Production of macrosphelide A by the mycoparasite Coniothyrium minitans

Coniothyrium minitans, a mycoparasite of sclerotia of Sclerotinia sclerotiorum and Sclerotium cepivorum, produced four closely related metabolites inhibitory to fungal growth. The major metabolite, identified as macrosphelide A, had IG(50) values (the concentration of metabolite to inhibit growth by 50%) of 46.6 and 2.9 microgram ml(-1) against S. sclerotiorum and S. cepivorum, respectively. This is the first report of both antifungal activity due to macrosphelide A as well as isolation of macrosphelide A from C. minitans.     

Antimicrobial activity of Coniothyrium minitans and its macrolide antibiotic macrosphelide A

Aims: Assessment of antimicrobial activity of the mycoparasite Coniothyrium minitans and its macrolide antibiotic macrosphelide A. Methods and Results: Thirteen isolates of C. minitans were tested for ability to inhibit a number of filamentous fungi, yeasts, oomycetes and bacteria in agar based tests. Activity was found against some ascomycetes, basidiomycetes, oomycetes and Gram‐positive bacteria, but not against zygomycetes, yeasts or Gram‐negative bacteria tested. Six C. minitans isolates (Conio, Contans, IVT1, CM/AP/3118, B279/1, A1/327/1) were found to produce macrosphelide A in liquid culture and no other antibiotics were detected. On agar, macrosphelide A inhibited growth of some ascomycetes, basidiomycetes, oomycetes and all four Gram‐positive bacteria tested, including the medically important Staphylococcus aureus with a minimum inhibitory concentration of ≤500 μg ml^?1. There was no inhibition observed against the yeasts and Gram‐negative bacteria when macrosphelide A was tested at 700 μg ml^?1. Conclusions: The spectrum and level of activity of macrosphelide A produced by C. minitans against micro‐organisms are extended markedly compared to previous reports. Significance and Impact of the Study: Macrosphelide A was effective against Staph. aureus. Further study on the control of this bacterium is merited in view of the development of antibiotic resistance.     

Effect of chlorine substitution on the bacterial metabolism of various polychlorinated biphenyls.

Of 36 pure isomers (chlorine numbers 1 to 5) of polychlorinated biphenyls examined, 23 compounds were metabolized by Alcaligenes sp. strain Y42, and 33 compounds were metabolized by Acinetobacter sp. strain P6. The major pathway of many polychlorinated biphenyl isomers examined was considered to proceed through 2',3'-dihydro-2',3'-diol compounds, concomitant dehydrogenated 2',3'-dihydroxy compounds, subsequently the 1',2'-meta-cleavage compounds (chlorinated derivatives of 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoic acids), and then chlorobenzoic acids. The meta-cleavage products were usually converted to chlorobenzoic acids upon further incubation in many polychlorinated biphenyls, but they accumulated specifically in the metabolism of 2,4'-, 2,4,4'-, and 2,5,4'-chlorobiphenyls, which are all chlorinated at the 2,4'-position in the molecules in common. Dihydroxy compounds accumulated mainly in the metabolism of 2,6-, 2,3,6-, 2,4,2',5'-, 2,5,2',5'-, and 2,4,5,2',5'-chlorobiphenyls by Acinetobacter sp. P6. The 2,3,2',3'-, 2,3,2',5'-, and 2,4,5,2',3'-chlorobiphenyls, which are chlorinated at the 2,3-position of one of the rings, were metabolized in a different fashion. Two major metabolites of a chlorobenzoic acid and an unknown compound accumulated always in the metabolism of this group of polychlorinated biphenyls. 2,4,6-Trichlorobiphenyl was metabolized quite differently between the two organisms. Alcaligenes sp. Y42 metabolized this compound very slowly to trichlorobenzoic acid by the major oxidative route. In contrast, Acinetobacter sp. P6 metabolized it to a trihydroxy compound via a dihydroxy compound.     

一株马兜铃内生真菌Colletotrichum sp.代谢产物中细胞毒活性成分的研究

从马兜铃内生真菌Colletotrichum sp.的大米发酵产物中分离得到6个化合物,经波谱数据分析分别鉴定为7-hydroxy-10-oxodehydrodihydrobotrydial(1)、格链孢酚(2)、5-甲氧基格链孢酚(3)、链格孢毒素I(4)、腾毒素(5)和二氢腾毒素(6)。以上化合物均为从该菌属中首次分离得到,其中化合物1～4对肺癌细胞和乳腺癌细胞有一定的细胞毒活性。     

Effect of chlorine substitution on the bacterial metabolism of various polychlorinated biphenyls.

