Filling in the gaps in biowaste biorefineries: The use of the solid residue after enzymatic hydrolysis for the production of biopesticides through solid-state fermentation

Alternative production processes using waste are necessary to preserve non-renewable resources and prevent scarcity of materials for future generations. Biowaste, the organic fraction of municipal solid waste, is abundant and easily available. It can be fractionated into building blocks for which fermentative processes can be designed. By using solid-state fermentation, this paper proposes a method of valorizing biowaste's residual solid fraction after enzymatic hydrolysis. In a 22 L bioreactor, two digestates from anaerobic digestion processes were evaluated as cosubstrates to modify the acidic pH of the solid residue after enzymatic hydrolysis and promote the growth of the bacterial biopesticide producer Bacillus thuringiensis. Regardless of the cosubstrate used, the final microbial populations were similar indicating microbial specialization. The final product contained 4 × 10⁸ spores per gram of dry matter and also crystal proteins of Bacillus thuringiensis var israelensis, which have insecticidal activity against pests. This method allows for the sustainable use of all materials liberated during the enzymatic hydrolysis of biowaste, including residual solids.

Characterization of Sphingobacterium sp. Ab3 Lipase and Its Coexpression with LEA Peptides

Sphingobacterium sp. is a yellowish Gram-negative bacterium that is usually characterized by high concentrations of sphingophospholipids as lipid components. As microbial enzymes have been in high demand in industrial fields in the past few decades, this study hopes to provide significant information on lipase activities of Sphingobacterium sp., since limited studies have been conducted on the Sphingobacterium sp. lipase. A microbe from one collected Artic soil sample, ARC4, was identified as psychrotolerant Sphingobacterium sp., and it could grow in temperatures ranging from 0°C to 24°C. The expression of Sphingobacterium sp. lipase was successfully performed through an efficient approach of utilizing mutated group 3 late embryogenesis abundant (G3LEA) proteins developed from Polypedilum vanderplanki. Purified enzyme was characterized using a few parameters, such as temperature, pH, metal ion cofactors, organic solvents, and detergents. The expressed enzyme is reported to be cold adapted and has the capability to work efficiently under neutral pH (pH 5.0 to 7.0), cofactors like Na+ ion, and the water-like solvent methanol. Addition of nonionic detergents greatly enhanced the activity of purified enzyme. IMPORTANCE The mechanism of action of LEA proteins has remained unknown to many; in this study we reveal their presence and improved protein expression due to the molecular shielding effect reported by others. This paper should be regarded as a useful example of using such proteins to influence an existing expression system to produce difficult-to-express proteins.

Sphingobacterium rhinopitheci sp. Nov., isolated from the faeces of Rhinopithecus bieti in China

A novel bacterium, WQ 047^T, was isolated from the faeces of Rhinopithecus bieti, a highly endangered primate endemic to China. The cells were aerobic, oval/rod-shaped, Gram-stain-negative, non-motile, catalase positive, and produced yellow pigmented colonies on Columbia Agar. The taxonomic position of WQ 047^T was clarified by applying a polyphasic study based on 16S rRNA gene sequence phylogenetic analysis, extensive biological typing, and whole genome sequencing. Phylogenetic analysis indicated that stain WQ 047^T belonged to the genus Sphingobacterium and its 16S rRNA gene sequence exhibited 96.47% pairwise similarity with that of the closest relatives Sphingobacterium nematocida M-SX103^T. The calculated whole genome average nucleotide identity (ANI) value between strain WQ 047^T and strain M-SX103 was 72.3%. The digital DNA-DNA hybridization value of strain WQ 047^T and M-SX103^T was 15.73%, which was obtained by calculating the genome-to-genome distance. The major fatty acids were C_15:0 iso, C_17:0 iso 3-OH, Summed Feature 3 (C_16:1 ω7c/C_16:1 ω6c) and Summed feature 9 (iso-C_17:1ω9c and/or 10-methyl C_16:0). The predominant polar lipids were PE, PL and APL. MK-7 was the predominant menaquinone. The G + C content of WQ 047^T was 34.89 mol% according to genome analysis. All these characteristics were consistent with those of the genus of Sphingobacterium. Therefore, based on these results, we propose a novel species for which the name Sphingobacterium rhinopitheci sp. Nov. is proposed, with the type strain WQ 047^T (= CCTCC AA 2020026^T = KCTC82393^T).

