Bacillus eiseniae sp. nov., a swarming, moderately halotolerant bacterium isolated from the intestinal tract of an earthworm (Eisenia fetida L.)

Cytobacillus citreus sp. nov., isolated from citrus rhizosphere soil

A Gram-stain-positive, rod-shaped and motile strain, designated FJAT-49705^T, was isolated from the citrus rhizosphere soil sample. Strain FJAT-49705^T grew at 20-40 °C (optimum, 30 °C) and pH 6.0-11.0 (optimum, pH 7.0) with 0-5 % (w/v) NaCl (optimum, 2 %). Strain FJAT-49705^T showed high 16S rRNA gene sequence similarity to 'Bacillus dafuensis' FJAT-25496^T (99.7 %) and Cytobacillus solani FJAT-18043^T (98.0 %). In phylogenetic (based on 16S rRNA gene sequences) and phylogenomic trees (based on 71 bacterial single-copy genes), strain FJAT-49705^T clustered with the members of the genus Cytobacillus. MK-7 was the only isoprenoid quinone present. The main polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and an unidentified phospholipid. The major fatty acids were anteiso-C_15 : 0 and iso-C_15 : 0. The genomic DNA G+C content was 36.9 %. The average nucleotide identity (ANI) values between FJAT-49705^T and 'B. dafuensis' FJAT-25496^T and C. solani FJAT-18043^T were below the cut-off level (95-96 %) recommended as the ANI criterion for interspecies identity. Based on the above results, strain FJAT-49705^T represents a novel species of the genus Cytobacillus, for which the name Cytobacillus citreus sp. nov. is proposed. The type strain is FJAT-49705^T (=CCTCC AB 2019243^T= LMG 31580^T).

Categorisation of culturable bioaerosols in a fruit juice manufacturing facility

Bioaerosols are defined as aerosols that comprise particles of biological origin or activity that may affect living organisms through infectivity, allergenicity, toxicity, or through pharmacological or other processes. Interest in bioaerosol exposure has increased over the last few decades. Exposure to bioaerosols may cause three major problems in the food industry, namely: (i) contamination of food (spoilage); (ii) allergic reactions in individual consumers; or (iii) infection by means of pathogenic microorganisms present in the aerosol. The aim of this study was to characterise the culturable fraction of bioaerosols in the production environment of a fruit juice manufacturing facility and categorise isolates as harmful, innocuous or potentially beneficial to the industry, personnel and environment. Active sampling was used to collect representative samples of five areas in the facility during peak and off-peak seasons. Areas included the entrance, preparation and mixing area, between production lines, bottle dispersion and filling stations. Microbes were isolated and identified using 16S, 26S or ITS amplicon sequencing. High microbial counts and species diversity were detected in the facility. 239 bacteria, 41 yeasts and 43 moulds were isolated from the air in the production environment. Isolates were categorised into three main groups, namely 27 innocuous, 26 useful and 39 harmful bioaerosols. Harmful bioaerosols belonging to the genera Staphylococcus, Pseudomonas, Penicillium and Candida were present. Although innocuous and useful bioaerosols do not negatively influence human health their presence act as an indicator that an ideal environment exists for possible harmful bioaerosols to emerge.

A phylogenomic and comparative genomic framework for resolving the polyphyly of the genus Bacillus: Proposal for six new genera of Bacillus species, Peribacillus gen. nov., Cytobacillus gen. nov., Mesobacillus gen. nov., Neobacillus gen. nov., Metabacillus gen. nov. and Alkalihalobacillus gen. nov

The genus Bacillus, harbouring 293 species/subspecies, constitutes a phylogenetically incoherent group. In the absence of reliable means for grouping known Bacillus species into distinct clades, restricting the placement of new species into this genus has proven difficult. To clarify the evolutionary relationships among Bacillus species, 352 available genome sequences from the family Bacillaceae were used to perform comprehensive phylogenomic and comparative genomic analyses. Four phylogenetic trees were reconstructed based on multiple datasets of proteins including 1172 core Bacillaceae proteins, 87 proteins conserved within the phylum Firmicutes, GyrA-GyrB-RpoB-RpoC proteins, and UvrD-PolA proteins. All trees exhibited nearly identical branching of Bacillus species and consistently displayed six novel monophyletic clades encompassing 5-23 Bacillus species (denoted as the Simplex, Firmus, Jeotgali, Niacini, Fastidiosus and Alcalophilus clades), interspersed with other Bacillaceae species. Species from these clades also generally grouped together in 16S rRNA gene trees. In parallel, our comparative genomic analyses of Bacillus species led to the identification of 36 molecular markers comprising conserved signature indels in protein sequences that are specifically shared by the species from these six observed clades, thus reliably demarcating these clades based on multiple molecular synapomorphies. Based on the strong evidence from multiple lines of investigations supporting the existence of these six distinct 'Bacillus' clades, we propose the transfer of species from these clades into six novel Bacillaceae genera viz. Peribacillus gen. nov., Cytobacillus gen. nov., Mesobacillus gen. nov., Neobacillus gen. nov., Metabacillus gen. nov. and Alkalihalobacillus gen. nov. These results represent an important step towards clarifying the phylogeny/taxonomy of the genus Bacillus.

