Paracoccus aminophilus sp. nov. and Paracoccus aminovorans sp. nov., which utilize N,N-dimethylformamide

Two methylamine- and N,N-dimethylformamide-utilizing Paracoccus spp. are described. These bacteria are gram-negative, nonsporeforming, nonmotile, coccoid or short rod-shaped organisms. Their DNA base composition is 62 to 68 mol% G + C. Their cellular fatty acids include large amounts of C18:1 acid. Their major hydroxy acids are 3-OH C10:0 and 3-OH C14:0 acids. The major ubiquinone is Q-10. These bacteria are distinguished from Paracoccus denitrificans and Paracoccus alcaliphilus by physiological characteristics and by DNA-DNA-homology. Paracoccus aminophilus sp. nov. and Paracoccus aminovorans sp. nov. are proposed. The type strain of P. aminophilus is DM-15 (= JCM 7686), and the type strain of P. aminovorans is DM-82 (= JCM 7685). Paracoccus halodenitrificans is distinguished from other Paracoccus species on the basis of cellular fatty acid composition, hydroxy fatty acid composition, and DNA-DNA homology. It may not be a valid member of the genus Paracoccus.     

Paracoccus beibuensis sp. nov., Isolated from the South China Sea

A Gram-negative, non-motile, short rod-shaped or spherical bacterial strain that accumulates poly-β-hydroxybutyrate (PHB) granules was isolated from the Beibu Gulf in the South China Sea. Cells have no polar or subpolar flagella, dividing by binary fission. Phylogenetic analyses based on 16S rRNA gene sequences showed that the strain formed a monophyletic branch at the periphery of the evolutionary radiation occupied by the genus Paracoccus, family Rhodobacteraceae, order Rhodobacterales, class Alphaproteobacteria. The closest neighbours were Paracoccus aestuarii strain B7(T) (97.2% similarity), Paracoccus zeaxanthinifaciens ATCC 21588(T) (97.1% similarity) and Paracoccus homiensis DD-R11(T) (96.8%). The predominant fatty acids were C(18:1) ω7c (82.1%), and significant amounts of C(18:0) (5.6%), C(10:0) 3-OH (2.3%) and C(16:0) (1.5%) were present. The predominant respiratory ubiquinone of strain JLT1284(T) was Q-10 and the DNA G+C content of strain JLT1284(T) was 67.0 mol%. The isolate was also distinguishable from members of the genus Paracoccus on the basis of phenotypic and biochemical characteristics. It is evident from the genotypic, chemotaxonomic and phenotypic data, therefore, that strain JLT1284(T) represents a novel species of the genus Paracoccus, for which the name Paracoccus beibuensis sp. nov. is proposed. The type strain is JLT1284(T)=LMG 24871(T)=CGMCC 1.7295(T)).     

Paracoccus niistensis sp. nov., isolated from forest soil, India

A Gram-negative, non-motile, catalase-positive and oxidase-positive, aerobic bacterium designated as NII-0918(T) was isolated from soil sample in Western ghat forest, India. 16S rRNA gene sequence analysis showed that strain NII-0918(T) belongs to the subclass α-Proteobacteria, being related to the genus Paracoccus, and sharing highest sequence similarity with Paracoccus chinensis NBRC 104937(T) (99.4%), Paracoccus marinus NBRC 100640(T) (97.3%), Paracoccus koreensis Ch05(T) (97.1%) and Paracoccus kondratievae GB(T) (97.0%). Other members of Paracoccus showed below 97.0% similarity. The DNA-DNA hybridization values between these four strains and NII-0918(T) were 44.7, 28, 32 and 41%, respectively. The major fatty acids of strain NII-0918(T) were summed feature 7 (C18:1 ω7c/ω 9t/ω 12t) (83.0%) and C18:0 (12.5%). Ubiquinone Q-10 was detected as the major respiratory quinone. The G+C content of genomic DNA of NII-0918(T) was 66.6 mol%. On the basis of physiological, morphological, chemotaxonomical and DNA-DNA hybridization data, it is proposed that strain NII-0918(T) should be placed as a novel species, for which we propose Paracoccus niistensis sp. nov. The type strain is NII-0918(T) (CCTCC AA 209055(T) = NCIM 5340(T) = KCTC 22789(T)).     

