Estimation of root nodule development by <Emphasis Type="Italic">Rhizobium</Emphasis> sp. Using hydroponic culture

A nitrogen-fixing bacterium isolated from the root nodules of a cultivated leguminous plant, soybean (Glycine max L.), was cultivable and was identified as Rhizobium sp. Bacterial species isolated from root nodules of wild leguminous plants including -bush clover, white dutch clover, wisteria, and false acacia were identified as Burkholderia cepacia, Pseudomonas migulae, Pseudomonas putida, and Flavobacterium sp, respectively, all of which are heterotrophic bacteria that grow in the rhizosphere. Temperature gradient gel electrophoresis (TGGE) 16S-rDNA bands extracted directly from the bacterial population within the root nodules of the wild leguminous plants were identified as Rhizobium sp, Mesorhizobium sp, and Bradyrhizobium sp. none were cultivable. Rhizobium sp. isolated from soybean root nodule generated approximately 48 and 19 mg/L of ammonium in glucose- and starch-defined medium, respectively, during 8 days of growth. The growth rate of Rhizobium sp. was increased by the addition of yeast extract but not by the addition of ammonium. K _m and V _max for starch saccharification measured with the extracellular crude enzyme of Rhizobium sp. were 0.7556 mg/L and 0.1785 mg/L/min, respectively. The inoculation of Rhizobium sp. culture into a hydroponic soybean plant culture activated root nodule development and soybean plant growth. The inoculated Rhizobium sp. survived for at least 4 weeks, based on the TGGE pattern of 16S-rDNA. The 16S-rDNA of Rhizobium sp. isolated from newly developed root nodules was homologous with the inoculated species.     

内生青霉菌对黄花蒿组培苗生长和青蒿素合成的影响

从黄花蒿茎中分离得到了17株内生真菌,其中内生青霉菌(Penicilliumsp.Y2)能有效促进黄花蒿组培苗生长及青蒿素合成。内生青霉菌悬浮培养5d后,分别将培养液与菌丝匀浆后经过高压灭菌处理,或将培养液经过高压灭菌、过滤除菌处理获得3种内生菌诱导子(A、B和C)。结果表明,3种内生菌诱导子对植株生长、抗氧化酶活性及青蒿素合成都有促进作用,诱导子C青蒿素合成诱导效果最好,可促进黄花蒿组培苗的干重增长44.44%、可溶性糖含量提高38.24%,诱导超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)活性,从而提高青蒿素合成达58.86%,黄花蒿组培苗青蒿素含量达4.701mg.g-1(干重)。     

产碱杆菌ECU0401催化拆分扁桃酸及其衍生物

从土壤中分离的1株产碱杆菌Alcaligenes sp.ECU0401具有扁桃酸脱氢酶活性,可以以扁桃酸、苯甲酰甲酸或苯甲酸为唯一C源生长,并且具有较高的脱氢酶活力。以外消旋扁桃酸为C源,采用分批补料策略培养（或反应）99h,扁桃酸累计投入量为30.4g/L,（S）-（＋）-扁桃酸被完全降解,（R）-（-）-扁桃酸回收产率为32.8%,对映体过量值（e.e.）〉99.9%。利用静息细胞作为催化剂不对称降解外消旋扁桃酸的氯代衍生物,制备获得光学活性的（R）-（-）-邻氯扁桃酸、（S）-（＋）-间氯扁桃酸和（S）-（＋）-对氯扁桃酸,光学纯度均超过99.9%e.e.。     

Effect of surfactants and identification of metabolites on the biodegradation of fluoranthene by basidiomycetes fungal isolate Armillaria sp. F022

