Pedobacter rhodius sp. nov. and Pedobacter punctiformis sp. nov., isolated from soil.

Two Gram-staining negative, catalase- and oxidase-positive, pinkish-colored and rod-shaped strains, designated SJ11T and HCMS5-2 T, were isolated from soil in South Korea. The growth of strain SJ11T was observed from 15℃ to 35℃ (optimum, 30℃), from pH 6.0 to 11.0 (optimum, pH 6.0-7.0) and with NaCl 0-1% (w/v) (optimum, 0%) and that of strain HCMS5-2 T was observed from 4℃ to 40℃ (optimum, 25℃), from pH 6.0 to pH 8.0 (optimum, pH 7.0) and with NaCl 0-5% (w/v) (optimum, 0-1%). Phylogenetic analysis based on 16S rRNA gene sequences showed that both strains belonged to the genus Pedobacter. Strain SJ11T had the highest 16S rRNA similarities with Pedobacter jejuensis THG-DR3T (98.5%) and strain HCMS5-2 T had the highest similarities with Pedobacter nototheniae 36B243T (98.7%). The digital DNA-DNA hybridization value of strain SJ11T with Pedobacter jejuensis THG-DR3T was 23.6%, with an average nucleotide identity value of 79.6%, and that of strain HCMS5-2 T with Pedobacter nototheniae 36B243T was 26.4%, with an average nucleotide identity value of 83.1%. The predominant cellular fatty acids (> 10%) of SJ11T and HCMS5-2 T were iso-C15:0, summed feature 3 (comprising C16:1ω7c and/or C16:1ω6c) and iso-C17:0 3-OH. The genome size of strain SJ11T was approximately 4.7 Mb with a G + C content of 37.7% and that of strain HCMS5-2 T was approximately 4.1 Mb with a G + C content of 36.4%. The major polar lipid and respiratory quinone of SJ11T and HCMS5-2 T were phosphatidylethanolamine and menaquinone NK-7, respectively. Results of this study showed that strains SJ11T and HCMS5-2 T belonged to the genus Pedobacter as novel species, of which the name Pedobacter rhodius sp. nov., with the type strain SJ11T (= KACC 22884 T = TBRC 16597 T) and Pedobacter punctiformis sp. nov., with the type strain HCMS5-2 T (= KACC 22863 T = TBRC 16598 T) were respectively proposed.

Screening and Characterization of Two Extracellular Polysaccharide-Producing Bacteria from the Biocrust of the Mu Us Desert.

The extracellular polysaccharide (EPS) matrix embedding microbial cells and soil particles plays an important role in the development of biological soil crusts (BSCs), which is widely recognized as beneficial to soil fertility in dryland worldwide. This study examined the EPS-producing bacterial strains YL24-1 and YL24-3 isolated from sandy soil in the Mu Us Desert in Yulin, Shaanxi province, China. The strains YL24-1 and YL24-3 were able to efficiently produce EPS; the levels of EPS were determined to be 257.22 µg/mL and 83.41 µg/mL in cultures grown for 72 h and were identified as Sinorhizobium meliloti and Pedobacter sp., respectively. When the strain YL24-3 was compared to Pedobacter yulinensis YL28-9T using 16S rRNA gene sequencing, the resemblance was 98.6% and the strain was classified as Pedobacter sp. using physiological and biochemical analysis. Furthermore, strain YL24-3 was also identified as a subspecies of Pedobacter yulinensis YL28-9T on the basis of DNA-DNA hybridization and polar lipid analysis compared with YL28-9T. On the basis of the EPS-related genes of relevant strains in the GenBank, several EPS-related genes were cloned and sequenced in the strain YL24-1, including those potentially involved in EPS synthesis, assembly, transport, and secretion. Given the differences of the strains in EPS production, it is possible that the differences in gene sequences result in variations in the enzyme/protein activities for EPS biosynthesis, assembly, transport, and secretion. The results provide preliminary evidence of various contributions of bacterial strains to the formation of EPS matrix in the Mu Us Desert.