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).

Investigation of the bacterial cell envelope nanomechanical properties after long-term exposure to nitrofurans

Antibiotic residues in the environment may negatively affect biological communities in the natural ecosystems. However, their influence on environmental bacterial strains has not been thoroughly investigated. In this study, two representatives of 5-nitrofuran antibiotics (nitrofurantoin and furaltadone) were investigated in terms of their long-term influence on the cell envelopes of newly isolated environmental bacterial strains (Sphingobacterium caeni FTD2, Achromobacter xylosoxidans NFZ2 and Pseudomonas hibiscicola FZD2). A 12-month exposure of bacterial cells to nitrofurans at a concentration of 20 mg L^-1 induced changes in the cell structure and texture (bacteria under stress conditions showed a loss of their original shape and seemed to be vastly inflated, the cells increased average surface roughness after exposure to NFT and FTD, respectively). AFM observations allowed the calculation of the bacterial cell nanomechanical properties. Significant increase in adhesion energy of bacteria after prolonged contact with nitrofurantoin was demonstrated. Changes in the permeability of bacterial membrane, fatty acids' composition and bacterial cell surface hydrophobicity were determined. Despite visible bacterial adaptation to nitrofurans, prolonged presence of pharmaceuticals in the environment has led to significant alterations in the cells' structures which was particularly visible in P. hibiscicola.

Sphingobacterium chungjuense sp. nov., isolated from a freshwater lake

A Gram-stain-negative, rod-shaped, aerobic, non-flagellated, chemoheterotrophic bacterium, designated strain IMCC25678^T, was isolated from an artificial freshwater reservoir, Chungju Lake, in the Republic of Korea. The 16S rRNA gene sequence analysis indicated that strain IMCC25678^T belongs to the genus Sphingobacterium with ≤98.7 % sequence similarities to Sphingobacterium species. Whole genome sequencing of strain IMCC25678^T revealed a 3.9 Mbp genome size with a DNA G+C content of 42.2 mol%. The IMCC25678^T genome shared ≤89.7 % average nucleotide identity and ≤21.4 % digital DNA-DNA hybridization values with closely related species of the genus Sphingobacterium, indicating that the strain represents a novel species. Summed feature 3 (C_16 : 1  ω6c and/or C_16 : 1  ω7c), iso-C_15 : 0 and iso-C_17 : 0 3-OH were found to be the predominant cellular fatty acid constituents in the strain. The major respiratory quinone was MK-7. The major polar lipids were phosphatidylethanolamine, one unidentified phosphoglycolipid, one unidentified sphingolipid and three unidentified polar lipids. Based on the phylogenetic and phenotypic characteristics, strain IMCC25678^T was considered to represent a novel species within the genus Sphingobacterium, for which the name Sphingobacterium chungjuense sp. nov. is proposed. The type strain is IMCC25678^T (=KACC 19485^T=NBRC 113130^T).

The applicability of gene sequencing and MALDI-TOF to identify less common gram-negative rods (Advenella, Castellaniella, Kaistia, Pusillimonas and Sphingobacterium) from environmental isolates

Our aim was to identify less common non-fermenting gram-negative rods during the bioremediation process. Five genera were found: Advenella, Castellaniella, Kaistia, Pusillimonas and Sphingobacterium, for a total of 15 isolates. Therefore, we evaluated the applicability of four methods currently available for bacteria identification: (1) conventional biochemical methods, (2) the VITEK^®-2 system, (3) MALDI-TOF mass spectrometry and (4) 16S rRNA gene sequencing. The biochemical methods and the VITEK^®-2 system were reliable only for the Sphingobacterium isolate and solely at the genus level. Both MALDI-TOF mass spectrometry platforms (Bruker and VITEK^® MS) did not achieve reliable identification results for any of these genera. 16S rRNA gene sequencing identified eight isolates to the species level but not to the subspecies level, when applicable. The remaining seven isolates were reliably identified through 16S rRNA gene sequencing to the genus level only. Our findings suggest that the detection and identification of less common genera (and species) that appeared at certain moments during the bioremediation process can be a challenge to microbiologists considering the most used techniques. In addition, more studies are required to confirm our results.

