[show abstract][hide abstract] ABSTRACT: Variations in the patterns of diversity of symbionts have been described worldwide on Mimosa pudica, a pan-tropical invasive species that interacts with both α and β-rhizobia. In this study, we investigated if symbiont competitiveness can explain these variations and the apparent prevalence of β- over α-rhizobia. We developed an indirect method to measure the proportion of nodulation against a GFP reference strain and tested its reproducibility and efficiency. We estimated the competitiveness of 54 strains belonging to four species of β-rhizobia and four of α-rhizobia, and the influence of the host genotype on their competitiveness. Our results were compared with biogeographical patterns of symbionts and host varieties. We found: (i) a strong strain effect on competitiveness largely explained by the rhizobial species, with Burkholderia phymatum being the most competitive species, followed by B. tuberum, whereas all other species shared similar and reduced levels of competitiveness; (ii) plant genotype can increase the competitiveness of Cupriavidus taiwanensis. The latter data support the likelihood of the strong adaptation of C. taiwanensis with the M. pudica var. unijuga and help explain its prevalence as a symbiont of this variety over Burkholderia species in some environments, most notably in Taiwan.
[show abstract][hide abstract] ABSTRACT: Background and AimsThe large monophyletic genus Mimosa comprises approx. 500 species, most of which are native to the New World, with Central Brazil being the main centre of radiation. All Brazilian Mimosa spp. so far examined are nodulated by rhizobia in the betaproteobacterial genus Burkholderia. Approximately 10 Mya, transoceanic dispersal resulted in the Indian subcontinent hosting up to six endemic Mimosa spp. The nodulation ability and rhizobial symbionts of two of these, M. hamata and M. himalayana, both from north-west India, are here examined, and compared with those of M. pudica, an invasive species.Methods
Nodules were collected from several locations, and examined by light and electron microscopy. Rhizobia isolated from them were characterized in terms of their abilities to nodulate the three Mimosa hosts. The molecular phylogenetic relationships of the rhizobia were determined by analysis of 16S rRNA, nifH and nodA gene sequences.Key ResultsBoth native Indian Mimosa spp. nodulated effectively in their respective rhizosphere soils. Based on 16S rRNA, nifH and nodA sequences, their symbionts were identified as belonging to the alphaproteobacterial genus Ensifer, and were closest to the 'Old World' Ensifer saheli, E. kostiensis and E. arboris. In contrast, the invasive M. pudica was predominantly nodulated by Betaproteobacteria in the genera Cupriavidus and Burkholderia. All rhizobial strains tested effectively nodulated their original hosts, but the symbionts of the native species could not nodulate M. pudica.Conclusions
The native Mimosa spp. in India are not nodulated by the Burkholderia symbionts of their South American relatives, but by a unique group of alpha-rhizobial microsymbionts that are closely related to the 'local' Old World Ensifer symbionts of other mimosoid legumes in north-west India. They appear not to share symbionts with the invasive M. pudica, symbionts of which are mostly beta-rhizobial.
[show abstract][hide abstract] ABSTRACT: A novel nitrogen-fixing strain, designated DQS-4T was isolated from oil-contaminated soil in Taiwan and was characterized using a polyphasic taxonomy approach. Cells of strain DQS-4T stained Gram-negative, contained poly-β-hydroxybutyrate granules, and were motile rods surrounded by a thin capsule. Cells have a strictly aerobic type of metabolism and fix nitrogen microaerobically. Growth occurred at 10-45 °C (optimum, 35-40 °C), at pH 7.0-8.0 (optimum, pH 7.0) and with 0-2 % NaCl (optimum, 0.5-1 %). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain DQS-4T belonged to the genus Azoarcus, and its closest neighbours were Azoarcus indigens LMG 9092T and Azoarcus communis DSM 12120T, with sequence similarities of 97.4 and 96.4 %, respectively. The major cellular fatty acids of strain DQS-4T were summed feature 3 (comprising C16:1ω7c and/or C16:1ω6c), C16:0 and C18:1ω7c. The major cellular hydroxy fatty acid was C10:0 3-OH. The DNA G+C content was 64.5 mol%. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and several uncharacterized aminophospholipids and phospholipids. The mean level of DNA-DNA relatedness between strain DQS-4T and Azoarcus indigens LMG 9092T was 27.4 %. On the basis of the genotypic and phenotypic data, strain DQS-4T represents a new species in the genus Azoarcus, for which the name Azoarcus olearius sp. nov. is proposed. The type strain is DQS-4T (=BCRC 80407T =KCTC 23918T =LMG 26893T).
INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY 05/2013; · 2.11 Impact Factor
[show abstract][hide abstract] ABSTRACT: An aerobic, Gram-negative, rod-shaped bacterium with single polar flagellum, designated as strain CC-OPY-1T, was isolated from an oil-contaminated site in Taiwan. Strain CC-OPY-1T produces siderophores, and can grow at temperature 25-37°C, pH 5.0-9.0 and tolerate <5% (w/v) NaCl. The 16S rRNA gene sequence analysis of strain CC-OPY-1T showed high pairwise sequence similarity to Pseudomonas alcaligenes BCRC 11893T (97.1%), P. alcaliphila DSM 17744T (97.1%), P. tuomuerensis JCM 14085T (97.1%), P. toyotomiensis JCM 15604T (96.9%) and lower sequence similarity to remaining Pseudomonas species. The phylogenetic trees reconstructed based on gyrB and rpoB gene sequences supported the classification of strain CC-OPY-1T as a novel member of the genus Pseudomonas. The predominant quinone system is ubiquinone (Q-9) and the DNA G+C content is 68.4±0.3 mol%. The major fatty acids were C12:0, C16:0, C17:0 cyclo, and summed features 3, and 8 consisting of C16:1 ω7c/C16:1 ω6c and C18:1 ω7c/C18:1 ω6c, respectively. The major polar lipids were phosphatidylethanolamine (PE), phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), phosphatidylcholine (PC) and two unknown phospholipids (PL1-2). Due to distinct phylogenetic, phenotypic and chemotaxonomic features, strain CC-OPY-1T is proposed to represent a novel species within the genus Pseudomonas for which the name Pseudomonas sagittaria sp. nov. is proposed. The type strain is CC-OPY-1T (=BCRC 80399T =JCM 18195T).
INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY 11/2012; · 2.11 Impact Factor
[show abstract][hide abstract] ABSTRACT: A beige-coloured, Gram-stain negative, aerobic, non-motile moderately thermotolerant, rod-shaped organism, strain CC-SPIO-10-1T, was isolated from a coastal hot spring of Green Island (Lutao), located off Taituang, Taiwan, on Marine Agar 2216. Based on the 16S rRNA gene sequence analysis this organism was grouped into genus Stappia, showing 98.3% sequence similarity to Stappia indica and 98.2% gene sequence similarity to Stappia stellulata. Ubiquinone Q-10 was the major respiratory quinone and C18:1 ω7c and C18:1ω7c 11-methyl were detected as the major fatty acids. The hydroxylated fatty acid C18:0 3-OH was detected as well. Predominant polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylglycerol, unidentified aminolipid AL1 and unidentified phospholipid PL1. Minor amounts of several unidentified lipids (PL2, L1-L7) are present as well. The polyamine pattern contains the major compounds spermidine and spermine. Strain CC-SPIO-10-1T could be differentiated from the type strains of S. stellulata and S. indica by a set of biochemical tests. On the basis of the 16S rRNA gene sequence analysis and of the chemotaxonomic and physiological data, strain CC-SPIO-10T represents a new species of the genus Stappia for which the name Stappia taiwanensis sp. nov. is proposed. The type strain is CC-SPIO-10 T (= CCUG 59208T = LMG 25538 T = CCM 7757T).
INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY 07/2012; · 2.11 Impact Factor
[show abstract][hide abstract] ABSTRACT: A strictly aerobic, Gram-negative, rod-shaped bacterium (strain CC-SAMT-1(T)) showing gliding motility was isolated from coastal seawater of China Sea, Taiwan. Strain CC-SAMT-1(T) synthesizes all-trans-zeaxanthin (6.5 ± 0.5 mg g(-1) dry biomass) as a predominant xanthophyll carotenoid. As determined by 16S rRNA gene analysis, strain CC-SAMT-1(T) shared very high sequence similarity to the members of the genera Mariniflexile (96.1-95.3%) and Gaetbulibacter (96.0-95.9%); however, it formed a distinct phyletic lineage distantly associated with Mariniflexile species. Polar lipid profile constitutes phosphatidylethanolamine, four unidentified aminolipids, four unidentified lipids, and an unidentified glycolipid. Strain CC-SAMT-1(T) contains excessive unidentified aminolipid lipid (AL2-4) and glycolipid contents, and therefore clearly distinct from Mariniflexile species. Major fatty acids (> 5% of total fatty acids) were iso-C(15:0) (14.8%), iso-C(17:0) 3-OH (11.8%), iso-C(15:1) G (10.6%), anteiso-C(15:0) (9.7%), C(16:0) (8.1%), iso-C(16:0) 3-OH (7.9%), iso-C(15:0) 3-OH (7.5%), and summed feature 3 (containing C(16:1) ω6c and/or C(16:1) ω7c) (7.5%). Menaquinone-6 (MK-6) was major respiratory quinone. DNA G+C content was 33.7 mol%. Based on polyphasic taxonomy, strain CC-SAMT-1(T) represents a novel genus and species in the family Flavobacteriaceae for which the name Siansivirga zeaxanthinifaciens gen. nov., sp. nov. is proposed. The type strain is CC-SAMT-1(T) (= BCRC 80315(T) = JCM 17682(T)).
[show abstract][hide abstract] ABSTRACT: Burkholderia phymatum STM815 and Cupriavidus taiwanensis LMG19424 are betaproteobacterial strains that can effectively nodulate several species of the large legume genus Mimosa. A Tn5 mutant, derived from B. phymatum STM815 (KM60), and another derived from C. taiwanensis LMG19424 (KM184-55) induced Fix(-) nodules on Mimosa pudica. The Tn5-interrupted genes of the mutants showed strong homologies to ilvE, which encodes a branched-chain amino acid aminotransferase, and leuC, which encodes the large subunit of isopropylmalate isomerase. Both enzymes are known to be involved in the biosynthetic pathways for branched-chain amino acids (BCAAs) (leucine, valine and isoleucine). The B. phymatum ilvE mutant, KM60, was not auxotrophic for BCAAs and could grow well on minimal medium with pyruvate as a carbon source and ammonia as a nitrogen source. However, it grew less efficiently than the wild-type (WT) strain when ammonia was substituted with valine or isoleucine as a nitrogen source. The BCAA aminotransferase activity of KM60 was significantly reduced relative to the WT strain, especially with isoleucine and valine as amino group donors. The C. taiwanensis leuC mutant, KM184-55, could not grow on a minimal medium with pyruvate as a carbon source and ammonia as a nitrogen source, but its growth was restored when leucine was added to the medium. The isopropylmalate isomerase activity of KM184-55 was completely lost compared with the WT strain. Both mutants recovered their respective enzyme activities after complementation with the WT ilvE or leuC genes and were subsequently able to grow as well as their parental strains on minimal medium. They were also able to form nitrogen-fixing nodules on M. pudica. We conclude that the biosynthesis of BCAAs is essential for the free-living growth of betarhizobia, as well as for their ability to form effective symbioses with their host plant.