Exploration of Social Spreading Reveals That This Behavior Is Prevalent among Pedobacter and Pseudomonas fluorescens Isolates and That There Are Variations in the Induction of the Phenotype.

Within soil, bacteria are found in multispecies communities, where interactions can lead to emergent community properties. Studying bacteria in a social context is critical for investigating community-level functions. We previously showed that cocultured Pseudomonas fluorescens Pf0-1 and Pedobacter sp. V48 engage in interspecies social spreading (ISS) on a hard agar surface, a behavior which required close contact and depended on the nutritional environment. Here, we investigate whether social spreading is widespread among P. fluorescens and Pedobacter isolates and whether the requirements for interaction vary. We find that this phenotype is not restricted to the interaction between P. fluorescens Pf0-1 and Pedobacter sp. V48 but is a prevalent behavior found in one clade in the P. fluorescens group and two clades in the Pedobacter genus. We show that the interaction with certain Pedobacter isolates occurred without close contact, indicating induction of spreading by a putative diffusible signal. As with ISS by Pf0-1+V48, the motility of interacting pairs is influenced by the environment, with no spreading behaviors (or induction of motility) observed under high nutrient conditions. While Pf0-1+V48 require low nutrient but high NaCl conditions, in the broader range of interacting pairs, the high salt influence was variable. The prevalence of motility phenotypes observed here and found within the literature indicates that community-induced locomotion in general, and social spreading in particular, is likely important within the environment. It is crucial that we continue to study microbial interactions and their emergent properties to gain a fuller understanding of the functions of microbial communities. IMPORTANCE Interspecies social spreading (ISS) is an emergent behavior observed when Pseudomonas fluorescens Pf0-1 and Pedobacter sp. V48 interact, during which both species move together across a surface. Importantly, this environment does not permit the movement of either individual species. This group behavior suggests that communities of microbes can function in ways not predictable by knowledge of the individual members. Here, we have asked whether ISS is widespread and thus potentially of importance in soil microbial communities. The significance of this research is the demonstration that surface spreading behaviors are not unique to the Pf0-1-V48 interaction but rather is a more widespread phenomenon observed among members of distinct clades of both P. fluorescens and Pedobacter isolates. Furthermore, we identify differences in mechanisms of signaling and nutritional requirements for ISS. Emergent traits resulting from bacterial interactions are widespread, and their characterization is necessary for a complete understanding of microbial community function.

Pedobacter changchengzhani sp. nov., isolated from soil of Antarctica.

A Gram-negative, aerobic, non-motile, pink and rod-shaped bacterium, designated E01020T, was isolated from soil collected from the Chinese Great Wall Station, Antarctica. Comparative analysis of 16S rRNA gene sequences revealed that strain E01020T is a member of the genus Pedobacter, related to Pedobacter alluvionis DSM 19624T (96.8% similarity), Pedobacter agri JCM 15120T (96.5% similarity) and Pedobacter chinensis JDX94T (96.3% similarity). The dDDH values and ANI values of strain E01020T with closely related strains indicate that it can be distinguished from them as a novel species. The DNA G+C content was determined to be 35.2 mol%. The growth of strain E01020T was observed at 4-25 °C (optimal 20 °C), in the presence of 0-1% NaCl (w/v, optimal 0%) and at pH 6.0-8.0 (optimal pH 7.0). Strain E01020T was found to contained menaquinon-7 (MK-7) as only respiratory quinone, iso-C15:0, iso-C17:0 3-OH and Summed feature 3 (C16:1ω6c and/or C16:1ω7c) as major fatty acids. The major polar lipids were phosphatidylethanolamine, one unidentified lipid and two unidentified aminolipids. On the basis of the results of the phylogenetic and phenotypic analyses, it was suggested that strain E01020T represents a novel species of the genus Pedobacter, for which the name Pedobacter changchengzhani sp. nov. is proposed. The type strain is E01020T (= KCTC 62990T = MCCC 1H00357T).

