Enhancing polyhydroxyalkanoate production in Cupriavidus sp. L7L through wcaJ gene deletion.

Cupriavidus sp. L7L synthesizes a high content of ductile polyhydroxyalkanoate. However, during fermentation, the medium's viscosity gradually increases, eventually reaching a level similar to 93 % glycerol, leading to fermentation termination and difficulties in cell harvest. A non-mucoid variant was isolated from a mini-Tn5 mutant library with the transposon inserted at the promoter sequence upstream of the wcaJ gene. Deletion of wcaJ eliminated the mucoid-colony appearance. The complementation experiment confirmed the association between wcaJ gene expression and mucoid-colony formation. Additionally, the wild-type strain exhibited a faster specific growth rate than the deletion strain using levulinate (Lev) as a carbon source. In fed-batch fermentation, Cupriavidus sp. L7L∆wcaJ showed similar PHA content and monomer composition to the wild-type strain. However, the extended fermentation time resulted in a 42 % increase in PHA concentration. After fed-batch fermentation, the deletion strain's medium had only 8.75 % of the wild-type strain's extracellular polymeric substance content. Moreover, the deletion strain's medium had a much lower viscosity (1.04 mPa·s) than the wild-type strain (194.7 mPa·s), making bacterial cell collection easier through centrifugation. In summary, Cupriavidus sp. L7L∆wcaJ effectively addressed difficulties in cell harvest, increased PHA production, and Lev-to-PHA conversion efficiency, making these characteristics advantageous for industrial-scale PHA production.

Hymenobacter piscis sp. nov., isolated from a fish pond.

Bacterial strain NST-14T, isolated from a freshwater fish pond in Taiwan, was characterized using a polyphasic taxonomy approach. The strain was Gram-stain-negative, strictly aerobic, non-motile, rod-shaped and formed pink colonies. Optimal growth occurred at 30 °C, pH 7 and in the absence of NaCl. Phylogenetic analyses based on 16S rRNA gene sequences and coding sequences of 92 protein clusters indicated that strain NST-14T formed a phylogenetic lineage in the genus Hymenobacter. Analysis of 16S rRNA gene sequences showed that strain NST-14T had the highest similarity to Hymenobacter actinosclerus CCUG 39621T (97.7%), Hymenobacter amundsenii P5136T (97.3%) and Hymenobacter humicola P6312T (96.9%). Strain NST-14T showed 75.1-85.3 % average nucleotide identity, 73.7-89.8 % average amino acid identity and 14.5-26.0 % digital DNA-DNA hybridization with the type strains of other closely related Hymenobacter species. Strain NST-14T contained iso-C15 : 0, C16 : 1 ω5c and summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) as the predominant fatty acids. The major hydroxyl fatty acids were iso-C17 : 0 3-OH and iso-C15 : 0 3-OH. The polar lipids were phosphatidylethanolamine, one unidentified glycolipid, four unidentified aminophospholipids, one unidentified aminolipid, two unidentified phospholipids and three unidentified lipids. The major polyamine was homospermidine. The major isoprenoid quinone was MK-7. The DNA G+C content of the genomic DNA was 62.4 mol%. Differential phenotypic properties, together with the phylogenetic inference, demonstrate that strain NST-14T should be classified as a novel species of the genus Hymenobacter, for which the name Hymenobacter piscis sp. nov. is proposed. The type strain is NST-14T (=BCRC 81249T=LMG 31686T).

Rhodobacter amnigenus sp. nov. and Rhodobacter ruber sp. nov., isolated from freshwater habitats.

