RESUMEN
A Gram-stain-positive, facultatively anaerobic, thermophilic bacterium, designated ZQ18-1T, was isolated from a high temperature daqu sample collected from the sesame-flavour liquor-making process. Oval endospores were formed at the centre of cells with swollen sporangia. The isolate was able to grow at temperatures of 20-60 °C (optimum growth at 50 °C), at pH 4-9 (optimum growth at pH 8) and in the presence of 0-10 % (w/v) NaCl (optimum growth with 2 % NaCl). Glucose and galactose were major cell-wall sugars, and meso-diaminopimelic acid was the diagnostic amino acid. The major polar lipids consisted of phosphatidylglycerol, diphosphatidylglycerol and three glycolipids. The major cellular fatty acids were anteiso-C17 : 0 and iso-C16 : 0, and the predominant menaquinone was MK-7. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain ZQ18-1T was most closely related to Scopulibacillus darangshiensis DLS-06T, Pullulanibacillus pueri YN3T, Tuberibacillus calidus 607T, Pullulanibacillus naganoensis ATCC 53909T, Pullulanibacillus uraniitolerans UG-2T, Sporolactobacillus terrae DSM 11697T and Sporolactobacillus inulinus NRIC 1133T. Strain ZQ18-1T showed low DNA-DNA relatedness (40.7, 23.1, 46.5, 27.2, 45.6, 33.7 and 55.1 %) with the strains mentioned above. Based on morphological characteristics, chemotaxonomic characteristics, DNA-DNA hybridization data and physiological properties, strain ZQ18-1T represents a novel species of the genus Scopulibacillus, for which the name Scopulibacillus daqui sp. nov. is proposed. The type strain is Scopulibacillus daqui ZQ18-1T (=DSM 28236T=CICC 10824T). An emended description of the genus Scopulibacillus is provided.
Asunto(s)
Bacillales/clasificación , Microbiología de Alimentos , Filogenia , Bacillales/genética , Bacillales/aislamiento & purificación , Técnicas de Tipificación Bacteriana , Composición de Base , China , ADN Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Grasos/química , Calor , Hibridación de Ácido Nucleico , Peptidoglicano/química , Fosfolípidos/química , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Esporas Bacterianas , Vitamina K 2/químicaRESUMEN
Daqu is a fermentation starter used in the production of Chinese liquors. A thermophilic bacterium, designated strain H-18(T), was isolated from a high-temperature Daqu sample collected from the manufacturing process of a sesame-flavoured liquor in Shandong province, China. It was investigated in a taxonomic study using a polyphasic approach. Strain H-18(T) formed white aerial mycelium and greyish-yellow substrate mycelium, bearing single endospores on aerial and substrate hyphae or on unbranched short sporophores. The cell-wall peptidoglycan contained meso-diaminopimelic acid. The major fatty acids were iso-C15â:â0 and iso-C17â:â0. The predominant menaquinone was MK-7. These chemotaxonomic properties are similar to those of members of the genus Thermoactinomyces. The G+C content of the genomic DNA was 49.1 mol%. 16S rRNA gene sequence comparisons indicated that strain H-18(T) was most closely related to Thermoactinomyces vulgaris KCTC 9076(T) (96.42â% similarity), Thermoactinomyces intermedius KCTC 9646(T) (96.06â%), Laceyella putida KCTC 3666(T) (96.32â%) and Laceyella sacchari KCTC 9790(T) (95.55â%). Strain H-18(T) showed low DNA-DNA relatedness (40.8, 33.4, 20.0 and 14.4â%) with the above strains. Based on morphological and chemotaxonomic characteristics, DNA-DNA hybridization data and physiological properties, strain H-18(T) represents a novel species of the genus Thermoactinomyces, for which the name Thermoactinomyces daqus sp. nov. is proposed. The type strain is H-18(T) (â=âDSM 45914(T)â=âCICC 10681(T)).
Asunto(s)
Bebidas Alcohólicas/microbiología , Filogenia , Thermoactinomyces/clasificación , Técnicas de Tipificación Bacteriana , Composición de Base , China , ADN Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Grasos/química , Fermentación , Calor , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Peptidoglicano/química , Fosfolípidos/química , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Esporas Bacterianas , Thermoactinomyces/genética , Thermoactinomyces/aislamiento & purificación , Vitamina K 2/análogos & derivados , Vitamina K 2/químicaRESUMEN
Distiller's grains (DGs) possessed great potential utilization value due to their rich active ingredients. However, its utilization efficiency was limited by the large amount of lignocellulose components and water-insoluble proteins. In this work, single screw extrusion was applied to modify physicochemical properties of DGs. Results indicated that extruded distiller's grains (EDGs) exhibited the lower crude fiber content (26.01%), the higher soluble fiber (9.07%) and the smaller particle size when compared with those of Control, and subsequently achieving the increased bulk density, swelling capacity and water/oil holding capacity. The crude protein in EDGs decreased slightly, while the total amount of acid hydrolyzed amino acids showed a significant increase. Additionally, the looser, coarser and fragmentary microstructure of EDGs were observed. The main macromolecules in EDGs had been modified distinctly based on thermal analysis, crystallinity and functional groups analyses, while the possible schematic diagram was conducted to better understand the modification mechanism.
Asunto(s)
Aminoácidos , Grano Comestible , Aminoácidos/análisis , Alimentación Animal/análisis , Grano Comestible/química , Estructuras de las Plantas/química , Proteínas/análisis , Agua/químicaRESUMEN
Thermoactinomyces daqus H-18 is a new species of Thermoactinomyces isolated from high-temperature Daqu used in the fermentation of Bandongjing sesame-flavor liquor. Its genome was sequenced and assembled (3.44 Mb). The coding sequences (CDSs) that correlated to high-temperature tolerance were annotated. The metabolic pathways for the compounds responsible for flavor were also found.