n-Alkane dissimilation by Rhodopseudomonas sphaeroides transferred OCT plasmid

The OCT plasmid from Pseudomonas maltophilia N246-1 was transferred to Rhodopseudomonas sphaeroides M1 with very low frequency (1.4–1.9 × 10^–5 per recipient cell at pH 7–8 for a 3-hour reaction time). P. maltophilia N246-1 was able to utilize C₈-C₁₄ of n-alkanes, whereas R. gas-liquid chromatography determined that the broad range of carbon numbers of n-alkanes in crude oil was remarkably degraded by the transconjugant, R. sphaeroides M1-C1, compared with donor strain N246-1. The fact that donor and transconjugant strains simultaneously lost the capacity to utilize n-alkanes on L-broth medium suggests that the OCT plasmids are unstable. It was found that the OCT plasmid of P. maltophilia N246 was incompatible with the IncP-2 group of P. aeruginosa KCTC 11245. Offprint requests to: K.-H. Min, Sookmyung Women's University.     

The regulation of aromatic amino acid biosynthesis in amino acid liberating mutant strains of Anabaena variabilis

Mutant strains of Anabaena variabilis which are resistant to the tryptophan analogue, 6-fluorotryptophan, liberated a wide range of amino acids although none liberated tryptophan in detectable quantities. Four strains (FT-7, FT-8, FT-9, FT-10) produced predominantly alanine together with small amounts of phenylalamine and tyrosine, strain FT-2 liberated mainly phenylalanine and tyrosine and strain FT-6 liberated mainly glutamate, NH ₄ ⁺ and several unidentified ninhydrin-positive compounds. Two forms of 3-deoxy-D-arbinoheptulosonate 7-phosphate (DAHP) synthase were identified in the parent strain, a tyrosine-sensitive form and a phenylalanine-sensitive form. In strains FT-2 and FT-6 the phenylalanine-sensitive enzyme was not detected and in strain FT-7 it was apparently deregulated with respect to inhibition by phenylalanine. No deregulation of anthranilate synthase was observed but mutant strains were found to have higher specific activities of this enzyme than the parent strain.Abbreviations chla chlorophyll a - 6-FT 6-fluorotryptophan - DAHP 3-deoxy-D-arabinoheptulosonate 7-phosphate - PEP phosphoenolpyruvate     

Morphological,physiological and enzymatic characteristics of cephalosporin acylase-producing Arthrobacter strain 45-8A

A bacterial strain producing cephalosporin acylases was isolated from soil. The morphological and physiological properties of this strain suggest that it belongs to the genus Arthrobacter, and the isolate was therefore designated Arthrobacter strain 45-8A. Substrate specificity of the enzyme was examined. The enzyme can convert both cephalosporin C and 7-(4-carboxylbutan-amino)cephalosporanic acid to 7-aminocephalosporanic acid. An interesting feature of the acylases is their temperature-dependent regulation. Activity of acylases was detected in strain 45-8A grown at temperature below 30 °C, but was not observed at higher temperature. Arthrobacter strain 45-8A did not exhibit -lactamase activity, even though its resistance to cephalosporin C was very strong (>2000 g/ml). This is quite beneficial for its application in the manufacture of 7-aminocephalosporanic acd.Abbreviations used NBHAB 2-Nitro-5-(6-bromohexanoylamino)-benzoic acid - NIPAB 2-Nitro-5-phenylacetaminobenzoic acid - CPC cephalosporin C - GL-7ACA 7-(4-carboxybutanamino)cephalosporanic acid - 6-APA aminopenicillanic acid - 7-ACA 7-aminocephalosporanic acid - PDAB p-Dimethylaminobenzaldehyde     

Effects of three insecticides on the expression of cytochrome P450 CYP6B7 in Helicoverpa armigera