Bacillus ciccensis sp. nov., isolated from maize (Zea mays L.) seeds

Two Gram-stain-positive bacterial strains, designated as 5L6^T and 6L6, isolated from seeds of hybrid maize (Zea mays L., Jingke 968) were investigated using a polyphasic taxonomic approach. The cells were aerobic, motile, endospore-forming and rod-shaped. Phylogenetic analysis based on 16S rRNA gene sequences showed that the isolates were recognized as a species of the genus Bacillus, to which the five closest neighbours are Bacillus solani FJAT-18043^T (99.8 % similarity), Bacillus horneckiae DSM 23495^T (97.7 %), Bacillus eiseniae A1-2^T (97.4 %), Bacillus kochii WCC 4582^T (97.1 %) and Bacillus purgationiresistens DS22^T (97.0 %). The DNA G+C content of strain 5L6^T was 37.4 mol%. Its polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The predominant respiratory quinone was MK-7 and the major fatty acids were iso-C15 : 0, anteiso-C15 : 0, iso-C16 : 0, iso-C14 : 0, anteiso-C17 : 0 and C16 : 1 ω7c alcohol. The cell-wall peptidoglycan contained ornithine, serine, aspartic acid, glutamic acid and alanine while diaminopimelic acid could not be detected. Strains 5L6^T and 6L6 were clearly distinguished from the type strains of related validly named species using phylogenetic analysis, DNA-DNA hybridization, fatty acid analysis, peptidoglycan analysis and comparison of a range of physiological and biochemical characteristics. The genotypic and phenotypic data show that strains 5L6^T and 6L6 represent a novel species of the genus Bacillus, for which the name Bacillusciccensis sp. nov. is proposed. The type strain is 5L6^T (=KCTC 33663^T=CICC 23855^T=DSM 104513^T).

Discovery of a new species within Bacillus genus in a stool sample from Gabon: "Bacillus massiliogabonensis" sp. nov

The discovery of new bacteria from the human gut using a culturomics method is a novel field of increasing interest in microbiology. Here the main characteristics of "Bacillus massiliogabonensis" strain Marseille P2639, a new Gram-negative bacterium isolated from the stool sample of a healthy 16-year-old Gabonese boy, are reported.

Bacillus solani sp. nov., isolated from rhizosphere soil of a potato field

A novel Gram-stain-positive, endospore-forming bacterium, designated strain FJAT-18043T, was isolated from a soil sample of a potato field in Xinjiang Autonomous Region, China. Cells were rods that were catalase-positive and motile by peritrichous flagella. The strain grew at 20–45 °C (optimum 35 °C), at pH 6.0–10.0 (optimum pH 9) and with 0–10 % (w/v) NaCl (optimum 0 %). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain FJAT-18043T belonged to the genus Bacillus and exhibited similarities of 97.7, 97.6, 97.2 and 97.2 % with Bacillus eiseniae A1-2T, Bacillus horneckiae DSM 23495T, Bacillus gottheilii WCC 4585T and Bacillus purgationiresistens DS22T, respectively. DNA–DNA relatedness between strain FJAT-18043T and B. eiseniae A1-2 T was lower than 70 % (36.1 %). The menaquinone was identified as MK-7 and the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The major fatty acids detected were anteiso-C15 : 0, iso-C15 : 0, iso-C16 : 0, anteiso-C17 : 0, C16 : 0 and iso-C14 : 0. The DNA G+C content was 48.8 mol%. Phenotypic, chemotaxonomic and genotypic properties clearly indicated that isolate FJAT-18043T represents a novel species within the genus Bacillus, for which the name Bacillus solani sp. nov. is proposed. The type strain is FJAT-18043T ( = DSM 29501T = CCTCC AB 2014277T).

