microbiology Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: June 10, 1998
Publication Date: N/A
Technical Abstract: Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a natural polyester with commercial potential as a biodegradable replacement for petroleum-derived thermoplastics. A number of soil bacteria are known to degrade PHBV. However, much less is known about the turnover of this material in marine environments. A novel marine bacterium was isolated that grew on PHBV as a sole carbon source and produced halos of clearing on solid medium containing PHBV. In complex medium, the isolate grew well at temperatures between 23 deg C and 33 deg C, with an optimal doubling time of about 30 min. NaCl was required at concentrations between 0.4 N and 1.2 N. Optimal pH levels for growth were between pH 6.5 and pH 8.5. Liquid cultures grew well on PHBV under optimal conditions, although only low levels of PHBV depolymerase activity were detected in culture supernatants. Ribosomal DNA sequencing placed this gram negative, motile organism in the genus Pseudoalteromonas. Degradation of PHBV by such marine organisms has implications for the MARPOL Treaty, which prohibits disposal of plastics at sea.