Comparative study of plant growth-promoting bacteria on the physiology, growth and fruit quality of strawberry.

BACKGROUND: The strawberry (Fragaria × ananassa Duch.) is, among small fruits, the most cultivated and commercialized in Portugal. Recent studies have evidenced the positive effect of plant growth-promoting bacteria (PGPB) inoculation on strawberry production and, at the same time, provided an alternative strategy to reduce the use of fertilizers. In this study the effects of root inoculation with three PGPB strains (Pedobacter sp. CC1, Bacillus safensis B106 and Bacillus subtilis B167A) on the physiology, growth, fruit production and quality of strawberry cv. Camarosa are presented. RESULTS: PGPB inoculation significantly accelerated crop maturation, with inoculated plants fruiting about 2 weeks earlier than non-inoculated plants. Inoculated plants with Pedobacter sp. CC1 and Bacillus safensis B106 influenced the gas exchange parameters of strawberry plants. The contents of total phenolics and flavonoids in strawberry leaves were found to be greater with Pedobacter sp. CC1, when compared with non-inoculated plants. Furthermore, plants inoculated with the same bacterial strain showed enhancement in the dimensions of fruits, especially fruit length, and shape as well as in the total soluble solids content (°Brix). CONCLUSIONS: The results showed that the PGPB Pedobacter sp. CC1 improved performance of strawberry plants, suggesting that it could be a potential biofertilizer for strawberry plant nutrition. © 2019 Society of Chemical Industry.

Proposal of Pedobacter nototheniae sp. nov., isolated from the spleen of a black rock cod (Notothenia coriiceps, Richardson 1844) from the Chilean Antarctica.

A pink pigmented, Gram-negative, rod-shaped, non-spore-forming bacterium (strain 36B243T), was isolated from the spleen of a black rock cod (Notothenia coriiceps, Richardson 1844) in the Chilean Antarctica. Strain 36B243T has a 5.26 Mb chromosome with a DNA G + C content of 35.4 mol%. The draft genome includes the prediction and annotation of 4585 coding genes, and 46 tRNA, 1 tmRNA, and 2735 hypothetical proteins. Phylogenetic analysis based on the 16S rRNA gene sequence placed strain 36B243T into the genus Pedobacter with high sequence similarity to the type strains of Pedobacter sandarakinus (97.5%) and Pedobacter petrophilus (97.1%). Sequence similarities to type strains of all other current Pedobacter species were below 97.1%. Predominant fatty acids are summed feature 3 (C16:1ω7c and/or C16:1ω6c) and iso-C15:0 followed by iso-C17:0 3-OH and C16:0. The major respiratory quinone was menaquinone MK-7. The polar lipid profile contained the major lipids phosphatidylethanolamine, five unidentified aminolipids, two lipids lacking a functional group and two minor glycolipids and one lipid lacking a functional group. An alkali-stable lipid was present. The polyamine pattern contained the predominant compound sym-homospermidine. Characterization by 16S rRNA gene sequence analysis, physiological parameters, pigment analysis, ubiquinone, polar lipid, and fatty acid composition revealed that strain 36B243T represents a new species of the genus Pedobacter. For this reason, we propose the name Pedobacter nototheniae sp. nov. with the type strain 36B243T (= LMG 30634T = CCM 8855T = CIP 111622T).

Interspecies Social Spreading: Interaction between Two Sessile Soil Bacteria Leads to Emergence of Surface Motility.