[show abstract][hide abstract] ABSTRACT: For eco-friendly recycling and reuses of biomaterials with sustainability, this feasibility study tended to use indigenous pollutant degrading bacteria for the production of biodegradable polymers – polyhydroxyalkanotes (PHAs) during wastewater treatment. First, feasible PHA-producing strains were qualitatively screened among pollutant-degrading microbes via Sudan black B staining (SB staining). Next, according to batch cultures using lauric acid as sole carbon source, the promising PHA-generating strains were obtained via comparative analysis upon the characteristics of cell growth and poly 3-hydroxybutyrate (PHB) production. Aeromonas hydrophila NIU01, YTl1, KB23 and A. salmonicida 741 were found to generate intracellular PHA content at higher levels of 19.35, 24.48, 22.52%, respectively. Plus, Klebsiella pneumoniae ZMd31, Pseudomonas plecoglossicida NIU-Y3 and Chromobacterium violaceum P1 produced lower PHA contents at 18.25, 5.37 and 4.17%, respectively.
Journal of The Taiwan Institute of Chemical Engineers - J TAIWAN INST CHEM ENG. 05/2012;
[show abstract][hide abstract] ABSTRACT: Acidic lipase finds its commercial values in medical applications and bioremediation of food wastes. In this work, approaches
for rapid screening of lipase-producing bacteria were developed and the feasibility assessment of the screening methods was
performed. From food waste samples, the proposed screening procedures allowed isolation of sixteen pure bacterial strains
expressing higher lipase activity at acidic pH (pH 6.0) than at alkaline pH (pH 9.0). To enhance the accuracy of lipase activity
determination under acidic conditions, a novel assay procedure was also developed by deactivating lipase activity by microwave
treatment prior to back titration. This additional step could minimize interferences arising from residual lipase activity
during conventional direct back-titration methods in measuring lipase activity at acidic pH. Using the four strategies proposed
in this work, the best acidic-lipase-producing isolate was obtained by strategy C (SSC) and was identified as Aeromonas sp. C14, displaying an optimal lipase activity of 0.7U/ml at an acidic pH of 6.0.
World Journal of Microbiology and Biotechnology 04/2012; 23(5):633-640. · 1.26 Impact Factor
[show abstract][hide abstract] ABSTRACT: Five strains, JPY461T, JPY359, JPY389, DPU-3 and STM4206 were isolated from nitrogen-fixing nodules on the roots of Mimosa spp. and their taxonomic positions were investigated by a polyphasic approach. All five strains grew at 15-40 °C (optimum, 30-37 °C), at pH 4.0-8.0 (optimum, pH 6.0-7.0) and with 0-1 % (w/v) NaCl [optimum, 0 % (w/v)]. On the basis of 16S rRNA gene sequence analysis, a representative strain (JPY461T) showed 97.2 % sequence similarity to the closest species Burkholderia acidipaludis SA33T, a similarity of 97.2 % to Burkholderia terrae KMY02T, 97.1 % to Burkholderia phymatum STM815T and 97.1 % to Burkholderia hospita LMG 20598T. The predominant fatty acids were summed feature 2 (comprising C16:1 iso I and/or C14:0 3-OH; 5.2 %), summed feature 3 (comprising C16:1 ω7c and/or C16:1 ω6c; 6.2 %), C16:0 (18.2 %), C16:0 3-OH (5.2 %), C17:0 cyclo (8.4 %), C18:1 ω7c (32.2 %) and C19:0 cyclo ω8c (8.4 %). The major isoprenoid quinone was Q-8 and the DNA G+C content of the strains was 63.0-65.0 mol%. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and several uncharacterized aminophospholipid, aminolipid and phospholipids. The DNA-DNA relatedness of the novel strain with respect to recognized species of the genus Burkholderia was less than 54 %. On the basis of 16S rRNA and recA gene sequence similarities, chemotaxonomic and phenotypic data, all the strains represent a novel species in the genus Burkholderia, for which the name Burkholderia diazotrophica sp. nov. is proposed with the type strain, JPY461T (=LMG 26031T=BCRC 80259T=KCTC 23308T).
INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY 03/2012; · 2.11 Impact Factor
[show abstract][hide abstract] ABSTRACT: The thermophile Cupriavidus sp. strain S-6 accumulated polyhydroxybutyrate (PHB) from glucose at 50°C. A 9.0-kbp EcoRI fragment cloned from the genomic DNA of Cupriavidus sp. S-6 enabled Escherichia coli XL1-Blue to synthesize PHB at 45°C. Nucleotide sequence analysis showed a pha locus in the clone. The thermophilic polyhydroxyalkanoate (PHA) synthase (PhaC(Csp)) shared 81% identity with mesophilic PhaC of Cupriavidus necator H16. The diversity between these two strains was found dominantly on their N and C termini, while the middle regions were highly homologous (92% identity). We constructed four chimeras of mesophilic and thermophilic phaC genes to explore the mutations related to its thermostability. Among the chimeras, only PhaC(H16β), which was PhaC(H16) bearing 30 point mutations derived from the middle region of PhaC(Csp), accumulated a high content of PHB (65% [dry weight]) at 45°C. The chimera phaC(H16)(β) and two parental PHA synthase genes were overexpressed in E. coli BLR(DE3) cells and purified. At 30°C, the specific activity of the chimera PhaC(H16β) (172 ± 17.8 U/mg) was 3.45-fold higher than that of the parental enzyme PhaC(H16) (50 ± 5.2 U/mg). At 45°C, the half-life of the chimera PhaC(H16β) (11.2 h) was 127-fold longer than that of PhaC(H16) (5.3 min). Furthermore, the chimera PhaC(H16β) accumulated 1.55-fold (59% [dry weight]) more PHA content than the parental enzyme PhaC(H16) (38% [dry weight]) at 37°C. This study reveals a limited number of point mutations which enhance not only thermostability but also PhaC(H16) activity. The highly thermostable and active PHA synthase will provide advantages for its promising applications to in vitro PHA synthesis and recombinant E. coli PHA fermentation.
Journal of bacteriology 03/2012; 194(10):2620-9. · 3.94 Impact Factor
[show abstract][hide abstract] ABSTRACT: This study tended to use indigenous PHA-generating and dye-decolorizing microorganisms Aeromonas hydrophila NIU01, YTl1, KB23 and Aeromonas salmonicida 741, Klebsiella pneumoniae ZMd31 for comparing PHA production performance at various dye or amine-bearing conditions. Batch cultures using lauric acid (C12) at various concentrations as sole carbon source were carried out to determine optimal concentration for microbial growth and the production of poly 3-hydroxybutyrate (PHB). At optimal concentration of C12, cultures laden with dyes at different concentrations were conducted to explore whether dye-bearing cultures could stimulate or inhibit capabilities of PHA production. In addition, as aromatic amines were generated during reductive decolorization, effects of supplemented amines on capabilities of PHA-production were also conducted to uncover whether PHA generation during dye decolorization was attenuated. According to biostatistics, the finding indicated that strains NIU01, YTl1, KB23 could significantly tolerate dye pollutant(s) and aromatic amines for cell growth and PHA-production, suggesting promising feasibility to be used for PHA production during wastewater decolorization.
Journal of The Taiwan Institute of Chemical Engineers - J TAIWAN INST CHEM ENG. 03/2012;
[show abstract][hide abstract] ABSTRACT: Burkholderia phymatum STM815 is a β-rhizobial strain that can effectively nodulate several species of the large legume genus Mimosa. Two Tn5-induced mutants of this strain, KM16-22 and KM51, failed to form root nodules on Mimosa pudica, but still caused root hair deformation, which is one of the early steps of rhizobial infection. Both mutants grew well in a complex medium. However, KM16-22 could not grow on minimal medium unless a sugar and a metabolic intermediate such as pyruvate were provided, and KM51 also could not grow on minimal medium unless a sugar was added. The Tn5-interrupted genes of the mutants showed strong homologies to pgm, which encodes 2,3-biphosphoglycerate-dependent phosphoglycerate mutase (dPGM), and fbp, which encodes fructose 1,6-bisphosphatase (FBPase). Both enzymes are known to be involved in obligate steps in carbohydrate metabolism. Enzyme assays confirmed that KM16-22 and KM51 had indeed lost dPGM and FBPase activity, respectively, whilst the activities of these enzymes were expressed normally in both free-living bacteria and symbiotic bacteroids of the parental strain STM815. Both mutants recovered their enzyme activity after the introduction of wild-type pgm or fbp genes, were subsequently able to use carbohydrate as a carbon source, and were able to form root nodules on M. pudica and to fix nitrogen as efficiently as the parental strain. We conclude that the enzymes dPGM and FBPase are essential for the formation of a symbiosis with the host plant.