Two bacterial strains, designated HSP-20T and CCP-1T, isolated from freshwater habitats in Taiwan, were characterized by polyphasic taxonomy. Both strains were Gram-stain-negative, aerobic, non-motile and rod-shaped. Cells of strains HSP-20T and CCP-1T formed pink and dark red coloured colonies, respectively. Both strains contained bacteriochlorophyll a, and showed optimum growth under anaerobic conditions by photoheterotrophy, but no growth by photoautotrophy. Phylogenetic analyses based on 16S rRNA gene and whole-genome sequences indicated that both strains belonged to the genus Rhodobacter. Analysis of 16S rRNA gene sequences showed that strains HSP-20T and CCP-1T shared 98.3 % sequence similarity and were closely related to Rhodobacter tardus CYK-10T (96.0 %) and Rhodobacter flagellatus SYSU G03088T (96.0 %), respectively. Both strains shared common chemotaxonomic characteristics including Q-10 as the major isoprenoid quinone, C18 : 1 ω7c as the predominant fatty acid, and phosphatidylethanolamine, phosphatidylglycerol and phosphatidylcholine as the main polar lipids. The DNA G+C content of both strains was 66.2 mol%. The average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization values between these two novel isolates and their closest relatives were below the cut-off values of 95-96, 90 and 70 %, respectively, used for species demarcation. On the basis of phenotypic and genotypic properties and phylogenetic inference, both strains should be classified as novel species within the genus Rhodobacter, for which the names Rhodobacter amnigenus sp. nov. (=BCRC 81193T=LMG 31334T) and Rhodobacter ruber sp. nov. (=BCRC 81189T=LMG 31335T) are proposed.

Zophobihabitans entericus gen. nov., sp. nov., a new member of the family Orbaceae isolated from the gut of a superworm Zophobas morio.

A novel bacterial strain, designated IPMB12T, isolated from the gut of the superworm Zophobas morio in Taiwan, was characterized using a polyphasic taxonomic approach. Cells were Gram-stain-negative, facultatively anaerobic, non-motile, coccoid or rod-shaped and formed translucent colonies. Optimal growth occurred at 25-37 °C, pH 9-10, and with 0-2 % NaCl. Phylogenetic analyses based on 16S rRNA gene sequences and coding sequences of 92 protein clusters indicated that strain IPMB12T is affiliated with genus in the the family Orbaceae in the class Gammaproteobacteria. Strain IPMB12T was most closely related to Gilliamella mensalis LMG 29880T with a 94.6 % 16S rRNA gene sequence similarity. Strain IPMB12T showed less than 71.6 % average nucleotide identity, less than 71.5 % average amino acid identity and less than 21.2 % digital DNA-DNA hybridization identity compared to the strains of related genera within the family Orbaceae. The major fatty acids of strain IPMB12T were summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c), C16 : 0 and C14 : 0. The polar lipid profile consisted of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, one uncharacterized phosphoaminoglycolipid and one uncharacterized aminophospholipid. The major isoprenoid quinone was Q-8. Genomic DNA G+C content of strain IPMB12T was 39.3 mol%. On the basis of phenotypic and genotypic properties and phylogenetic inference, strain IPMB12T represents a novel species of a new genus in the family Orbaceae, for which the name Zophobihabitans entericus gen. nov., sp. nov. is proposed. The type strain is IPMB12T (=BCRC 80908T =LMG 32079T=KCTC 82347T=KACC 22323T).

Flavobacterium difficile sp. nov., isolated from a freshwater waterfall.

A bacterial strain designated KDG-16 T is isolated from a freshwater waterfall in Taiwan and characterized to determine its taxonomic affiliation. Cells of strain KDG-16 T are Gram-stain-negative, strictly aerobic, motile by gliding, rod-shaped and form light yellow colonies. Optimal growth occurs at 20-25 °C, pH 6-7, and with 0% NaCl. Phylogenetic analyses based on 16S rRNA gene sequences and an up-to-date bacterial core gene set reveal that strain KDG-16 T is affiliated with species in the genus Flavobacterium. Analysis of 16S rRNA gene sequences shows that strain KDG-16 T shares the highest similarity with Flavobacterium terrigena DSM 17934 T (97.7%). The average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization values between strain KDG-16 T and the closely related Flavobacterium species are below the cut-off values of 95-96, 90 and 70%, respectively, used for species demarcation. Strain KDG-16 T contains iso-C15:0, iso-C15:1 G and iso-C17:0 3-OH as the predominant fatty acids. The polar lipid profile consists of phosphatidylethanolamine, one uncharacterized aminophospholipid, one uncharacterized phospholipid, two uncharacterized aminolipids and two uncharacterized lipids. The major polyamine is homospermidine. The major isoprenoid quinone is MK-6. Genomic DNA G + C content of strain KDG-16 T is 31.6%. Based on the polyphasic taxonomic data obtained, strain KDG-16 T is considered to represent a novel species in the genus Flavobacterium, for which the name Flavobacterium difficile sp. nov. is proposed. The type strain is KDG-16 T (= BCRC 81194 T = LMG 31332 T).