Bacteria often live in complex communities in which they interact with other organisms. Consideration of the social environment of bacteria can reveal emergent traits and behaviors that would be overlooked by studying bacteria in isolation. Here we characterize a social trait which emerges upon interaction between the distantly related soil bacteria Pseudomonas fluorescens Pf0-1 and Pedobacter sp. strain V48. On hard agar, which is not permissive for motility of the monoculture of either species, coculture reveals an emergent phenotype that we term "interspecies social spreading," where the mixed colony spreads across the hard surface. We show that initiation of social spreading requires close association between the two species of bacteria. Both species remain associated throughout the spreading colony, with reproducible and nonhomogenous patterns of distribution. The nutritional environment influences social spreading: no social behavior is observed under high-nutrient conditions, but low-nutrient conditions are insufficient to promote social spreading without high salt concentrations. This simple two-species consortium is a tractable model system that will facilitate mechanistic investigations of interspecies interactions and provide insight into emergent properties of interacting species. These studies will contribute to the broader knowledge of how bacterial interactions influence the functions of communities they inhabit.IMPORTANCE The wealth of studies on microbial communities has revealed the complexity and dynamics of the composition of communities in many ecological settings. Fewer studies probe the functional interactions of the community members. Function of the community as a whole may not be fully revealed by characterizing the individuals. In our two-species model community, we find an emergent trait resulting from the interaction of the soil bacteria Pseudomonas fluorescens Pf0-1 and Pedobacter sp. V48. Observation of emergent traits suggests there may be many functions of a community that are not predicted based on a priori knowledge of the community members. These types of studies will provide a more holistic understanding of microbial communities, allowing us to connect information about community composition with behaviors determined by interspecific interactions. These studies increase our ability to understand communities, such as the soil microbiome, plant-root microbiome, and human gut microbiome, with the final goal of being able to manipulate and rationally improve these communities.

Pedobacter pollutisoli sp. nov., Isolated from Tetrabromobisphenol A-Contaminated Soil.

A Gram-stain negative, strictly aerobic, non-spore forming, non-motile, rod-shaped bacterium, designated TBBPA-24T, was isolated from tetrabromobisphenol A-contaminated soil in China. Phylogenetic analysis based on the 16S rRNA gene sequences showed that strain TBBPA-24T was most closely related to Pedobacter nanyangensis Q4T (96.5%) and Pedobacter 'zeaxanthinifaciens' TDMA-5T (96.1%). Chemotaxonomic analysis revealed that strain TBBPA-24T possessed MK-7 as the major respiratory quinone and lipid, aminolipid, phospholipid, phosphatidylethanolamine, and phosphoaminolipid as the major polar lipid. The major fatty acids were iso-C15:0 (40.2%), summed feature 3 (C16:1ω6c and/or C16:1ω7c, 25.6%) and iso-C17:0 3-OH (16.4%). The genomic DNA G+C content of strain TBBPA-24T was 43.9 mol%. Based on the phylogenetic, phenotypic characteristics, and chemotaxonomic data, strain TBBPA-24T is considered a novel species of the genus Pedobacter, for which the name Pedobacter pollutisoli sp. nov. is proposed. The type strain TBBPA-24T (= KCTC 62314T = CCTCC AB 2017244T) is proposed.

Environmental superbugs: The case study of Pedobacter spp.

The environment is one of the main reservoirs of antibiotic resistance genes (ARGs) but multidrug resistant (MDR) environmental isolates are barely characterised. As suggested by the name, Pedobacter species have been predominantly isolated from soils, but are also recovered from water (including drinking water), chilled food, fish, compost, sludge, glaciers and other extreme environments. The susceptibility phenotype of Pedobacter lusitanus NL19 (isolated from a deactivated uranium mine), its closely related species and the genus type strain were investigated. All strains are MDR bacteria, resistant to ß-lactams, colistin, aminoglycosides and ciprofloxacin. Therefore, Pedobacter spp. are likely intrinsically resistant to ß-lactams (including ertapenem) and to other three classes of antibiotics. 6%-8% of their total protein-encoding genes encode a diverse collection of putative ARGs, including ß-lactamases. These enzymes are highly abundant in all the other Pedobacter strains with sequenced genomes, especially class C, class B3 and class A. LUS-1 and PLN-1 were further characterised in E. coli. LUS-1 is a class A ß-lactamase and it conferred an increase in the MIC of cefotaxime, albeit very low. PLN-1 is a class B3 ß-lactamase with carbapenemase activity, conferring resistance to ertapenem and a 66x and 16x increase in the MIC of imipenem and meropenem, respectively. PLN-1 also hydrolyses ampicillin, 1st and 3rd generation cephalosporins, and at a lower extent cephamycins and 4th generation cephalosporins. Therefore, Pedobacter spp. encode a large and diverse arsenal of resistance mechanisms that make them environmental superbugs.