Bacillus formosensis sp. nov., isolated from pesticide wastewater

A Gram-stain-positive, endospore-forming rod (designated strain CC-LY275T) was isolated from a pesticide wastewater sample. The isolate grew at a temperature 20-45 °C, at pH 7.0-8.0 and tolerated NaCl 6 % (w/v). The most closely related strains in terms of 16S rRNA gene sequence similarity were Bacillus horneckiae (97.1 %) and Bacillus oceanisediminis (96.8 %), respectively. The G+C content of the genomic DNA was 37.9 mol%. Strain CC-LY275T was determined to possess iso-C14 : 0, iso-C15 : 0 and anteiso-C15 : 0 as predominant fatty acids. The major polar lipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. Cell-wall peptidoglycan contained meso-diaminopimelic acid; menaquinone (MK-7) was the predominant respiratory quinone. According to the distinct phylogenetic, phenotypic and chemotaxonomic properties, the name Bacillus formosensis sp. nov. (type strain CC-LY275T = BCRC 80443T = JCM 18448T) is proposed.

Bacillus fengqiuensis sp. nov., isolated from a typical sandy loam soil under long-term fertilization

A Gram-staining-positive, endospore-forming, moderately alkaliphilic bacterium, strain NPK15(T), was isolated from a typical sandy loam soil under long-term NPK fertilization in northern China and was subjected to a polyphasic taxonomic study. The diamino acid of the cell-wall peptidoglycan of strain NPK15(T) was found to be meso-diaminopimelic acid and the cell-wall sugars were xylose, glucose and traces of mannose. The only respiratory quinone found in strain NPK15(T) was menaquinone 7 (MK-7). The major cellular fatty acids were iso-C(15 : 0), anteiso-C(15 : 0), C(16 : 0) and C(16 : 1)ω6c/C(16 : 1)ω7c. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. Phylogenetic analysis of the strain based on its 16S rRNA gene sequence showed that it was related most closely to 'Bacillus thaonhiensis' KACC 17216 (99.59%), B. songklensis KCTC 13881(T) (99.52%) and B. abyssalis CCTCC AB 2012074(T) (99.00%). DNA-DNA hybridization results indicated that the strain was distinct from other species of the genus Bacillus, the degree of relatedness being 35.4% with B. abyssalis CCTCC AB 2012074(T), 39.7% with B. songklensis KCTC 13881(T) and 51.2% with 'B. thaonhiensis' KACC 17216. The DNA G+C content of strain NPK15(T) was 45.5 mol%. Phenotypic, chemotaxonomic and molecular analyses identified strain NPK15(T) as a member of a novel species of the genus Bacillus, for which the name Bacillus fengqiuensis sp. nov. is proposed. The type strain is NPK15(T) ( = DSM 26745(T) = CCTCC AB 2013156(T)).

Bacillus panacisoli sp. nov., isolated from ginseng soil

A Gram-staining-positive, motile, facultatively anaerobic, endospore-forming and rod-shaped bacterium, designated strain CJ32(T), was isolated from ginseng soil at Geumsan in Korea. The isolate grew optimally at 30 °C, 2% (w/v) NaCl and pH 7.0. Colonies of strain CJ32(T) were beige and circular with an entire margin on LB agar plates. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain CJ32(T) was associated with the genus Bacillus and was most closely related to Bacillus graminis YC6957(T) (97.3% similarity) and Bacillus lentus IAM 12466(T) (97.1%). DNA-DNA hybridization with closely related strains was below 31.3%. The major respiratory isoprenoid quinone was MK-7. The diagnostic diamino acid in the cell-wall peptidoglycan was meso-diaminopimelic acid. The polar lipid profile of strain CJ32(T) consisted of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and several unidentified lipids, including phospholipids, aminolipids and aminophospholipids. The predominant fatty acids of strain CJ32(T) were iso-C15:0 and anteiso-C15:0. The G+C content of the genomic DNA was 35.1 mol%. Based on phenotypic, genotypic and phylogenetic data, strain CJ32(T) should be classified within a novel species of the genus Bacillus, for which the name Bacillus panacisoli sp. nov. is proposed. The type strain is strain CJ32(T) ( = KACC 17503(T) = JCM 19226(T)).