Paenibacillus plantiphilus sp. nov. from the plant environment of Zea mays.

A Gram-strain positive, aerobic, endospore-forming bacterial strain (JJ-246T) was isolated from the rhizosphere of Zea mays. The 16S rRNA gene sequence similarity comparisons showed a most closely relationship to Paenibacillus oenotherae DT7-4T (98.4%) and Paenibacillus xanthinolyticus 11N27T (98.0%). The pairwise average nucleotide identity and digital DNA-DNA hybridisation values of the JJ-246T genome assembly against publicly available Paenibacillus type strain genomes were below 82% and 33%, respectively. The draft genome of JJ-246T shared many putative plant-beneficial functions contributing (PBFC) genes, related to plant root colonisation, oxidative stress protection, degradation of aromatic compounds, plant growth-promoting traits, disease resistance, drug and heavy metal resistance, and nutrient acquisition. The quinone system of strain JJ-246T, the polar lipid profile and the major fatty acids were congruent with those reported for members of the genus Paenibacillus. JJ-246T was shown to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus plantiphilus sp. nov. is proposed, with JJ-246T (= LMG 32093T = CCM 9089T = CIP 111893T) as the type strain.

Paenibacillus auburnensis sp. nov. and Paenibacillus pseudetheri sp. nov., isolated from the rhizosphere of Zea mays.

Two Gram-stain-positive, aerobic, endospore-forming bacterial strains, isolated from the rhizosphere of Zea mays were studied for their detailed taxonomic allocation. Based on 16S rRNA gene sequence similarity comparisons, both strains JJ-7T and JJ-60T were shown to be members of the genus Paenibacillus. Strain JJ-7T was most closely related to the type strains of Paenibacillus tianjinensis (99.6 %) and P. typhae (98.7 %), and strain JJ-60T to Paenibacillus etheri (99.5 %). The 16S rRNA gene sequence similarities to all other Paenibacillus species were ≤98.4 %. Both strains JJ-7T and JJ-60T showed 97.6 % 16S rRNA gene sequence similarity between each other. Genomic comparisons showed that the average nucleotide identity and digital DNA-DNA hybridization values to next related type strain genomes were always <94 and <56 %, respectively. The polar lipid profiles of both strains contain a number of phospholipids including diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine, which is in accord with the genus Paenibacillus. The major quinone was MK-7 in both strains. Major fatty acids were iso- and anteiso-branched. Physiological and biochemical characteristics allowed a further phenotypic differentiation of strains JJ-7T and JJ-60T from the most closely related species. Thus, each strain represents a novel species of the genus Paenibacillus, for which the names Paenibacillus auburnensis sp. nov. and Paenibacillus pseudetheri sp. nov. are proposed, with JJ-7T (=CIP 111892T=DSM 111785T=LMG 32088T=CCM 9087T) and JJ-60T (=CIP 111894T=DSM 111787T=LMG 32090T=CCM 9086T) as the type strains, respectively.

Neobacillus rhizosphaerae sp. nov., isolated from the rhizosphere, and reclassification of Bacillus dielmonensis as Neobacillus dielmonensis comb. nov.

A Gram-stain-positive, facultative anaerobic endospore-forming bacterium, which originated from roots/rhizosphere of maize (Zea mays), was investigated for its taxonomic position. On the basis of 16S rRNA gene sequence similarities, strain JJ-3T was grouped together with Neobacillus species showing the highest similarities to Neobacillus bataviensis (98.8 %) and the three species Neobacillus dendrensis, Neobacillus soli and Neobacillus cucumis (all 98.6 %). The 16S rRNA gene sequence similarities to the sequences of the type strains of other Neobacillus species were lower than 98.5 %. The average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization values between the JJ-3T genome assembly and those of the other Neobacillus type strains were <83, <85 and <27 %, respectively. Chemotaxonomic features supported the grouping of the strain to the genus Neobacillus, e.g. the major fatty acids were C15 : 0 anteiso and C15 : 0 iso, the polar lipid profile contained the major components diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine, and the major quinone was menaquinone MK-7. Physiological and biochemical test results were slightly different from those of the most closely related species. For this reason, JJ-3T represents a novel species of the genus Neobacillus, for which we propose the name Neobacillus rhizosphaerae sp. nov., with JJ-3T (= CIP 111895T=LMG 32087T=DSM 111784T=CCM 9084T) as the type strain. We also propose to reclassify Bacillus dielmonensis as Neobacillus dielmonensis comb. nov. based mainly on the results of phylogenomic and conserved signature indel analyses.

