Proposal of Vibrionimonas magnilacihabitans gen. nov., sp. nov., a curved Gram-stain-negative bacterium isolated from lake water

Colored stains: Microbial survey of cellulose-based and lignin rich papers

During the centuries diverse types of paper were produced and were characterized by a different ratio of natural macromolecules, mainly lignin and cellulose. Handmade paper has a higher content of cellulose respect to the early machine-made paper, where the lignin is the other important component. Microorganisms are able to colonize and deteriorate both types of papers. They can release on their surfaces pigments and colorants which produced anesthetic stains. The microbiota colonising 17 stains on handmade and machine-made paper surfaces together with that in library and archive environments was analyzed. Combination of microbiological and high-throughput sequencing (HTS) approaches were applied. The culture-dependent methodology comprised: isolation, DNA identification, hydrolytic and paper staining assays. The HTS was performed by MinION platform and for the mycobiome a more suitable bioinformatics analysis pipeline, MetONTIIME based on QIIME2 framework, was applied. The paper model staining assay permitted the direct recognition of colorizing isolates which in combination with sequencing data evidenced a complex microbial community able to stain the two types of paper. Staining abilities were confirmed by frequently isolated and detected fungi and also by new ones such as Roussoella euonymi and Achaetomium. We have also evidenced the staining ability of several bacteria.

Effects of Different Storage Temperatures on Bacterial Communities and Functional Potential in Pork Meat

Storage temperature is considered one of the most important factors that affect the microbial spoilage of fresh meat. Chilling and superchilling are the most popular storage techniques on the market, but during transportation, the temperature may reach 10 °C and may even reach room temperature during local retail storage. In the present study, we stored fresh pork meat at different temperatures, −2 °C, 4 °C, 10 °C, and 25 °C. The composition and functional potential of fresh or spoiled meat resident microbes were analyzed based on 16S rRNA gene amplicon sequencing. The microbial composition exhibited high similarity between pork meat stored at −2 °C and 4 °C, with Pseudomonads and Brochothrix being the dominant taxa. Acinetobacter sp., Myroides sp., and Kurthia sp. were markers for spoiled pork meat stored at 25 °C. Both psychrophilic and mesophilic bacteria were observed to grow under a storage temperature of 10 °C, but the overall composition and functional potential based on Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were found to be similar to that of meat stored at room temperature. Our results broaden the knowledge of possible microbial changes in pork meat during storage, transportation, or retail.

Sediminibacterium soli sp. nov., isolated from soil

A Gram-stain-negative, facultative anaerobic strain, designated WSJ-3^T, was isolated from soil. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain WSJ-3^T belongs to genus Sediminibacterium and exhibits the highest sequence similarities to Sediminibacterium roseum SYL130^T (97.0%), Sediminibacterium goheungense DSM 28323^T (96.9%), Sediminibacterium aquarii AA5^T (96.7%), and Sediminibacterium salmoneum NBRC 103935^T (95.2%). The average nucleotide identity values of strain WSJ-3^T/S. roseum SYL130^T and strain WSJ-3^T/S. goheungense DSM 28323^T are 72.2% and 70.4%, respectively, and digital DNA-DNA hybridization values for these are 19.2% and 19.1%, respectively. Strain WSJ-3^T has a genome size of 3.88 Mb, with a DNA G + C content of 50.1 mol% and comprises of 3263 predicted genes. A phylogenetic tree constructed using the genomic core protein coding sequences revealed that strain WSJ-3^T clusters with S. roseum SYL130^T. Strain WSJ-3^T has menaquinone-7 as the only respiratory quinone and phosphatidylethanolamine, three unidentified phospholipids, four unidentified aminophospholipids, two unidentified aminolipids, and three unidentified lipids as the polar lipids. The major fatty acids of strain WSJ-3^T are iso-C_15:0, iso-C_17:0 3-OH, and iso-C_15:1 G. On the basis of the polyphasic results, the isolate represents a novel species of the genus Sediminibacterium, for which the name Sediminibacterium soli sp. nov. is proposed. The type strain is WSJ-3^T (= KCTC 72839^T = CCTCC AB 2019408^T).

