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ABSTRACT: Two strains of acid-neutralizing bacteria, E25(T) and E21, were isolated from torpedo grass (Panicum repens) growing in highly acidic swamps (pH 2-4) in actual acid sulfate soil areas of Thailand. Cells of the strains were gram-negative, aerobic, non-spore-forming rods, 0.6-0.8 µm wide and 1.6-2.1 µm long. The strains showed good growth at pH 4.0-8.0 and 17-37 °C. The organisms contained ubiquinone Q-8 as the predominant isoprenoid quinone and C(16 : 0), C(17 : 0) cyclo and C(18 : 1)ω7c as the major fatty acids. Their fatty acid profiles were similar to those reported for other Burkholderia species. The DNA G+C content of the strains was 65 mol%. On the basis of 16S rRNA gene sequence similarity, the strains were shown to belong to the genus Burkholderia. Although the calculated 16S rRNA gene sequence similarity of E25(T) to strain E21 and the type strains of Burkholderia unamae, B. tropica, B. sacchari, B. nodosa and B. mimosarum was 100, 98.7, 98.6, 97.6, 97.4 and 97.3 %, respectively, strains E25(T) and E21 formed a group that was distinct in the phylogenetic tree; the DNA-DNA relatedness of E25(T) to E21 and B. unamae CIP 107921(T), B. tropica LMG 22274(T), B. sacchari LMG 19450(T), B. nodosa LMG 23741(T) and B. mimosarum LMG 23256(T) was 90, 42, 42, 42, 45 and 35 %, respectively. The results of physiological and biochemical tests including whole-cell protein pattern analysis allowed phenotypic differentiation of these strains from previously described Burkholderia species. Therefore, strains E25(T) and E21 represent a novel species, for which the name Burkholderia bannensis sp. nov. is proposed. The type strain is E25(T) ( = NBRC 103871(T) = BCC 36998(T)).
INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY 07/2011; 61(Pt 7):1645-50. · 2.11 Impact Factor
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ABSTRACT: Rhodococcus erythropolis PR4 is an alkane-degrading bacterium, which grows well in media containing high concentrations of alkanes. These properties give the organism potential in the bioremediation of various environments contaminated by alkanes. In this study, we report the translocation of R. erythropolis PR4 from an aqueous phase to an alkane phase during growth in a two phase culture medium. When the alkane chain length was between C10 and C12, PR4 was located at the aqueous-alkane interface, but when the alkane chain length was above C14, PR4 translocated into the alkane phase. Complete translocation into alkane phase was accompanied by normal growth, whereas interfacial localization hampered growth, indicating that localization among other possible factors, play an important role in the growth of R. erythropolis PR4 in two phase cultures. The PR4 cell surface was physico-chemically characterized in terms of its cell surface charge and surface free energy. Contact angles were measured on bacterial lawns, followed by thermodynamic analyses of Gibbs free energies for localization of PR4 in the aqueous or alkane phase or at the interface. Although entry into the alkane phase of PR4 grown in the presence of both C12 and C19 was thermodynamically favorable, translocation from the inside of the alkane phase to the interface was only favorable for PR4 grown in the presence of C12. In line with these thermodynamic analyses, two phase partitioning showed that PR4 grown in the presence of C12 and C19 were more hydrophobic than PR4 grown in the presence of lower alkanes, while C12 grown bacteria were less lipophilic than C19 grown bacteria. In conclusion, the localization of R. erythropolis PR4 in a two phase culture medium is thermodynamically driven to facilitate its optimal growth.
Environmental Science and Technology 11/2009; 43(21):8290-4. · 5.23 Impact Factor
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ABSTRACT: Two strains of aluminium-tolerant bacteria, SA33(T) and 7A078, were isolated from Chinese water chestnut (Eleocharis dulcis) growing in highly acidic swamps (pH 2-4) in actual acid sulfate soil areas of Vietnam (SA33(T)) and Thailand (7A078). The strains were Gram-negative, aerobic, non-spore-forming rods, 0.6-0.7 mum wide and 1.3-1.7 mum long. These strains showed good growth at pH 3.0-8.0 and 17-37 degrees C. The organisms contained ubiquinone Q-8 as the predominant isoprenoid quinone and C(16 : 0), C(18 : 1) ω 7c and C(17 : 0) cyclo as the major fatty acids. Their fatty acid profiles were similar to those reported for other Burkholderia species. The DNA G+C content of these strains was 64 mol%. On the basis of 16S rRNA gene sequence similarity, the strains were shown to belong to the genus Burkholderia. Although the 16S rRNA gene sequence similarity values calculated for strain SA33(T) to 7A078 and the type strains of Burkholderia kururiensis, B. sacchari and B. tuberum were 100, 97.3, 97.1 and 97.0 %, respectively, strains SA33(T) and 7A078 formed a group that was distinct in the phylogenetic trees; the DNA-DNA relatedness of strain SA33(T) to 7A078 and these three type strains were respectively 90, 47, 46 and 45 %. The results of physiological and biochemical tests, including whole-cell protein pattern analysis, allowed phenotypic differentiation of these strains from described Burkholderia species. Therefore, strains SA33(T) and 7A078 represent a novel species, for which the name Burkholderia acidipaludis sp. nov. is proposed. The type strain is SA33(T) (=NBRC 101816(T) =VTCC-D6-6(T)). Strain 7A078 (=NBRC 103872 =BCC 36999) is a reference strain.