Sutcliffiella rhizosphaerae sp. nov. isolated from roots.

An aerobic, Gram-staining-positive, endospore-forming bacterium, isolated from the rhizosphere of roots of maize (Zea mays), was taxonomically studied. On the basis of 16S rRNA gene sequence similarity comparisons, strain JJ-125T clustered together with species of the genus Sutcliffiella and showed the highest similarities with Sutcliffiella zhanjiangensis (98.7 %). The 16S rRNA gene sequence similarities to the sequences of the type strains of other species of the genus Sutcliffiella were <98.4 %. The genome sequence of JJ-125T was 4 516 360 bp long and had a DNA G+C content of 37.3 %. A DNA-DNA hybridization with the type strain of S. zhanjiangensis DSM 23010T resulted in values of 42.3 and 43.9 % (reciprocal). The average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization values between the JJ-125T genome assembly and those of the other type strains of species of the genus Sutcliffiella were <75%, <80 % and <21 %, respectively. Chemotaxonomic features supported the grouping of the strain with the genus Sutcliffiella, e.g. the major fatty acids included iso-C15 : 0, iso-C17 : 1 ω10c and iso-C17 : 0, the polar lipid profile contained the major components diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine, the only quinone was menaquinone MK-7 and the characteristic diamino acid was meso-diaminopimelic acid. Physiological and biochemical test results were also different from those of the most closely related species. As a consequence, JJ-125T represents a novel species of the genus Sutcliffiella, for which we propose the name Sutcliffiella rhizosphaerae sp. nov., with JJ-125T (= CIP 111883T = LMG 32156T = CCM 9046T) as the type strain.

Paenibacillus allorhizoplanae sp. nov. from the rhizoplane of a Zea mays root.

A Gram-positive staining, aerobic, endospore-forming bacterial strain, isolated from the rhizosphere of Zea mays was studied for its detailed taxonomic allocation. Based on the 16S rRNA gene sequence similarity comparisons, strain JJ-42 T was shown to be a member of the genus Paenibacillus, most closely related to the type strain of Paenibacillus pectinilyticus (98.8%). The 16S rRNA gene sequence similarity to all other Paenibacillus species was below 98.5%. The pairwise average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values of the JJ-42 T genome assembly against publicly available Paenibacillus type strain genomes were below 92% and 47%, respectively. The quinone system of strain JJ-42 T consisted exclusively of menaquinone MK-7. The polar lipid profile consisted of the major components diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, three aminophospholipids (APL), and one unidentified lipid. The major fatty acids were iso- and anteiso-branched with the major compound anteiso C15:0. Physiological and biochemical characteristics allowed a further phenotypic differentiation of strain JJ-42 T from the most closely related species. Thus, JJ-42 T represents a novel species of the genus Paenibacillus, for which the name Paenibacillus allorhizoplanae sp. nov. is proposed, with JJ-42 T (= LMG 32089 T = CCM 9085 T = DSM 111786 T = CIP 111891 T) as the type strain.

Bacillus rhizoplanae sp. nov. from maize roots.