The effects of structure and concentration of surfactants on the biodegradation of fluoranthene, a three rings polycyclic aromatic hydrocarbon in the aqueous phase, as well as their effects on the biodegradation and enzyme activity were investigated. The toxicity ranking of studied surfactants is: non-ionic Tween 80 <anionic sodium dodecyl sulfate <cationic Tetradecyltrimethylammonium bromide. The maximum growth of Armillaria sp. F022 (>4,500 mg/L) was showed by Tween 80 (10 mg/L) culture, manifesting that the non-ionic surfactant present in the culture were beneficial to the fungal growth. Laccase showed the highest enzymes activity in all surfactants culture. Non-ionic Tween 80 showed a significant result for laccase activity (1,902 U/L) in the Armillaria sp. F022 culture. The increased enzymes cumulative activity may stem directly from the rising fluoranthene biodegradability as addition of appropriate surfactants. The biotransformation of fluoranthene was greatly improved by Tween 80, and totally fluoranthene degradation was obtained as Tween 80 was 10 mg/L. Two fluoranthene metabolites were isolated from the culture medium and analyzed by a thin layer chromatography, UV visible spectrometer and gas chromatography–mass spectrometry (GC–MS). The oxidation of fluoranthene is initiated by oxygenation at the C-2,3 positions resulting 9-fluorenone. At the end of experiment, one metabolite was detected in the culture extract and identified as phthalic acid. Evidently, Armillaria sp. F022 seems efficient, high effective and deserves further application on the enhanced bioremediation technologies for the treatment of fluoranthene-contaminated soil.     

Incubation of water samples containing amoebae improves detection of legionellae by the culture method.

Some protozoans isolated from aquatic habitats, including domestic water supplies, can support the intracellular replication of autochthonous legionellae in vitro. We studied the effect of incubating water samples containing amoebae on the sensitivity of culture for legionellae. Samples collected during investigations of legionellosis epidemics and shown by conventional culture procedures to contain amoebae, but not legionellae, were incubated at 35 degrees C and replated. Legionellae were recovered from 59 of 144 such samples. Species isolated included L. pneumophila, L. anisa, L. bozemanii, L. gormanii, L. micdadei, L. rubrilucens, L. sainthelensi, L. steigerwaltii, and an unnamed species. Acanthamoeba polyphaga, Acanthamoeba hatchetti, a Rosculus sp., Hartmannella vermiformis, and Vahlkampfia spp. were among the autochthonous amoebae identified. Legionellae were recovered by this procedure from only 3 of 63 samples that were negative for amoebae by conventional culture procedures. These results show that water samples negative for legionellae, but positive for amoebae, by standard culture techniques should be incubated and replated to maximize the sensitivity of culture for legionellae.     

Incubation of water samples containing amoebae improves detection of legionellae by the culture method.

Some protozoans isolated from aquatic habitats, including domestic water supplies, can support the intracellular replication of autochthonous legionellae in vitro. We studied the effect of incubating water samples containing amoebae on the sensitivity of culture for legionellae. Samples collected during investigations of legionellosis epidemics and shown by conventional culture procedures to contain amoebae, but not legionellae, were incubated at 35 degrees C and replated. Legionellae were recovered from 59 of 144 such samples. Species isolated included L. pneumophila, L. anisa, L. bozemanii, L. gormanii, L. micdadei, L. rubrilucens, L. sainthelensi, L. steigerwaltii, and an unnamed species. Acanthamoeba polyphaga, Acanthamoeba hatchetti, a Rosculus sp., Hartmannella vermiformis, and Vahlkampfia spp. were among the autochthonous amoebae identified. Legionellae were recovered by this procedure from only 3 of 63 samples that were negative for amoebae by conventional culture procedures. These results show that water samples negative for legionellae, but positive for amoebae, by standard culture techniques should be incubated and replated to maximize the sensitivity of culture for legionellae.     