International journal of systematic and evolutionary microbiology 10/2009; 60(Pt 9):2036-41. · 2.27 Impact Factor
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ABSTRACT: Nitrogen-fixing bacteria, strains SA41(T), SA42 and SA53, were isolated from an aquatic plant, Eleocharis dulcis, that grows in highly acidic swamps (pH 2-4) in actual acid sulfate soil areas of Vietnam. The isolates were Gram-negative, aerobic, non-spore-forming, rod-shaped bacteria, having a cell width of 0.6-0.7 microm and a length of 1.5-1.7 microm. They showed good growth between pH 3.0 and 7.0, and between 17 and 37 degrees C. The organisms contained ubiquinone Q-8 as the predominant isoprenoid quinone, and C(16 : 0), C(17 : 0) cyclo, C(18 : 1) omega7c and summed feature 3 (C(16 : 1) omega7c and/or iso-C(15 : 0) 2-OH) as major fatty acids. Their fatty acid profiles are similar to those reported for other Burkholderia species. The DNA G+C content of these strains was 64 mol%. On the basis of 16S rRNA gene sequence similarity, these strains were shown to belong to the genus Burkholderia. Although their calculated 16S rRNA gene sequence similarity values to Burkholderia silvatlantica, Burkholderia mimosarum, Burkholderia ferrariae and Burkholderia tropica were 98.5, 98.2, 98.0 and 97.0 %, respectively, the isolates formed a distinct group in phylogenetic trees, and the DNA-DNA relatedness values of strain SA41(T) to these species were 39, 41, 39 and 33 %, respectively. The results of physiological and biochemical tests, including whole-cell protein pattern analysis, allowed phenotypic differentiation of these strains from the published Burkholderia species. Therefore, strains SA41(T), SA42 and SA53 represent a novel species for which the name Burkholderia heleia sp. nov. is proposed. The type strain is SA41(T) (=NBRC 101817(T)=VTCC-D6-7(T)).
International journal of systematic and evolutionary microbiology 09/2009; 60(Pt 5):1152-7. · 2.27 Impact Factor
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ABSTRACT: An aluminium-tolerant bacterium, strain AL46(T), was isolated from a waterweed, Panicum repens, grown in a highly acidic swamp (pH 3) at an actual acid sulfate soil area of Vietnam. Cells were Gram-negative, aerobic, non-spore-forming, non-motile rods (0.3 microm wide and 1.2-1.6 microm long). 16S rRNA gene sequence analysis indicated that strain AL46(T) belongs to the genus Acidocella, class Alphaproteobacteria. Strain AL46(T) was related most closely to the type strains of Acidocella facilis and Acidocella aminolytica (99.4 and 97.8 % 16S rRNA gene sequence similarity, respectively). Levels of DNA-DNA relatedness between strain AL46(T) and the above type strains were 40 %. The results of physiological and biochemical tests allowed the novel strain to be differentiated phenotypically from the two recognized Acidocella species. Data for predominant cellular fatty acids (cyclopropyl C(19 : 0) and C(18 : 1)), major isoprenoid quinone (Q-10) and DNA G+C content (65.6 mol%) were in accordance with those reported for the genus Acidocella. Therefore, strain AL46(T) is considered to represent a novel species of the genus Acidocella, for which the name Acidocella aluminiidurans sp. nov. is proposed. The type strain is AL46(T) (=NBRC 104303(T) =VTCC-D9-1(T)).