A Gram-stain-positive, aerobic and endospore-forming bacterial strain, isolated from the root surface of maize (Zea mays) was taxonomically studied. It could be clearly shown that, based on 16S rRNA gene sequence similarity comparisons, strain JJ-63T is a member of the genus Bacillus, most closely related to the type strain of Bacillus pseudomycoides (98.61%), followed by Bacillus cereus (98.47 %). Detailed phylogenetic analysis based on the 16S rRNA gene and the 87 proteins conserved within the phylum Firmicutes placed the strain into the Cereus clade. The average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization values against the type strain of B. pseudomycoides were 80.97, 81.45 and 26.30 %, respectively. The quinone system of strain JJ-63T consisted exclusively of menaquinone MK-7. The polar lipid profile consisted of the major components diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and an unidentified glycolipid. Major fatty acids were iso- and anteiso-branched with the major compounds iso-C15 : 0 and iso-C17 : 0. Also, the characteristic compounds C13 : 0 iso and C16 : 1 cis10 were found. Physiological and biochemical characteristics allowed a further phenotypic differentiation of strain JJ-63T from the most closely related species. For this reason, JJ-63T represents a novel species of the genus Bacillus, for which the name Bacillus rhizoplanae sp. nov. is proposed, with JJ-63T (=LMG 32091T=CCM 9090T=DSM 111827T= CIP 111899T) as the type strain.

Pseudoneobacillus rhizosphaerae gen. nov., sp. nov., isolated from maize root rhizosphere.

A facultative anaerobic, Gram-stain-positive, endospore-forming bacterium, isolated from the rhizosphere of maize roots (Zea mays), was taxonomically studied. Based on 16S rRNA gene sequence similarity comparisons, strain JJ-79T clustered only loosely with Neobacillus species and showed the highest similarity to Neobacillus soli (97.9%). The 16S rRNA gene sequence similarities to the sequences of the type strains of other Neobacillus species were 97.5 % and below. Chemotaxonomic features supported the grouping of the strain to the Neobacillus group, e.g. the major fatty acids were C15 : 0 anteiso, C15 : 0 iso and C16 : 0, the polar lipid profile contained the major components diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and an unidentified glycolipid, the major quinone was menaquinone MK-7, and major compound in the polyamine pattern was spermidine. However, the JJ-79T genome assembly did not share most of the 11 conserved signature indels that are indicative of the genus Neobacillus. The average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization values between the JJ-79T genome assembly and those of the closest relative Bacillaceae type strains were <71, <71 and <25 %, respectively. Physiological and biochemical test results were also different from those of the most closely related Bacillaceae species. As a consequence, JJ-79T represents a novel genus for which we propose the name Pseudoneobacillus rhizosphaerae gen. nov., sp. nov., with JJ-79T (=CIP 111885T=CCM 9045T) as the type strain.

Leucobacter soli sp. nov., from soil amended with humic acid.

A Gram-positive, non-spore-forming actinobacterium (IMT-300T) was isolated from soil amended with humic acid in Malvern, AL, USA. This soil has been used for 50+years for the cultivation of earthworms for use as fish bait. Based on 16S rRNA gene sequence similarity studies, strain IMT-300T was shown to belong to the genus Leucobacter and was closely related to the type strain of 'Leucobacter margaritiformis' L1T (97.8%). Similarity to all other type strains of Leucobacter species was lower than 97.2 %. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between the IMT-300T genome assembly and those of the closest relative Leucobacter type strain were 81.4 and 23.3 % (Leucobacter chironomi), respectively. The peptidoglycan of strain IMT-300T contained l-2,4-diaminobutyric acid as the diagnostic diamino acid. In addition, glycine, d- and l-alanine and d-glutamic acid were found. The peptidoglycan type represents a variant of B2δ (B11). The major quinones were menaquinones MK-10 and MK-11. The polar lipid profile consisted of the major lipids diphosphatidylglycerol, phosphatidylglycerol and moderate to minor amounts of two unidentified phospholipids, two unidentified glycolipids and an unidentified aminophospholipid. The polyamine pattern contained major amounts of spermidine and spermine. Strain IMT-300T contained the major fatty acids C15 : 0 anteiso, C16 : 0 iso and C17 : 0 anteiso, like other members of the genus Leucobacter. The results of ANI and dDDH analyses and physiological and biochemical tests allowed a genotypic and phenotypic differentiation of strain IMT-300T from the most closely related Leucobacter species. Strain IMT-300T represents a novel Leucobacter species, for which we propose the name Leucobacter soli sp. nov., with the type strain IMT-300T (CIP 111803T=DSM 110505T=CCM 9020T=LMG 31600T).