锐劲特降解菌株R-2的分离、鉴定及降解特性

从长期受锐劲特污染的农药厂活性污泥中分离到一株锐劲特降解菌株R-2, 根据其生理生化特征和16S rRNA基因序列同源性分析, 将该菌株鉴定为Paracoccus sp.。菌株R-2能以锐劲特为唯一碳源生长, 在含有50 mg/L的锐劲特的基础盐培养基中, 3 d的降解率达到85%。菌株R-2降解锐劲特的最适温度为30 °C, 最适pH值为6.0?7.0, 其降解锐劲特的效率与锐劲特初始浓度呈负相关。添加0.1 mmol/L的Zn2+或Fe3+能够显著促进菌株对锐劲特的降解。灭菌与非灭菌土壤降解试验表明, 菌株R-2均可以在10 d内降解63.4%?71.2%的100 μg/g的锐劲特。     

日本三宅岛火山土壤中硫代硫酸盐氧化菌的分离、生物学特性及鉴定

【目的】利用培养法从日本三宅岛火山土壤(堆积年限131年)中分离到一株能氧化分解硫代硫酸盐的细菌MU2A-22T。【方法】用培养法对该菌株MU2A-22T进行了生理生化性质以及分类学位置上的确定。【结果】菌株MU2A-22T为革兰氏阴性,短杆状或球状。理化性质表明该菌株能利用葡萄糖、L-阿拉伯糖、葡萄糖酸盐、己二酸酯、dL-苹果酸钠、硫代硫酸钠(最适浓度为2.5 mmol/L)为唯一碳源进行自养生长。最适生长温度为25°C 30°C,最适pH为6.0 8.0。菌株MU2A-22T的16S rRNA序列与菌株Paracoccus solventivorans 6637T亲缘关系最近,序列相似性为97%,编码核酮糖-1,5-二磷酸羧化酶/加氧酶(Rubisco)的基因也被确定。对Paracoccus属内几种近缘菌的脂肪酸分析,证明菌株MU2A-22T中含有Paracoccus属的特征氨基酸,其中含量大于10%的分别为C18:1(74.7%)和C18:0(12.1%)。DNA-DNA杂交实验表明,菌株MU2A-22T与Paracoccus solventivorans 6637TDNA的相似度为49.3%。MU2A-22T菌株G+C含量为66.5%66.7%。【结论】菌株MU2A-22T为Paracoccus属内的一新种菌(登录号GQ452286),命名为Paracoccus scorialis sp.nov.。     

Paracoccus kocurii sp. nov., a tetramethylammonium-assimilating bacterium

A new species of tetramethylammonium-assimilating bacteria was isolated from an activated sludge which was used for the treatment of tetramethylammonium hydroxide contained in the wastewater from semiconductor manufacturing processes. Cells of the bacteria were gram-negative, nonmotile, short rods (0.5 to 0.8 micron by 0.7 to 1.1 microns). The major respiratory quinone component of the bacteria was Q-10. The G + C content was 71 mol%. Isolates are mesophilic and assimilate methylated amines such as tetramethylammonium, trimethylamine, dimethylamine, and methylamine under neutral conditions. The isolates resemble Paracoccus species with respect to morphology but were distinguishable from the known species of the genus. We propose Paracoccus kocurii sp. nov. The type strain is strain B (= JCM 7684).     