Cytochrome P450 genes can be induced by xenobiotics, which may contribute to insect's adaptability to the environments and resistance to insecticides. Previous studies indicated that cytochrome P450 CYP6B7 played a vital role in the resistance of Helicoverpa armigera to fenvalerate. However, effects of different insecticides on the expression of CYP6B7 in H. armigera are still unclear. In this study, resistance level of H. armigera to six insecticides was determined by topical application method, and effects of fenvalerate, phoxim and indoxacarb on the expression of CYP6B7 in susceptible (HDS) and fenvalerate-resistant (BJR) strains of H. armigera were evaluated by RT-qPCR. The results showed that BJR strain had an extremely high level of resistance to fenvalerate (1990.57-fold), and the induction of CYP6B7 in different tissues of BJR strain was significantly higher than that of HDS strain after exposure to fenvalerate for 24 and 48 hr. The highest induction level by fenvalerate was observed in the midgut, which were 13.7-fold in HDS strain and 127.9-fold in BJR strain at 24 and 48 hr, respectively. After exposure to phoxim, the expression level of CYP6B7 in HDS and BJR strains was induced by 2.3- and 316.8-fold at 24 hr, respectively. It is worth to note that CYP6B7 could be induced by phoxim at different time points in BJR strain, but only induced at 24 and 72 hr in HDS strain. After indoxacarb exposure, the expression of CYP6B7 was induced by 1.6-fold at 72 hr in BJR strain, whereas it was induced at 24 and 48 hr in HDS strain. These results demonstrated that the expression level of CYP6B7 could be induced by fenvalerate, phoxim and indoxacarb, but the induction time and levels varied; moreover, the induction in BJR strain was markedly higher than that in HDS strain after exposure to fenvalerate and phoxim.     

Close linkage between mouse genes determining the two forms of complement component C6 and component C7, and cis action of a C6 Regulatory Gene

Two forms of mouse complement component C6, with molecular weights (M _rs) of 90 and 100 kilodaltons (kd), are present in the sera from certain inbred strains such as the CBA strain; other strains, such as the BALB/c and DBA/2 strains, have only the 90 kd C6A form. The present work was undertaken to determine whether the two M _r forms were the products of genes coding at separate loci. We screened sera from mice from a number of inbred strains by isoelectric focusing and found one strain, AKR, exhibiting allotypic structural variations of C6 forms. To distinguish the various types, we designated the 90 kd types from CBA and AKR mice C6A1 and C6A2, respectively, and the corresponding 100 kd types C6B 1 and C6B2, respectively. Mice possessing only one M _r form were all typed as C6A1. Results of breeding experiments strongly suggested that the two M _r forms of C6 are coded for at two closely linked loci. Sera from a number of inbred strains were also screened for a complement C7 polymorphism by means of isoelectric focusing and functional overlay. C7 from all strains, excepting the AKR strain, produced identical C7 band patterns. AKR C7 produced a unique band pattern, and results of breeding experiments with AKR and BALB/c mice showed the C6 and C7 loci to be closely linked. In addition, we identified a regulatory gene for C6 production. The gene apparently requires androgen to facilitate C6 production in the majority of strains. In these strains C6 activity is virtually absent from female sera. However, we observed moderate levels of C6 activity in sera from IS/Cam females, indicating that, in this strain, male physiological androgen levels are not necessary for C6 production. IS/Cam possess one form of circulating C6 which appears identical with BALB/c C6A1, and therefore IS/Cam mice differ from AKR mice at both the C6 structural and regulatory loci. These two strains were thus suitable for use in breeding experiments to determine the manner of action of the regulatory gene. Results showed that it acted in a cis manner.Abbreviations used in this paper M _r molecular weight - kd kilodaltons - SDS sodium dodecyl sulfate - PAGE polyacrylamide gel electrophoresis - IEF isoelectric focusing - Slp sex-limited protein - MHC major histocompatibility complex     

Sphingobacterium pakistanensis sp. nov., a novel plant growth promoting rhizobacteria isolated from rhizosphere of Vigna mungo