Flavobacterium undicola sp. nov., isolated from a freshwater lake.

Bacterial strain BBQ-18T, isolated from a freshwater lake in Taiwan, is characterized using a polyphasic taxonomy approach. Phylogenetic analyses based on 16S rRNA gene sequences and coding sequences of 92 protein clusters indicate that strain BBQ-18T forms a phylogenetic lineage in the genus Flavobacterium. Strain BBQ-18T is most closely related to Flavobacterium alvei HR-AYT with 98.5% 16S rRNA gene sequence similarity. Strain BBQ-18T shows 70.5-89.5% average nucleotide identity and 13.7-38.2% digital DNA-DNA hybridization identity with the type strains of other closely related Flavobacterium species. The strain is Gram-stain negative, strictly aerobic, motile by gliding, rod shaped and formed yellow colonies. Optimal growth occurs at 25 °C, pH 6, and in the absence of NaCl. Strain BBQ-18T contains iso-C15:0, summed feature 3 (C16:1ω6c and/or C16:1ω7c) and anteiso-C15:0 as the predominant fatty acids. The polar lipid profile consists of phosphatidylethanolamine, four uncharacterized aminophospholipids and two uncharacterized phospholipids. The major polyamine is homospermidine. The major isoprenoid quinone is MK-6. The DNA G+C content of the genomic DNA is 33.8%. Differential phenotypic properties, together with the phylogenetic inference, demonstrate that strain BBQ-18T should be classified as a novel species of the genus Flavobacterium, for which the name Flavobacterium undicola sp. nov. is proposed. The type strain is BBQ-18T (= BCRC 81050T = LMG 30052T = KCTC 52810T).

Sphingomonas lacunae sp. nov., isolated from a freshwater pond.

A novel bacterial strain, designated CSW-10T, isolated from a freshwater pond in Taiwan, was characterized using a polyphasic taxonomic approach. Cells were Gram-stain-negative, aerobic, non-motile, rod-shaped and formed yellow-coloured colonies. Optimal growth occurred at 30 °C, pH 7, and in the absence of NaCl. Phylogenetic analyses based on 16S rRNA gene sequences and coding sequences of 92 protein clusters indicated that strain CSW-10T formed a phylogenetic lineage in the genus Sphingomonas. The 16S rRNA gene sequence similarity indicated that strain CSW-10T was most closely related to Sphingomonas fonticola TNR-2T (97.6%). Strain CSW-10T showed 69.8-70.7% average nucleotide identity and 19.0-23.0% digital DNA-DNA hybridization identity with the strains of other related Sphingomonas species. The major fatty acids of strain CSW-10T were summed feature 8 (C18:1 ω7c and/or C18:1 ω6c) and C17:1 ω6c. The polar lipid profile consisted of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidyldimethylethanolamine, phosphatidylcholine, one uncharacterized sphingoglycolipid, five uncharacterized aminophospholipids, one uncharacterized phospholipid and one uncharacterized lipid. The predominant polyamines were homospermidine and spermidine. The major isoprenoid quinone was Q-10. Genomic DNA G+C content of strain CSW-10T was 62.0 mol%. On the basis of phenotypic and genotypic properties and phylogenetic inference, strain CSW-10T should represent a novel species of the genus Sphingomonas, for which the name Sphingomonas lacunae sp. nov. is proposed. The type strain is CSW-10T (=BCRC 81190T =LMG 31340T).

Orrella amnicola sp. nov., isolated from a freshwater river, reclassification of Algicoccus marinus as Orrella marina comb. nov., and emended description of the genus Orrella.

