Sphingobacterium faecale sp. nov., a 1-aminocyclopropane-1-carboxylate deaminase producing bacterium isolated from camel faeces

An investigation of the diversity of 1-aminocyclopropane-1-carboxylate deaminase producing bacteria associated with camel faeces revealed the presence of a novel bacterial strain designated C459-1T. It was Gram-stain-negative, short-rod-shaped and non-motile. Strain C459-1T was observed to grow optimally at 35 °C, at pH 7.0 and in the presence of 0 % NaCl on Luria–Bertani agar medium. The cells were found to be positive for catalase and oxidase activities. The major fatty acids (>10 %) were identified as iso-C15 : 0, summed feature 3 (C16 : 1  ω6c and/or C16 : 1  ω7c) and iso-C17 : 0 3-OH. The predominant menaquinone was MK-7. The major polar lipids consisted of phosphatidylethanolamine, one sphingophospholipid, two unknown aminophospholipids, three unknown glycolipids and five unknown lipids. The genomic DNA G+C content was 40.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain C459-1T was affiliated with the genus Sphingobacterium and had the highest sequence similarity to Sphingobacterium tabacisoli h337T (97.0 %) and Sphingobacterium paucimobilis HER1398T (95.6 %). The average nucleotide identity and digital DNA–DNA hybridization values between strain C459-1T and S. tabacisoli h337T were 83.8 and 33.8 %, respectively. Phenotypic characteristics including enzyme activities and carbon source utilization differentiated strain C459-1T from other Sphingobacterium species. Based on its phenotypic, chemotaxonomic and phylogenetic properties, strain C459-1T represents a novel species of the genus Sphingobacterium , for which the name Sphingobacterium faecale sp. nov. is proposed, with strain is C459-1T (CGMCC 1.18716T=KCTC 82381T) as the type strain.

Sphingobacterium micropteri sp. nov. and Sphingobacterium litopenaei sp. nov., isolated from aquaculture water

Two novel bacterial strains, designated as DN00404^T and DN04309^T, were isolated from aquaculture water and characterized by using a polyphasic taxonomic approach. Cells of strains DN00404^T and DN04309^T were Gram-stain-negative, aerobic, non-motile, oxidase-positive and catalase-positive. Cells of DN00404^T were short rod-shaped and those of DN04309^T were long rod-shaped. Strain DN00404^T was found to grow at 15-37 °C (optimum, 25-30 °C), at pH 6.0-11.0 (optimum, pH 7.5) and in 0-2.0 % (w/v) NaCl (optimum, 1.0 %). Strain DN04309^T was found to grow at 15-45 °C (optimum, 20-37 °C), at pH 5.5-11.0 (optimum, 7.5) and in 0-4.0 % (w/v) NaCl (optimum, 0.5 %). Phylogenetic analyses based on 16S rRNA gene and genome sequences revealed that the two strains belonged to the genus Sphingobacterium and were distinct from all known species of this genus. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between the two strains and between each of the two strains and related type strains of this genus were well below the recognized thresholds of 95.0-96.0 % ANI and 70.0 % dDDH for species delineation. The genomic DNA G+C contents of strains DN00404^T and DN04309^T were 41.6 and 36.0 mol%, respectively. The respiratory quinone in both strains was identified as MK-7, and their major fatty acids were iso-C_15 : 0 and summed feature 3 (C_16 : 1  ω6c and/or C_16 : 1  ω7c), which were similar to those of other species of this genus. The two major fatty acids C_16 : 0 and iso-C_17 : 0 3-OH were also found in strain DN00404^T. Based on genotypic and phenotypic characteristics, two novel species of the genus Sphingobacterium are proposed: Sphingobacterium micropteri sp. nov. with DN00404^T (=GDMCC 1.1865^T=KACC 21924^T) as the type strain and Sphingobacterium litopenaei sp. nov. with DN04309^T (=GDMCC 1.1984^T=KCTC 82348^T) as the type strain.

Effect of the Manufacturing Process on the Microbiota, Organoleptic Properties and Volatilome of Three Salmon-Based Products