Of 36 pure isomers (chlorine numbers 1 to 5) of polychlorinated biphenyls examined, 23 compounds were metabolized by Alcaligenes sp. strain Y42, and 33 compounds were metabolized by Acinetobacter sp. strain P6. The major pathway of many polychlorinated biphenyl isomers examined was considered to proceed through 2',3'-dihydro-2',3'-diol compounds, concomitant dehydrogenated 2',3'-dihydroxy compounds, subsequently the 1',2'-meta-cleavage compounds (chlorinated derivatives of 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoic acids), and then chlorobenzoic acids. The meta-cleavage products were usually converted to chlorobenzoic acids upon further incubation in many polychlorinated biphenyls, but they accumulated specifically in the metabolism of 2,4'-, 2,4,4'-, and 2,5,4'-chlorobiphenyls, which are all chlorinated at the 2,4'-position in the molecules in common. Dihydroxy compounds accumulated mainly in the metabolism of 2,6-, 2,3,6-, 2,4,2',5'-, 2,5,2',5'-, and 2,4,5,2',5'-chlorobiphenyls by Acinetobacter sp. P6. The 2,3,2',3'-, 2,3,2',5'-, and 2,4,5,2',3'-chlorobiphenyls, which are chlorinated at the 2,3-position of one of the rings, were metabolized in a different fashion. Two major metabolites of a chlorobenzoic acid and an unknown compound accumulated always in the metabolism of this group of polychlorinated biphenyls. 2,4,6-Trichlorobiphenyl was metabolized quite differently between the two organisms. Alcaligenes sp. Y42 metabolized this compound very slowly to trichlorobenzoic acid by the major oxidative route. In contrast, Acinetobacter sp. P6 metabolized it to a trihydroxy compound via a dihydroxy compound.     

Unveiling antimicrobial activity of microalgae Chlorella sorokiniana (UKM2), Chlorella sp. (UKM8) and Scenedesmus sp. (UKM9)

Microalgae represent promising sources of bioactive compounds for pharmaceutical and industrial applications. The emergence of antibiotic resistant bacteria leads to the need to explore new cost-effective, safe, and potent bioactive compounds from the microalgae. This study aimed to investigate the potential of local microalgae for their antimicrobial properties and bioactive compounds. Three local microalgae namely Chlorella sorokiniana (UKM2), Chlorella sp. UKM8, and Scenedesmus sp. UKM9 biomass methanol extracts (ME) were prepared and tested against Gram-positive and Gram-negative bacteria. Chlorella sp. UKM8-ME showed the highest antibacterial activity. UKM8-ME minimum inhibitory concentrations were in the range of 0.312 to 6.25 mg/mL. Cytotoxicity evaluation using MTT assay showed that the microalgae methanolic extracts did not exhibit cytotoxicity against Vero-cells. The UKM8-ME was mainly containing 28 compounds from the Gas Chromatography-Mass Spectrometry (GC–MS) analysis. Major compounds of UKM8-ME included phenol (18.5%), hexadecanoic acid (18.25%), phytol (14.43%), 9,12-octadecadienoic acid (13.69%), and bicyclo[3.1.1]heptane (7.23%), which have been previously described to possess antimicrobial activity. Hence, Chlorella sp. (UKM8) methanol extracts showed promising antibacterial activity. More comprehensive studies are required to purify these antimicrobial compounds and develop our understanding on their mechanism in UKM8-ME to unleash their specific potential.     

Five Sesquiterpenes from Paraconiothyrium sp. and Their Anti-inflammatory Activity

Five eremophilane sesquiterpenes including three new ones, named paraconions A–C ( 1 – 3 ), were isolated from an endophytic fungus, Paraconiothyrium sp. from Artemisia selengensis. The structures of these new compounds were established based on spectroscopic methods, including nuclear magnetic resonance (NMR), ultraviolet (UV), and infrared (IR) spectroscopy, as well as high resolution electrospray ionization mass spectrometry (HR-ESI-MS). An anti-inflammatory assay indicated that paraconion B ( 2 ) inhibited lipopolysaccharide-induced nitric oxide (NO) production in RAW 264.7 cells, with an IC₅₀ value of 51.7 μM. The compounds discovered in this study will enrich the structural types of secondary metabolites of the endophytic fungus Paraconiothyrium sp.     