A novel Gram-negative, aerobic, non-motile, ovoid to rod-shaped bacterium, designated NBD-18T, was isolated from a freshwater river in Taiwan. Optimal growth occurred at 30 °C, at pH 6 and in the absence of NaCl. The predominant fatty acids of strain NBD-18T were C16 : 0, summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), C17 : 0 cyclo and summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c). The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and phosphatidyldimethylethanolamine. The major polyamine was putrescine. The major isoprenoid quinone was Q-8. The genomic DNA G+C content of strain NBD-18T was 50.9 %. Strain NBD-18T was most closely related to Orrella dioscoreae LMG 29303T and Algicoccus marinus HZ20T at a 16S rRNA gene sequence similarity of 97.7 %. 16S rRNA gene sequence similarity between O. dioscoreae LMG 29303T and A. marinus HZ20T was 97.7 %. Phylogenetic analyses based on 16S rRNA gene sequences and an up-to-date bacterial core gene set indicated that strain NBD-18T, O. dioscoreae LMG 29303T and A. marinus HZ20T are affiliated with the same genus. Digital DNA-DNA hybridization, average nucleotide identity and average amino acid identity values among these three strains supported that they belong to the same genus and that strain NBD-18T represents a novel species. Thus, A. marinus HZ20T should be reclassified as Orrella marina comb. nov. based on the rules for priority of publication and validation. On the basis of the genotypic, chemotaxonomic and phenotypic data, strain NBD-18T represents a novel species in the genus Orrella, for which the name Orrella amnicola sp. nov. is proposed. The type strain is NBD-18T (=BCRC 81197T=LMG 31338T).

Tabrizicola oligotrophica sp. nov. and Rhodobacter tardus sp. nov., two new species of bacteria belonging to the family Rhodobacteraceae.

Two Gram-stain-negative, aerobic, non-motile bacteria, designated KMS-5T and CYK-10T, were isolated from freshwater environments. 16S rRNA gene sequence similarity results indicated that these two novel strains belong to the family Rhodobacteraceae. Strain KMS-5T is closely related to species within the genus Tabrizicola (96.1-96.8 % sequence similarity) and Cypionkella (96.5-97.0 %). Strain CYK-10T is closest to Rhodobacter thermarum YIM 73036T with 96.6 % sequence similarity. Phylogenetic analyses based on 16S rRNA gene sequences and an up-to-date bacterial core gene set showed that strain KMS-5T is affiliated with species in the genus Tabrizicola and strain CYK-10T is placed in a distinct clade with Rhodobacter blasticus ATCC 33485T, Rhodobacter thermarum YIM 73036T and Rhodobacter flagellatus SYSU G03088T. These two strains shared common chemotaxonomic features comprising Q-10 as the major quinone, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylcholine as the principal polar lipids, and C18 : 1 ω7c as the main fatty acid. The average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization values between these two novel isolates and their closest relatives were below the cut-off values of 95-96, 90 and 70 %, respectively, used for species demarcation. The obtained polyphasic taxonomic data suggested that strain KMS-5T represents a novel species within the genus Tabrizicola, for which the name Tabrizicola oligotrophica sp. nov. is proposed with KMS-5T (=BCRC 81196T=LMG 31337T) as the type strain, and strain CYK-10T should represent a novel species of the genus Rhodobacter, for which the name Rhodobacter tardus sp. nov. is proposed with CYK-10T (=BCRC 81191T=LMG 31336T) as the type strain.

Novosphingobium ovatum sp. nov., isolated from a freshwater mesocosm.

A bacterial strain, designated FSY-8T, was isolated from a freshwater mesocosm in Taiwan and characterized using the polyphasic taxonomy approach. Cells of strain FSY-8T were aerobic, Gram-stain-negative, rod-shaped, non-motile and formed yellow coloured colonies on Reasoner's 2A agar. Growth occurred at 20-40 °C (optimum, 30-37 °C) and pH 5-7 (optimum, pH 6) and in the presence of 0-0.5 % NaCl (optimum, 0 %, w/v). The major fatty acids (>10 %) of strain FSY-8T were summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c) and summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c). The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, phosphatidylmonomethylethanolamine, phosphatidyldimethylethanolamine, sphingoglycolipid, diphosphatidylglycerol, an uncharacterized aminophospholipid, an uncharacterized glycolipid and an uncharacterized lipid. The major polyamine was spermidine. The major isoprenoid quinone was Q-10. The DNA G+C content was 64.8 mol %. Phylogenetic analyses based on 16S rRNA gene sequences and coding sequences of 92 protein clusters indicated that strain FSY-8T formed a phylogenetic lineage in the genus Novosphingobium. Strain FSY-8T showed 71.6-77.2 % average nucleotide identity and 19.9-22.8 % digital DNA-DNA hybridization identity with the strains of other Novosphingobium species. On the basis of phenotypic and genotypic properties and phylogenetic inference, strain FSY-8T should be classified in a novel species of the genus Novosphingobium, for which the name Novosphingobium ovatum sp. nov. is proposed. The type strain is FSY-8T (=BCRC 81051T=LMG 30053T=KCTC 52812T).