Isolation and Characterization of a New Extracellular Bacteriolytic Endopeptidase of <Emphasis Type="Italic">Lysobacter</Emphasis> sp. XL1

The previously unstudied bacteriolytic enzyme L(4) was isolated from the culture liquid of the bacterium Lysobacter sp. XL1 in electrophoretically homogeneous state. The enzyme L(4) is a diaminopimelinoyl-alanine endopeptidase relative to peptidoglycan of Lysobacter sp. XL1. The enzyme is an alkaline protein of approximately 21 kD. The N-terminal amino acid sequence of the enzyme has been determined - A V V N G V N Y V Gx T T A ... The maximal activity of the enzyme was observed in 0.05 M Tris-HCl at pH 8.0 and 50-55 degrees C. The half-inactivation temperature of the enzyme is 52 degrees C. The endopeptidase L(4) is not a metalloenzyme since it is not affected by EDTA. The enzyme is inhibited by p-chloromercuribenzoic acid by 72% and by phenylmethylsulfonyl fluoride by 43%, which indicates the involvement of serine and thiol groups in its functioning.     

一株银杏内生真菌的分离及其产黄酮类物质的初步研究

从银杏(Ginkgo biloba L.)树叶中分离得到一株内生真菌EG4,经鉴定为刺盘孢Colle-totrichum sp．。应用薄层层析、显色反应及分光光度法对该菌的发酵产物进行了初步分析,结果表明该真菌能够产生黄酮类化合物。     

Microalgal biomass production and on-site bioremediation of carbon dioxide, nitrogen oxide and sulfur dioxide from flue gas using Chlorella sp. cultures

The growth and on-site bioremediation potential of an isolated thermal- and CO?-tolerant mutant strain, Chlorella sp. MTF-7, were investigated. The Chlorella sp. MTF-7 cultures were directly aerated with the flue gas generated from coke oven of a steel plant. The biomass concentration, growth rate and lipid content of Chlorella sp. MTF-7 cultured in an outdoor 50-L photobioreactor for 6 days was 2.87 g L?1 (with an initial culture biomass concentration of 0.75 g L?1), 0.52 g L?1 d?1 and 25.2%, respectively. By the operation with intermittent flue gas aeration in a double-set photobioreactor system, average efficiency of CO? removal from the flue gas could reach to 60%, and NO and SO? removal efficiency was maintained at approximately 70% and 50%, respectively. Our results demonstrate that flue gas from coke oven could be directly introduced into Chlorella sp. MTF-7 cultures to potentially produce algal biomass and efficiently capture CO?, NO and SO? from flue gas.     

Leptographium tereforme sp. nov. and other Ophiostomatales isolated from the root-feeding bark beetle Hylurgus ligniperda in California

The redhaired pine bark beetle Hylurgus ligniperda (F.) is native to Europe but was discovered in Los Angeles, California, in 2003. This root-and stump-feeding beetle is a common vector of Ophiostomatales, which are potential tree pathogens or causes of blue stain of conifer sapwood. In this study Ophiostomatales were isolated on a cycloheximide-amended medium from 118 adult H. ligniperda collected from infested logs of Pinus halepensis and P. pinea at two sites in California. In total eight species of Ophiostomatales were identified and seven species that occasionally were isolated were unidentified. The most frequently isolated species were Ophiostoma ips and Grosmannia galeiforme, which were isolated respectively from 31% and 23% of the 118 beetles. The other species isolated included O. piceae (isolated from 9% of the beetles), O. querci (8%) and Leptographium tereforme sp. nov. (6%). Grosmannia huntii, L. serpens, three Sporothrix species, O. floccosum, O. stenoceras, two unidentified Hyalorhinocladiella sp. and a sterile fungus each were isolated from fewer then 5% of beetles. Most of the identified species already were known in USA and have been found in association with H. ligniperda in other countries. However the new species, L. tereforme, and G. galeiforme were recorded from USA for the first time, and this is the first report of L. serpens from western North America.     

Isolation and characterization of a unicellular manganese-oxidizing bacterium from a freshwater lake in northwestern Russia

A unicellular manganese-oxidizing bacterium (strain L7), isolated from Lake Ladoga, is identified as "Siderocapsa" sp. according to its morphology. However, this bacterium belongs to the phylogenetic cluster of Pseudomonas putida. The physiological characteristics (utilization of sugars, polyatomic alcohols, organic acids, and phenolic substrates as carbon and energy sources) also indicate the similarity of strain L7 to representatives of the genus Pseudomonas. The growing culture oxidizes Mn(II); the rate of oxidation depends on the type of added organic substrate. Carbonate requirement for this process indicates mixotrophic metabolism. The relatedness of the isolated bacterium to the representatives of the genus Pseudonomas and their phenotypic similarity provide a basis for considering strain L7 not as "Siderocapsa" sp., but as a new species, Pseudomonas siderocapsa sp. nov., of the P. putida cluster.     