Nitrate-dependent [Fe(II)EDTA]2- oxidation by Paracoccus ferrooxidans sp. nov., isolated from a denitrifying bioreactor

Enrichments with [Fe(II)EDTA]2- as electron donor and nitrate or nitrite as electron acceptor were established using an inoculum from a bioreactor performing denitrification. A nitrate-reducing, [Fe(II)EDTA]2- oxidizing strain was isolated and named strain BDN-1. The G + C content of strain BDN-1 was 67%, and the organism was closely affiliated to Paracoccus denitrificans, P. pantotrophus and P. versutus by 16S rRNA sequence comparison. Results from DNA-DNA hybridization, rep-PCR, and whole cell protein analysis gave congruent results confirming the genotypic and phenotypic differences between strain BDN-1 and the other species of Paracoccus. From these results, we considered strain BDN-1 as a novel species for which we propose the name Paracoccus ferrooxidans. Apart from [Fe(II)EDTA]2-, BDN-1 could also use thiosulfate and thiocyanate as inorganic electron donors. Nitrate, nitrite, N2O, [Fe(II)EDTA.NO]2- and oxygen could be used by strain BDN-1 as electron acceptors. Repeated transfer on a culture medium with bicarbonate as the sole carbon source confirmed that strain BDN-1 was a facultative autotroph. [Fe(II)EDTA]2- oxidation dependent denitrification was also performed by other Paracoccus species, that were closely affiliated to P. ferrooxidans.     

n-Amyl alcohol as a substrate for the production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) by bacteria

Abstract n -Amyl alcohol was examined as a source for the synthesis of the 3-hydroxyvalerate (3HV) unit of the biopolyester, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (P(3HB-co-3HV)), by Alcaligenes sp., Pseudomonas sp. and several methylotrophic bacteria. A. eutrophus and Ps. lemoignei synthesized P(3HB-co-3HV) from glucose and n -amyl alcohol under nitrogen-deficient conditions. Many of methylotrophic bacteria grown on methanol synthesized the copolyester from methanol and n -amyl alcohol under nitrogen-deficient conditions. The content and composition of the polyester varied from strain to strain. Paracoccus denitrificans differed from all others in having a higher content of 3-hydroxyvalerate units in the copolyester synthesized.     

Paracoccus siganidrum sp. nov., isolated from fish gastrointestinal tract

A bacterial strain, designated M26^T, was isolated from a fish gastrointestinal tract, collected from Zhanjiang Port, South China. 16S rRNA gene sequence analysis indicated that strain M26^T belongs to the subclass α-Proteobacteria, being related to the genus Paracoccus, and sharing highest sequence similarity with Paracoccus alcaliphilus JCM 7364^T (98.1 %), Paracoccus huijuniae FLN-7^T (97.3 %), Paracoccus stylophorae KTW-16^T (97.1 %) and Paracoccus seriniphilus DSM 14827^T (96.9 %). The major quinone was determined to be ubiquinone Q-10, with Q-9 and Q-8 as minor components. The major fatty acid was identified as C_18:1ω7c, with smaller amounts of C_18:0 and C_16:0. The G+C content of the genomic DNA was determined to be 64.3 mol%. The DNA hybridization value between strain M26^T and the most closely related type strain, P. alcaliphilus, was 29.0 ± 1.0 %. The results of physiological and biochemical tests and low DNA–DNA relatedness showed that the strain could be readily distinguished from closely related species. On the basis of these phenotypic and genotypic data, strain M26^T is concluded to represent a novel species of the genus Paracoccus, for which the name Paracoccus siganidrum sp. nov. is proposed. The type strain is M26^T (=CCTCC AB 2012865^T = DSM 26381^T).     

Biodegradation of chlorpyrifos and 3,5,6-trichloro-2-pyridinol by a newly isolated Paracoccus sp. strain TRP

A bacterium, isolated from activated sludge and named strain TRP, could biodegrade chlorpyrifos and 3,5,6-trichloro-2-pyridinol. Phenotypic features, physiological and chemotaxonomic characteristics, and phylogenetic analysis of 16S rRNA sequence revealed that the isolate belongs to the genus of Paracoccus. Strain TRP could also degrade pyridine, methyl parathion and carbonfuran when provided as sole carbon and energy sources. Native-PAGE and enzymatic degradation assay of the cell-free extracts indicated that an alternative degradation mechanism might involve an inducible enzyme. Degradation study of chlorpyrifos by strain TRP was examined by GC–MS and HPLC; no persistent accumulated metabolite was observed. To the best of our knowledge, this is the first report of a bacterium that could completely mineralize chlorpyrifos. This isolate will be potentially useful in biotreatment of wastewaters and bioremediation of contaminated soils.     