Rhodovarius crocodyli sp. nov., isolated from a crocodile pond.

Bacterial strain CCP-6T, isolated from a freshwater pond in Taiwan, was characterized using a polyphasic taxonomy approach. Phylogenetic analyses based on 16S rRNA gene sequences and an up-to-date bacterial core gene set (92 protein clusters) indicated that strain CCP-6T is affiliated with species in the genus Rhodovarius. Strain CCP-6T was most closely related to Rhodovarius lipocyclicus CCUG 44693T with a 98.9% 16S rRNA gene sequence similarity. Cells were Gram-stain-negative, aerobic, non-motile, rod-shaped and formed light pink-coloured colonies. Optimal growth occurred at 30 °C, pH 6 and in the absence of NaCl. The major fatty acids of strain CCP-6T were C18 : 1 ω7c, C16 : 0 and C19 : 0 cyclo ω8c. The polar lipid profile consisted of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, phosphatidyldimethylethanolamine, phosphatidylmethylethanolamine, diphosphatidylglycerol, three unidentified aminophospholipids and an unidentified phospholipid. The predominant polyamine was spermidine. The major isoprenoid quinone was Q-10. The DNA G+C content of the genomic DNA was 69.3 mol%. Strain CCP-6T showed 85.8% average nucleotide identity and 14.5% digital DNA-DNA hybridization identity with Rhodovarius lipocyclicus CCUG 44693T. On the basis of the genotypic, chemotaxonomic and phenotypic data, strain CCP-6T represents a novel species in the genus Rhodovarius, for which the name Rhodovarius crocodyli sp. nov. is proposed. The type strain is CCP-6T (=BCRC 81095T=LMG 30310T=KCTC 62188T).

Flavobacterium ichthyis sp. nov., isolated from a fish pond.

Bacterial strain NST-5T, isolated from a fish pond in Taiwan, was characterized using a polyphasic taxonomy approach. Results of phylogenetic analyses based on 16S rRNA gene sequences and coding sequences of 92 protein clusters indicated that strain NST-5T formed a phylogenetic lineage in the genus Flavobacterium. Analysis of 16S rRNA gene sequences showed that strain NST-5T showed the highest similarity to Flavobacterium enshiense DK69T (94.9 %), Flavobacterium ahnfeltiae 10Alg 130T (94.8 %) and Flavobacterium vireti THG-SM1T (94.8 %). Strain NST-5T showed 68.9-72.5% average nucleotide identity and 19.1-23.7% digital DNA-DNA hybridization identity with the type strains of other close related Flavobacterium species. Cells of the strain were Gram-stain-negative, strictly aerobic, motile by gliding, rod-shaped and formed yellow colonies. Optimal growth occurred at 30 °C, pH 7 and with 0.5% NaCl. Strain NST-5T contained iso-C15:0, C15:0 and iso-C16:0 as the predominant fatty acids. The major hydroxyl fatty acids were iso-C16:0 3-OH and iso-C17:0 3-OH. The polar lipid profile consisted of phosphatidylethanolamine, three uncharacterized aminophospholipids, two uncharacterized phospholipids and one uncharacterized aminolipid. The major polyamine was homospermidine. The major isoprenoid quinone was MK-6. The DNA G+C content of the genomic DNA was 35.5 mol%. Differential phenotypic properties, together with the phylogenetic inference, demonstrate that strain NST-5T should be classified as a novel species of the genus Flavobacterium, for which the name Flavobacterium ichthyis sp. nov. is proposed. The type strain is NST-5T (=BCRC 81198T=LMG 31341T).

Ideonella livida sp. nov., isolated from a freshwater lake.