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).

Sphingobacterium haloxyli sp. nov., an endophytic bacterium isolated from Haloxylon ammodendron stems in Kumtag desert

A Gram-stain-negative, non-motile, aerobic, non-spore-forming, rod-shaped, bacterial strain, designated 5JN-11^T, was isolated from Haloxylonammodendron stems in Kumtag desert, Xinjiang province, China. Strain 5JN-11^T grew at salinities of 0-6 % (w/v; optimum 0-2 %), a pH of 7.0-9.0 (pH 7.0-8.0) and temperatures of 20-42 °C (28-30 °C). Based on 16S rRNA gene sequences, the strain was designated a member of the genus Sphingobacterium and the phylogenetic analysis showed that strain 5JN-11^T shared the highest similarity to Sphingobacterium gobiense H7^T, followed by Sphingobacterium chuzhouense DH-5^T and Sphingobacterium arenae H-12^T. The unfinished draft genome of strain 5JN-11^T was 4.69 Mb. The G+C content of strain 5JN-11^T was 42.8 mol%. The average nucleotide identity to S. gobiense H7^T was 90.5 %. The respiratory quinone was MK-7, and the major polar lipids were phosphatidylethanolamine and phosphoglycolipid. The predominant cellular fatty acids were summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), iso-C15 : 0 and iso-C17 : 0 3-OH. On the basis of phenotypic, genotypic and phylogenetic evidence, strain 5JN-11^T represents a novel species in the genus Sphingobacterium, for which the name Sphingobacteriumhaloxyli sp. nov. is proposed. The type strain is 5JN-11^T (=ACCC 60072^T=KCTC 62457^T).

Sphingobacteriumsoli sp. nov., isolated from soil

A Gram-stain-negative, strictly aerobic, rod-shaped, non-motile, non-spore-forming bacterial strain, designated YIM X0211T, was isolated from a soil sample of Shiling County, Yunnan Province, south-west China. The new isolate was characterized taxonomically by using a polyphasic approach. The strain grew optimally at 30 °C, at pH 7.0 and with 0-3 % (w/v) NaCl. It was positive for catalase and oxidase but negative for H2S production. Comparative 16S rRNA gene sequence analysis showed that strain YIM X0211T fell within the cluster comprising Sphingobacterium species and clustered with Sphingobacterium mizutaii DSM 11724T (97.93 % similarity). The G+C content of the genomic DNA was 41.2 mol%. The predominant respiratory quinone was menaquinone MK-7. The major fatty acids were iso-C15 : 0 2-OH, iso-C17 : 0 3-OH and summed feature 3 (C16 : 1ω7c/C16 : 1ω6c). The polar lipids consisted of phosphatidylethanolamine, sphingolipid, and several unknown phospholipids or lipids. The DNA-DNA hybridization value between strain YIM X0211T and S. mizutaii DSM 11724T was 42.3±0.4 %, which is below the 70 % limit for species delineation. These chemotaxonomic data supported the affiliation of strain YIM X0211T to the genus Sphingobacterium. Based on the recorded phenotypic and genotypic characteristics, it is determined that the isolate represents a novel species of the genus Sphingobacterium, for which the name Sphingobacterium soli sp. nov. is proposed. The type strain is YIM X0211T (=KCTC 42696T=CGMCC 1.15966T).