International journal of systematic and evolutionary microbiology 09/2009; 60(Pt 4):764-8. · 2.27 Impact Factor
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ABSTRACT: Three xylanase-producing alkaliphilic strains, SU1(T), 36AC4 and 36AC6, were isolated from the guts of larvae of the Japanese horned beetle (Trypoxylus dichotomus septentrionalis). The isolates stained Gram-positive and were aerobic, spore-forming, non-motile and rod-shaped and grew optimally at 30 degrees C and pH 9. They contained MK-7 as the major isoprenoid quinone and iso-C(15 : 0), anteiso-C(15 : 0), anteiso-C(17 : 0) and iso-C(17 : 0) as the major fatty acids. The DNA G+C contents of the strains were 37.4-37.7 mol%. On the basis of 16S rRNA gene sequence similarity, these strains were shown to belong to the genus Bacillus. Although their 16S rRNA gene sequence similarity to the type strains of the alkaliphilic species Bacillus pseudalcaliphilus and B. alcalophilus was 97 %, the novel isolates formed a distinct group in the phylogenetic trees and DNA-DNA relatedness values to the type strains of these species were less than 30 %. Results of physiological and biochemical tests, including salt preference, enabled these strains to be differentiated phenotypically from described Bacillus species. Therefore, strains SU1(T), 36AC4 and 36AC6 represent a novel species for which the name Bacillus trypoxylicola sp. nov. is proposed; the type strain is SU1(T) (=NBRC 102646(T) =KCTC 13244(T)).
International journal of systematic and evolutionary microbiology 08/2009; 60(Pt 1):61-6. · 2.27 Impact Factor
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ABSTRACT: An extracellular polysaccharide-producing bacterium, strain SCK(T), was isolated from a soil sample taken from Kameino, Fujisawa, Japan. The isolate was Gram-negative and cells were non-motile, irregular-shaped rods that grew optimally at 25 degrees C and grew between pH 5 and 8. Strain SCK(T) contained MK-7 as the major isoprenoid quinone, iso-C(15:0) and C(16:1)omega7c and/or iso-C(15:0) 2-OH as the major fatty acids and sphingolipids, with d-17:0 as the main dihydrosphingosine. Flexirubin-type pigments were also present. The DNA G+C content was 43.7 mol%. On the basis of 16S rRNA gene sequence analysis, strain SCK(T) was shown to belong to the genus Mucilaginibacter. The 16S rRNA gene sequence similarity between strain SCK(T) and the two type strains of Mucilaginibacter was 93%. The results of physiological and biochemical tests allowed phenotypic differentiation of the strain from published Mucilaginibacter species. Therefore, strain SCK(T) represents a novel species, for which the name Mucilaginibacter kameinonensis sp. nov. is proposed. The type strain is SCK(T) (=NBRC 102645(T) =KCTC 22227(T)).
International journal of systematic and evolutionary microbiology 10/2008; 58(Pt 9):2046-50. · 2.27 Impact Factor
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Tomoko Aizawa,
Nguyen Bao Ve,
Ken-ichiro Kimoto,
Noriyuki Iwabuchi,
Hiroaki Sumida,
Isao Hasegawa,
Satohiko Sasaki,
Tomohiko Tamura,
Takuji Kudo,
Ken-ichiro Suzuki, Mutsuyasu Nakajima,
Michio Sunairi
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ABSTRACT: The ammonia-producing bacteria B55(T), CA73, SA69 and SA72 were isolated from the waterweeds Ludwigia adscendens (B55(T)) and Eleocharis dulcis (CA73, SA69 and SA72) grown in highly acidic swamps (pH 2-4) in actual acid sulfate soil areas of Vietnam. The isolates were Gram-positive, irregular rod-shaped, non-spore-forming bacteria. On the basis of 16S rRNA gene sequence similarity, strain B55(T) was shown to belong to the genus Curtobacterium of the class Actinobacteria. Chemotaxonomic data (MK-9 as major isoprenoid quinone, d-ornithine as cell-wall diamino acid, acetyl as the acyl type of peptidoglycan) supported the affiliation of all four strains to this genus. Although their 16S rRNA gene sequence similarity was 99 % to species with validly published names within the genus, they formed a group that was distinct in the phylogenetic tree, and DNA-DNA relatedness values to these established species were less than 10 %. The results of physiological and biochemical tests and major fatty acids (cyclohexyl-C(17 : 0), anteiso-C(17 : 0) and cyclohexyl-C(19 : 0)) allowed phenotypic differentiation of these strains from the species of Curtobacterium with validly published names. Therefore, strains B55(T), CA73, SA69 and SA72 represent a novel species, for which the name Curtobacterium ammoniigenes sp. nov. is proposed. The type strain is B55(T) (=NBRC 101786(T)=VTCC D6-11(T)=JCM 14609(T)).