苍耳化学成分及生物活性研究

采用硅胶柱色谱、制备薄层色谱、正反高效液相色谱和重结晶等方法,对苍耳石油醚、乙酸乙酯萃取物进行分离,研究了中药苍耳(Xanthium sibiricum)全草的化学成分和抗菌活性。结果表明:共得到14个化合物。根据理化性质和波谱数据分析,鉴定化合物结构分别为对甲氧基苯甲酸(1)、蒲公英赛醇(2)、羽扇豆醇(3)、熊果酸(4)、豆甾醇(5)、齐墩果酸(6)、lasidiol p-methoxybenzoate(7)、羽扇豆酮(8)、苍耳亭(9)、α-菠甾醇(10)、槲皮素(11)、苍耳皂素(12)、芹菜素(13)、羽扇豆醇乙酸酯(14)。化合物2、7、8为首次从该植物中分离得到。以平板打孔法测试提取化合物对不同菌种的抑制作用,结果表明化合物2、8、9、12对蕃茄早疫、黄瓜枯萎、蕃茄灰霉和苹果腐烂病菌有较好的抑菌活性。     

Identity and biodegradative abilities of yeasts isolated from plants growing in an arid climate

Plants harvested in the Canary Islands Lanzarote and Fuerteventura were analyzed for the yeasts inhabiting their surface. Half of the isolates (22 out of 44) were identified as Debaryomyces hansenii. Black ascomycetes, viz. Hortaea werneckii and two Hormonema species were represented by 7 strains. Basidiomycetous yeasts, viz. Cryptococcus sp. (8 strains), Rhodotorula sp. (5 strains), Cerinosterus cyanescens (1 strain) and Pseudozyma sp. (1 strain) constituted a minority of 33%. Thirty strains were screened for their ability to assimilate various plant constituents including lipids of the cuticle and the cell membrane, hemicelluloses, nitrogenous compounds (protein, nucleic acids, amino acids) and benzene compounds. All strains were able to assimilate or to hydrolyze lipids, lecithin included. Many strains of D. hansenii, H. dematioides, H. werneckii, C. cyanescens, Cr. laurentii, Pseudozyma sp. and Rh. glutinis were proteolytic. Hemicelluloses like xylan and pectin were assimilated by black ascomycetous yeasts, Cryptococcus sp., Pseudozyma sp. and Rh. glutinis. Ferulic and hydroxycinnamic acids, gallic and tannic acids were assimilated by some strains of H. dematioides, C. cyanescens, Pseudozyma sp. and Rhodotorula sp.     

Chlorophenol and nitrophenol metabolism by Sphingomonas sp UG30

Sphingomonas sp UG30 is a pentachlorophenol (PCP)-degrading bacterial strain capable of degrading several nitrophenolic compounds, including p-nitrophenol (PNP), 2,4-dinitrophenol (2,4-DNP), p-nitrocatechol and 4,6-dinitro-o-cresol (DNOC). The ability to degrade both chlorophenolic and nitrophenolic compounds is probably not restricted to UG30, but may also be possessed by other pentachlorophenol-degrading Sphingomonas spp. The interesting question arises as to whether there is any point of convergence between the initial pathways of PCP and nitrophenol degradation in these microorganisms. There is some experimental evidence that PCP-4-monooxygenase is involved in metabolism of both p-nitrophenol and 2,4-dinitrophenol. Further studies are needed to confirm this and to examine the role(s) of other PCP-degrading enzymes in nitrophenol metabolism by this microorganism. In this paper, we review some of the taxonomic, biochemical, physiological and ecological properties of Sphingomonas sp UG30 with respect to biodegradation of PCP and nitrophenolic compounds. Received 19 April 1999/ Accepted in revised form 21 August 1999     

Isolation and molecular characterization of thiosulfate-oxidizing bacteria from an Italian rice field soil

In rice paddy soils an active cycling of sulfur compounds takes place. To elucidate the diversity of thiosulfate-oxidizing bacteria these organisms were enriched from bulk soil and rice roots by the most probable number method in liquid medium. From the MPN enrichment cultures 21 bacterial strains were isolated on solid mineral medium, and could be further shown to produce sulfate from thiosulfate. These strains were characterized by 16S rDNA analyses. The isolates were affiliated to seven different phylogenetic groups within the alpha- and beta-subclass of Proteobacteria. Two of these phylotypes were already described as S-oxidizers in this environment (Xanthobacter sp. and Bosea sp. related strains), but five groups represented new S-oxidizers in rice field soil. These isolates were closely related to Mesorhizobium loti, to Hydrogenophaga sp., to Delftia sp., to Pandoraea sp. or showed sequence similarity to a strain of Achromobacter sp.     

