Catabolism of Naphthalenesulfonic Acids by Pseudomonas sp. A3 and Pseudomonas sp. C22

Naphthalene and two naphthalenesulfonic acids were degraded by Pseudomonas sp. A3 and Pseudomonas sp. C22 by the same enzymes. Gentisate is a major metabolite. Catabolic activities for naphthalene, 1-naphthalenesulfonic acid, and 2-naphthalenesulfonic acid are induced by growth with naphthalene, 1-naphthalenesulfonic acid, 2-naphthalenesulfonic acid, methylnaphthalene, or salicylate. Gentisate is also an inducer in strain A3. Inhibition kinetics show that naphthalene and substituted naphthalenes are hydroxylated by the same naphthalene dioxygenase. Substrates with nondissociable substituents such as CH₃, OCH₃, Cl, or NO₂ are hydroxylated in the 7,8-position, and 4-substituted salicylates are accumulated. If CO₂H, CH₂CO₂H, or SO₃H are substituents, hydroxylation occurs with high regioselectivity in the 1,2-position. Thus, 1,2-dihydroxy-1,2-dihydronaphthalene-2-carboxylic acids are formed quantitatively from the corresponding naphthalenecarboxylic acids. Utilization of naphthalenesulfonic acids proceeds by the same regioselective 1,2-dioxygenation which labilizes the C—SO₃⁻ bond and eliminates sulfite.     

Deoxyribonuclease-susceptible Floc Forming Pseudomonas sp.

A bacterium belonging to Pseudomonas which was isolated from activated sludge formed flocs in glycerol-containing medium. The flocs were deflocculated by deoxyribonuclease treatment in the presence of magnesium ions. Flocs were also deflocculated by 2 m NaCl, heating at temperatures higher than 50°C, and at pH below 1 or above 11. The observations suggest that deoxyribonucleic acid is directly involved in the association of cells and that ionic bonds are responsible for the flocculation of cells.     

A novel EDTA-degrading Pseudomonas sp.

A bacterial strain LPM-410 capable of utilizing ethylenediaminetetraacetate (EDTA) as the sole source of energy, carbon, and nitrogen was isolated from sewage sludge and identified as a Pseudomonas sp. on the basis of its phenotypic characteristics. Suspensions of exponential-phase cells degraded EDTA, Mg–, Ca–, Ba–, and Mn–EDTA at constant specific rates ranging from 0.363 to 0.525 mmol EDTA/(g cells h). The more stable chelate, Zn–EDTA, was degraded at a lower rate (0.195 ± 0.030 mmol EDTA/(g cells h)), and here was no degradation of Co–, Cu–, Pb–, and Fe(III)–EDTA.     

Cytotoxic Spliceostatin Analogs from Pseudomonas sp.

Two new spliceostatin analogs, designed as spliceostatins J and K ( 1 and 2 ), were isolated and identified from the culture of Pseudomonas sp., along with two known ones, FR901464 ( 3 ) and spliceostatin E ( 4 ). Their structures were elucidated by detailed interpretation of their spectroscopic data, especially 2D‐NMR and HR‐ESI‐MS. Spliceostatin J ( 1 ) represented the first example of spliceostatins bearing an unusual hexahydrofuro[3,4‐b]furan moiety. Biological assay showed all the isolated compounds except 1 displayed potent cytotoxic activities against two cancer cell lines (MDA‐MB‐231 and A‐549). Structure‐activity‐relationship studies revealed that the tetrahydropyran ring in spliceostatin analogs was necessary for their bioactive retention.     

假单胞菌产生铁氧化酶条件的研究

以氧化铁锰假单胞菌FEl3-26为实验菌株,对其铁氧化酶的产酶条件进行研究,结果表明柠檬酸铁铵和硝酸钠分别是该菌产酶的最佳碳氮源.最适产酶条件为温度28～30℃.起始pH值6.5～7.5,接种量2%,150 r/min振荡培养72 h.酶的定位研究结果显示该菌产生的铁氧化酶是一种胞外酶.     

Metabolism of benzalphthalide by Pseudomonas sp.