Analysis of 1,000 Type-Strain Genomes Improves Taxonomic Classification of Bacteroidetes

Although considerable progress has been made in recent years regarding the classification of bacteria assigned to the phylum Bacteroidetes, there remains a need to further clarify taxonomic relationships within a diverse assemblage that includes organisms of clinical, piscicultural, and ecological importance. Bacteroidetes classification has proved to be difficult, not least when taxonomic decisions rested heavily on interpretation of poorly resolved 16S rRNA gene trees and a limited number of phenotypic features. Here, draft genome sequences of a greatly enlarged collection of genomes of more than 1,000 Bacteroidetes and outgroup type strains were used to infer phylogenetic trees from genome-scale data using the principles drawn from phylogenetic systematics. The majority of taxa were found to be monophyletic but several orders, families and genera, including taxa proposed long ago such as Bacteroides, Cytophaga, and Flavobacterium but also quite recent taxa, as well as a few species were shown to be in need of revision. According proposals are made for the recognition of new orders, families and genera, as well as the transfer of a variety of species to other genera. In addition, emended descriptions are given for many species mainly involving information on DNA G+C content and (approximate) genome size, both of which can be considered valuable taxonomic markers. We detected many incongruities when comparing the results of the present study with existing classifications, which appear to be caused by insufficiently resolved 16S rRNA gene trees or incomplete taxon sampling. The few significant incongruities found between 16S rRNA gene and whole genome trees underline the pitfalls inherent in phylogenies based upon single gene sequences and the impediment in using ordinary bootstrapping in phylogenomic studies, particularly when combined with too narrow gene selections. While a significant degree of phylogenetic conservation was detected in all phenotypic characters investigated, the overall fit to the tree varied considerably, which is one of the probable causes of misclassifications in the past, much like the use of plesiomorphic character states as diagnostic features.

Characterization of Bacterial Microbiota in Tilapia Fillets Under Different Storage Temperatures

This paper investigates the bacterial microbiota in tilapia fillets under cold (4 °C), iced (0 °C), and superchilled (-3 °C) storage conditions. At 4 °C, at least seven species/strains of Pseudomonas were detected in the fillets, five of which were dominant either at a certain stage or throughout the entire storage period. Shewanella was less dominant than Pseudomonas at 4 °C, while Serratia became dominant after 6 days storage at 4 °C. The microbiota in fillets stored at 0 and -3 °C were very similar and rarely changed during storage, yet differed greatly from the microbiota at 4 °C. Only two Pseudomonas species/strains grew at 0 and -3 °C, one of which was the most dominant. A Vibrionimonas sp. not found at 4 °C was found to be the second most dominant species at 0 and -3 °C. Shewanella and Psychrobacter were also present at 0 and -3 °C but were the minor genera. The most dominant strains at -3, 0, and 4 °C were separately isolated and subjected to full length 16S rDNA sequencing, which demonstrated that they were identical and were Pseudomonas fluorescens. The changes of the total bacterial count and TVBN value of the fillets inoculated with the isolated P. fluorescens were very similar to those of fillets with natural microbiota. This implies that P. fluorescens is the most important spoiler of tilapia fillets at -3, 0, or 4 °C. PRACTICAL APPLICATION: This research shows that fewer species of bacteria survive at 0 and -3 °C than those at 4 °C, while among these bacteria, the most important spoiler is P. fluorescens. This may provide some clues to extend the shelf life of tilapia fillets by taking some inhibitory measures targeted at P. fluorescens in the future.

Complete Genome Sequence for Asinibacterium sp. Strain OR53 and Draft Genome Sequence for Asinibacterium sp. Strain OR43, Two Bacteria Tolerant to Uranium

Asinibacterium sp. strains OR43 and OR53 belong to the phylum Bacteroidetes and were isolated from subsurface sediments in Oak Ridge, TN. Both strains grow at elevated levels of heavy metals. Here, we present the closed genome sequence of Asinibacterium sp. strain OR53 and the draft genome sequence of Asinibacterium sp. strain OR43.