International journal of systematic and evolutionary microbiology 08/2007; 57(Pt 7):1447-52. · 2.27 Impact Factor
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ABSTRACT: Rhodococcus erythropolis PR4 is a marine bacterium that can degrade various alkanes including pristane, a C(19) branched alkane. This strain produces a large quantity of extracellular polysaccharides (EPS), which are assumed to play an important role in the hydrocarbon tolerance of R. erythropolis PR4. The strain produced an acidic EPS, mucoidan, together with a fatty acid-containing EPS, PR4 FACEPS. The chemical structure of the mucoidan was determined using (1)H and (13)C NMR spectroscopy and by conducting 2D DQF-COSY, TOCSY, HMQC, HMBC, and NOESY experiments. The mucoidan was shown to consist of a pentasaccharide repeating unit with the following structure: [structure: see text].
Carbohydrate Research 06/2007; 342(7):927-32. · 2.33 Impact Factor
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ABSTRACT: Rhodococcus erythropolis PR4 is a marine bacterium that can degrade various alkanes including pristane, a C(19) branched alkane. This strain produces a large quantity of extracellular polysaccharides, which are assumed to play an important role in the hydrocarbon tolerance of this bacterium. The strain produced two acidic extracellular polysaccharides, FR1 and FR2, and the latter showed emulsifying activity toward clove oil, whereas the former did not. FR2 was composed of D-galactose, D-glucose, D-mannose, D-glucuronic acid, and pyruvic acid at a molar ratio of 1:1:1:1:1, and contained 2.9% (w/w) stearic acid and 4.3% (w/w) palmitic acid attached via ester bonds. Therefore, we designated FR2 as a PR4 fatty acid-containing extracellular polysaccharide or FACEPS. The chemical structure of the PR4 FACEPS polysaccharide chain was determined by 1D (1)H and (13)C NMR spectroscopies as well as by 2D DQF-COSY, TOCSY, HMQC, HMBC, and NOESY experiments. The sugar chain of PR4 FACEPS was shown to consist of tetrasaccharide repeating units having the following structure: [structure: see text].
Carbohydrate Research 06/2007; 342(7):933-42. · 2.33 Impact Factor
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ABSTRACT: A possibility has been suggested of applying the EPS produced by Rhodococcus rhodochrous strain S-2 (S-2 EPS) to the bioremediation of oil-contaminated environments, because its addition, together with minerals, to oil-contaminated seawater resulted in emulsification of the oil, increased the degradation of polyaromatic hydrocarbons (PAH) of the oil, and led to the dominance of PAH-degrading marine bacteria. To understand the underlying principles of these phenomena, we determined the chemical structure of the sugar chain of S-2 EPS. The EPS was found to be composed of D-galactose, D-mannose, D-glucose, and D-glucuronic acid, in a molar ratio of 1:1:1:1. In addition, 0.8% (w/w) of octadecanoic acid and 2.7% (w/w) of hexadecanoic acid were also contained in its structure. By 1H and 13C NMR spectroscopy, including 2D DQF-COSY, TOCSY, HMQC, HMBC, and NOESY experiments, as well as chemical and enzymatic analyses, the polysaccharide was shown to consist of tetrasaccharide repeating units with the following structure: (see formula in text).
Carbohydrate Research 06/2006; 341(6):766-775. · 2.33 Impact Factor
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ABSTRACT: Rhodococcus sp. 33 can tolerate and efficiently degrade various concentrations of benzene, one of the most toxic and prevailing environmental pollutants. This strain produces a large quantity of extracellular polysaccharide (33 EPS), which plays an important role in the benzene tolerance in Rhodococcus sp. 33, especially by helping the cells to survive an initial challenge with benzene. This EPS has been reported to be composed of D-galactose, D-glucose, D-mannose, D-glucuronic acid, and pyruvic acid at a molar ratio of 1:1:1:1:1. To understand the protective effect of 33 EPS, we determined its chemical structure by using 1H and 13C NMR spectroscopy including 2D DQF-COSY, TOCSY, HMQC, HMBC, and NOESY experiments. The polysaccharide was shown to consist of tetrasaccharide repeating units with the following structure: [structure: see text].