A Pseudomonas sp. degraded benzalphthalide to o-phthalate and benzoate. A tentative pathway for the metabolism of benzalphthalide in this Pseudomonas sp. is proposed on the basis of isolated metabolites, oxygraphic assay and enzymatic studies.     

Recharacterization of Pseudomonas fulva Iizuka and Komagata 1963, and proposals of Pseudomonas parafulva sp. nov. and Pseudomonas cremoricolorata sp. nov

Seven Pseudomonas fulva strains obtained from culture collections were taxonomically studied. The seven strains were separated into three clusters (Clusters I to III) on the basis of 16S rRNA gene sequences, and located phylogenetically in the genus Pseudomonas sensu stricto. Further, the strains were classified into 4 groups (Groups I to IV) on the basis of DNA-DNA similarity. As a result, Cluster I was split into Groups I and II. Group I included the type strain of P. fulva and two strains, and levels of DNA-DNA similarity ranged from 88 to 100% among the strains. Group II contained two strains, and the level between the two strains ranged from 91 to 100%. Group III consisted of one strain. Group IV included one strain, and this strain showed a high level of DNA-DNA similarity with the type strain of Pseudomonas straminea NRIC 0164(T). Clusters II and III corresponded to Groups III and IV, respectively. The four groups were separated from one another and from related Pseudomonas species at the level from 3 to 45% of DNA-DNA similarity. The strains of Groups I, II, and III had ubiquinone 9 as the major quinone. According to numerical analysis by the use of 133 phenotypic characteristics, the seven P. fulva strains were split into four phenons (Phenons I to IV). The groups by DNA-DNA similarity corresponded well with the phenons produced by numerical taxonomy, and differential characteristics were recognized. Consequently, Group I was regarded as P. fulva because the type strain (NRIC 0180(T)) of this species was included in this group. Strains in Group II were identified as a new species, Pseudomonas parafulva sp. nov., and the type strain is AJ 2129 (=IFO 16636=JCM 11244=NRIC 0501). NRIC 0181 in Group III was identified as a new species, Pseudomonas cremoricolorata sp. nov., and the type strain is NRIC 0181 (=IFO 16634=JCM 11246). NRIC 0182 in Group IV was identified as P. straminea on the basis of the high level of DNA-DNA similarity with the type strain of this species.     

New species of pathogenic Pseudomonas isolated from citrus in Tunisia: Proposal of Pseudomonas kairouanensis sp. nov. and Pseudomonas nabeulensis sp. nov.

A collection of Pseudomonas strains was isolated in different regions of Tunisia in the period 2016–2017 from the fruits and leaves of Citrus sinensis cv. ‘Valencia Late’ and Citrus limon cv. ‘Eureka’ plants with symptoms of blast and black pit disease. A phylogenetic analysis of the housekeeping gene rpoD was used for strain identification at the species level. The results demonstrated the affiliation of these strains with the genus Pseudomonas and revealed the presence of 11 strains representing two putative new species in two monophyletic branches. These strains were analyzed morphologically and genotypically by multilocus sequence analyses of the rpoD, gyrB and 16S rRNA (rrs) gene sequences, and their phenotypic characteristics by API 20NE and Biolog GEN III. Plant pathogenic properties were confirmed on fruits and detached leaves of C. limon cv. ‘Eureka’. Fatty acids and WC MALDI-TOF MS major protein profiles were determined. The genomes of both representatives were sequenced. The average nucleotide index and genome-to-genome distance from KC12^T and E10B^T are below the cut-off established for a described species. These results support the conclusion that the strains KC12^T, KC17, KC20, KC22, KC24A, KC25 and KC26 represent a novel species of Pseudomonas, for which the name of Pseudomonas kairouanensis is proposed. The type strain is KC12^T (=CECT9766 and CFBP 8662). The strains E10B^T, E10AB, E10CB1 and Iy3BA represent another novel species of Pseudomonas for which the name of Pseudomonas nabeulensis is proposed; the type strain is E10B^T (=CECT9765 and CFBP 8661).     

