Psychroflexus halocasei sp. nov., isolated from a microbial consortium on a cheese

Abstract

A novel halophilic, Gram-reaction-negative, strictly aerobic, non-motile, rod-shaped and oxidaseand catalase-positive bacterial strain, designated WCC 4520 T , was isolated from a semi-hard, Raclette-type cheese. The colonies were yellow-orange; flexirubin-type pigments were not found. The strain hydrolysed gelatin, hippurate, tyrosine and Tweens 20 and 80. Optimal growth was observed with 6-8 % (w/v) NaCl, at pH 7-8 and at 27-30 6C. The genomic DNA G+C content was 33.6 mol%. In phylogenetic analysis based on 16S rRNA gene sequences, strain WCC 4520 T appeared to be a member of the family Flavobacteriaceae and the closest phylogenetic neighbours were identified as Psychroflexus gondwanensis DSM 5423 T (94.0 % 16S rRNA gene sequence similarity) and Psychroflexus salinarum CCUG 56752 T (94.0 %). The predominant cellular fatty acids were iso-C 15 : 0 , anteiso-C 15 : 0 , iso-C 15 : 1 G and iso-C 17 : 0 3-OH. The only detected quinone was MK-6 and the major polar lipids were phosphatidylethanolamine, an unidentified aminolipid and an unidentified polar lipid. Minor polar lipids and traces of polyamines were also detected. On the basis of the data presented, strain WCC 4520 T represents a novel species of the genus Psychroflexus, for which the name Psychroflexus halocasei sp. nov. is proposed. The type strain is WCC 4520 T (5LMG 25857 T 5CCUG 59705 T ).At the time of its creation, the genus Psychroflexus, a member of the family Flavobacteriaceae (Bernardet et al., 2002), comprised Gram-staining-negative, non-motile or slowly gliding, psychrophilic or psychrotolerant, slightly or moderately halophilic, rod-like bacteria with genomic DNA G+C contents of 32-36 mol% (Bowman et al., 1998). Unfortunately, the type strain of the type species of this genus, Psychroflexus torquis 651 T , is no longer available from the CIP, LMG or ACAM culture collections and it is questionable whether it can still be used in physiological and biochemical analyses. At the time of writing, the genus Psychroflexus comprised five recognized species: P. gondwanensis (Dobson et al., 1993;Bowman et al., 1998), P. torquis (Bowman et al., 1998) (Euzéby, 2012). All known strains in the genus Psychroflexus have been isolated from seawater, marine salterns or hypersaline lakes.In this report, we describe a novel strain, designated WCC 4520 T , that was isolated from the salted surface of a cheese. When the taxonomy of this strain was investigated, using a polyphasic approach, the strain was identified as a novel species in the genus Psychroflexus. Strain WCC 4520T was isolated from a semi-hard, Raclettetype cheese that had a defective, unusually sticky surface. Raclette is one of several 'red-smear' cheeses that, as part of the ripening process, are inoculated with microbial consortia that have been washed off the surfaces of mature cheeses with brine. The microbial 'red-smear' consortium from the defective cheese was unusual in being yelloworange and slimy to sticky. The cheese had been produced in an Austrian dairy and then ripened in a cliff cave at...

Comparison of prokaryotic community structure from Mediterranean and Atlantic saltern concentrator ponds by a metagenomic approach

“…However, in IC21 the second predominant genus is Psychroflexus , also a member of the phylum Bacteroidetes , at 4.6% of the sequences. The six species comprising the genus Psychroflexus ( P. gondwanense , P. halocasei , P. salinarum , P. sediminis , P. torquis , and P. tropicus ) have been characterized as slightly or moderately halophilic bacteria and most of them have been isolated from saline environments (Bowman et al, 1998; Donachie et al, 2004; Chen et al, 2009; Yoon et al, 2009; Seiler et al, 2012). With respect to genera of the class Gammaproteobacteria , in SS19 and IC21, Spiribacter is identified as one of the most abundant.…”

Mesonia hippocampi sp. nov., isolated from the brood pouch of a diseased Barbour's Seahorse (Hippocampus barbouri)

“…In the polyamine pattern, 3.0 μmol (g dry weight) − 1 sym -homospermidine, 0.1 μmol (g dry weight) − 1 cadaverine and trace amounts [ < 0.10 μmol (g dry weight) − 1 ] of putrescine and spermine were detected. So far, a polyamine pattern has not been reported for a member of the genus Mesonia , but the presence of the major polyamine sym- homospermidine was confirmed in a representative of a closely related genus, Psychroflexus halocasei (Seiler et al , 2012). Homospermidine was so far detected as major polyamine in several further genera of the family Flavobacteriaceae including Bergeyella , Riemerella , Ornithobacterium , Weeksella , Capnocytophaga , Polaribacter and Psychroflexus (Hamana & Nakagawa, 2001).…”

Lysinibacillus meyeri sp. nov., isolated from a medical practice

“…Amino acid and sugar analysis of cell-wall hydrolysate, determination of the genomic DNA G+C content by HPLC, spectroscopical genomic DNA–DNA hybridization, analysis of whole-cell fatty acids, extraction and two-dimensional TLC identification of isoprenoid quinones and polar lipids were carried out by the identification service of the DSMZ as described previously (Seiler et al , 2012a, b). The complete cell-wall hydrolysate contained the amino acids alanine, glutamate, lysine and aspartate and the peptide d -Asp- l -Lys; the partial hydrolysate contained the peptides d -Asp- l -Lys, d -Asp- l -Lys- d -Ala and l -Ala- d -Glu.…”