The taxonomic status of a bacterium, strain NCCP-246^T, isolated from rhizosphere of Vigna mungo, was determined using a polyphasic taxonomic approach. The strain NCCP-246^T can grow at 16–37 °C (optimum 32 °C), at pH ranges of 6–8 (optimum growth occurs at pH 7) and in 0–4 % (w/v) NaCl. Phylogenetic analysis based upon on 16S rRNA gene sequence comparison revealed that strain NCCP-246^T belonged to genus Sphingobacterium. Strain NCCP-246^T showed highest similarity to the type strain of Sphingobacterium canadense CR11^T (97.67 %) and less than 97 % with other species of the genus. The DNA–DNA relatedness value of strain NCCP-246^T with S. canadense CR11^T and Sphingobacterium thalpophilum JCM 21153^T was 55 and 44.4 %, respectively. The chemotaxonomic data revealed the major menaquinone as MK-7 and dominant cellular fatty acids were summed feature 3 [C_16:1 ω7c/C_16:1 ω6c] (37.07 %), iso-C_15:0 (28.03 %), C_16:0 (11.85 %), C_17:0 cyclo (8.84 %) and C_14:0 (2.42 %). The G+C content of the strain was 39.2 mol%. On the basis of DNA–DNA hybridization, phylogenetic analyses, physiological and, biochemical data, strain NCCP-246^T can be differentiated from the validly named members of genus Sphingobacterium and thus represents as a new species, for which the name, Sphingobacterium pakistanensis sp. nov. is proposed with the type strain NCCP-246^T (= JCM18974 ^T = KCTC 23914^T).     

Seed treatment with lactic acid bacteria against seed-borne pathogens of spring wheat

Antifungal potential of lactic acid bacteria (LAB) such as Lactobacillus sakei KTU05-6, Pediococcus acidilactici KTU05-7 and Pediococcus pentosaceus KTU05-8, KTU05-9 and KTU05-10 was tested on naturally contaminated wheat seeds. LAB influence on fungal growth on kernels, seedling diseases and seed germination was examined by laboratory and field experiments. KTU05-10 was selected and later used for seed treatment as solitary strain and in two- or three-component mixtures with KTU05-7 and KTU05-6. The occurrence of Fusarium spp. on wheat kernels in agar plate assays was decreased by seed treatment with all LAB cultures, and the efficacy of each strain depended on incubation temperature. Inoculation of wheat kernels with strains of solitary KTU05-10 and in mixtures with KTU05-7 and KTU05-6 significantly reduced the incidence of Fusarium spp., Bipolaris sorokiniana and Alternaria spp. LAB influence on seed germination and seedling diseases was observed in laboratory and field experiments, but in most cases, this influence was insignificant.     

Arg-7 mutant x wild-type crosses in Chlamydomonas reinhardi: Study of the enzyme produced in diploid strains

Summary The arg-7 locus is the structural gene for the argininosuccinate lyase (ASL). Interallelic complementation was previously found to occur between several mutants of the locus: this is indicative for the homomultimeric nature of ASL.Two complementing (arg-7-5 and arg-7-7) and two non-complementing (arg-7-1 and arg-7-6) mutants of the arg-7 locus were crossed to the pab-2 strain (which is wild-type for the arg-7 locus). In each cross, heterozygote phenotypically wild-type strains were isolated; their diploid pattern was demonstrated by various criteria: mating type, cell volume, nuclear size.The four heterozygotes were compared to the haploid wild-type and in some experiments, to the diploid strain arg-1xpab-2 homozygous for the arg-7 locus. No difference was found in growth rate and in the Michaelis constant values for ASL. The specific activity of the enzyme produced in the heterozygotes was about 50 percent of the activity found in haploid or diploid wild-type. The heat sensitivity of ASL was also investigated in the different strains: two (containing the complementing mutations arg-7-5 and arg-7-7) of the four heterozygotes produce ASL varieties different from the wild-type enzyme as far as the thermolability is concerned.These results suggest that hybrid ASL can be formed by interaction between the products of wild-type and mutant genes. A clear dominance of the wild-type allele is expected only when the mutant allele has no product of the gene: this could be the case for arg-7-1 and arg-7-6.     

