RESUMO
A rapidly growing marine derived Bacillus sp. strain NQ-11/A2, identified as Bacillus megaterium, accumulated 61% polyhydroxyalkanoate by weight. Diverse carbon sources served as substrates for the accumulation of short chain length polyhydroxyalkanoate. Three to nine granules either single or attached as buds could be isolated intact from each cell. Maximum activity of polyhydroxyalkanoate synthase was associated with the granules. Granule-bound polyhydroxyalkanoate synthase had a K(m) of 7.1 x 10(-5) M for DL-beta-hydroxybutyryl-CoA. Temperature and pH optima for maximum activity were 30 degrees C and 7.0, respectively. Sodium ions were required for granule-bound polyhydroxyalkanoate synthase activity and inhibited by potassium. Granule-bound polyhydroxyalkanoate synthase was apparently covalently bound to the polyhydroxyalkanoate-core of the granules and affected by the chaotropic reagent urea. Detergents inhibited the granule-bound polyhydroxyalkanoate synthase drastically whilst glycerol and bovine serum albumin stabilized the synthase.
Assuntos
Aciltransferases/genética , Aciltransferases/metabolismo , Bacillus megaterium/enzimologia , Poli-Hidroxialcanoatos/metabolismo , Água do Mar/microbiologia , Bacillus megaterium/classificação , Bacillus megaterium/genética , Bacillus megaterium/isolamento & purificação , Metabolismo dos Carboidratos , Coenzimas/farmacologia , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Inibidores Enzimáticos/farmacologia , Estabilidade Enzimática , Concentração de Íons de Hidrogênio , Hidroxibutiratos/metabolismo , Cinética , Dados de Sequência Molecular , Potássio/farmacologia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Sódio/farmacologia , TemperaturaRESUMO
Pseudomonas mendocina P2d grew in sodium benzoate at as high as 1% concentration and formed a quinonoid compound, identified as ortho-benzoquinone, that rendered the medium orange to wine-red in colour. The quinone was not metabilised further by the organism. Sodium benzoate was converted to catechol, which was a central metabolite forming ortho-benzoquinone and 2- hydroxymuconic semialdehyde (2-HMS) via. meta ring cleavage pathway.
