RESUMEN
The cDNA of cellobiose dehydrogenase (CDH) from Phanerochaete chrysosporium has been cloned and sequenced. The 5' end was obtained by PCR amplification. The cDNA contains 2310 translated bases excluding the poly(A) tail. The deduced mature protein contains 770 amino acid residues and is preceded by a 18 residue long signal peptide. The regions of the amino acid sequence corresponding to the heme and FAD domains of CDH were identified as well as the nucleotide-binding motif, the disulfide pairing and a methionine residue chelating the heme iron. No homologous sequences were found for the heme domain, however, the FAD domain appears to be distantly related to the GMC oxidoreductase family.
Asunto(s)
Basidiomycota/genética , Deshidrogenasas de Carbohidratos/genética , Genes Fúngicos/genética , Secuencia de Aminoácidos , Aminoácidos/análisis , Secuencia de Bases , Basidiomycota/enzimología , Deshidrogenasas de Carbohidratos/química , Deshidrogenasas de Carbohidratos/aislamiento & purificación , Clonación Molecular , ADN Complementario/genética , ADN de Hongos/genética , Flavina-Adenina Dinucleótido , Hemo , Datos de Secuencia Molecular , Alineación de Secuencia , Análisis de Secuencia de ADNRESUMEN
A procedure more efficient than the earleir one was developed for the isolation of mycobacteria from heavily contaminated materials. The contaminating microbes were killed by acid decontamination preceded by an incubation of 1g sample in 5ml nutrient broth varying concentrations of dimetridazole and/or clotrimazole (Canesten Bayer). None of 40 mycobacterial strains representing all 4 Runyon groups was inhibited by 80ug/ml of either of the inhibitors. From the sediment of acid-decontaminated samples, Lowestein-Jensen medium with and without glycerol and Sula media were inoculated. Model experiments and processing of 44 routine samples have made likely that aerobic sporeformers on the one hand and fungi and anaerobes on the other are killed, or that least depressed in growth, by pre-incubation combined with the addition of clotrimazole and dimetridazole to the culture medium. Thus, the isolation rate of mycobacteria can be improved.
Asunto(s)
Bacillus/crecimiento & desarrollo , Clotrimazol , Dimetridazol , Medios de Cultivo , Micobacterias no Tuberculosas/aislamiento & purificación , Mycobacterium avium/aislamiento & purificación , Mycobacterium/crecimiento & desarrollo , Mycobacterium/aislamiento & purificación , Técnicas Bacteriológicas , Ácidos SulfúricosRESUMEN
Streptomycetes constituted about 46--48 per cent of the total aerobic microflora in the cultivated horizon of the studied ferralitic tropical soil below sugar cane plantation. This streptomycete fraction of the soil microbial community was composed of 13 (or more) species of Streptomyces (S. chromofuscus, S. chromogenus, S. diastatochromogenes, S. flavochromogenes, S. griseolus, S. nigrescens, S. phaeofaciens, S. sterilis, S. violaceus, Streptomyces sp. I--III), and Streptoverticillium (Sv. aspergilloides). None of these organisms did occur, with detectable frequency of occurrence, in the root surface region of sugar cane. Here, in the rhizoplane, we found a numerically small population of streptomycetes (about 5 per cent of the total bacterial flora), composed of two species (Streptomyces sp. IV and S. griseorubiginosus) which were, however, not detected in soil samples.