<Emphasis Type="Italic">Virgibacillus xinjiangensis</Emphasis> sp. nov., isolated from a Salt Lake of Xin-jiang Province in China

A strictly aerobic Gram-positive, moderately halophilic spore forming bacterium, designated strain SL6-1^T, was isolated from a salt lake in Xin-jiang province, China. Growth of strain SL6-1^T was observed at NaCl concentrations of 0∼20% (w/v) (the optimum being 5∼7%, w/v). The peptidoglycan type of strain SL6-1^T was Alγ-meso-diaminopimelic acid and its major cellular fatty acids were iso-C_14:0 and iso-C_16:0 and ante-iso-C_15:0. The major respiratory isoprenoid quinone was MK-7 and the G+C content of the genomic DNA was 44.5 mol%. The major cellular phospholipids were phosphatidylglycerol and diphosphatidylglycerol. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain SL6-1^T formed a phylogenetic lineage within the genus Virgibacillus. Based on 16S rRNA gene sequence similarity, the strain was most closely related to Virgibacillus olivae E₃₀8^T, Virgibacillus kekensis YIM kkny16^T, Virgibacillus marismortui DSM 12325^T with 97.1%, 97.1%, and 97.0% gene sequence similarities, respectively and the sequence similarities to other related taxa were less than 96.7%. The DNA relatedness values between strain SL6-1^T and V. olivae E₃₀8^T, V. kekensis YIM kkny16^T, V. marismortui DSM 12325^T were 16.7%, 51.0%, and 22.8%, respectively. On the basis of physiological, biochemical and phylogenetic properties, strain SL6-1^T represents a novel species, for which the name Virgibacillus xinjiangensis sp. nov. is proposed. The type strain is SL6-1^T (=KCTC 13128^T =DSM 19031^T).     

Improved Extraction of Rice Prolamin

A considerable amount of menaquinone (MK)-4 was found in cells of a l-hydroxy-2- naphthoate-resistant mutant, strain HNA 250–15, which was derived from Flavobacterium sp. 238- 7, in which MK-6 is the major isoprenoid quinone. The MK-4 productivity was further improved by making the mutant resistant to usnic acid and menadione. The amount of MK produced by the resultant mutant, strain K₃–15, produced 125.4mg/1 of culture broth and 12.8 mg/g of dry cell weight, in the ratio of MK-4 and MK-6 of 6:1, under the optimal culture conditions in the presence of cedar wood oil.     

Deletion mutation as a means of isolating avirulence genes in flax rust

Summary The interaction between flax rust,Melampsora lini, and its host, flax,Linum usitatissimum, has been extensively studied, and certain genetic features make the system an appropriate choice to utilize in isolating genes conferring avirulence in rust. A mutant that was selected for virulence on Lx plants was isolated, after treatment with gamma rays, from a strain that is genotypicallyA-L5,A-L6,A-L7,A-Lx/A-L5,A-L6,a-L7,a-Lx. These four specificities are tightly linked. Breeding tests showed that this mutant was genotypicallyA-L5,A-L6,a-L7,a-Lx/a-L5,a-L6,a-L7,a-Lx and, when made homozygous for the mutant chromosome, was virulent onL5,L6,L7, andLx. This result excludes somatic recombination as a source of the mutation and indicates deletion as a likely cause. A 250 bp genomic sequence from a strain of rust homozygous for these four linked avirulence genes (A-L5,A-L6,A-L7,A-Lx) was isolated, using a method that allows the differential cloning of the specific DNA sequences located within a deletion in the mutant genome. This clone hybridized to two EcoRI bands in genomic DNA from the strain homozygous for the four linked avirulence genes and from the strain homozygousA-L5 andA-L6 and heterozygousA-L7 andA-Lx, but showed no homology to DNA from the strain carrying the putative chromosomal deletion. The correlation between the genetically characterized deletion mutation and the isolation of a sequence from within a region of chromosome missing from this strain of rust suggests that this 250 bp tract may be part of, or closely linked to, the defined set of avirulence genes.     

Aerobic secondary utilization of a non-growth and inhibitory substrate 2,4,6-trichlorophenol by Sphingopyxis chilensis S37 and sphingopyxis-like strain S32

This paper reports 2,4,6-trichlorophenol (246TCP) degradation bySphingopyxis chilensis S37 and Sphingopyxis chilensis-like strain S32,which were unable to use 246TCP as the sole carbon and energy source. In R2A broth, the strainsdegraded 246TCP up to 0.5 mM. Results with mixtures of different 246TCP and glucose concentrations in mineral salt media demonstrated dependence on glucose to allow bacterial growth and degradation of 246TCP. Strain S32 degraded halophenol up to 0.2 mM when 5.33 mM glucose was simultaneously added, while strain S37 degraded the compound up to 0.1 mM when 1.33 mM glucose was added. These 246TCP concentrations were lethal for inocula in absence of glucose. Stoichiometricreleases of chloride and analysis by HPLC, GC-ECD and GC-MS indicated 246TCP mineralisation by both strains. To our knowledge, this is the first report of bacteriaable to mineralize a chlorophenol as a non-growth and inhibitory substrate. The concept of secondary utilization instead of cometabolism is proposed for this activity.     