Intracellular L-aspartate-beta-decarboxylase of Pseudomonas sp. and Alcaligenes sp. and its immobilization

Intracellular L-aspartate-beta-decarboxylase of Pseudomonas sp. and Alcaligenes sp. was isolated, purified and characterized. The cells were destroyed by ultrasonic treatment; the enzymes were precipitated by ammonium sulfate fractionation, dialyzed and lyophylized using Biogel P-150. After gel electrophoresis homogeneous enzyme preparations were obtained. The activity of L-aspartate-beta-decarboxylase is rather high--up to 92.1 U/min/mg of protein and is maximal at pH 5.5 and at temperatures of 45-55 degrees C. The Km and Vmax values for the Pseudomonas sp. enzyme are 0.1 M and 0.33 mM/min, respectively: those for the Alcaligenes sp. enzyme are 0.15 M and 1.0 mM/min, respectively. The results of amino acid analysis suggest that the enzymes slightly differ from one another with regard to aspartic and glutamic acid, alanine, valine and isoleucine content. Immobilization of the enzymes on various carriers was performed.     

Transport of methylamine by Pseudomonas sp. MA.

Pseudomonas sp. MA grows on methylamines as a sole source of carbon, nitrogen, and energy. The transport of methylamine into the organism was investigated. It was found that this organism possesses an inducible transport system for methylamine having the following physical parameters: pH optimum, 7.2; temperature optimum, 30 to 35 degrees C; Km, 1 to 30 mM; Vmax, 90 to 120 nmol/min per mg (dry weight) of cells. Methylamine uptake was curtailed by azide, cyanide, and carbonyl cyanide-m-chlorophenylhydrazone; osmotic shock treatment reduced the uptake by 50%. The uptake was not effectively inhibited by ammonium ion, amino acids, or amides, but was competitively inhibited by short-chain alkylamines. Cells grown on succinate-ammonium chloride did not possess the transport system, but it could be induced in such cells by methylamine in 20 h. Cells grown with methylamine as a sole nitrogen, but not carbon, source transported methylamine at a reduced rate.     

Carbohydrates Oxidation by Pseudomonas albosesamae nov. sp.

An oxidation product of glucose, gluconate and 2-ketogluconate by Pseudomonas albosesamae was isolated and examined for its chemical structure. Shaking culture is available for the high yield production. Paper chromatographic analysis of fermented broth for the product gives one spot as “an reducing acid.” The acid was isolated as the unstable powder of calcium salt by methanol precipitation. On periodate oxidation, oxalic and glycolic acids were formed, but formaldehyde was hardly detected. On Ruff’s oxidation of the reduced product prepared by sodium borohydrate or catalytic reduction, D-arabinose and a small amount of L-xylose were detected. On catalytic reduction using Raney nickel, 2-ketogluconic acid was isolated as the main reductant. Bis-2, 4-dinitrophenylhydrazone of the product was obtained as analytically pure yellow needle crystals, m.p. dec. 156~157°C, 5+57.0, pyridine, 1 dm. From the above results, the product was certified to be 2,5-diketogluconic acid.     

Carbohydrates Oxidation by Pseudomonas albosesamae nov. sp.

Taxonomic behaviors of a newly isolated bacterium which produces 2,5-diketogluconic acid in high yield were examined in this paper. The bacterium was isolated from sesame seed. It is aerobic, rod-shaped bacilli (0.6~0.8 × 1.0~3.0 microns) with rounded ends. It occurs singly or as a small mass and shows motility with a polar flagellum. Gram staining and acid-fast staining are both negative. Endospore and capsule are not observed. It does not possess photosynthetic and usual pigments the cell. Glucose and other sugars are attacked with acid production, but no gas formation. Polysaccharides and sucrose are not attacked. This bacterium does not produce acetic acid from ethanol. The above behaviors and other physiological properties which are described in the text lead to the conclusion that the bacterium is a new species situated in the genus Pseudomonas. So, it was named Pseudomonas albosesamae, nov. sp. (Wakisaka) in relation with its isolated origin.     