The effect of phylogenetically different bacteria on the fitness of Pseudomonas fluorescens in sand microcosms.

In most environments many microorganisms live in close vicinity and can interact in various ways. Recent studies suggest that bacteria are able to sense and respond to the presence of neighbouring bacteria in the environment and alter their response accordingly. This ability might be an important strategy in complex habitats such as soils, with great implications for shaping the microbial community structure. Here, we used a sand microcosm approach to investigate how Pseudomonas fluorescens Pf0-1 responds to the presence of monocultures or mixtures of two phylogenetically different bacteria, a Gram-negative (Pedobacter sp. V48) and a Gram-positive (Bacillus sp. V102) under two nutrient conditions. Results revealed that under both nutrient poor and nutrient rich conditions confrontation with the Gram-positive Bacillus sp. V102 strain led to significant lower cell numbers of Pseudomonas fluorescens Pf0-1, whereas confrontation with the Gram-negative Pedobacter sp. V48 strain did not affect the growth of Pseudomonas fluorescens Pf0-1. However, when Pseudomonas fluorescens Pf0-1 was confronted with the mixture of both strains, no significant effect on the growth of Pseudomonas fluorescens Pf0-1 was observed. Quantitative real-time PCR data showed up-regulation of genes involved in the production of a broad-spectrum antibiotic in Pseudomonas fluorescens Pf0-1 when confronted with Pedobacter sp. V48, but not in the presence of Bacillus sp. V102. The results provide evidence that the performance of bacteria in soil depends strongly on the identity of neighbouring bacteria and that inter-specific interactions are an important factor in determining microbial community structure.

Pedobacter lotistagni sp. nov. isolated from lotus pond water.

A light-yellow coloured, Gram-stain negative, rod-shaped, aerobic, non-motile bacterium, designated THG-DN6.8(T), was isolated from a lotus pond near Donghaksa temple in Daejeon, South Korea. The strain was found to grow well on nutrient agar, optimally at pH 6.0-7.5, at temperature 25-28 °C and in the presence of 0.5 % NaCl. Based on 16S rRNA gene sequence analysis, strain THG-DN6.8(T) was found to share the highest sequence similarity with Pedobacter koreensis KCTC 12536(T), followed by Pedobacter glacialis CCTCC AB 2012941(T), Pedobacter kyungheensis KACC 16221(T), Pedobacter caeni LMG 22862(T), Pedobacter insulae KCTC 12820(T) and Pedobacter boryungensis KCTC 23344 (T). The DNA G+C content was determined to be 36.8 mol%. In DNA-DNA hybridization tests, the DNA relatedness between strain THG-DN6.8(T) and its closest phylogenetic neighbour P. koreensis was found to be below 10 %. The predominant isoprenoid quinone was identified as menaquinone MK-7 and the major polar lipid as phosphatidylethanolamine. The major fatty acids of strain THG-DN6.8(T) were identified as iso-C15:0, C16:0, C18:0 and C16:1 ω6c and/or C16:1 ω7c (summed feature 3). On the basis of the phenotypic characteristics, genotypic analysis and chemotaxonomic characteristics, strain THG-DN6.8(T) is considered to represent a novel species of the genus Pedobacter, for which the name Pedobacter lotistagni sp. nov. is proposed. The type strain is THG-DN6.8(T) (= KCTC 42229(T) = JCM 30354(T)).

