RESUMEN
OBJECTIVE: To improve the production of 10-hydroxy-12,15(Z,Z)-octadecadienoic acid (HODA) from α-linolenic acid in Stenotrophomonas nitritireducens. RESULTS: Cells of the bacterium were permeabilized with 1.25% (v/v) methanol. The optimal conditions for HODA production by permeabilized cells were pH 7, 35 °C, 5% (v/v) DMSO, 50 g cells l(-1), and 22.5 g α-linolenic acid l(-1). Under these conditions, permeabilized cells produced 16.4 g HODA l(-1) after 2 h, with a conversion yield of 73 % (w/w) and a volumetric productivity of 8.2 g l(-1) h(-1). These values were 153 and 230 % of the values for non-permeabilized cells CONCLUSIONS: This is the highest concentration and volumetric and specific productivities of HODA reported thus far.
Asunto(s)
Ácidos Grasos Insaturados/metabolismo , Stenotrophomonas/metabolismo , Ácido alfa-Linolénico/metabolismo , Biotecnología , Permeabilidad de la Membrana Celular , Stenotrophomonas/química , Stenotrophomonas/citología , Ácido alfa-Linolénico/análogos & derivadosRESUMEN
Based on previous results of 16S rDNA sequence homologuous and results of physic-biochemical indexes and morphological characteristics in the present work, bacterial strain ge15 isolated from roots of ginseng plants was identified as Stenotrophomonas rhizophila. Confronting incubation results showed that, strain ge15 inhibited the growth of Alternaria panax, Phytophthora cactorum, and Cylindrocapon destructans significantly, and the width of inhibition zone was 13.3, 24.0, 12.0 mm, respectively. Further results showed that the emergence rate and seedling survive rate of ge15 treatment was significantly higher than those of the control, and which was similar to pesticide carbendazol treatment. The ge15 strain has good application potential in ginseng diseases control without contamination.
Asunto(s)
Alternaria/crecimiento & desarrollo , Hypocreales/crecimiento & desarrollo , Panax/microbiología , Phytophthora/crecimiento & desarrollo , Enfermedades de las Plantas/microbiología , Stenotrophomonas/fisiología , Alternaria/fisiología , Antibiosis , Agentes de Control Biológico , Hypocreales/fisiología , Panax/crecimiento & desarrollo , Phytophthora/fisiología , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/microbiología , Plantones/crecimiento & desarrollo , Plantones/microbiología , Stenotrophomonas/clasificación , Stenotrophomonas/citología , Stenotrophomonas/aislamiento & purificaciónRESUMEN
Cell-assemblies with different cell shapes were used as macrotemplates in the bioinspired synthesis of hierarchical macro-mesoporous titania with tunable macroporous morphology and enhanced photocatalytic performance.
Asunto(s)
Células , Titanio/química , Catálisis , Grifola/citología , Microscopía Electrónica de Rastreo , Fotoquímica , Porosidad , Saccharomyces cerevisiae/citología , Stenotrophomonas/citologíaRESUMEN
The conversion of linoleic acid into 10-hydroxy-12(Z)-octadecenoic acid by whole cells of Stenotrophomonas nitritireducens as an isolated bacterium was optimized, and the optimal temperature, pH, and cell and substrate concentrations were 30 degrees C, 7.5, and 20 and 20 g/L, respectively. Under these conditions, whole cells in a bioreactor produced 15 g/L 10-hydroxy-12(Z)-octadecenoic acid in 2 h of reaction time without detectable byproducts. Using 2 g/L linoleic acid, the cells produced 1.92 g/L 10-hydroxy-12(Z)-octadecenoic acid. These are the highest concentration and yield of 10-hydroxy-12(Z)-octadecenoic acid ever reported.
Asunto(s)
Ácido Linoleico/metabolismo , Ácidos Esteáricos/metabolismo , Stenotrophomonas/metabolismo , Reactores Biológicos/microbiología , Concentración de Iones de Hidrógeno , Microbiología Industrial/instrumentación , Microbiología Industrial/métodos , Ácido Linoleico/química , Ácidos Esteáricos/química , Stenotrophomonas/citología , Stenotrophomonas/crecimiento & desarrollo , TemperaturaRESUMEN
A Gram-negative, rod-shaped, Stenotrophomonas-like bacterial strain, DS-16(T), was isolated from soil from Dokdo, Korea, and subjected to a polyphasic taxonomic study. Strain DS-16(T) grew optimally at pH 6.0-7.0 and 30 degrees C in the presence of 0.5 % (w/v) NaCl. It contained Q-8 as the predominant ubiquinone and iso-C(16 : 0), iso-C(15 : 0) and iso-C(17 : 1)omega9c as the major fatty acids. The DNA G + C content was 65.1 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain DS-16(T) joined the cluster comprising Stenotrophomonas species. The levels of 16S rRNA gene sequence similarity between strain DS-16(T) and the type strains of Stenotrophomonas species ranged from 95.5 to 97.5 %. DNA-DNA relatedness data and differential phenotypic properties, together with the phylogenetic distinctiveness of strain DS-16(T), demonstrated that this novel strain differs from Stenotrophomonas species with validly published names. On the basis of phenotypic, phylogenetic and genetic data, strain DS-16(T) (=KCTC 12543(T) = CIP 108839(T)) should be classified in the genus Stenotrophomonas as a member of a novel species, for which the name Stenotrophomonas dokdonensis sp. nov. is proposed.