Sphingobacterium alkalisoli sp. nov., isolated from a saline-alkaline soil

A Gram-staining-negative, non-motile, non-spore-forming bacterium designated Y3L14T was isolated from the saline-alkaline soil of a farmland, Inner Mongolia, northern China. Strain Y3L14T could grow at 10-40 °C (optimally at 30 °C), pH 6.0-10.0 (optimally at pH 8.0), and in the presence of 0-6.0 % (w/v) NaCl (optimally with 0-2.0 %). Phylogenetic analysis based on the 16S rRNA gene and DNA gyrase subunit B (gyrB) gene sequences revealed that strain Y3L14T clustered with strains belonging to the genus Sphingobacterium, sharing the highest 16S rRNA gene sequence similarity with Sphingobacterium lactis WCC 4512T (94.99 %). Its major cellular fatty acids contained iso-C15 : 0, C16 : 0, iso-C17 : 0 3-OH and summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1ω7c). Menaquinone-7 (MK-7) was the only isoprenoid quinone. Strain Y3L14T contained phosphatidylethanolamine, sphingophospholipid, two unknown phospholipids and three unknown lipids as the major polar lipids. The genomic DNA G+C content of strain Y3L14T was 36.0 mol%. Based on the phenotypic, phylogenetic and genotypic characteristics, strain Y3L14T represents a novel species within the genus Sphingobacterium, for which Sphingobacterium alkalisoli sp. nov. is proposed; the type strain is Y3L14T (=CGMCC 1.15782T=KCTC 52379T).

Characterization of antibiotic resistance genes in representative organic solid wastes: Food waste-recycling wastewater, manure, and sewage sludge

In this research, the distribution of antibiotic resistance genes (ARGs) was characterized in representative organic solid waste (OSW) in Korea: food waste-recycling wastewater (FRW), manure, and sewage sludge. The amounts of total ARG (gene copies/16S rRNA gene copies) was greatest in manure followed by sewage sludge and FRW. Interestingly, there were significantly different patterns in the diversity and mechanisms of ARGs. For example, a significant proportion of ARGs were tetracycline resistant genes in all the OSW (40.4-78.2%). β-lactam antibiotics resistant genes were higher in the FRW samples than in other types of OSW but sulfonamides resistant genes represented the greatest proportion in sludge. Regarding the characteristics of antibiotic resistance mechanisms, there was a relatively higher proportion of the ribosomal protection mechanism to tetracycline observed in the FRW and manure samples. However, tetracycline resistant genes with direct interaction were relatively higher in the sewage sludge samples. sul1 was the dominant subtype in all the OSW types and detection of ermB was observed although there was no ermC detected in sewage sludge. There were significant correlations between the occurrences of ARG subtypes: tetB and tetG in all OSW (P<0.01); tetE and tetQ only in sludge (P<0.01). The Class 1 integron-integrase gene (intI1) was significantly correlated with total ARGs only in manure and sludge (P<0.05), revealing potential horizontal gene transfer in these OSW.

Sphingobacterium chuzhouense sp. nov., isolated from farmland soil

A novel Gram-staining-negative bacterium, designated DH-5T, was isolated from a farmland soil in Chuzhou, Anhui province, China. Cells of strain DH-5T were aerobic, non-motile, non-spore-forming and rod-shaped. The organism grew at 20-37 °C, pH 6.0-9.0 and with 0-5 % NaCl (w/v). The DNA G+C content was 42.8 mol%. The major fatty acids (>5 %) were iso-C15 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), iso-C17 : 0 3-OH and C16 : 0. The respiratory quinone was MK-7, and the major polar lipids were phosphatidylethanolamine and phosphoglycolipid. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain DH-5T was a member of the genus Sphingobacterium and shared the highest similarity with Sphingobacterium gobiense H7T (96.0 %), followed by Sphingobacterium arenae H-12T (94.5 %). Strain DH-5T exhibited low DNA-DNA relatedness with S. gobiense H7T (35.1±1.4 %) and S. arenae H-12T (21.4±1.0 %). On the basis of phenotypic, genotypic and phylogenetic evidence, DH-5T is considered to represent a novel species of the genus Sphingobacterium, for which the name Sphingobacterium chuzhouense sp. nov. is proposed. The type strain is DH-5T (=ACCC 19856T=KCTC 42746T).