Paenibacillus allorhizosphaerae sp. nov., from soil of the rhizosphere of Zea mays.

A Gram-stain-positive, aerobic, endospore-forming bacterial strain, isolated from the rhizosphere of Zea mays, was studied for its detailed taxonomic allocation. Based on 16S rRNA gene sequence similarity comparisons, strain JJ-447T was shown to be a member of the genus Paenibacillus, most closely related to the type strain of Paenibacillus solanacearum (97.8 %). The 16S rRNA gene sequence similarity values to all other Paenibacillus species were below 97.0 %. DNA-DNA hybridization (DDH) values with the type strain of P. solanacearum were 35.9 % (reciprocal 27%), respectively. The average nucleotide identity and in silico DDH values with the type strain of P. solanacearum were 84.86 and 28.9 %, respectively. The quinone system of strain JJ-447T consisted exclusively of menaquinones and the major component was MK-7 (96.4 %) but minor amounts of MK-6 (3.6 %) were detected as well. The polar lipid profile consisted of the major components diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and an unidentified aminolipid. Major fatty acids were iso- and anteiso-branched with the major compounds anteiso-C15 : 0 and iso-C15 : 0. Physiological and biochemical characteristics allowed a further phenotypic differentiation of strain JJ-447T from the most closely related species on the basis of d-glucose, l-arabinose and d-mannose assimilation and other physiological tests. Thus, JJ-447T represents a novel species of the genus Paenibacillus, for which the name Paenibacillus allorhizosphaerae sp. nov. is proposed, with JJ-447T (=LMG 31601T=CCM 9021T=CIP 111802T) as the type strain.

Pseudomonas carbonaria sp. nov., isolated from charcoal.

A beige-pigmented, oxidase-positive bacterial isolate, Wesi-4T, isolated from charcoal in 2012, was examined in detail by applying a polyphasic taxonomic approach. Cells of the isolates were rod shaped and Gram-stain negative. Examination of the 16S rRNA gene sequence of the isolate revealed highest sequence similarities to the type strains of Pseudomonas matsuisoli and Pseudomonas nosocomialis (both 97.3 %). Phylogenetic analyses on the basis of the 16S rRNA gene sequences indicated a separate position of Wesi-4T, which was confirmed by multilocus sequence analyses (MLSA) based on the three loci gyrB, rpoB and rpoD and a core genome-based phylogenetic tree. Genome sequence based comparison of Wesi-4T and the type strains of P. matsuisoli and P. nosocomialis yielded average nucleotide identity values <95 % and in silico DNA-DNA hybridization values <70 %, respectively. The polyamine pattern contains the major amines putrescine, cadaverine and spermidine. The quinone system contains predominantly ubiquinone Q-9 and in the polar lipid profile diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine are the major lipids. The fatty acid contains predominantly C16 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and summed feature 8 (C18 : 1ω7c and/or C18 : 1 ω6c). In addition, physiological and biochemical tests revealed a clear phenotypic difference from P. matsuisoli. These cumulative data indicate that the isolate represents a novel species of the genus Pseudomonas for which the name Pseudomonas carbonaria sp. nov. is proposed with Wesi-4T (=DSM 110367T=CIP 111764T=CCM 9017T) as the type strain.

Flavobacterium panici sp. nov. isolated from the rhizosphere of the switchgrass Panicum virgatum.