Streptomyces sp. strain isolated from river water has high bisphenol A degradability

AIMS: We report the identification of the bisphenol A (BPA) biodegradability in Streptomyces sp. strain isolated from river water. METHODS AND RESULTS: The water samples spiked with BPA (1 mg l(-1)) and the culture solution of Streptomyces sp. strain were placed at 30 degrees C for 10 days and were analysed by high-performance liquid chromatography. A half-life for BPA degradation was between 3 and 4 days. The removal rate of BPA was >90% for 10 days. CONCLUSIONS: These results show that the Streptomyces sp. strain isolated from river water has high BPA degradability. SIGNIFICANCE AND IMPACT OF THE STUDY: To our knowledge, this is the first report of BPA degradation by Streptomyces sp. strain.     

Optimum conditions for the biological production of lactic acid by a newly isolated lactic acid bacterium,Lactobacillus sp. RKY2

Lactic acid is a green chemical that can be used as a raw material for biodegradable polymer. To produce lactic acid through microbial fermentation, we previously screened a novel lactic acid bacterium. In this work, we optimized lactic acid fermentation using a newly isolated and homofermentative lactic acid bacterium. The optimum medium components were found to be glucose, yeast extract, (NH₄)₂HPO₄, and MnSO₄. The optimum pH and temperature for a batch culture ofLactobacillus sp. RKY2 was found to be 6.0 and 36°C, respectively. Under the optimized culture conditions, the maximum lactic acid concentration (153.9 g/L) was obtained from 200 g/L of glucose and 15 g/L of yeast extract, and maximum lactic acid productivity (6.21 gL⁻¹h⁻¹) was obtained from 100 g/L of glucose and 20 g/L of yeast extract. In all cases, the lactic acid yields were found to be above 0.91 g/g. This article provides the optimized conditions for a batch culture ofLactobacillus sp. RKY2, which resulted in highest productivity of lactic acid.     

Taxonomic characterisation of Pseudomonas strain L48 and formal proposal of Pseudomonas entomophila sp. nov

An entomopathogenic, Gram-negative bacterium isolated from a female specimen of the fruit fly Drosophila melanogaster was taxonomically characterised. Strain L48(T) was strictly aerobic, non-fermentative, oxidase and catalase positive, rod-shaped, and motile due to a polar inserted flagellum. Phylogenetic analysis of the 16S rRNA gene and three other housekeeping genes placed strain L48 (T) in the Pseudomonas putida phylogenetic group. DNA-DNA hybridisation studies together with phenotypic metabolic tests and MALDI-TOF MS analysis justified the proposal of strain L48(T) as a representative of a novel species, for which the name Pseudomonas entomophila sp. nov. is proposed. The type strain is deposited in culture collections under accession numbers CCUG 61470(T) and CECT 7985(T).     

Taxonomic study of the Lactobacillus acidophilus group, with recognition of Lactobacillus gallinarum sp. nov. and Lactobacillus johnsonii sp. nov. and synonymy of Lactobacillus acidophilus group A3 (Johnson et al. 1980) with the type strain of Lactobacillus amylovorus (Nakamura 1981).

Biochemical properties and DNA-DNA reassociation studies of Lactobacillus acidophilus strains isolated from humans and animals indicate that these include six genomospecies. Two new species can be differentiated from the established species of the genus Lactobacillus: L. gallinarum sp. nov. (type strain, ATCC 33199) and L. johnsonii sp. nov. (type strain, ATCC 33200). Furthermore, it was clarified that L. acidophilus group A3 (Johnson et al. 1980) is synonymous with L. amylovorus.     