Pedobacter bambusae sp. nov., isolated from soil of a bamboo plantation.

An ivory white, rod-shaped, non-motile, non-spore forming, Gram-staining-negative, and aerobic bacterium designated THG-G118T, was isolated from a soil sample collected in a bamboo plantation in Seoul, Republic of Korea. The 16S rRNA gene sequence analysis revealed a clear affiliation of strain THG-G118T with the genus Pedobacter. Strain THG-G118T was found to show the closest phylogenetic relationship with Pedobacter metabolipauper WB2.3-71T with 16S rRNA gene sequence similarity of 97.3 %. The major cellular fatty acids of strain THG-G118T were identified as C16:0, C18:0, iso-C15:0 and summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), and the predominant menaquinone as menaquinone MK-7. The major polar lipids were found to be phosphatidylethanolamine (PE), unidentified phospholipid and unidentified aminophospholipids. Strain THG-G118T was found to contain ceramide phosphorylethanolamine 2 (CerPE-2) and dihydrosphingosine as the major ceramide. The G+C content of the genomic DNA was found to be 41.7 mol%. DNA-DNA hybridization experiments revealed a low level of DNA-DNA relatedness (<42.5 %) between strain THG-G118T and its closest relatives. The phenotypic, chemotaxonomic and phylogenetic data showed that strain THG-G118T could be clearly distinguished from the members of the genus Pedobacter. Based on the results of a polyphasic study, a new species, Pedobacter bambusae sp. nov., is proposed. The type strain is THG-G118T (=KACC 17544T = JCM 19364T).

Pedobacter seoulensis sp. nov., isolated from soil of a bamboo field.

A Gram-stain negative, strictly aerobic, motile by gliding, rod-shaped and yellow pigmented strain THG-G12T was isolated from soil of a bamboo field in Seoul, Republic of Korea. Strain THG-G12T was observed to grow well at 20­28 °C and pH 7.0­7.5 in the absence of NaCl on nutrient agar. Based on 16S rRNA gene sequence comparisons, strain THG-G12T was found to be most closely related to Pedobacter ginsengisoli Gsoil 104T (97.5 % sequence similarity), Pedobacter steynii WB2.3-45T (97.4 %), Pedobacter metabolipauper WB2.3-71T (97.2 %), Pedobacter nyackensis NWG-II14T (97.2 %), Pedobacter caeni LMG 22862T (97.1 %) and Pedobacter duraquae WB2.1-25T (97.0 %), but DNA relatedness between strain THG-G12T and its phylogenetically closest neighbours was below 9.5 %. The G+C content of the genomic DNA was determined to be 39.9 mol%. The only isoprenoid quinone detected in strain THG-G12T was menaquinone-7 (MK-7). The major component in the polyamine pattern was sym-homospermidine. The major polar lipids were found to be phosphatidylethanolamine, unidentified phosphoglycolipids, unidentified aminophosphoglycolipids, unidentified aminolipids and unidentified lipids. Strain THG-G12T showed the presence of two ceramide phosphorylethanolamines (CerPE-2' and CerPE-2″), dihydrosphingosines and an unidentified ceramide as the major ceramide. The major fatty acids were identified as summed feature 3 (as defined by the MIDI system; C16:1 ω7c and/or C16:1 ω6c) and iso-C15:0. These data support the affiliation of strain THG-G12T to the genus Pedobacter. The results of physiological and biochemical tests enabled strain THG-G12T to be differentiated genotypically and phenotypically from the recognized species of the genus Pedobacter. Therefore, the novel isolate represents a novel species, for which the name Pedobacter seoulensis sp. nov. is proposed, with THG-G12T as the type strain (=KACC 17529T =JCM 19363T).

Pedobacter soyangensis sp. nov., isolated from Lake Soyang in Korea.