Lightly preserved seafood products, such as cold-smoked fish and fish gravlax, are traditionally consumed in Europe and are of considerable economic importance. This work aimed to compare three products that were obtained from the same batch of fish: cold-smoked salmon (CSS) stored under vacuum packaging (VP) or a modified atmosphere packaging (MAP) and VP salmon dill gravlax (SG). Classical microbiological analyses and 16S rRNA metabarcoding, biochemical analyses (trimethylamine, total volatile basic nitrogen (TVBN), biogenic amines, pH, volatile organic compounds (VOCs)) and sensory analyses (quantitative descriptive analysis) were performed on each product throughout their storage at a chilled temperature. The three products shared the same initial microbiota, which were mainly dominated by Photobacterium, Lactococcus and Lactobacillus genera. On day 28, the VP CSS ecosystem was mainly composed of Photobacterium and, to a lesser extent, Lactococcus and Lactobacillus genera, while Lactobacillus was dominant in the MAP CSS. The diversity was higher in the SG, which was mainly dominated by Enterobacteriaceae, Photobacterium, Lactobacillus and Lactococcus. Although the sensory spoilage was generally weak, gravlax was the most perishable product (slight increase in amine and acidic off-odors and flavors, fatty appearance, slight discoloration and drop in firmness), followed by the VP CSS, while the MAP CSS did not spoil. Spoilage was associated with an increase in the TVBN, biogenic amines and spoilage associated VOCs, such as decanal, nonanal, hexadecanal, benzaldehyde, benzeneacetaldehyde, ethanol, 3-methyl-1-butanol, 2,3-butanediol, 1-octen-3-ol, 2-butanone and 1-octen-3-one. This study showed that the processing and packaging conditions both had an effect on the microbial composition and the quality of the final product.

Considerations on the Identity and Diversity of Organisms Affiliated with Sphingobacterium multivorum-Proposal for a New Species, Sphingobacterium paramultivorum

Plant biomass offers great potential as a sustainable resource, and microbial consortia are primordial in its bioconversion. The wheat-straw-biodegradative bacterial strain w15 has drawn much attention as a result of its biodegradative potential and superior degradation performance in bacterial-fungal consortia. Strain w15 was originally assigned to the species Sphingobacterium multivorum based on its 16S ribosomal RNA (rRNA) gene sequence. A closer examination of this taxonomic placement revealed that the sequence used has 98.9% identity with the ‘divergent’ 16S rRNA gene sequence of S. multivorum NCTC 11343^T, yet lower relatedness with the canonical 16S rRNA sequence. A specific region of the gene, located between positions 186 and 210, was found to be highly variable and determinative for the divergence. To solve the identity of strain w15, genome metrics and analyses of ecophysiological niches were undertaken on a selection of strains assigned to S. multivorum and related species. These analyses separated all strains into three clusters, with strain w15, together with strain BIGb0170, constituting a separate radiation, next to S. multivorum and S. siyangense. Moreover, the strains denoted FDAARGOS 1141 and 1142 were placed inside S. siyangense. We propose the renaming of strains w15 and BIGb0170 as members of the novel species, coined Sphingobacterium paramultivorum.

Sphingobacterium lumbrici sp. nov., a novel bacterium isolated from wormcast of Eisenia foetida

A novel Gram-stain-negative, rod-shaped, non-motile, yellowish bacterium, designated strain 1.3611^T, was isolated from the wormcast of Eisenia foetida. The strain grew optimally at 30-37 ℃, at pH 7.0 and with 0-1.0 % (w/v) NaCl. Based on the results of 16S rRNA gene sequence and phylogenetic analyses, strain 1.3611^T showed the highest degree of 16S rRNA gene sequence similarity to Sphingobacterium olei HAL-9^T (97.0 %), followed by Sphingobacterium alkalisoli Y3L14^T (95.8 %). The respiratory quinone of strain 1.3611^T was menaquinone-7 (MK-7) and its major cellular fatty acids were iso-C_15 : 0 (41.3 %), summed feature 3 (C_16 : 1  ω7c and/or C_16 : 1  ω6c, 22.1 %) and iso-C_17 : 0 3-OH (16.2 %). The major polar lipids were sphingophospholipid, phosphatidylethanolamine, four unidentified glycolipids, two unidentified phospholipids and five unidentified polar lipids. The genomic DNA G+C content was 39.0 mol%. The digital DNA-DNA hybridization and average nucleotide identity values between the genomes of strain 1.3611^T and S. olei HAL-9^T were 37.9 and 88.9 %, respectively. According to the phenotypic and chemotaxonomic phylogenetic results, strain 1.3611^T should represent a novel species of the genus Sphingobacterium, for which the name Sphingobacterium lumbrici sp. nov. is proposed, with strain 1.3611^T (=KCTC 62980^T=CCTCC AB 2018349^T) as the type strain.