A Gram-staining-negative non endospore-forming strain, PXU-55T, was isolated from the rhizosphere of the switchgrass Panicum virgatum and studied in detail to determine its taxonomic position. The results of 16S rRNA gene sequence analysis indicated that the isolate represented a member of the genus Flavobacterium. The isolate shared highest 16S rRNA gene sequence similarities with the type strains of Flavobacterium chungangense (98.78 %) and Flavobacterium chilense (98.64 %). The average nucleotide identity (ANI) and in silico DNA-DNA hybridization (isDDH) values between the PXU-55T genome assembly and the ones of the most closely related type strains of species of the genus Flavobacterium were 87.3 and 31.9% (Flavobacterium defluvii), and 86.1 and 29.9% (Flavobacterium johnsoniae). Menaquinone MK-6 was the major respiratory quinone. As major polar lipids, phosphatidylethanolamine, an ornithine lipid and the unidentified polar lipids L2, L3 and L4 lacking a functional group were found. Moderate to minor amounts of another ornithine lipid, the unidentified lipid L1 and a glycolipid were present, as well. The major polyamine is sym-homospermidine. The fatty acid profiles contained major amounts of iso-C15:0, iso-C15:0 3-OH, iso-C17:0 3-OH, C15:0, summed feature 3 (C16:1ω7c and/or iso-C15:0 2-OH) and various hydroxylated fatty acids in smaller amounts, among them iso C16:0 3-OH, C16:0 3-OH and C15:0 3-OH, which supported the classification of the isolate as a member of the genus Flavobacterium. Physiological and biochemical characterisation and ANI calculations with the type strains of the most closely related species allowed a clear phenotypic and genotypic differentiation of the strain. For this reason, we propose that strain PXU-55T (=CIP 111646T=CCM 8914T) represents a novel species with the name Flavobacterium panici sp. nov.

Xinfangfangia humi sp. nov., isolated from soil amended with humic acid.

Two slightly beige-pigmented, Gram-stain-negative, rod-shaped bacterial strains, IMT-291T and IMT-297, were isolated from soil in a field located in Malvern, Alabama, USA. The source soil had been amended with humic acid and continuously used for the cultivation of worms used for fish bait. It is still conceivable that the source of the strains is from the humic acid amendment, although all attempts to isolate the novel phenotypes from the humic acid source have failed. The two strains were identical based on morphology, growth rate and subsequently by 16S rRNA gene sequences, but showed differences in genomic fingerprint patterns generated by rep-PCR. Phylogenetic analysis based on the 16S rRNA gene revealed a placement of the strain in a distinct cluster with Xinfangfangia soli (97.2 % 16S rRNA gene sequence similarity) and in close proximity to the genus Falsirhodobacter with highest 16S rRNA gene sequence similarity of 95.3 % to the type strain of Falsirhodobacter deserti. Sequence similarities to all other type strains were below 95.0 %. The chemotaxonomic analysis showed a clear similarity to the genus Xinfangfangia. The main cellular fatty acids of the strain were C18 : 1 ω7c, 11-methly-C18 : 1 ω7c and C16 : 0. The major quinone was ubiquinone Q-10. Phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylglycerol and phosphatidylcholine were predominant in the polar lipid profile. The polyamine pattern contained the major compound spermidine and moderate amounts of putrescine and cadaverine. The diamino acid of the peptidoglycan was meso-diaminopimelic acid. Based on phylogenetic, chemotaxonomic and phenotypic analyses we propose a new species of the genus Xinfangfangia, with the name Xinfangfangiahumi sp. nov. and strain IMT-291T (=LMG 30636T=CIP 111625T=CCM 8858T) as type strain.

Pectin-Rich Amendment Enhances Soybean Growth Promotion and Nodulation Mediated by Bacillus Velezensis Strains.