[show abstract][hide abstract] ABSTRACT: Cupriavidus necator is well known for its ability to accumulate polyhydroxybutyrate (PHB). When supplemented with propionic acid (or sodium propionate) in the growth medium, the bacterium is also able to synthesize polyhydroxybutyrate-co-hydroxyvalerate (PHBV). In order to increase the fraction of 3-hydroxyvalerate (3HV) in PHBV, we cloned the propionate permease gene prpP from C. necator and the propionyl-CoA synthase gene prpE from Cupriavidus taiwanensis and transformed into an Escherichia coli containing phaCAB operon of C. necator. The effects on PHBV accumulation in cells co-expressed with phaCAB and prpE or prpP in the media contained mixed carbon sources (glucose and sodium propionate) were evaluated. The HV fraction in PHBV increased when prpE or prpP was overexpressed in the cells. Concentrations of yeast extracts could also affect the fraction of HV. In addition, when glucose was replaced by sodium pyruvate, sodium succinate, or sodium gluconate, only PHB were detected in the recombinant strains.
Applied biochemistry and biotechnology 12/2011; 166(3):796-804. · 1.94 Impact Factor
[show abstract][hide abstract] ABSTRACT: This study unveiled a new strategy to explore new indigenous strains with excellent decolorization capabilities from freshwaters and seawaters. Two new bacterial decolorizers DX2b and SH7b, which have the capability to decolorize textile dyes, were isolated from Cross-Strait Taiwan and China. According to PCR-augmented 16S rRNA gene analyses for strain identification, >99% of nucleotide sequences in isolated strains were identical to type strains Rahnella aquatilis, Acinetobacter guillouiae, Microvirgula aerodenitrificans, and Pseudomonas sp. Time-series inspection upon azoreductase activity assay and generation of decolorized intermediates all confirmed in parallel with reductive decolorization of new decolorizers DX2b and SH7b. The result also showed that bacterial decolorization of these new strains was mainly catalyzed via the enzymatic expression of azoreductase and riboflavin reductase, and biosorption seemed not to play a crucial role color removal (approximately <10%).
Journal of Bioscience and Bioengineering 12/2011; 113(4):508-14. · 1.74 Impact Factor
[show abstract][hide abstract] ABSTRACT: A Gram-negative, non-spore-forming rod (CC-LN1-12(T)) was isolated from coastal soil samples of Lutao Island (Green Island), Taiwan, and its taxonomic position was studied. 16S rRNA gene sequence analysis showed that isolate CC-LN1-12(T) was grouped into the Microbulbifer cluster, with the highest similarities to Microbulbifer okinawensis ABABA23(T) (97.9 %), Microbulbifer maritimus TF-17(T) (97.7 %) and Microbulbifer donghaiensis CN85(T) (97.7 %), similarities to all other species of the genus Microbulbifer were lower than 96.8 %. The polyamine pattern contained the major compounds spermidine and cadaverine. The fatty acid profile, comprising the major fatty acids iso-C(15 : 0), iso-C(17 : 1)ω9c, C(18 : 1)ω7c and iso-C(11 : 0) 3-OH as the major hydroxylated fatty acid, supported the affiliation of strain CC-LN1-12(T) to the genus Microbulbifer. DNA-DNA hybridizations between strain CC-LN1-12(T) and Microbulbifer okinawensis ABABA23(T), M. donghaiensis CN85(T) and M. maritimus JCM 12187(T) resulted in relatedness values of 21.5 % (14.3 %, reciprocal analysis), 35.9 % (48.5 %, reciprocal analysis) and 48.1 % (52.1 %, reciprocal analysis), respectively. From these data, as well as from physiological and biochemical tests, strain CC-LN1-12(T) could be clearly differentiated from the most closely related species of the genus Microbulbifer. It is concluded that strain CC-LN1-12(T) represents a novel species, for which the name Microbulbifer taiwanensis sp. nov. is proposed. The type strain is CC-LN1-12(T) ( = LMG 26125(T) = CCM 7856(T)).
INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY 12/2011; 62(Pt 10):2485-9. · 2.11 Impact Factor
[show abstract][hide abstract] ABSTRACT: Four strains, designated JPY-345(T), JPY-347, JPY-366 and JPY-581, were isolated from nitrogen-fixing nodules on the roots of two species of Mimosa, Mimosa cordistipula and Mimosa misera, that are native to North East Brazil, and their taxonomic positions were investigated by using a polyphasic approach. All four strains grew at 15-43 °C (optimum 35 °C), at pH 4-7 (optimum pH 5) and with 0-2 % (w/v) NaCl (optimum 0 % NaCl). On the basis of 16S rRNA gene sequence analysis, strain JPY-345(T) showed 97.3 % sequence similarity to the closest related species Burkholderia soli GP25-8(T), 97.3 % sequence similarity to Burkholderia caryophylli ATCC25418(T) and 97.1 % sequence similarity to Burkholderia kururiensis KP23(T). The predominant fatty acids of the strains were C(18 : 1)ω7c (36.1 %), C(16 : 0) (19.8 %) and summed feature 3, comprising C(16 : 1)ω7c and/or C(16 : 1)ω6c (11.5 %). The major isoprenoid quinone was Q-8 and the DNA G+C content of the strains was 64.2-65.7 mol%. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and several uncharacterized aminophospholipids and phospholipids. DNA-DNA hybridizations between the novel strain and recognized species of the genus Burkholderia yielded relatedness values of <51.8 %. On the basis of 16S rRNA and recA gene sequence similarities and chemotaxonomic and phenotypic data, the four strains represent a novel species in the genus Burkholderia, for which the name Burkholderia symbiotica sp. nov. is proposed. The type strain is JPY-345(T) ( = LMG 26032(T) = BCRC 80258(T) = KCTC 23309(T)).
INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY 11/2011; 62(Pt 9):2272-8. · 2.11 Impact Factor
[show abstract][hide abstract] ABSTRACT: A brownish yellow pigmented bacterial strain, designated antisso-27, was recently isolated from a water area of saltpan in Southern Taiwan. Phylogenetic analyses based on 16S rRNA gene sequences indicate that strain antisso-27 belongs the genus Aquimarina in the family Flavobacteriacea and its only closest neighbor is Aquimarina spongiae (96.6%). Based on screening for algicidal activity, strain antisso-27 exhibits potent activity against the toxic cyanobacterium Microcystis aeruginosa. Both the strain antisso-27 bacterial culture and its culture filtrate show algicidal activity against the toxic cyanobacterium, indicating that an algicidal substance is released from strain antisso-27. The algicidal activity of strain antisso-27 occurs during the late stationary phase of bacterial growth. Strain antisso-27 can synthesize an algicidal protein with a molecular mass of 190 kDa, and its isoelectric point is approximately 9.4. This study explores the nature of this algicidal protein such as L-amino acid oxidase with broad substrate specificity. The enzyme is most active with L-leucine, L-isoleucine, L-methionine and L-valine and the hydrogen peroxide generated by its catalysis mediates algicidal activity. This is the first report on an Aquimarina strain algicidal to the toxic M. aeruginosa and the algicidal activity is generated through its enzymatic activity of L-amino acid oxidase.
Enzyme and microbial technology. 09/2011; 49(4):372-9.