Effect of inoculation ofAzospirillum spp. on nitrogen accumulation by field-grown wheat

Summary Two experiments were performed to examine the effects of inoculation of field grown wheat with various Azospirillum strains. In the first experiment the soil was sterilized with methyl bromide to reduce the Azospirillum population and¹⁵N labelled fertilizer was added to all treatments. Two strains ofAzospirillum brasilense isolated from surface sterilized wheat roots and theA. brasilense type strain Sp7 all produced similar increases in grain yield and N content. From the¹⁵N and acetylene reduction data it was apparent that these increases were not due to N₂ fixation. In the second experiment performed in the same (unsterilized) soil, twoA. brasilense strains (Sp245, Sp246) and oneA. amazonense strain (Am YTr), all isolated from wheat roots, produced responses of dry matter and N content while the response to the strain Sp7 was much smaller. These data confirm earlier results which indicate that if natural Azospirillum populations in the soil are high (the normal situation under Brazilian conditions), strains which are isolated from wheat roots are better able to produce inoculation responses than strains isolated from other sources. The inoculation of a nitrate reductase negative mutant of the strain Sp245 produced only a very small inoculation response in wheat. This suggests that the much greater inoculation response of the original strain was not due to N₂ fixation but to an increased nitrate assimilation due to the nitrate reductase activity of the bacteria in the roots. Consultant Inter-American Institute for Cooperation in Agriculture IICA/EMBRAPA World Bank Project.     

Preliminary report on the biological effects of space flight on the producing strain of a new immunosuppressant, Kanglemycin C

Kanglemycin C (K-C) is a new immunosuppressant isolated from the culture broth of Nocardia mediterranei var. kanglensis 1747-64. To improve the productivity of K-C and to study the biological effects of space flight on its producing strain, spores from five K-C producing strains (U-10, U-15, U-7, M-13, γ-33) mutated from the wild strain N. mediterranei var. kanglensis 1747-64 were carried into space by an unmanned spaceship, “Shenzhou III” (Divine Vessel III) on March 25, 2002. Comparatively, the strain U-7 was the highest K-C producing strain among the above five starting strains when cultivated in 500-ml Erlenmeyer flasks. After a 6 day and 18 h flight, the treated spores went through serial screening processes to screen for high-yield K-C mutant strains, using thin layer chromatography and high performance liquid chromatography (HPLC). The K-C yield produced by one mutant strain, designated as F-16, derived from the starting strain U-7 was increased by up to 200% when compared to that produced by the starting strain U-7 in 500-ml Erlenmeyer flasks after careful postflight HPLC analysis. Another mutant strain, designated as F-210, derived from the starting strain M-13 showed reduced productivity of K-C as well as exhibited changes in some morphological and physiological characteristics. For example, the broth color of the strain F-210 changed from yellow to purple after 96 h of culture, but that of the ground control strain M-13 remained yellow. Similarly, the mycelium morphological change from filamentous to coccoid of F-210 occurred later than that of ground control M-13. Examination of the survivability of postflight spores indicated that exposure to radiation, during the 162 h of space flight, plays a critical role in the survival rates of spores such that spores exposed to strong radiation exhibited lower survival rates than spores exposed to weak radiation.Jianqin Zhou and Chenghang Sun have contributed equally to this work.     