Sphingobacterium phlebotomi sp. nov., a new member of family Sphingobacteriaceae isolated from sand fly rearing substrate

A Gram-stain-negative, rod-shaped, non-motile, non-spore-forming, aerobic bacterium, designated type strain SSI9T, was isolated from sand fly (Phlebotomus papatasi Scopoli; Diptera: Psychodidae) rearing substrate and subjected to polyphasic taxonomic analysis. Strain SSI9T contained phosphatidylethanolamine as a major polar lipid, MK-7 as the predominant quinone, and C16 : 1ω6c/C16 : 1ω7c, iso-C15 : 0, iso-C17 : 0 3-OH and C16 : 0 as the major cellular fatty acids. Phylogenetic analysis based on 16S rRNA gene sequences revealed that SSI9T represents a member of the genus Sphingobacterium, of the family Sphingobacteriaceae sharing 96.5-88.0 % sequence similarity with other species of the genus Sphingobacterium. The results of multilocus sequence analysis using the concatenated sequences of the housekeeping genes recA, rplC and groL indicated that SSI9T formed a separate branch in the genus Sphingobacterium. The genome of SSI9T is 5 197 142 bp with a DNA G+C content of 41.8 mol% and encodes 4395 predicted coding sequences, 49 tRNAs, and three complete rRNAs and two partial rRNAs. SSI9T could be distinguished from other species of the genus Sphingobacterium with validly published names by several phenotypic, chemotaxonomic and genomic characteristics. On the basis of the results of this polyphasic taxonomic analysis, the bacterial isolate represents a novel species within the genus Sphingobacterium, for which the name Sphingobacterium phlebotomi sp. nov. is proposed. The type strain is SSI9T (=ATCC TSD-210T=LMG 31664T=NRRL B-65603T).

Co-enhanced activated sludge system by static magnetic field and two halotolerant yeasts for azo dye treatment

The effect of static magnetic field (SMF) on azo dye Acid Red B (ARB) decolorization by the co-culture of activated sludge (AS) and two halotolerant yeasts Candida tropicalis A1 and Pichia occidentalis A2 was investigated. Microbial community structure of the co-cultures before and after treatment with SMFs of different intensity was analyzed through high-throughput sequencing and quantitative real-time polymerase chain reaction. The results showed that ARB decolorization efficiency by the defined co-culture was 1.25-fold to 1.51-fold elevated by 24.6-305.0 mT SMF. The best ARB decolorization and chemical oxygen demand (COD) removal performances by the co-culture were both achieved with 95.0 mT SMF. By contrast, biomass multiplication and sedimentation property of AS systems were not significantly influenced by SMF. Higher activities of intracellular key enzymes were determined (with 95.0 mT SMF) as responsible for better decolorization and COD removal performances. Bacteria belonging to Prolixibacter, Corynebacterium, Pelagibacterium, Demequina, and Sphingobacterium which might be responsible for azo dye decolorization and aromatic compounds biodegradation were significantly enriched only in presence of SMF. Fungal genera Candida and Pichia were also significantly enriched by 41.4-305.0 mT SMF, which might be responsible for higher treatment efficiency. PRACTITIONER POINTS: Dye degradation was enhanced by combination of static magnetic field and yeasts. Improvement of enzyme activity was responsible for better treatment performance. Putative azo-degrading-related bacteria and fungi were selectively enriched. High relative abundance of Candida and Pichia ensured high decolorization effects. Potentially effective improvement of bioprocesses for treating hypersaline wastewater.

Sphingobacterium puteale sp. nov., isolated from a deep subsurface aquifer

A bacterial strain M05W1-28^T was isolated from a well that collected water for irrigation from a deep aquifer at a depth of 400 m. Cells were observed to be rod-shaped, non-motile, aerobic, stained Gram-negative. Optimal growth was obtained at pH 7.0 (range: 6.0-9.0), 28 °C (range: 15-37 °C) and 0 % NaCl (range: 0-1.5 %, w/v) in modified tryptic soy broth (mTSB) without added NaCl and R2A. The cells were found to be positive for catalase and oxidase activities. The major fatty acids (>10 %) were identified as summed feature 3 (C_16 : 1  ω7c / C_16 : 1  ω6c) and iso-C_15 : 0. The major polar lipids were phosphatidylethanolamine, glycolipid, phosphoglycolipids, phospholipids, and unidentified lipids. The major respiratory quinone was menaquinone-7 (MK-7). The genomic G+C content of strain M05W1-28^T was 40.7 %. Based on similarities of 16S rRNA gene sequences, strain M05W1-28^T was affiliated with the genus Sphingobacterium, exhibiting the highest sequence similarities with S. multivorum LMG 8342^T (97.5 %), S. ginsenosidimutans THG07^T (97.1 %) and less than 97.0 % to other members of the genus. The average nucleotide identity (ANI) and digital DNA-DNA hybridisation values (dDDH) between M05W1-28^T and S. multivorum LMG 8342^T were 78.1 and 22.5 %, respectively. Phenotypic characteristics including enzyme activities and carbon source utilisation differentiated the strain from other Sphingobacterium species. The phenotypic, chemotaxonomic and phylogenetic properties suggested that strain M05W1-28^T represented a novel species within the genus Sphingobacterium, for which the name Sphingobacterium puteale sp. nov. is proposed. The type strain is M05W1-28^T (=CGMCC 1.13711^T=KCTC 72027^T).