Strain HME6451(T) was isolated from Lake Soyang in Korea. Phylogenetic tree based on 16S rRNA gene sequence showed that strain HME6451(T) formed a lineage within the genus Pedobacter. The strain HME6451(T) was closely related to Pedobacter daechungensis (95.4% sequence similarity), Pedobacter lentus (94.4%), and Pedobacter glucosidilyticus (93.8%). And strain HME6451(T) was a Gram-staining-negative, short rod-shaped, strictly aerobic bacterium. The major fatty acids were iso-C15:0 (41.2%), summed feature 3 (comprising C16:1 ω7c and/or C16:1 ω6c; 23.1%), and iso-C17:0-3OH (10.1%). The polar lipids of HME6451(T) were consisted of one phosphatidylethanolamine, one unidentified aminolipid, one unidentified phospholipid and four unidentified polar lipids. The DNA G+C content was 36.0 mol%. On the basis of the evidence presented in this study, strain HME6451(T) represent a novel species of the genus Pedobacter, for which the name Pedobacter soyangensis sp. nov., is proposed the type strain HME6451(T) (=KCTC 23467(T) =CECT 7865(T)).

Different types of synchrony in chaotic and cyclic communities.

Stability and persistence of populations is of great interest for management and conservation purposes. Spatial dynamics can have a crucial role in population stability via synchronization, and beneficial and detrimental effects on population persistence have been shown. Despite a theoretical understanding of synchronization, empirical data on synchrony of populations are restricted to systems that do not display the full spectrum of complex dynamics that may occur in nature (that is, chaos or quasiperiodicity). Here we show in experiments that the qualitative form of dynamic behaviour of chaotic and periodic oscillating communities did not change when unidirectionally coupled to oscillating driver communities. Driver and response populations were phase locked in cyclic communities, whereas chaotic communities showed only short periods of statistical coherencies. Our study provides the first empirical analysis of synchronization of chaotic communities and shows that the likelihood for chaos is not lowered in spatially explicit systems but that cyclic and chaotic systems differ in synchronization.

Isolation and characterization of bacterial isolates algicidal against a harmful bloom-forming cyanobacterium Microcystis aeruginosa.

Algicidal bacteria MaI11-2, MaI11-5 and MaI11-10, which inhibited the growth of a harmful bloom-forming cyanobacterium Microcystis aeruginosa, were isolated from a sewage treatment plant. The isolate MaI11-5 was phylogenetically affiliated into the genus Pedobacter, while MaI11-2 and MaI11-10 were closely related to Bacillus aerophilus, Bacillus altitudinis and Bacillus stratosphericus with 100% identity based on 16S ribosomal RNA sequences. Co-cultivation of M. aeruginosa with the algicidal isolates showed their high algicidal activity. MaI11-5 showed the highest inhibitory effect on the cyanobacterial growth: the inhibitory effect exceeded 50% after 2 days, and reached to 75-85% after 10 days, regardless of the bacterial cell density. The cyanobacterial cells aggregated and produced mucilaginous, glycocalyx-like compounds when attacked by the algicidal bacteria. These results suggest that the algicidal bacteria isolated in the present study are potentially useful as biocontrol agents against M. aeruginosa bloom.

Pedobacter kyungheensis sp. nov., with ginsenoside converting activity.