A novel bacterial strain, designated TBM-1T, isolated from a freshwater lake in Taiwan, was characterized using a polyphasic taxonomic approach. Phylogenetic analyses based on 16S rRNA gene sequences and coding sequences of 92 protein clusters indicated that strain TBM-1T formed a phylogenetic lineage in the genus Ideonella. Analysis of 16S rRNA gene sequences showed that strain TBM-1T was most closely related to Ideonella dechloratans CCUG 30898T with 98.4 % sequence similarity. The average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization values between strain TBM-1T and closely related strains of the genus Ideonella were 74.4-77.5 %, 69.7-75.4 % and 19.8-21.8 %, respectively, supporting that strain TBM-1T represents a novel species of the genus Ideonella. Cells were Gram-stain-negative, motile by means of a single polar flagellum, rod-shaped and formed blue colonies. Optimal growth occurred at 30 °C, pH 6 and 0 % NaCl. The predominant fatty acids of strain TBM-1T were summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), C18 : 1 ω7c and C16 : 0. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, two uncharacterized aminophospholipids and two uncharacterized phospholipids. The main polyamine was putrescine. The major isoprenoid quinone was Q-8. The estimated genome size was 5.26 Mb, with an average G+C content of 70.0 mol%. On the basis of phenotypic and genotypic properties and phylogenetic inference, strain TBM-1T should be classified in a novel species of the genus Ideonella, for which the name Ideonella livida sp. nov. is proposed. The type strain is TBM-1T (=BCRC 81199T =LMG 31339T).

Oleiharenicola lentus sp. nov., isolated from irrigation water.

Bacterial strain TWA-58T, isolated from irrigation water in Taiwan, was characterized using a polyphasic taxonomy approach. Phylogenetic analyses based on 16S rRNA gene sequences and coding sequences of 92 protein clusters indicated that strain TWA-58T formed a phylogenetic lineage in the genus Oleiharenicola of the family Opitutaceae. Strain TWA-58T was most closely related to Oleiharenicola alkalitolerans NVTT with a 96.7 % 16S rRNA gene sequence similarity. Strain TWA-58T showed 75.2 % average nucleotide identity, 70.9 % average amino acid identity and 21.0 % digital DNA-DNA hybridization identity with O. alkalitolerans NVTT. Cells were Gram-stain-negative, aerobic, motile, coccoid-shaped and formed transparent colonies. Optimal growth occurred at 25 °C, pH 6, and 0 % NaCl. The major fatty acids of strain TWA-58T were iso-C15 : 0 and anteiso-C15 : 0. The predominant hydroxy fatty acid was iso-C13 : 0 3-OH. The polar lipid profile consisted of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and two unidentified aminophospholipids. The major isoprenoid quinone was MK-7. Genomic DNA G+C content of strain TWA-58T was 65.3 mol%. On the basis of phenotypic and genotypic properties and phylogenetic inference, strain TWA-58T should be classified in a novel species of the genus Oleiharenicola, for which the name Oleiharenicola lentus sp. nov. is proposed. The type strain is TWA-58T (=BCRC 81161T=LMG 31019T=KCTC 62872T).

Aquirufa rosea sp. nov., isolated from a freshwater lake.

A bacterial strain designated CAR-16T was isolated from a freshwater lake in Taiwan and characterized using the polyphasic taxonomic approach. Cells were Gram-stain-negative, aerobic, motile by gliding, rod-shaped and formed rose-colored colonies. Optimal growth occurred at 30 °C, pH 7 and with 0 % NaCl. Phylogenetic analyses based on 16S rRNA gene sequences and coding sequences of 92 protein clusters indicated that CAR-16T represented a member of the family Cytophagaceae and formed a phylogenetic lineage in the genus Aquirufa. CAR-16T was most closely related to Aquirufa nivalisilvae 59G-WUEMPELT with a 99.7 % 16S rRNA gene sequence similarity. CAR-16T showed 71.2-79.5 % average nucleotide identity and 17.8-21.7 % digital DNA-DNA hybridization identity with the strains of other species of the genus Aquirufa. The major fatty acids of strain CAR-16T were iso-C15 : 0, iso-C15 : 0 3-OH, C16 : 1ω5c and summed feature 3 (C16 : 1ω7c/C16 : 1ω6c and/or iso-C15 : 0 2-OH). The polar lipid profile consisted of a mixture of phosphatidylethanolamine and several uncharacterized aminophospholipids, phospholipids and lipids. The major isoprenoid quinone was MK-7. The genomic DNA G+C content of CAR-16T was 38.8 mol%. On the basis of phenotypic and genotypic properties and phylogenetic inference, CAR-16T should be classified as representing a novel species of the genus Aquirufa, for which the name Aquirufa rosea sp. nov. is proposed. The type strain is CAR-16T (=BCRC 81153T=LMG 30923T=KCTC 62869T).

Aquabacterium lacunae sp. nov., isolated from a freshwater pond.

