| Abstract |
A novel, extremely psychrotolerant, facultative anaerobe, strain PmagG1(T), was isolated from guano of Magellanic penguins (Spheniscus magellanicus) collected in Chilean Patagonia. Gram-variable, motile cocci with a diameter of 1.3-2.0 mum were observed singularly or in pairs, short chains and irregular conglomerates. Growth occurred within the pH range 6.0-10.0, with optimum growth at pH 8.5. The temperature range for growth of the novel isolate was from -5 to 35 degrees C, with optimum growth at 28-30 degrees C. Strain PmagG1(T) did not require NaCl, as growth was observed in the presence of 0-6.5 % NaCl with optimum growth at 0.5 % (w/v). Strain PmagG1(T) was a catalase-negative chemo-organoheterotroph that used sugars and some organic acids as substrates. The metabolic end products were lactate, formate, acetate, ethanol and CO(2). Strain PmagG1(T) was sensitive to ampicillin, tetracycline, chloramphenicol, rifampicin, kanamycin and gentamicin. The G+C content of its genomic DNA was 45.8 mol%. 16S rRNA gene sequence analysis showed 100 % similarity of strain PmagG1(T) with Trichococcus collinsii ATCC BAA-296(T), but DNA-DNA hybridization between them demonstrated relatedness values of <45+/-1 %. Another phylogenetically closely related species, Trichococcus pasteurii, showed 99.85 % similarity by 16S rRNA sequencing and DNA-DNA hybridization showed relatedness values of 47+/-1.5 %. Based on genotypic and phenotypic characteristics, the novel species Trichococcus patagoniensis sp. nov. is proposed, with strain PmagG1(T) (=ATCC BAA-756(T)=JCM 12176(T)=CIP 108035(T)) as the type strain.
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