The Gram-negative, aerobic, non-motile, non-spore forming, and rod-shaped bacterium designated as THG-T17(T) was isolated from the soil of a ginseng field of Pocheon in Korea, and its taxonomic position was investigated by using a polyphasic approach. The growth of strain THG-T17(T) occurred at 4-40°C and pH 4.0-9.0 with 1-2% (w/v) NaCl on nutrient agar. Strain THG-T17(T) displayed ß-glucosidase activity that was responsible for its ability to transform ginsenoside Rb(1) (one of the dominant ginsenosides of ginseng) to compound F2 via gypenoside XVII. On the basis of 16S rRNA gene sequence similarity, strain THG-T17(T) was shown to belong to the genus Pedobacter and was related to Pedobacter soli 15-51(T) (98.8%), Pedobacter sandarakinus DS-27(T) (98.0%) and Pedobacter terrae DS-57(T) (98.1%). The G+C content of the genomic DNA was 42.4 mol%. The DNA-DNA relatedness values between strain THG-T17(T) and its phylogenetically closest neighbors were below 14%. Phenotypic and chemotaxonomic data, especially analysis of cellular fatty acid, supported the affiliation of strain THG-T17(T) to the genus Pedobacter. The results of genotyping and biochemical tests showed strain THG-T17(T) to be differentiated genotypically and phenotypically from the recognized species of the genus Pedobacter. Therefore, the novel isolate represents a novel species, for which the name Pedobacter kyungheensis sp. nov. is proposed, with the type strain THG-T17(T) (=KACC 16221(T) = LMG 26577(T)).

Pedobacter jeongneungensis sp. nov., isolated from forest soil.

Strain BH45(T) was isolated from forest soil of Mt. Bukhan in Jeongneung, Seoul, Korea. The Gram-staining-negative strain BH45(T) grows at 4-30°C (optimum of 25-30°C) and between pH 5-8 (optimum of pH 6-8). Its major cellular fatty acids are C(18:3) ω6c (6,9,12) and C(10:0). The G+C content of genomic DNA was 40.2 mol%. The major respiratory quinone system in strain BH45(T) is menaquinone-7. Phylogenetic analysis based on 16S rRNA gene sequences indicates that strain BH45(T) is closely related to the genus Pedobacter. Sequence similarities with P. terrae KCTC 12762(T), P. suwonensis KACC 11317(T), P. soli KACC 14939(T), P. alluvionis DSM 19624(T), P. roseus KCCM 42272(T), P. yonginense KCTC 22721(T) were 97.5, 97.1, 97.0, 97.0, 97.0, and 96.0%, respectively. DNA-DNA hybridization results distinguish strain BH45(T) from two Pedobacter species with high 16S rRNA gene sequence similarities. According to the phenotypic and molecular data, the strain BH45(T) clearly represents a novel species within the genus Pedobacter; thus, the name Pedobacter jeongneungensis sp. nov. is proposed for this strain. The type strain is BH45(T) (=KACC 15514(T) =JCM 17626(T)).

Pedobacter boryungensis sp. nov., isolated from soil.

A Gram-negative, non-sporulating, non-flagellated rod, designated BR-9(T), was isolated from soil collected on the Korean peninsula. Strain BR-9(T) grew optimally at pH 6.0-7.0, at 30 °C and in the absence of NaCl. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain BR-9(T) belonged to the genus Pedobacter and clustered with Pedobacter insulae DS-139(T) and Pedobacter koreensis WPCB189(T). Strain BR-9(T) exhibited 98.2 and 97.5% 16S rRNA gene sequence similarity with P. insulae DS-139(T) and P. koreensis WPCB189(T), respectively, and <96.7% sequence similarity with the type strains of other species in the genus Pedobacter. Strain BR-9(T) contained MK-7 as the predominant menaquinone and iso-C(15:0) and summed feature 3 (C(16:1)ω7c and/or iso-C(15:0) 2-OH) as the major fatty acids. The DNA G+C content of strain BR-9(T) was 38.5 mol%. DNA-DNA relatedness between strain BR-9(T) and P. insulae DS-139(T) and P. koreensis KCTC 12536(T) was 3.4-4.2%, which indicated that the isolate was genetically distinct from these type strains. Strain BR-9(T) was also distinguishable by differences in phenotypic properties. On the basis of the data presented, strain BR-9(T) is considered to represent a novel species of the genus Pedobacter, for which the name Pedobacter boryungensis sp. nov. is proposed. The type strain is BR-9(T) (=KCTC 23344(T) =CCUG 60024(T)).