A novel C1-using denitrifier alcaligenes sp. STC1 and its genes for copper-containing nitrite reductase and azurin.

A novel denitrifier Alcaligenes sp. STC1 was identified. The strain efficiently denitrifies under an atmosphere of 10% oxygen (O2) where Paracoccus denitrificans, one of the most studied aerobic denitrifiers, had less denitrifying activity, indicating that the strain has an O2-torelant denitrifying system. It denitrified by using C1-carbon sources such as formate and methanol as well as glucose, glycerol, and succinate. The genes for the copper-containing nitrite reductase and azurin of this C1-using denitrifier were cloned. Their predicted products of them were similar to those of their counterparts and the maximum similarities were 90% and 92%, respectively.     

一株茶碱降解菌的分离和鉴定

从制药废水生物处理系统的活性污泥中经富集分离到一株能以茶碱作为唯一碳、氮源生长的茶碱降解菌Tcn3,该菌株可以利用茶碱的最高浓度为3 000 mg/L。当茶碱浓度为1000 mg/L时被彻底降解的时间仅需48 h。Tcn3菌株降解茶碱的最适pH为80。K＋是该菌株降解茶碱的必需元素。采用16S rDNA序列分析法及传统的生理生化特征鉴定法对该菌株进行鉴定,结果表明,Tcn3的16S rDNA的核苷酸序列与善变副球菌(Paracoccus versutus) ATCC 25364的同源性为997%,在细菌系统发育分类学上属于变形菌α亚类,Rhodobacter组：副球菌属,善变副球菌。     

A Novel C1-Using Denitrifier Alcaligenes sp. STC1 and Its Genes for Copper-containing Nitrite Reductase and Azurin

A novel denitrifier Alcaligenes sp. STC1 was identified. The strain efficiently denitrifies under an atmosphere of 10% oxygen (O₂) where Paracoccus denitrificans, one of the most studied aerobic denitrifiers, had less denitrifying activity, indicating that the strain has an O₂-torelant denitrifying system. It denitrified by using C1-carbon sources such as formate and methanol as well as glucose, glycerol, and succinate. The genes for the copper-containing nitrite reductase and azurin of this C1-using denitrifier were cloned. Their predicted products of them were similar to those of their counterparts and the maximum similarities were 90% and 92%, respectively.     

Arrangement of genes TRP1 and TRP3 of Saccharomyces cerevisiae strains

The tryptophan biosynthetic genes TRP1 and TRP3 and partly also TRP2 and TRP4 have been compared by the technique of Southern hybridization and enzyme measurements in twelve wild isolates of Saccharomyces cerevisiae from natural sources of different continents, in the commonly used laboratory strain S. cerevisiae X2180-1A and in a Kluyveromyces marxianus strain. We could classify these strains into four groups, which did not correlate with their geographical distribution. In no case are the TRP3 and TRP1 genes fused as has been found in other ascomycetes. Two strains were found which, in contrast to strain X2180-1A, show derepression of gene TRP1. Two examples are discussed to demonstrate the usefulness of Southern hybridizations for the identification of closely related strains.Non-standard abbreviations InGP Indole-3-glycerolphosphate - PRA N(5-phosphoribosyl)-anthranilate     

Transfer of kanamycin resistance mediated by plasmid R68.45 in Paracoccus denitrificans.

Plasmid R68.45 mediates the transfer of kanamycin resistance from Pseudomonas aeruginosa to Paracoccus denitrificans. Kanamycin resistance could be transferred from one strain of P. denitrificans to another, thus opening up the possibility of using R68.45 as a sex factor in P. denitrificans.     