Investigation of C-phycoerythrin from the cyanobacterium Pseudanabaena W 1174

A cyanobacterium which produces high amounts of C-phycoerythrin was classified as a new Pseudanabaena strain. This strain (number W 1173 of our collection) has been cultivated for 6 years without changing its properties. It resembles Pseudanabaena catenata (strain B 1464-1) morphologically but differs in the pigmentation. Contrary to strain B 1464-1, no chromatic adaptation was observed with strain W 1173. It was found that phycoerythrins from both strains differ in the following properties: isoelectric points, number of bilin chromophores, and immunochemical properties. Besides native C-phycoerythrin (PEI, _max = 558 nm), a degradation product (PEII, _max = 544 nm and 562nm) has been found in crude extracts from strain W 1173. Criteria for integrity of C-phycoerythrin were discussed which are essential if this biliprotein is used as taxonomic character.Abbreviations PE C-Phycoerythrin - SDS sodiumdodecylsulfate Dedicated to Professor Dr. O. Kandler on the occasion of his 60th birthday     

<Emphasis Type="Italic">Methylobacterium dankookense</Emphasis> sp. nov., isolated from drinking water

A pink-pigmented bacterium, designated SW08-7^T was isolated from the drinking water of a water purifier. Cells were Gram-negative, rod-shaped, strictly aerobic, and non-spore-forming. It grew optimally at 25°C, pH 6∼7. Phylogenese analysis based on 16S rRNA gene sequence showed that strain SW08-7^T belongs to the genus Methylobacterium. The highest 16S rRNA gene sequence similarities were found to Methylobacterium mesophilicum JCM 2829^T (96.9%), Methylobacterium brachiatum B0021^T (96.9%), Methylobacterium phyllosphaerae CBMB27^T (96.6%), Methylobacterium radiotolerans JCM 2831^T (96.6%), and Methylobacterium hispanicum GP34^T (96.5%). DNA-DNA hybridization experiment revealed low-level (28.5%) of DNA-DNA relatedness between strain SW08-7^T and Methylobacterium hispanicum. The genomic DNA G+C content was 68.9 mol% and the major isoprenoid quinone was Q-10. The major cellular fatty acid of strain SW08-7^T was C_18:1 ω7c (79.8±2.1%). Results of phylogenetic, phenotypic, and biochemical analyses revealed that strain SW08-7^T could be classified as representing a novel species of genus Methylobacterium, for which the name Methylobacterium dankookense sp. nov. is proposed. The type strain is SW08-7^T (=KCTC 22512^T =DSM 22415¹).     

Halolysin SptA有助于嗜盐古菌Natrinema sp.J7-2长期生存

【背景】嗜盐古菌可以在盐沉积物中存活长达几百万年,是著名的长寿菌。许多嗜盐古菌分泌胞外蛋白酶,大多数分泌的胞外蛋白酶被称为Halolysin,具有以下特征：属于枯草杆菌蛋白酶类蛋白酶;在胞内折叠后经Tat途径高效分泌至胞外;可自加工形成成熟酶;尤其在天然宿主中大多数Halolysin在对数生长后期表达并在稳定期达到最高水平。目前Halolysin的酶学性质、加工成熟及分泌机制已被广泛研究,然而其生理功能的研究较少。Halolysin SptA是嗜盐古菌Natrinema sp.J7-2的主要胞外蛋白酶,前期研究发现多个顺式调控元件协同调节SptA的生长期依赖性表达,使SptA参与J7-2菌株不同生长期之间的转变,而且在衰亡期之后SptA有助于J7-2菌株继续生存。【目的】研究Halolysin SptA对Natrinema sp.J7-2长期生存的作用。【方法】将J7-2菌株和突变体ΔsptA1分别在寡营养、无外源营养物质（液体）及营养丰富（固体）条件下长期培养,通过比较二者的生长、生存和SptA的表达分泌情况进一步探讨SptA的作用。【结果】J7-2菌株在寡营养条件下产生更多SptA,培养后期（33 d） J7-2菌株活细胞数显著高于ΔsptA1。在无外源营养物质情况下长期温育,J7-2菌株和ΔsptA1经历多次细胞分裂和细胞死亡,在延长温育期间（73—200 d）存活的J7-2菌株细胞数量均显著多于存活的ΔsptA1细胞数量。在营养丰富的固体平板上培养的后期（160 d）,由于营养物质消耗,J7-2菌株通过SptA吸收和利用来源于死细胞蛋白的降解产物,帮助其群体长期生存。【结论】SptA介导的细胞死亡和死细胞蛋白降解,促进J7-2菌株利用来源于死细胞的营养物质,从而有助于菌株群体在营养缺乏条件下长期存活。本研究提供了关于Halolysin生理作用的新见解。     