Plant growth-promoting rhizobacteria (PGPR) are increasingly used in crops worldwide. While selected PGPR strains can reproducibly promote plant growth under controlled greenhouse conditions, their efficacy in the field is often more variable. Our overall aim was to determine if pectin or orange peel (OP) amendments to Bacillus velezensis (Bv) PGPR strains could increase soybean growth and nodulation by Bradyrhizobium japonicum in greenhouse and field experiments to reduce variability. The treatments included untreated soybean seeds planted in field soil that contained Bv PGPR strains and non-inoculated controls with and without 0.1% (w/v) pectin or (1 or 10 mg/200 µL) orange peel (OP) amendment. In greenhouse and field tests, 35 and 55 days after planting (DAP), the plants were removed from pots, washed, and analyzed for treatment effects. In greenhouse trials, the rhizobial inoculant was not added with Bv strains and pectin or OP amendment, but in the field trial, a commercial B. japonicum inoculant was used with Bv strains and pectin amendment. In the greenhouse tests, soybean seeds inoculated with Bv AP193 and pectin had significantly increased soybean shoot length, dry weight, and nodulation by indigenous Bradyrhizobium compared to AP193 without pectin. In the field trial, pectin with Bv AP193 significantly increased the shoot length, dry weight, and nodulation of a commercial Bradyrhizobium japonicum compared to Bv AP193 without pectin. In greenhouse tests, OP amendment with AP193 at 10 mg significantly increased the dry weight of shoots and roots compared to AP193 without OP amendment. The results demonstrate that pectin-rich amendments can enhance Bv-mediated soybean growth promotion and nodulation by indigenous and inoculated B. japonicum.

Pigmentiphaga humi sp. nov., isolated from soil amended with humic acid.

A slightly beige-pigmented, Gram-stain-negative, rod-shaped bacterium, strain IMT-318T, was isolated from soil in a field located in Malvern, Alabama, USA. Phylogenetic analysis based on the 16S rRNA gene placed the strain within the genus Pigmentiphaga with highest 16S rRNA gene sequence similarity of 98.74 % and 98.67 % to the type strains of Pigmentiphaga kullae and Pigmentiphaga daeguensis, respectively. Sequence similarities to all other species of the genus were below 98.0 %. Results of the chemotaxonomic analysis, however, showed clear similarities to the genus Pigmentiphaga. The main cellular fatty acids of the strain were C16 : 0, C18 : 1 ω7c, C17 : 0 cyclo and C19 : 0 cyclo ω8c. The major quinone was ubiquinone Q-8. The polar lipid profile was composed of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and an unidentified aminophospholipid. In the polyamine pattern, putrescine and 2-hydroxyputrescine were predominant. The diamino acid of the peptidoglycan was meso-diaminopimelic acid. Based on phylogenetic, chemotaxonomic and phenotypic analyses, we propose a new species of the genus Pigmentiphaga, with the name Pigmentiphaga humi sp. nov. and strain IMT-318T (=LMG 30658T=CIP 111626T=CCM 8859T) as the type strain.

Filibacter tadaridae sp. nov., isolated from within a guano pile from a colony of Mexican free-tailed bats Tadarida brasiliensis.

A Gram-stain-positive, aerobic bacterium, TB-66T, was isolated from a pile of bat guano in a cave of New Mexico, USA. On the basis of 16S rRNA gene sequence similarity comparisons, strain TB-66Tgrouped together with Filibacter limicola showing a 16S rRNA gene sequence similarity of 98.5 % to the type strain. The quinone system of strain TB-66T consisted predominantly of menaquinone MK-7. The polar lipid profile contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylserine and three unidentified phospholipids. The peptidoglycan type was A4α l-Lys-d-Glu (A11.33). The major fatty acids were C15 : 0 anteiso, C16 : 0, and C16 : 1 ω7c. The G+C content of the genomic DNA was 37.6 (±1.8) mol%. On the basis of the genotypic and phenotypic properties it is clear that strain TB-66T represents a member of the genus Filibacter, but is distinct from the only other species in the genus, Filibacter limicola DSM 13886T. We propose a novel species with the name Filibacter tadaridae sp. nov. The type strain is TB-66T (= CIP 111629T= LMG 30660T= CCM 8866T).

