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Poly-b-hydroxybutyrate (PHB) is an intracellular carbon and
energy storagematerial accumulated in many bacteria. Its
biodegradable properties can be usedin various ways similsr to
plastics derived from conventional petrochemicals.To establish
PHB-producing and biosynthesis gene screening systems,
Alcaligenes eutrophus H16 was used as a reference bacteria.
First, high C/N ratio (C/N=76)and molasses (5%) media were
selected for PHB production. Under thesis conditions,PHB content
was accumulated to 44% of bacteria dry weight. PHB biosynthesis
genesfrom Alcaligenes eutrophus H16 were cloned by colony
hybridization probed with 780 bp conserved phbC fragment. In
order to screen the PHB-producing indigenousbacteria, PCR
followed by Southern blotting analysis was carried out. Result
showed that a 780 bp PCR amplified fragment was detected in
three (Alcaligenesfaecalis NE and unidentified strains T2, NF)
of five indigenous bacteria, including;Corynebacterium sp. CB
showed a smear from 780 bp to 300 bp by touchdown PCR.Production
of PHB in both Corynebacterium sp. CB and unidentified strain T2
wereconfirmed by extraction of PHB and transmission electro-
microscopy. The PHB contents in Corynebacterium sp. CB and
unidentified strain T2 were 0.1 g/l and 0.08 g/l respectively.
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