Complete amino acid sequence of cytochrome c551 from Erythrobacter species strain OCh 114

The complete amino acid sequence of cytochrome c551 isolated from an aerobic photosynthetic bacterium, Erythrobacter sp. strain OCh 114, was determined. The cytochrome molecule was composed of a total of 119 amino acid residues and its molecular weight including heme was calculated to be 13,235. The sequence was (Sequence: see text). Its molecular weight indicates that this cytochrome is of the L-type. Sequence alignment with other bacterial cytochromes c shows that this cytochrome is similar to cytochromes c of Rhodobacter capsulatus, Rhodobacter sphaeroides, and Paracoccus denitrificans, which were grouped into the alpha-3 subcluster from the 16S rRNA sequence analysis.     

Isolation and nucleotide sequence of the methanol dehydrogenase structural gene from Paracoccus denitrificans.

A genomic clone bank of Paracoccus denitrificans DNA has been constructed in the expression vector set pEX1, pEX2, and pEX3. Screening of this clone bank with antibodies raised against P. denitrificans methanol dehydrogenase resulted in the isolation of a clone, pNH3, that synthesized methanol dehydrogenase cross-reactive proteins. The nucleotide sequence of the P. denitrificans DNA fragment inserted in this clone has been determined and shown to contain the full methanol dehydrogenase structural gene. DNA cross-hybridization was found with DNA fragments which have been reported to contain the methanol dehydrogenase structural genes from Methylobacterium sp. strain AM1 and Methylobacterium organophilum.     

Cloning, nucleotide sequencing, and expression in Escherichia coli of the gene for formate dehydrogenase of Paracoccus sp. 12-A, a formate-assimilating bacterium

The gene for the NAD-dependent formate dehydrogenase (FDH) of Paracoccus sp. 12-A, a formate-assimilating bacterium, was cloned through screening of the genomic library with activity staining. The FDH gene included an open reading frame of 1,200 base pairs, and encoded a protein of 43,757 Da, which had high amino acid sequence identity with known FDHs, in particular, with bacterial enzymes such as those of Moraxella sp. (86.5%) and Pseudomonas sp. 101 (83.5%). The gene was highly expressed in Escherichia coli cells using an expression plasmid with the pUC ori and tac promoter. The recombinant enzyme was somewhat inactive in the stage of the cell-free extract, but its activity markedly increased with purification, in particular, with the step of heat-treatment at 50 degrees C. The purified enzyme showed essentially the same properties as the enzyme from the original Paracoccus cells.     

Lindane removal in contaminated soil by defined microbial consortia and evaluation of its effectiveness by bioassays and cytotoxicity studies

International Microbiology - Lindane contamination in different environmental matrices has been a global concern for long. Bacterial consortia consisting of Paracoccus sp. NITDBR1, Rhodococcus...     

A novel denitrifying bacterial isolate that degrades trimethylamine both aerobically and anaerobically via two different pathways

The aerobic and anaerobic degradation of trimethylamine by a newly isolated denitrifying bacterium from an enrichment culture with trimethylamine inoculated with activated sludge was studied. Based on 16S rDNA analysis, this strain was identified as a Paracoccus sp. The isolate, strain T231, aerobically degraded trimethylamine, dimethylamine and methylamine and released a stoichiometric amount of ammonium ion into the culture fluid as a metabolic product, indicating that these methylated amines were completely degraded to formaldehyde and ammonia. The strain degraded trimethylamine also under denitrifying conditions and consumed a stoichiometric amount of nitrate, demonstrating that complete degradation of trimethylamine was coupled with nitrate reduction. Cell-free extract prepared from cells grown aerobically on trimethylamine exhibited activities of trimethylamine mono-oxygenase, trimethylamine N-oxide demethylase, dimethylamine mono-oxygenase, and methylamine mono-oxygenase. Cell-free extract from cells grown anaerobically on trimethylamine and nitrate exhibited activities of trimethylamine dehydrogenase and dimethylamine dehydrogenase. These results indicate that strain T231 had two different pathways for aerobic and anaerobic degradation of trimethylamine. This is a new feature for trimethylamine metabolism in denitrifying bacteria.