Variation in Bat Guano Bacterial Community Composition With Depth.

Bats are known to be reservoirs for a variety of mammalian pathogens, including viruses, fungi, and bacteria. Many of the studies examining the microbial community inhabiting bats have investigated bacterial taxa found within specific bat tissues and isolated bat guano pellets, but relatively few studies have explored bacterial diversity within bat guano piles. In large bat caves, bat guano can accumulate over time, creating piles several meters deep and forming complex interactions with coprophagous organisms in a habitat with low light and oxygen. As the guano decays, the nutrient composition changes, but the bacterial communities deep within the pile have not been characterized. Here, we assess the bacterial communities across varying depths within the guano pile using both culture-independent and culture-dependent methods. We found that although similar taxa are found throughout the guano pile, the relative abundances of taxa within the pile shift, allowing certain taxa to dominate the bacterial community at varying depths. We also identified potential bacterial functions being performed within the bat guano as various depths within the pile and found little variation in terms of the dominant predicted functions, suggesting that although the relative abundances of bacterial taxa are changing, the functions being performed are similar. Additionally, we cultured 15 different bacterial species, including 2 not present in our culture-independent analysis, and discuss the pathogenicity potential of these taxa. This study represents the first characterization of the bacterial community from the extreme environment within a bat guano pile and demonstrates the potential for bat caves as resources for identifying new bacterial species.

Isolation and characterization of N2 -fixing bacteria from giant reed and switchgrass for plant growth promotion and nutrient uptake.

The aims of this study were to isolate and characterize N2 -fixing bacteria from giant reed and switchgrass and evaluate their plant growth promotion and nutrient uptake potential for use as biofertilizers. A total of 190 bacteria were obtained from rhizosphere soil and inside stems and roots of giant reed and switchgrass. All the isolates were confirmed to have nitrogenase activity, 96.9% produced auxin, and 85% produced siderophores. Then the top six strains, including Sphingomonas trueperi NNA-14, Sphingomonas trueperi NNA-19, Sphingomonas trueperi NNA-17, Sphingomonas trueperi NNA-20, Psychrobacillus psychrodurans NP-3, and Enterobacter oryzae NXU-38, based on nitrogenase activity, were inoculated on maize and wheat seeds in greenhouse tests to assess their potential benefits to plants. All the selected strains promoted plant growth by increasing at least one plant growth parameter or increasing the nutrient concentration of maize or wheat plants. NNA-14 outperformed others in promoting early growth and nutrient uptake by maize. Specifically, NNA-14 significantly increased root length, surface area, and fine roots of maize by 14%, 12%, and 17%, respectively, and enhanced N, Ca, S, B, Cu, and Zn in maize. NNA-19 and NXU-38 outperformed others in promoting both early growth and nutrient uptake by wheat. Specifically, NNA-19 significantly increased root dry weight and number of root tips of wheat by 25% and 96%, respectively, and enhanced Ca in wheat. NXU-38 significantly increased root length, surface area, and fine roots of wheat by 21%, 13%, and 26%, respectively, and enhanced levels of Ca and Mg in wheat. It is concluded that switchgrass and giant reed are colonized by N2 -fixing bacteria that have the potential to contribute to plant growth and nutrient uptake by agricultural crops.

Mixtures of Plant-Growth-Promoting Rhizobacteria Enhance Biological Control of Multiple Plant Diseases and Plant-Growth Promotion in the Presence of Pathogens.