<Emphasis Type="Italic">Porifericola rhodea</Emphasis> gen. nov., sp. nov., a new member of the phylum <Emphasis Type="Italic">Bacteroidetes</Emphasis> isolated by the bait-streaked agar technique

A strictly aerobic, gram-negative, non-motile, reddish-pink pigmented, rod-shaped strain designated N5EA6-3A2B^T, was isolated from an unidentified marine sponge by use of a bait-streaked agar technique. Phylogenetic analyses based on the 16S rRNA gene sequence revealed that the novel isolate represented a distinct and deep evolutionary lineage of descent in the family Flammeovirgaceae within the phylum Bacteroidetes and clustered with as yet uncultured bacteria. The most closely related established species was Roseivirga spongicola UST030701-084^T (89% sequence similarity) in the family of Flammeovirgaceae. The strain could be differentiated phenotypically and physiologically from recognized members of the family Flammeovirgaceae. The G+C content of DNA was 43 mol%, the major respiratory quinone was menaquinone 7 (MK-7) and iso-C15:0, C16:1ω5c and iso-C17:0 3-OH were the major fatty acids. From the distinct phylogenetic position and combination of genotypic and phenotypic characteristics, the name Porifericola rhodea gen. nov., sp. nov. is proposed. The type strain of Porifericola rhodea is N5EA6-3A2B^T (=MBIC08357^T = NBRC 107748^T).     

<Emphasis Type="Italic">Mucilaginibacter composti</Emphasis> sp. nov., with ginsenoside converting activity,isolated from compost

The Gram-negative, strictly aerobic, non-motile, non-spore-forming, rod shaped bacterial strain designated TR6-03^T was isolated from compost, and its taxonomic position was investigated by using a polyphasic approach. Strain TR6-03^T grew at 4–42°C and at pH 6.0–8.0 on R2A and nutrient agar without NaCl supplement. Strain TR6-03^T had β-glucosidase activity, which was responsible for its ability to transform ginsenoside Re (one of the dominant active components of ginseng) to Rg₂. On the basis of 16S rRNA gene sequence similarity, strain TR6-03^T was shown to belong to the family Sphingobacteriaceae and to be related to Mucilaginibacter lappiensis ANJLI2^T (96.3% sequence similarity), M. dorajii FR-f4^T (96.1%), and M. rigui WPCB133^T (94.1%). The G+C content of the genomic DNA was 45.6%. The predominant respiratory quinone was MK-7 and the major fatty acids were summed feature 3 (comprising C_16:1 ω7c and/or iso-C_15:0 20H), iso-C_16:0 and iso-C_17:0 3OH. DNA and chemotaxonomic data supported the affiliation of strain TR6-03^T to the genus Mucilaginibacter. Strain TR6-03^T could be differentiated genotypically and phenotypically from the recognized species of the genus Mucilaginibacter. The isolate therefore represents a novel species, for which the name Mucilaginibacter composti sp. nov. is proposed, with the type strain TR6-03^T (=KACC 14956^T = KCTC 12642^T =LMG 23497^T).     

Assessment of faba bean (Vicia faba) response to inoculation with Rhizobium leguminosarum in clay loam Nile Delta soil

A field experiment was conducted to assess the response to inoculation with rhizobia in a clay loam soil of the Nile Delta using faba bean (Vicia faba) for two successive winter seasons (1985/6 and 1986/7). Three selected strains of Rhizobium leguminosarum, TAL 634, NRC 65 and TAL 1400, were used singly or in combination as peat-based inocula in 1985/6 winter season. Strain TAL 1400 was replaced by strain F9 in the 1986/7 winter season. A significant seed yield response was obtained only with strain TAL 1400, in the 1985/6 season. In the 1986/7 season, no significant yield response was observed with any of the strains. The serotyping of nodules collected in the 1985/6 season showed that strain TAL 1400 was more competitive than either the indigenous rhizobia or the two inoculant strains. However, the majority of nodules formed in the 1986/7 season were formed from strains other than the inoculant ones.