RESUMO
A bacterial strain (strain 224), which has the ability to utilize sulfanilic acid as a sole source of carbon, was isolated from soil. 16S rRNA gene sequence obtained from strain 224 exhibited 100% identical to that of species in the genus Bradyrhizobium. Strain 224 degraded 4.7 mM of sulfanilic acid and released almost the same molar concentration of sulfate ion.
Assuntos
Bradyrhizobium/metabolismo , Corantes/metabolismo , Microbiologia do Solo , Poluentes do Solo/metabolismo , Ácidos Sulfanílicos/metabolismo , Biodegradação Ambiental , Bradyrhizobium/classificação , Bradyrhizobium/genética , Cinética , Filogenia , RNA Ribossômico 16S/genética , Sulfatos/metabolismoRESUMO
Addition of stearyl alcohol to the culture medium of Ralstonia sp. NT80 induced expression of a significant amount of secretory lipase. Comparative proteomic analysis of extracellular proteins from NT80 cells grown in the presence or absence of stearyl alcohol revealed that stearyl alcohol induced expression of several secretory proteins including lipase, haemolysin-coregulated protein and nucleoside diphosphate kinase. Expression of these secreted proteins was upregulated at the transcriptional level. Stearyl alcohol also induced the synthesis of polyhydroxyalkanoate. Secretory protein EliA was required for all these responses of NT80 cells to stearyl alcohol. Accordingly, the effects of stearyl alcohol were significantly reduced in the eliA deletion mutant cells of NT80 (ΔeliA). The remaining concentration of stearyl alcohol in the culture supernatant of the wild-type cells, but not that in the culture supernatant of the ΔeliA cells, clearly decreased during the course of growth. These observed phenotypes of the ΔeliA mutant were rescued by gene complementation. The results suggested that EliA is essential for these cells to respond to stearyl alcohol, and that it plays an important role in the recognition and assimilation of stearyl alcohol by NT80 cells.
Assuntos
Proteínas de Bactérias/genética , Álcoois Graxos/metabolismo , Regulação Bacteriana da Expressão Gênica , Poliésteres/metabolismo , Ralstonia/metabolismo , Proteínas de Bactérias/metabolismo , Biofilmes/crescimento & desenvolvimento , Meios de Cultura/química , Deleção de Genes , Perfilação da Expressão Gênica , Proteínas Hemolisinas/biossíntese , Lipase/biossíntese , Microscopia Eletrônica de Transmissão , Núcleosídeo-Difosfato Quinase/biossíntese , Poli-Hidroxialcanoatos/biossíntese , Ralstonia/genéticaRESUMO
Extracellular lipase activity from Ralstonia sp. NT80 is induced significantly by fatty alcohols such as stearyl alcohol. We found that when lipase expression was induced by stearyl alcohol, a 14-kDa protein (designated EliA) was produced concomitantly and abundantly in the culture supernatant. Cloning and sequence analysis revealed that EliA shared 30% identity with the protein-like activator protein of Pseudomonas aeruginosa, which facilitates oxidation and assimilation of n-hexadecane. Inactivation of the eliA gene caused a significant reduction in the level of induction of lipase expression by stearyl alcohol. Furthermore, turbidity that was caused by the presence of emulsified stearyl alcohol, an insoluble material, remained in the culture supernatant of the ΔeliA mutant during the late stationary phase, whereas the culture supernatant of the wild type at 72 h was comparatively clear. In contrast, when lipase expression was induced by polyoxyethylene (20) oleyl ether, a soluble material, inactivation of eliA did not affect the extracellular lipase activity greatly. These results strongly indicate that EliA facilitates the induction of lipase expression, presumably by promoting the recognition and/or incorporation of the induction signal that is attributed to stearyl alcohol.
Assuntos
Proteínas de Bactérias/metabolismo , Álcoois Graxos/farmacologia , Lipase/biossíntese , Ralstonia/enzimologia , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Clonagem Molecular , Indução Enzimática/efeitos dos fármacos , Regulação Bacteriana da Expressão Gênica , Lipase/genética , Lipase/metabolismo , Dados de Sequência Molecular , Mutação , Filogenia , Polietilenoglicóis/farmacologia , Ralstonia/efeitos dos fármacos , Ralstonia/genética , Ralstonia/metabolismo , Alinhamento de Sequência , Transdução de SinaisRESUMO
Poly(butylene succinate-co-butylene adipate) (PBSA)-degrading bacterium, strain 1-A, was isolated from soil. Strain 1-A was identified as Bacillus pumilus on the basis of its physiological properties and partial 16S rRNA gene sequence. Strain 1-A also degraded poly(butylene succinate) (PBS) and poly(epsilon-caprolactone). On the other hand, poly(butylene adipate terephthalate) and poly(lactic acid) were minimally degraded by strain 1-A. The NMR spectra of degradation products from PBSA indicated that the adipate units were more rapidly degraded than 1,4-butanediol and succinate units. This seems to be one of the reasons why strain 1-A degraded PBSA faster than PBS.