Sphingobacterium jejuense sp. nov., with ginsenoside-converting activity, isolated from compost

A Gram-stain-negative, strictly aerobic, non-motile, light yellow, short-rod bacterium (designated GJ30-7T) isolated from compost, was characterized using a polyphasic approach, in order to clarify its taxonomic position. Strain GJ30-7T was observed to grow optimally at 30 °C and at pH 7.0 on R2A agar medium. Strain Gsoil GJ30-7T possessed β-glucosidase activity, which was responsible for its ability to transform ginsenosides Rb1 and Rc (the two main active components of ginseng) to ginsenoside F2. Phylogenetic analysis, based on 16S rRNA gene sequence similarities, indicated that GJ30-7T belongs to the genus Sphingobacterium of the family Sphingobacteriaceae and was most closely related to Sphingobacterium yanglingense JCM 30166T (92.6 %), Sphingobacterium psychroaquaticum KACC 18188T (92.6 %), and Sphingobacterium thermophilum KCTC 23708T (92.0 %). The DNA G+C content was 43 mol% and MK-7 was the major isoprenoid quinone. The main polar lipids were phosphatidylethanolamine, one unidentified phospolipid and one unknown polar lipid. In contrast to standard and reference strains, unidentified sphingolipid was also present. The predominant fatty acids of strain GJ30-7T were iso-C15 : 0, iso-C17 : 0 3-OH, C16 : 1ω7c and/or C16 : 1ω6c (summed feature 3) and iso-C17 : 1ω9c and/or C16 : 0 10-methyl (summed feature 9), supporting the affiliation of strain GJ30-7T to the genus Sphingobacterium. However, strain GJ30-7T could be distinguished genotypically and phenotypically from species of the genus Sphingobacterium with validly published names. The novel isolate therefore represents a novel species, for which the name Sphingobacterium jejuense sp. nov. is proposed, with the type strain GJ30-7T (=KACC 18625T=JCM 30948T).

Sphingobacterium suaedae sp. nov., isolated from the rhizosphere soil of Suaeda corniculata

A Gram-stain-negative, non-motile, non-spore-forming bacterium, designated T47T, was isolated from saline soil of the Suaeda corniculata rhizosphere, located on the bank of Wuliangsuhai Lake, Inner Mongolia, northern China. Strain T47T could grow at 10–40 °C (with 30 °C the optimal temperature), pH 6.0–8.0 (optimal pH 6.0) and in the presence of 0–6.0 % (w/v) NaCl [optimal 0–1.0 % (w/v)]. Phylogenetic analysis, based on 16S rRNA gene sequences, revealed that strain T47T formed a stable clade with Sphingobacterium composti 4M24T, Sphingobacterium bambusae IBFC2009T, Sphingobacterium paludis S37T and Sphingobacterium wenxiniae LQY-18T, with the 16S rRNA gene sequence similarities ranging from 91.9–95.4 %. Its major cellular fatty acids contained iso-C15 : 0 (39.9 %), summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1ω7c, 23.0 %), C16 : 0 (12.8 %) and iso-C17 : 0 3-OH (9.9 %). MK7 was the major menaquinone. The G+C content of the genomic DNA was 45.5 mol%. Based on the phenotypic, phylogenetic and genotypic characteristics, strain T47T represents a novel species within the genus Sphingobacterium, for which the name Sphingobacterium suaedae sp. nov. is proposed. The type strain is T47T ( = CGMCC 1.15277T = KCTC 42662T).

Sphingobacterium mucilaginosum sp. nov., isolated from rhizosphere soil of a rose

A Gram-stain-negative, strictly aerobic, motile, short-rod-shaped bacterium, designated strain THG-SQA8T, was isolated from rhizosphere soil of rose in PR China. Strain THG-SQA8T was closely related to members of the genus Sphingobacterium, showed the highest sequence similarities with Sphingobacterium multivorum KACC 14105T (98.0 %) and Sphingobacterium ginsenosidimutans KACC 14526T (97.4 %). DNA–DNA hybridization showed values of 35.2 ± 0.9 % and 8.8 ± 0.3 % DNA reassociation with S. multivorum KACC 14105T and S. ginsenosidimutans KACC 14526T, respectively. Chemotaxonomic data revealed that strain THG-SQA8T possesses menaquinone-7 as the only respiratory quinone, and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), iso-C15 : 0 and C16 : 0 as the major fatty acids. The major polar lipid was phosphatidylethanolamine. The DNA G+C content was 40.7 mol%. These data corroborated the affiliation of strain THG-SQA8T to the genus Sphingobacterium. Thus, the isolate represents a novel species, for which the name Sphingobacterium mucilaginosum sp. nov. is proposed, with THG-SQA8T as the type strain ( = CCTCC AB 2014317T = KCTC 42503T).