A novel bacterial strain, designated KMB7T, isolated from a freshwater pond in Taiwan, was characterized using a polyphasic taxonomic approach. Cells were Gram-stain-negative, motile by means of a single polar flagellum, rod-shaped and formed cream colonies. Optimal growth occurred at 25 °C, pH 7, and in the absence of NaCl. Phylogenetic analyses based on 16S rRNA gene sequences and an up-to-date bacterial core gene set (92 protein clusters) indicated that strain KMB7T is affiliated with species in the genus Aquabacterium. The 16S rRNA gene sequence similarity indicated that strain KMB7T is closely related to species within the genus Aquabacterium (95.2-97.6 % sequence similarity) and is most similar to A. fontiphilum CS-6T (97.6 %), followed by A. parvum B6T (97.5 %). The average nucleotide identity and digital DNA-DNA hybridization identity between strain KMB7T and the closely related strains were 74.6-78.0 % and 19.0-21.2 %, respectively. The major fatty acids of strain KMB7T were summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), C18 : 1 ω7c and C16 : 0. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylserine, diphosphatidylglycerol and four unidentified phospholipids. The sole isoprenoid quinone was ubiquinone-8 (Q-8). Genomic DNA G+C content of strain KMB7T was 65.4 %. On the basis of phenotypic and genotypic properties and phylogenetic inference, strain KMB7T should be classified in a novel species of the genus Aquabacterium, for which the name Aquabacterium lacunae sp. nov. is proposed. The type strain is KMB7T (=BCRC 81156T=LMG 30924T=KCTC 62867T).

Filimonas effusa sp. nov., isolated from a freshwater river.

Strain TTM-71T, isolated from a freshwater river in Taiwan, was characterized using a polyphasic taxonomic approach. Phylogenetic analyses based on 16S rRNA gene sequences and an up-to-date bacterial core gene set (92 protein clusters) indicated that strain TTM-71T is affiliated with species in the genus Filimonas. The 16S rRNA gene sequence similarity indicated that strain TTM-71T is closely related to species within the genus Filimonas (94.7-95.5 % sequence similarity) and had a high sequence similarity with Filimonas endophytica SR 2-06T (95.5 %). Strain TTM-71T showed 70.3 % average nucleotide identity and 24.9 % digital DNA-DNA hybridization identity with Filimonas lacunae YT21T. Cells were Gram-stain-negative, aerobic, motile by gliding, rod-shaped and formed beige-colored colonies. Optimal growth occurred at 20 °C, pH 8, and in the presence of 0.5 % NaCl. The major fatty acids of strain TTM-71T were iso-C15 : 0, iso-C15 : 1 G and summed feature 3 (comprising C16 : 1 ω7c and/or C16 : 1 ω6c). The predominant hydroxy fatty acid was iso-C17 : 0 3-OH. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, four uncharacterized aminophospholipids, one uncharacterized aminolipid, one uncharacterized phospholipid and one uncharacterized lipid. The predominant polyamine was homospermidine. The only isoprenoid quinone was MK-7. Genomic DNA G+C content was 45.6 mol%. On the basis of the polyphasic evidence presented, strain TTM-71T is considered to represent a novel species of the genus Filimonas, for which the name Filimonas effusa sp. nov. is proposed. The type strain is TTM-71T (=BCRC 81160T=LMG 31017T=KCTC 62871T).

Sandaracinomonas limnophila gen. nov., sp. nov., a new member of the family Cytophagaceae isolated from a freshwater mesocosm.

