ABSTRACT
Crude glycerol is a byproduct of biodiesel production. In this study, we isolated a yeast strain that grows vigorously using crude glycerol as a carbon source, and tested the effects of culture conditions on triacylglycerol (TG) production. TYC-2187, isolated from wild grapes and identified as Pseudozyma sp., converted high-concentration crude glycerol into TG more efficiently than other strains of the genus Pseudozyma. Sequence analysis of the 26S rRNA gene D1/D2 domain indicated that TYC-2187 diverged from other strains of the genus Pseudozyma. Optimum culture temperature and optimum initial pH of culture medium, that maximized TG yield of TYC-2187, were 25°C and pH 6.0, respectively. Optimum nitrogen source was yeast extract and optimum concentration was 10 g/L. Optimum concentration of glycerol, when the yeast was cultured for 48 h under optimum conditions, was 80 g/L. TG yield peaked at 15.7 g/L at 48 h and then remained at this level until 66 h. In addition, much of the glycerol in the medium had been consumed by 48 h. Fatty acid composition of TG produced by TYC-2187, including linolenic acid methyl ester content, iodine value, and cetane number, complied with biodiesel standards. These results suggest that the TYC-2187 yeast strain is superbly able to produce TG that is suitable for biodiesel production using crude glycerol.
Subject(s)
Basidiomycota/metabolism , Biochemistry/methods , Biofuels , Biotechnology/methods , Glycerol/metabolism , Triglycerides/biosynthesis , Basidiomycota/genetics , Basidiomycota/isolation & purification , Culture Media , Culture Techniques , Hydrogen-Ion Concentration , RNA, Fungal/genetics , RNA, Ribosomal/genetics , Sequence Analysis, RNA , Temperature , Time Factors , Vitis/microbiologyABSTRACT
This study aimed to investigate intestinal helminth infection in stray dogs in Osaka Prefecture by surveying coprological samples from dogs captured from 2006-2011. Of 212 fecal samples collected, overall prevalence of infection was 39.2%. The most common species was Toxocara canis (25.0%), followed by Trichuris vulpis (8.0%), Spirometra erinaceieuropaei (3.3%), Taeniidae (2.4%), Ancylostoma caninum (1.9%) and Toxascaris leonine (0.5%). In the molecular analysis, all of the taeniid eggs were negative for Echinococcus multilocularis and were identified as other taeniid species (e.g., Taenia pisiformis). Our results suggest that stray dogs remain important infection reservoirs of zoonotic parasites in Osaka Prefecture. Therefore, control of stray dogs is crucial for reducing the risk of public health problems due to parasitic infections.
Subject(s)
Cestoda/isolation & purification , Cestode Infections/veterinary , Dog Diseases/parasitology , Intestinal Diseases, Parasitic/veterinary , Zoonoses/parasitology , Animals , Cestoda/genetics , Cestode Infections/epidemiology , Cestode Infections/parasitology , DNA, Helminth/chemistry , DNA, Helminth/genetics , DNA, Mitochondrial/chemistry , DNA, Mitochondrial/genetics , Dog Diseases/epidemiology , Dogs , Electron Transport Complex IV/chemistry , Electron Transport Complex IV/genetics , Feces/parasitology , Female , Intestinal Diseases, Parasitic/epidemiology , Intestinal Diseases, Parasitic/parasitology , Japan/epidemiology , Male , Parasite Egg Count/veterinary , Polymerase Chain Reaction/veterinary , Prevalence , RNA, Ribosomal/chemistry , RNA, Ribosomal/genetics , Zoonoses/epidemiologyABSTRACT
Diphtheria-like human illness caused by Corynebacterium ulcerans is an emerging threat in developed countries, with incidence sometimes higher than that of diphtheria caused by Corynebacterium diphtheriae. Companion animals are considered a potential source of human infections. In order to determine the prevalence of C. ulcerans among dogs, we performed a screening for the bacterium in 583 dogs in the custody of the Osaka Prefectural government. Forty-four dogs (7.5 %) were positive for the bacterium, although they did not show any clinical symptoms. All bacterial isolates showed resistance or decreased sensitivity to clindamycin, and some showed decreased sensitivity to levofloxacin. Comparative analysis of isolates using PFGE, toxin gene typing and antibiotic sensitivities suggests that transmission between asymptomatic dogs might have occurred.