长序虎皮楠内生真菌Penicilliumsp.DCS82的化学成分

采用色谱技术从长序虎皮楠内生真菌Penicillium sp. DCS82菌株的PDA平板发酵物中分离纯化得到5个化合物。通过波谱数据分析及与文献对照进行结构解析,分别鉴定为:verrucosidinol acetate(1),verrucosidinol(2),viridicatin(3),fructigenine A(4),3-(dimethylaminomethyl)-1-(1,1-dimethyl-2-propenyl)indole(5)。所有化合物都是首次从该菌中分离里得到。     

Piericidins C5 and C6: new 4-pyridinol compounds produced by Streptomyces sp. and Nocardioides sp

Piericidins C5 (1) and C6 (2), two new members of the piericidin family, were isolated from a Streptomyces sp. and a Nocardioides sp., together with known piericidins C1 (3), C2 (4), C3 (5), C4 (6), D1 (7), and A3 (8). The structures were determined on the basis of their spectroscopic data. Both new compounds inhibited cell division of fertilized starfish (Asterina pectinifera) eggs at the minimum inhibitory concentration of 0.09 microg/mL.     

Degradation of pyrene, benz[a]anthracene, and benzo[a]pyrene by Mycobacterium sp. strain RJGII-135, isolated from a former coal gasification site.

The degradation of three polycyclic aromatic hydrocarbons (PAH), pyrene (PYR), benz[a]anthracene (BAA), and benzo[a]pyrene (BaP), by Mycobacterium sp. strain RJGII-135 was studied. The bacterium was isolated from an abandoned coal gasification site soil by analog enrichment techniques and found to mineralize [14C]PYR. Further degradation studies with PYR showed three metabolites formed by Mycobacterium sp. strain RJGII-135, including 4,5-phenanthrene-dicarboxylic acid not previously isolated, 4-phenanthrene-carboxylic acid, and 4,5-pyrene-dihydrodiol. At least two dihydrodiols, 5,6-BAA-dihydrodiol and 10,11-BAA-dihydrodiol, were confirmed by high-resolution mass spectral and fluorescence analyses as products of the biodegradation of BAA by Mycobacterium sp. strain RJGII-135. Additionally, a cleavage product of BAA was also isolated. Mass spectra and fluorescence data support two different routes for the degradation of BaP by Mycobacterium sp. strain RJGII-135. The 7,8-BaP-dihydrodiol and three cleavage products of BaP, including 4,5-chrysene-dicarboxylic acid and a dihydro-pyrene-carboxylic acid metabolite, have been isolated and identified as degradation products formed by Mycobacterium sp. strain RJGII-135. These latter results represent the first example of the isolation of BaP ring fission products formed by a bacterial isolate. We propose that while this bacterium appears to attack only one site of the PYR molecule, it is capable of degrading different sites of the BAA and BaP molecules, and although the sites of attack may be different, the ability of this bacterium to degrade these PAH is well supported. The proposed pathways for biodegradation of these compounds by this Mycobacterium sp. strain RJGII-135 support the dioxygenase enzymatic processes reported previously for other bacteria. Microorganisms like Mycobacterium sp. strain RJGII-135 will be invaluable in attaining the goal of remediation of sites containing mixtures of these PAH.     

海洋放线菌Streptomyces variabilis strain 6-1次级代谢产物的研究

目的:对来自海洋软珊瑚的链霉菌6-1(Streptomyces variabilis strain 6-1)进行次级代谢产物的分离和鉴定,寻找具有生物活性的化合物,为人类健康服务。方法:采用液体培养基对分自海洋软珊瑚Scleronephthya sp中的链霉菌6-1(Streptomyces variabi-lis strain 6-1)进行发酵培养,用乙酸乙酯对发酵液进行萃取;采用半制备高效液相色谱(semi-preparative HPLC)分离方法对乙酸乙酯萃取物进行分离纯化,得到单体化合物;运用电喷雾质谱(ESI-MS)、核磁共氢振(1H NMR)、核磁共振碳谱(13C NMR)和物理性质对所得单体化合物进行结构鉴定。结果:从海洋链霉菌6-1(strain 6-1)发酵液的乙酸乙酯萃取物中分离得到3个单体化合物,分别鉴定为:7,4'-二羟基异黄酮(1)、5,7,4'-三羟基异黄酮(2)和丁烯酸内酯-Ⅰ(3)。结论:丁烯酸内酯-Ⅰ是从链霉菌属首次分离得到,化合物1和2均是从Streptomyces variabilis中首次分离得到;变异链霉菌6-1(Streptomyces variabilis strain 6-1)可以作为活性化合物3(丁烯酸内酯-Ⅰ)的重要来源。     

南海链霉菌SCSIO 1635中抗霉素类化合物的分离鉴定(英文)