Carbohydrate Research 05/2006; 341(5):616-23. · 2.33 Impact Factor
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ABSTRACT: Rhodococcus rhodochrous S-2 produces extracellular polysaccharides (S-2 EPS) containing D-glucose, D-galactose, D-mannose, D-glucuronic acid, and lipids, which is important to the tolerance of this strain to an aromatic fraction of (AF) Arabian light crude oil (N. Iwabuchi, N. Sunairi, H. Anzai, M. Nakajima, and S. Harayama, Appl. Environ. Microbiol. 66:5073-5077, 2000). In the present study, we examined the effects of S-2 EPS on the growth of indigenous marine bacteria on AF. Indigenous bacteria did not grow significantly in seawater containing AF even when nitrogen, phosphorus, and iron nutrients were supplemented. The addition of S-2 EPS to seawater containing nutrients and AF resulted in the emulsification of AF, promotion of the growth of indigenous bacteria, and enhancement of the degradation of AF by the bacteria. PCR-denaturing gradient gel electrophoresis analyses show that addition of S-2 EPS to the seawater containing nutrients and AF changed the composition of the bacterial populations in the seawater and that bacteria closely related to the genus Cycloclasticus became the major population. These results suggest that Cycloclasticus was responsible for the degradation of hydrocarbons in AF. The effects of 15 synthetic surfactants on the degradation of AF by indigenous marine bacteria were also examined, but enhancement of the degradation of AF was not significant. S-2 EPS was hence the most effective of the surfactants tested in promoting the biodegradation of AF and may thus be an attractive agent to use in the bioremediation of oil-contaminated marine environments.
Applied and Environmental Microbiology 06/2002; 68(5):2337-43. · 3.83 Impact Factor
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Soil Science and Plant Nutrition 03/2000; 46(1):217-227. · 1.02 Impact Factor
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ABSTRACT: Cauliflower (Brassica oleracea var. botrytis) tolerates treatment with 25 M CdCl2 for eight days, but is killed by that with a 50 M concentration. However, even 15 M CdCl2 is toxic in the presence of 1 mM L-buthionine sulfoximine (BSO), suggesting the presence of a Cd-inducible phytochelatin and its involvement in Cd-tolerance in cauliflower. To develop heavy metal-tolerant transgenic plants, we ligated the structural gene of yeast metallothionein gene (CUP1) downstream of CaMV35S promoter and introduced the fused gene into cauliflower. A Cd-tolerant transgenic cauliflower was selected, which grew well in the presence of 400 M or less Cd, whereas the non-transformed cauliflower tolerated only up to 25 M Cd. The transgenic cauliflower accumulated more Cd, especially in the upper leaves, than the non-transformed plant.In conclusion, by transfer of the yeast metallothionein gene into cauliflower increased Cd-tolerance and Cd-accumulating ability can be conferred to the plant.
Plant and Soil 09/1997; 196(2):277-281. · 2.73 Impact Factor
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ABSTRACT: Geosmin (1α,10β-dimethyl-9α-decanol) and 2-methylisoborneol ((1-R-exo)-1,2,7,7-tetramethyl-bicyclo-(2,2,1)-heptan-2-ol) (MIB) are volatile terpene derivatives, and have received a great deal of attention because they can cause musty/muddy off-flavor in water and food resources. By the Ames test, these metabolites showed no mutagenicity but antimicrobial activity toward tester strains. While these compounds are produced by various organisms living in aquatic environments, there are few reports of their effects on aquatic organisms. The effects of geosmin and MIB on sea urchin development were examined. The estimated IC50 (50% inhibitory concentration) values for the formation of the fertilization membrane were 16.67 mg geosmin l−1 and 68.77 mg MIB l−1; those for the cell cleavage were 16.58 mg geosmin l−1 and 66.86 mg MIB l−1, suggesting that the toxicity of geosmin and MIB toward sea urchins are comparable to their toxicity toward Salmonella tester strains in the Ames test. These values are far greater than concentrations of these substances observed in aquatic environments with severe muddy off-flavor problems.
Water Research. 30(10):2508-2511.
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ABSTRACT: To elucidate the function of extracellular polysaccharide (EPS) produced by bacteria with hydrophobic surfaces we investigated relationships among colony morphotypes, cell-surface properties and bacterial adhesion to substrata in Rhodococcus. Rough strains adhered well to various materials and formed cell aggregates, while their mucoidal derivatives did so poorly. Cell surfaces of the rough strains were more hydrophobic than those of the corresponding mucoidal strains. Production of the EPS by the rough strains was far less than that by the corresponding mucoidal strains. Adhesion of the rough strains to quartz, glass or hydrocarbon was inhibited by the addition of EPS. Thus, rhodococcal EPS plays an important role in determination of the cell-surface hydrophobicity by acting as a hydrophilin, and its addition to the rough strains resulted in inhibition of their adhesion to the substrata.
Colloids and Surfaces B: Biointerfaces. 30:51-60.