Sphingobacterium rhinocerotis sp. nov., isolated from the faeces of Rhinoceros unicornis

A novel Gram-negative, strictly aerobic, short rod-shaped, non-motile bacterium, designated YIM 101302(T), was isolated from the faeces of Rhinoceros unicornis dwelling in the Yunnan Wild Animal Park, Yunnan province, South-West China. The 16S rRNA gene sequence analysis revealed a clear affiliation of strain YIM 101302(T) to the genus Sphingobacterium. The newly isolated bacterium was found to be closely related to Sphingobacterium composti T5-12(T) (97.1% 16S rRNA sequence identity) and Sphingobacterium alimentarium WCC 4521(T) (95.6% 16S rRNA sequence identity) forming a distinct clade with these two species. Polar lipids of strain YIM 101302(T) were identified as phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphatidylglycerol, phosphatidylinositol, an unidentified aminophospholipid, and three unidentified polar lipids; the predominant menaquinone as MK-7 and the major fatty as iso-C15:0. The genomic DNA G+C content was determined to be 38.9 mol%. The DNA-DNA hybridization values between strain YIM 101302(T) and S. composti T5-12(T), was 53.6 ± 5.8%. These results indicates that strain YIM 101302(T) represents a novel species of the genus Sphingobacterium, for which the name Sphingobacterium rhinocerotis sp. nov. is proposed. The type strain is YIM 101302(T) (=CCTCC AB 2013218(T) = KCTC 42533(T)).

Sphingobacterium yanglingense sp. nov., isolated from the nodule surface of soybean

A Gram-staining-negative, non-motile, catalase- and oxidase-positive strain, designated CCNWSP36-1(T), was isolated from the nodule surface of soybean [Glycine max (L.) Merrill] cultivar Zhonghuang 13. The 16S rRNA gene sequence analysis clearly showed that the isolate represented a member of the genus Sphingobacterium. On the basis of pairwise comparisons of 16S rRNA gene sequences, strain CCNWSP36-1(T) showed 96.8% similarity to Sphingobacterium nematocida CCTCC AB 2010390(T) and less than 95.2% similarity to other members of the genus Sphingobacterium. Growth of strain CCNWSP36-1(T) occurred at 10-40 °C and at pH 5.0-9.0. The NaCl range (w/v) for growth was 0-4%. The predominant isoprenoid quinone was MK-7. The polar lipids were phosphatidylethanolamine and several unidentified polar lipids. Sphingolipid was present. The major fatty acids were iso-C(15:0) and summed feature 3 (comprising C(16:1)ω6c and/or C(16:1)ω7c). The G+C content of the genomic DNA was 41.1 mol%. As the physiological and biochemical characteristics of strain CCNWSP36-1(T) and the type strains of its closest phylogenetic neighbours showed clear differences, a novel species, Sphingobacterium yanglingense, is proposed. The type strain is CCNWSP36-1(T) ( =ACCC 19328(T) =JCM 30166(T)).

Sphingobacterium paludis sp. nov., isolated from wetland soil

A novel Gram-stain-negative bacteria, designated S37T, was isolated from soil of the Xixi wetland, Zhejiang province, China. Cells of strain S37T were aerobic, non-motile rods. Growth occurred at 10–37 °C (optimum, 25 °C), pH 5.0–9.7 (optimum, pH 7.5) and with 0–6 % (w/v) NaCl (optimum, 0.5 %). Based on 16S rRNA gene sequence analysis, strain S37T was found to be a member of the genus Sphingobacterium and shared highest similarity with Sphingobacterium composti 4M24T (95.78 %). The major fatty acids were summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1ω7c), iso-C15 : 0 and iso-C17 : 0 3-OH, and the DNA G+C content was 43.8 mol%. The predominant respiratory quinone was MK-7. Based on its phenotypic and chemotaxonomic characteristics and phylogenetic data, strain S37T represents a novel species of the genus Sphingobacterium , for which the name Sphingobacterium paludis sp. nov. (type strain S37T = CGMCC 1.12801T = NBRC 110386T) is proposed.