Several studies have shown that mixtures of plant-growth-promoting rhizobacteria (PGPR) could enhance biological control activity for multiple plant diseases through the mechanisms of induced systemic resistance or antagonism. Prior experiments showed that four individual PGPR strains-AP69 (Bacillus altitudinis), AP197 (B. velezensis), AP199 (B. velezensis), and AP298 (B. velezensis)-had broad-spectrum biocontrol activity via antagonism in growth chambers against two foliar bacterial pathogens (Xanthomonas axonopodis pv. vesicatoria and Pseudomonas syringae pv. tomato) and one of two tested soilborne fungal pathogens (Rhizoctonia solani and Pythium ultimum). Based on these findings, the overall hypothesis of this study was that a mixture of two individual PGPR strains would exhibit better overall biocontrol and plant-growth promotion than the individual PGPR strains. Two separate greenhouse experiments were conducted. In each experiment, two individual PGPR strains and their mixtures were tested for biological control of three different diseases and for plant-growth promotion in the presence of the pathogens. The results demonstrated that the two individual PGPR strains and their mixtures exhibited both biological control of multiple plant diseases and plant-growth promotion. Overall, the levels of disease suppression and growth promotion were greater with mixtures than with individual PGPR strains.

Paenibacillus nebraskensis sp. nov., isolated from the root surface of field-grown maize.

A Gram-positive-staining, aerobic, non-endospore-forming bacterial strain (JJ-59T), isolated from a field-grown maize plant in Dunbar, Nebraska in 2014 was studied by a polyphasic approach. Based on 16S rRNA gene sequence similarity comparisons, strain JJ-59T was shown to be a member of the genus Paenibacillus, most closely related to the type strains of Paenibacillus aceris (98.6 % 16S rRNA gene sequence similarity) and Paenibacillus chondroitinus (97.8 %). For all other type strains of species of the genus Paenibacillus lower 16S rRNA gene sequence similarities were obtained. DNA-DNA hybridization values of strain JJ-59T to the type strains of P. aceris and P. chondroitinus were 26 % (reciprocal, 59 %) and 52 % (reciprocal, 59 %), respectively. Chemotaxonomic characteristics such as the presence of meso-diaminopimelic acid in the peptidoglycan, the major quinone MK-7 and spermidine as the major polyamine were in agreement with the characteristics of the genus Paenibacillus. Strain JJ-59T shared with its next related species P. aceris the major lipids diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and an unidentified aminophospholipid, but the presence/absence of certain lipids was clearly distinguishable. Major fatty acids of strain JJ-59T were anteiso-C15 : 0, iso-C15 : 0 and iso-C16 : 0, and the genomic G+C content is 47.2 mol%. Physiological and biochemical characteristics of strain JJ-59T were clearly different from the most closely related species of the genus Paenibacillus. Thus, strain JJ-59T represents a novel species of the genus Paenibacillus, for which the name Paenibacillus nebraskensis sp. nov. is proposed, with JJ-59T (=DSM 103623T=CIP 111179T=LMG 29764T) as the type strain.

Flavobacterium gossypii sp. nov. isolated from the root tissue of field-grown cotton.

A yellow-pigmented bacterial strain, JM-222T, isolated from the root tissue of field-grown cotton (Gossypium hirsutum) in Auburn, Alabama, USA, was studied for its taxonomic allocation. Cells of the isolate were rod-shaped and Gram-stain-negative. A blast analysis using the EzTaxon database showed that strain JM-222T shared highest 16S rRNA gene sequence similarity with the type strain of Flavobacterium endophyticum (98.9 %) followed by Flavobacterium qiangtangense (96.7 %). 16S rRNA gene sequence similarities to all other Flavobacterium species were below 95 %. The fatty acid profile of strain JM-222T consisted of the major fatty acids C15 : 0, iso-C15 : 0, iso-C15 : 0 2-OH/C16 : 1ω7c and iso-C17 : 0 3-OH. Major compounds in the polar lipid profile were phosphatidylethanolamine and several unidentified lipids. The quinone system consisted predominantly of menaquinone MK-6. The polyamine pattern consisted of the major compound sym-homospermidine and only minor amounts of other polyamines. These data and the differential biochemical and chemotaxonomic properties showed that the isolate JM-222T represents a novel species of the genus Flavobacterium, for which the name Flavobacterium gossypii sp. nov. is proposed. The type strain is JM-222T (LMG 28821T=CCM 8610T).