A bacterial strain designated FSY-15T was isolated from a freshwater mesocosm in Taiwan and characterised using a polyphasic taxonomic approach. Cells of strain FSY-15T were Gram-negative, aerobic, non-spore forming, non-motile rods and formed orange coloured colonies. Growth occurred at 20-30 °C (optimum, 25 °C), at pH 6-7.5 (optimum, pH 7) and with 0-0.5 % NaCl (optimum, 0 %). Phylogenetic analyses based on 16S rRNA gene sequences and coding sequences of 92 protein clusters indicated that strain FSY-15T formed a phylogenetic lineage in the the family Cytophagaceae. Strain FSY-15T was most closely related to the genera Pseudarcicella and Arcicella, and the levels of 16S rRNA gene sequence identity with respect to members of related genera are less than 94.1 %. Strain FSY-15T showed less than 68.8 % average nucleotide identity and less than 24.7 % digital DNA-DNA hybridisation identity compared to the type strains of related genera within the family Cytophagaceae. The predominant fatty acids were iso-C15 : 0, C16 : 1ω5c and the major hydroxyl fatty acid was iso-C15 : 0 3-OH. The major isoprenoid quinone was MK-7 and the DNA G+C content was 35.8 mol%. The major polar lipids were phosphatidylethanolamine and several uncharacterised aminophospholipid, aminolipid, phospholipid and lipid. The major polyamine was spermidine. On the basis of the genotypic and phenotypic data, strain FSY-15T represents a novel species of a new genus in the family Cytophagaceae, for which the name Sandaracinomonas limnophila gen. nov., sp. nov. is proposed. The type strain is FSY-15T (=BCRC 81011T =LMG 29732T =KCTC 52445T).

Sphingobium fluviale sp. nov., isolated from a river.

A Gram-stain-negative, rod-shaped, non-motile, poly-ß-hydroxybutyrate-accumulating and aerobic bacterial strain, designated CHR27T, was isolated and characterized by using the polyphasic taxonomy approach. The results of phylogenetic analyses based on 16S rRNA gene sequences and coding sequences of an up-to-date bacterial core gene set (92 protein clusters) indicated that strain CHR27T is affiliated with species in the genus Sphingobium. 16S rRNA gene sequence similarity results indicated that strain CHR27T was closely related to species of the genus Sphingobium (94.3-97.0 %), and had the highest sequence similarity to Sphingobium qiguonii X23T (97.0 %). Strain CHR27T showed 19.4-22.1 % digital DNA-DNA hybridization values and 73.2-74.8 % average nucleotide identity values with the strains of other Sphingobium species. Optimal growth occurred at 25 °C, pH 7.5 and in the absence of NaCl. The major fatty acids of strain CHR27T were C18 : 1ω7c and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c). The predominant hydroxy fatty acid was C14 : 0 2-OH. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylmonomethylethanolamine, phosphatidyldimethylethanolamine, two unidentified sphingoglycolipids and an unidentified aminophospholipid. Strain CHR27T contained spermidine as the major polyamine and putrescine as a minor component. The only isoprenoid quinone was ubiquinone-10. The genomic DNA G+C content of strain CHR27Twas 61.8 mol%. On the basis of the phylogenetic inference and phenotypic data, strain CHR27T was considered a representative of a novel species within the genus Sphingobium. The name Sphingobium fluviale sp. nov. is proposed, with strain CHR27T (=BCRC 81121T=LMG 30596T=KCTC 62510T) as the type strain.

Novosphingobium umbonatum sp. nov., isolated from a freshwater mesocosm.

A bacterial strain designated FSY-9T was isolated from a freshwater mesocosm in Taiwan and characterized to determine its taxonomic affiliation. Phylogenetic analyses based on 16S rRNA gene sequences and coding sequences of 92 protein clusters indicated that strain FSY-9T formed a phylogenetic lineage in the genus Novosphingobium. Strain FSY-9T was most closely related to Novosphingobium humi R1-4T with a 97.2 % 16S rRNA gene sequence similarity. Strain FSY-9T showed 71.3-72.6 % average nucleotide identity and 17.7-23.0 % digital DNA-DNA hybridization identity with the strains of other Novosphingobium species. Cells of strain FSY-9T were facultatively anaerobic, Gram-negative, rod-shaped, non-motile and formed light yellow coloured colonies. Growth occurred at 15-37 °C and pH 5.5-7, and in the presence of 0-0.5 % NaCl. The major fatty acids (>10 %) of strain FSY-9T were summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C18 : 1ω7c and C16 : 0. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, phosphatidyldimethylethanolamine, sphingoglycolipid, an uncharacterized aminophospholipid, an uncharacterized glycolipid and an uncharacterized lipid. The major polyamine was spermidine. The major isoprenoid quinone was Q-10. The DNA G+C content was 61.5 mol%. On the basis of phenotypic and genotypic properties and phylogenetic inference, strain FSY-9T should be classified as a novel species of the genus Novosphingobium, for which the name Novosphingobium umbonatum sp. nov. is proposed. The type strain is FSY-9T (=BCRC 81052T=LMG 30054T=KCTC 52813T).