Production of epsilon-poly-L-lysine by newly isolated Kitasatospora sp. PL6-3

A novel epsilon-poly-L-lysine (epsilon-PL)-producing strain PL6-3 was isolated from soil, and was identified as a strain of Kitasatospora sp. This is the first detailed report of production of epsilon-PL by a strain in the genera of Kitasatospora. By controlling the culture pH at 4.0, the yield of epsilon-PL from PL6-3 reached 13.9 g/L after 120 h of cultivation in fed-batch fermentation. The morphological characteristics of Kitasatospora sp. PL6-3 in culture broth were different from those reported from strains of Streptomycetaceae, as no mycelium pellets were observed during the course of fermentation of PL6-3, which was beneficial to the assimilation of nutrition and secretion of the products. Furthermore, the molecular mass of the purified epsilon-PL from PL6-3 was determined to be 5.01 kDa by SDS-PAGE and 5.05 kDa by gel permeation chromatography, indicating that the epsilon-PL produced by this strain might be composed of 40 lysine residues. Usually, epsilon-PL with more lysine residues showed higher antimicrobial activity; however, it was difficult to obtain epsilon-PL with more than 36 lysine residues in this study. As a result, epsilon-PL from Kitasatospora sp. PL6-3, which contains more lysine residues than that from other strains, is more promising in the field of food preservatives.     

L.SP.HXQ001菌对家免抗氧化能力的影响

目的：探讨乳酸细菌中的明串珠对家兔抗氧化能力的影响。方法：检测健康家兔口服L.sp.HXQ001菌液前后,血清丙二醛（MDA）、谷胱甘肽过氧化物酶（GSH-px）水平及红细胞超氧化物歧化酶（SOD）总活性。结果： L.sp.HXQ001菌及其发酵产物可明显提高GSH-ox、SOD活性,降低血清MDA水平,并维持较长时间。结论：L.sp.HXQ001菌及其发酵产物有提高家兔抗氧化能力的作用,有望成为新的微生态调节剂。     

产D-阿拉伯醇菌株的筛选、鉴定及其产D-阿拉伯醇条件的优化

摘要：【目的】产D-阿拉伯醇的耐高渗酵母的筛选、鉴定和产D-阿拉伯醇条件的优化。【方法】通过电镜、Biolog GN、(G+C)含量和26S rDNA D1/D2区序列分析法对所获得的菌株进行了描述。通过红外光谱、核磁共振氢谱和碳谱、质谱以及旋光度实验鉴定纯化产物的结构。通过单因素实验优化产D-阿拉伯醇的发酵条件。【结果】本文筛选得到一株产D-阿拉伯醇的新型菌株,经鉴定属于假丝酵母属并命名为Candida sp. H2。200 mL摇瓶发酵生产D-阿拉伯醇的单因素优化实验表明,最适发酵条件为：葡萄糖250     

Epigenetic regulation of carnitine metabolising enzymes in Proteus sp. under aerobic conditions

Proteus sp. is able to catalyse the reversible transformation of crotonobetaine into L(-)-carnitine during aerobic growth. Contrary to other Enterobacteriaceae no reduction of crotonobetaine into gamma-butyrobetaine could be detected in the culture supernatants. Activities of L(-)-carnitine dehydratase, carnitine racemasing system and crotonobetaine reductase could be determined enzymatically in cell-free extracts of Proteus sp. Small amounts of gamma-butyrobetaine were found in cell-free extracts, indicating that it accumulates in the cell and inhibits the crotonobetaine reductase. Crotonobetaine and L(-)-carnitine were able to induce enzymes of carnitine metabolism. gamma-Butyrobetaine and glucose repress carnitine metabolism in Proteus sp. Other betaines are neither inducers nor repressors. Monoclonal antibodies against purified CaiA from Escherichia coli O44K74 recognise an analogous protein in cell-free extract of Proteus sp. No cross-reactivity could be detected with monoclonal antibodies against purified CaiB and CaiD from E. coli O44K74.