一株假单胞菌(Pseudomonas sp.)石油脱有机氮分析

为了探讨咔唑降解菌在石油中的脱氮性能, 从研究咔唑降解菌Pseudomonas sp. XLDN4-9在双液相系统中降解咔唑的性能出发, 分别考察了XLDN4-9休止细胞体系对原油、润滑油及柴油的脱氮效果, 并借助于GC-MS分析了柴油中咔唑及其衍生物的降解状况。结果表明, 正十四烷-水系统有利于咔唑的降解; 以低氮柴油代替正十四烷, 2 g/L咔唑可在15 h内降解95.2%; XLDN4-9休止细胞体系对原油、润滑油、柴油均有显著脱氮效果。在柴油脱氮过程中, 发现3 天后, 99%的咔唑被降解, 四种单甲基咔唑的降解率为63.4%~87.6%, 二甲基咔唑共降解了15%。     

海洋细菌Pseudomonas sp．抗菌代谢产物的研究

从海洋细菌Pseudomonas sp.发酵液中分离鉴定9个环二肽和2个苯环类化合物,经波谱鉴定为环(酪氨酸-脯氨酸)(1),环(酪氨酸-异亮氨酸)(2),环(苯丙氨酸-脯氨酸)(3),环(缬氨酸-脯氨酸)(4),环(异亮氨酸-脯氨酸)(5),环(亮氨酸-脯氨酸)(6),环(丙氨酸-脯氨酸)(7),环(缬氨酸-丙氨酸)(8),环(丙氨酸-亮氨酸)(9),对羟基苯甲醛(10),二-(2-乙基己基)邻苯二甲酸酯(11).其中化合物1～4对多种海洋细菌显示一定的抗菌活性.     

Two novel species isolated from wheat rhizospheres in Serbia: Pseudomonas serbica sp. nov. and Pseudomonas serboccidentalis sp. nov.

Pseudomonas strains IT-194P, IT-215P, IT-P366^T and IT-P374^T were isolated from the rhizospheres of wheat grown in soils sampled from different fields (some of them known to be disease-suppressive) located near Mionica, Serbia. Phylogenetic analysis of the 16S rRNA genes and of whole genome sequences showed that these strains belong to two potentially new species, one containing strains IT-P366^T and IT-194P and clustering (whole genome analysis) next to P. umsongensis DSM16611^T, and another species containing strains IT-P374^T and IT-215P and clustering next to P. koreensis LMG21318^T. Genome analysis confirmed the proposition of novel species, as ANI was below the threshold of 95% and dDDH below 70% for strains IT-P366^T (compared with P. umsongensis DSM16611^T) and IT-P374^T (compared with P. koreensis LMG21318^T). Unlike P. umsongensis DSM16611^T, strains of P. serbica can grow on D-mannitol, but not on pectin, D-galacturonic acid, L-galactonic acid lactone and α-hydroxybutyric acid. In contrary to P. koreensis LMG21318^T, strains of P. serboccidentalis can use sucrose, inosine and α-ketoglutaric acid (but not L-histidine) as carbon sources. Altogether, these results indicate the existence of two novel species for which we propose the names Pseudomonas serbica sp. nov., with the type strain IT-P366^T (=CFBP 9060 ^T = LMG 32732 ^T = EML 1791 ^T) and Pseudomonas serboccidentalis sp. nov., with the type strain IT-P374^T (=CFBP 9061 ^T = LMG 32734 ^T = EML 1792 ^T). Strains from this study presented a set of phytobeneficial functions modulating plant hormonal balance, plant nutrition and plant protection, suggesting a potential as Plant Growth-Promoting Rhizobacteria (PGPR).     

一株假单胞菌(Pseudomonas sp.)石油脱有机氮分析

为了探讨咔唑降解菌在石油中的脱氮性能, 从研究咔唑降解菌Pseudomonas sp. XLDN4-9在双液相系统中降解咔唑的性能出发, 分别考察了XLDN4-9休止细胞体系对原油、润滑油及柴油的脱氮效果, 并借助于GC-MS分析了柴油中咔唑及其衍生物的降解状况。结果表明, 正十四烷-水系统有利于咔唑的降解; 以低氮柴油代替正十四烷, 2 g/L咔唑可在15 h内降解95.2%; XLDN4-9休止细胞体系对原油、润滑油、柴油均有显著脱氮效果。在柴油脱氮过程中, 发现3 天后, 99%的咔唑被降解, 四种单甲基咔唑的降解率为63.4%~87.6%, 二甲基咔唑共降解了15%。