我们从南海海底沉积环境分离了一株放线菌SCSIO1635,经16S rDNA的序列分析将该株菌鉴定为链霉菌属。我们从该菌的发酵液中分离得到了4个化合物,经质谱和核磁共振波谱解析,确定为抗霉素类化合物:异构体antimycin A1a和A1b(1)、deisovalerylblastmycin(2)、kitamycin A(3)和antimycin A9(4)。     

Structuring of bacterioplankton communities by specific dissolved organic carbon compounds

The main role of microorganisms in the cycling of the bulk dissolved organic carbon pool in the ocean is well established. Nevertheless, it remains unclear if particular bacteria preferentially utilize specific carbon compounds and whether such compounds have the potential to shape bacterial community composition. Enrichment experiments in the Mediterranean Sea, Baltic Sea and the North Sea (Skagerrak) showed that different low-molecular-weight organic compounds, with a proven importance for the growth of marine bacteria (e.g. amino acids, glucose, dimethylsulphoniopropionate, acetate or pyruvate), in most cases differentially stimulated bacterial growth. Denaturing gradient gel electrophoresis 'fingerprints' and 16S rRNA gene sequencing revealed that some bacterial phylotypes that became abundant were highly specific to enrichment with specific carbon compounds (e.g. Acinetobacter sp. B1-A3 with acetate or Psychromonas sp. B3-U1 with glucose). In contrast, other phylotypes increased in relative abundance in response to enrichment with several, or all, of the investigated carbon compounds (e.g. Neptuniibacter sp. M2-A4 with acetate, pyruvate and dimethylsulphoniopropionate, and Thalassobacter sp. M3-A3 with pyruvate and amino acids). Furthermore, different carbon compounds triggered the development of unique combinations of dominant phylotypes in several of the experiments. These results suggest that bacteria differ substantially in their abilities to utilize specific carbon compounds, with some bacteria being specialists and others having a more generalist strategy. Thus, changes in the supply or composition of the dissolved organic carbon pool can act as selective forces structuring bacterioplankton communities.     

Clotrimazole,ketoconazole, and clodinafop-propargyl as potent growth inhibitors of equine Babesia parasites during in vitro culture

The antifungal agents clotrimazole (CLT) and ketoconazole (KC) and the herbicide clodinafop-propargyl (CP) inhibit growth of Plasmodium sp., Toxoplasma sp., and Trypanosoma sp. In the present study, we evaluated these drugs against the in vitro growth of the equine protozoan parasites Babesia equi and B. caballi. Clotrimazole (IC50: 2 and 17 microM), KC (IC50: 6 and 22 microM), and CP (IC50: 450 and 354 microM) were effective growth inhibitors. Interestingly, intraerythrocytic KC-treated Babesia sp. were observed to be in immediate contact with the plasma fraction of the blood in electron microscopy. These results demonstrate the babesiacidial activities of these compounds and suggest their chemotherapeutic potential for the treatment of equine babesioses.     

Antibacterial metabolites from the Actinomycete <Emphasis Type="Italic">Streptomyces</Emphasis> sp. P294

The Actinomycete strain P294 was isolated from soil and identified as Streptomyces sp. based upon the results of 16S rRNA sequence analysis. Three compounds obtained from the solid fermentation products of this strain have been determined by 1D, 2D NMR and HRMS experiments. These compounds include two new compounds angumycinones C (1) and D (2), and the known compound X-14881 E (3). All compounds were assayed for antibacterial and nematicidal activity. The results showed the three compounds had different degrees of inhibitory activity against several target bacteria but no significant toxicity against the nematode Caenorhabditis elegans.     

海洋真菌Arthrinium sp. UJNMF0008代谢产物的研究

为丰富海洋真菌的化学多样性,发现海洋真菌活性代谢产物,对海洋沉积物来源真菌Arthriniumsp.UJNMF0008的化学成分及其生物活性进行研究,采用硅胶柱色谱、凝胶柱色谱、反向柱色谱和高效液相色谱等方法从海洋沉积物来源真菌Arthriniumsp.UJNMF0008的发酵提取物中分离到5个化合物,通过核磁共振、质谱等方法,结合文献对照,鉴定了化合物的结构分别为arthoneF(1)、arthoneG(2)、sydoxanthoneC(3)、(3R,4R)-cis-4-hydroxymellein(4)和2-(2′S-hydroxypropyl)-5-methyl-7-hydroxychromone(5),其中化合物1和2是新化合物,化合物3首次从该属真菌中分离到。活性测试显示,化合物1~5在50μmoL/L的测试浓度下均没有表现出明显的抗氧自由基活性、抗菌活性以及NO释放抑制活性。