Bosea psychrotolerans sp. nov., a psychrotrophic alphaproteobacterium isolated from Lake Michigan water

Three strains of a Gram-stain negative bacterium were isolated from Lake Michigan water. 16S rRNA gene sequence analysis revealed that strain 1131 had sequence similarities to Bosea vaviloviae LMG 28367^T, Bosea lathyri LMG 26379^T, Bosea lupini LMG 26383^T, Bosea eneae CCUG 43111^T, Bosea vestrisii CCUG 43114^T and Boseamassiliensis CCUG 43117^T of 99.8, 99.1, 98.4, 98.4, 98.4 and 98.2 %, respectively. The average nucleotide identity value between strain 1131^T and Bosea vaviloviae Vaf-18^T was 93.4 % and the DNA relatedness was 38 %. The primary cellular fatty acids of strain 1131^T were C16 : 1ω7c and C18 : 1ω7c. The primary polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and phosphatidylcholine. The major compound in the quinone system was ubiquinone Q-10 and in the polyamine pattern sym-homospermidine was predominant. Additional phenotypic characteristics included growth at 5-35 °C, pH values of pH 5.5-8.0, a salt tolerance range of 0.0-1.2 % (w/v), and production of an unknown water soluble brown pigment. After phenotypic, chemotaxonomic and genomic analyses, this isolate was identified as a novel species for which the name Bosea psychrotolerans is proposed. The type strain is 1131^T (NRRL B-65405=LMG 30034).

Edaphocola aurantiacus gen. nov., sp. nov., a new member of the family Chitinophagaceae isolated from wetland soil in South Korea

A short rod-shaped, yellow-orange pigmented, strictly aerobic bacterium, designated as strain H2^T, was isolated from the wetland soil of Halla Mountain, Jeju-island, South Korea. Growth was observed at temperatures of 10-30 °C (optimum at 25-30 °C), pH of 6-8 (optimum at pH 7), and salt concentrations of 0-1% (w/v) NaCl (optimum at 0%). The strain H2^T was found to be a catalase and oxidase-positive, non-motile, Gram-negative bacterium. On the basis of 16S rRNA gene sequence similarity and phylogenetic analysis, strain H2^T was found to be related to the members of the Chitinophagaceae family, being closely related to Taibaiella chishuiensis AY17^T (94.3% sequence similarity). The major polar lipids are phosphatidylethanolamine and glycolipid. Strain H2^T contained MK-7 as the only menaquinone as well as iso-C_15:0, iso-C_15:1 G and iso-C_17:0 3-OH as the major fatty acids (> 15%). The DNA G+C content of strain H2^T was determined to be 48.3 mol%. Based on the phylogenetic, phenotypic characteristics and chemotaxonomic analysis data, strain H2^T (= KCTC 62115^T = JCM 32353^T) should be classified as representative of a novel species of a novel genus within the family Chitinophagaceae, for which the name Edaphocola aurantiacus gen. nov., sp. nov., is proposed.

Compostibacter hankyongensis gen. nov.,  sp. nov., isolated from compost

A novel bacterial strain, designated strain BS27T, was isolated from mushroom compost and subjected to a taxonomic study using a polyphasic approach. Colonies of BS27T were milky-white, circular with regular fringes and opaque. Cells were short rods, 0.3-0.5 µm wide and 1.2-2.0 µm long. Phylogenetic study based on the 16S rRNA gene sequence placed BS27T in a distinct lineage in the family Chitinophagaceae, sharing 90.1-90.9 % sequence similarity with members of the closely related genera Chitinophaga, Flavitalea, Flavihumibacter, Lacibacter and Flavisolibacter. The novel isolate showed the highest sequence similarities with the members of the genus Chitinophaga. BS27T contained MK-7 as predominant quinone, and iso-C15 : 0, iso-C17 : 0 3-OH, C16 : 1ω7c and/or C16 : 1ω6c (summed feature 3) and iso-C17 : 1I and/or anteiso-C17 : 1B (summed feature 4) as major fatty acids. The DNA G+C content was 53.0 mol%. The major polar lipids of BS27T were phosphatidylethanolamine (PE) and five unidentified polar lipids (L1, L2, L5, L6 and L7). The results of physiological and biochemical tests allowed phenotypic differentiation of BS27T from its closest phylogenetic neighbours. On the basis of the evidence of this polyphasic study, isolate BS27T represents a novel genus and species in the family Chitinophagaceae for which the name Compostibacter hankyongensisgen. nov., sp. nov. is proposed. The type strain is BS27T (=KACC 18745T=JCM 17664T).