RESUMEN

The small ubiquitin-like modifier (SUMO) modification occurred at bud necks and sites of septum formation in hyphae of the opportunistic fungal pathogen Candida albicans. Three genes encoding putative SUMO deconjugation enzymes (Ulp, ubiquitin-like protein specific proteases) of C. albicans were obtained through sequence database searching with Ulp domain of Saccharomyces cerevisiae Ulp1 (ScUlp1). These genes were designated as CaULP1, CaULP2 and CaULP3. The open reading frames of three putative ULPs were cloned and expressed in Pichia pastoris, resulting recombinant proteins. Functional analysis of recombinant CaUlp1, CaUlp2 and CaUlp3 confirms that these proteins exhibit SUMO-processing activity. CaULP1, CaULP2 and CaULP3 only expressed active form enzyme in P. pastoris but not in Escherichia coli. The molecular weights of CaUlp1, CaUlp2 and CaUlp3 proteins expressed in P. pastoris were larger than theoretical molecular weights. This observation was in good agreement with result of Western blot analysis of CaUlp1 and CaUlp3 proteins in C. albicans. It was assumed that CaUlp1, CaUlp2 and CaUlp3 proteins may need post-translational modifications to exhibit SUMO-processing activity. To our knowledge, this is the first report on cloning and expression of Ulp genes from C. albicans. Furthermore RT-PCR and Western blot analysis show that CaULP2 has no detectable expression both in yeast and in hyphal forms of C. albicans.

Asunto(s)

Candida albicans/genética , Proteínas Modificadoras Pequeñas Relacionadas con Ubiquitina/genética , Secuencia de Aminoácidos , Western Blotting , Clonación Molecular , Cartilla de ADN , Electroforesis en Gel de Poliacrilamida , Hifa/metabolismo , Datos de Secuencia Molecular , Pichia/metabolismo , Plásmidos/genética , Proteínas Recombinantes/biosíntesis , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/metabolismo , Proteínas Modificadoras Pequeñas Relacionadas con Ubiquitina/biosíntesis

RESUMEN

Object To study the growth speed and dynamic spore production of CY-8202, which is an asexual strain of entomopathogenic fungi isloated from Cordyceps sinensis (Berk.) Sacc., to explore the method of artificial culture of CY-8208 strain, to assay its antibiotic activity and spectrem and to provide the experimental basis for studies of its active components. Methods Variations in colony diameter of the cordyceps hypha cultured on the fungi media were measured. The spore-count was used to determine the dynamic colony spore outputs of the hypha on several fungi media and water agar. The agar-piece method was used to test its antibiotic activity.Results There were linear relationships between the colony extensions and the culture times on common fungi media such as PDA medium, etc.. The amounts of spore produced by the single colony of the fungi were more than 10 7 and gradually increased, but the rates of increase tended to be gentle after 200 h. Antimicrobial tests against 22 microbial strains showed strong inhibition of gram positve bacteria including Bacillus subtilis, Micrococcus tetragenus and Staphylococcus albus, and to gram negative bacteria, including Proteus vulgaris, Salmonella typhi, Aerobacter aerogenes and Salmonella sp., as well as weak inhibition of three mold strains and one actinomycetes strain, but no inhibition was observed in four yeast tested.Conclusion The growth activity and the spore-production ability of Cordyceps hypha are two important factors to infect validly its insect-host. For the growth activity, its strong penetration seems more important than its fast growth. The ability to product numerous spores of Cordyceps hypha may be an important mark of its strong infectivity to insect-host. The antimicrobial tests show that CY-8202 may secrete some metabolites which have a more broad-spectrum antibacterial activity than cordycepin isolated initially from Cordyceps militaris.

RESUMEN

A non spore fungal strain designated as CR 9512 was isolated from a species of Cordyceps , found in Northern Guangdong of China The growth characteristics and the morphology of the organism were studied It was initially identified as Rhizoctonia sp ,Agonomycetales Its antimicrobial tests, against 26 strains of Gram positive and Gram negative bacteria, actinomycetes, filamentous fungi and yeast, showed strong inhibition to some yeast of Rhodotorula, Saccharomyces, Pichia and Cryptococcus , and weak inhibition to yeast of Candida The speciality on a limited spectrum anti yeast of the organism will show an enormous value for researches and applications