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1.
Hong-Sheng Wu Waseem Raza Dong-Yang Liu Cheng-Long Wu Ze-Shen Mao Yang-Chun Xu Qi-Rong Shen 《World journal of microbiology & biotechnology》2008,24(8):1297-1304
Watermelon production is threatened by fusarium wilt caused by Fusarium oxysporum f.sp. niveum (FON) in continuous cultivation system. Some elements, mainly allelochemicals, released from living roots or decayed plants
might be associated with the disease. The purpose of this work was to evaluate the possible impact of coumarin, one kind of
watermelon allelochemical, on FON. Furthermore, possible new mechanisms might be investigated during the ecological interactions
of plant-microbe. Results showed that coumarin strongly inhibited growth of FON leading to a decrease in its biomass, dry
weight of mycelia of FON in a liquid culture. The dry weight was decreased by 62.9% compared with control. The hyphal growth
of FON on plates was stopped at high (>400 mg l−1) concentrations of coumarin. At 320 mg l−1, sporulation and enzyme activities of FON were also severely suppressed by coumarin. The yield of conidia, and the activities
of proteinase, cellulase, and amylase were reduced by 98.9%, 79.7%, 29.8% and 15.9% respectively. However, conidial germination
and mycotoxin (MT) production of FON were greatly stimulated, being increased by 55.7% and 14.9 fold at 320 mg l−1 respectively. We conclude that coumarin acted as an allelochemical substance to inhibit growth and pathogenic enzyme activities
of FON but to stimulate mycotoxin production and conidial germination. It was suggested that coumarin acted as a signal transduction
element bridging plant and pathogen in the process of plant-microbe interactions. 相似文献
2.
E. Ruiz I. Romero M. Moya S. Sánchez V. Bravo E. Castro 《World journal of microbiology & biotechnology》2007,23(2):259-267
As a first step in the research on ethanol production from lignocellulose residues, sugar fermentation by Fusarium oxysporum in oxygen-limited conditions is studied in this work. As a substrate, solutions of arabinose, glucose, xylose and glucose/xylose
mixtures are employed. The main kinetic and yield parameters of the process are determined according to a time-dependent model.
The microorganism growth is characterized by the maximum specific growth rate and biomass productivity, the substrate consumption
is studied through the specific consumption rate and biomass yield, and the product formation via the specific production
rate and product yields. In conclusion, F. oxysporum can convert glucose and xylose into ethanol with product yields of 0.38 and 0.25, respectively; when using a glucose/xylose
mixture as carbon source, the sugars are utilized sequentially and a maximum value of 0.28 g/g ethanol yield is determined
from a 50% glucose/50% xylose mixture. Although fermentation performance by F.␣oxysporum is somewhat lower than that of other fermenting microorganisms, its ability for simultaneous lignocellulose-residue saccharification
and fermentation is considered as a potential advantage. 相似文献
3.
Fusarium oxysporum (isolate PSM 197) based mycoherbicide was evaluated for its efficacy under field conditions in trials conducted during 1999--2001 cropping seasons in the Nigerian savanna. In the 1999 cropping season, spot application of 5--10 g of mycoherbicide was found to give effective control of Striga hermonthica. Results of on-farm trials at Barhim and Dutsen-Ma areas showed the application of the mycoherbicide to significantly (p= 0.05) increase stand count at both 3 weeks and at harvest, reduced Striga shoot count and increased crop yield in both improved and local sorghum varieties, as compared with the same varieties not treated with the mycoherbicide. Results establish the efficacy of F. oxysporum as a mycoherbicide and the need for further development of the mycoherbicide into formulated granules or seed treatment for use in control of S. hermonthica under field conditions. 相似文献
4.
The anti-Fusarium oxysporum f. sp cicer (FOC) and anti-Alternaria porri (A. porri) effects were evaluated for 75 different essential oils. The most active essential oils found were those of lemongrass, clove,
cinnamon bark, cinnamon leaf, cassia, fennel, basil and evening primrose. However, the effectiveness of these essential oils
with both the tested fungi showed different responses. The level of inhibition was compared with Hexaconazole. GC–MS analysis
for five oils amongst the 75 essential oils tested was performed. The potential of these essential oils as an ecofriendly
and economic approach as a fungicide for FOC and A. porri is discussed. 相似文献
5.
Abhishek Tripathi Neeta Sharma Vinay Sharma 《World journal of microbiology & biotechnology》2009,25(3):503-512
Hyptis
suaveolens L. (Poit.) essential oil was tested in vitro on the growth and morphogenesis of Fusarium oxysporum f.sp. gladioli (Massey) Snyder & Hansen, which causes Fusarium corm rot and yellows in various susceptible cultivars of gladiolus. The fungitoxicity of the oil was measured by percentage radial growth inhibition using the poisoned food technique (PF)
and volatile activity assay (VA). The mycelial growth of the test fungus was completely inhibited at 0.998 and 0.748 μg ml−1 concentration of oil in PF and VA, respectively. Essential oil was found to be fungicidal in nature at 1.247 and 0.998 μg ml−1 concentration of oil in PF and VA, respectively. Determination of conidial germination in the presence of oil was also carried
out and it was found that the oil exhibited 100% inhibition of conidial germination at 0.450 μg ml−1 concentration. The effect of essential oil on the yield of mycelial weight was observed and it was found that at 0.873 μg ml−1 concentration no mycelium was recorded and 100% inhibition was observed. The fungitoxicity of oil did not change even on
exposure to 100°C temperature or to autoclaving, and the oil also retained its fungicidal nature even after storage of 24 months.
The main changes observed under light microscopy after oil treatment were a decrease and loss of conidiation and anomalies
in the hyphae such as a decrease in the diameter of hyphae and granulation of cytoplasm. The treatment of the oil also showed
highly reduced cytoplasm in the hyphae, showing clear retraction of the cytoplasm from the hyphae and ultimately in some areas
hyphae without cytoplasm were also found. GC-MS studies of the essential oil revealed that the oil consisted of 24 compounds
with 1,8-cineole as major component accounting for 44.4% of the total constituents. 相似文献
6.
Fujiwara M Sumitani J Koga S Yoshioka I Kouzuma T Imamura S Kawaguchi T Arai M 《Applied microbiology and biotechnology》2007,74(4):813-819
Fructosyl-amino acid oxidase (FOD-F) from Fusarium oxysporum f. sp. raphani (NBRC 9972) is the enzyme catalyzing the oxidative deglycation of fructosyl-amino acids such as -fructosyl -benzyloxycarbonyl-lysine (FZK) and fructosyl valine (FV), which are model compounds of the glycated proteins in blood. Wild-type
FOD-F has high activities toward both substrates. We obtained a mutant FOD-F, which reacts with FZK but not with FV by random
mutagenesis. One amino-acid substitution (K373R) occurred in the mutant FOD-F. In addition to K373R, K373W, K373M, K373T,
and K373V, which were selected for optimization of the substitution at position K373, were purified and characterized. Kinetic
analysis showed that the catalytic turnover for FV greatly decreased, whereas that for FZK did not. In consequence, the specificities
toward FZK were increased in the mutant FOD-Fs. The relation between the substrate specificity of the mutant FOD-Fs and the
position of the carboxyl group of the substrates was demonstrated using a series of the substrates having the carboxyl group
at the different position. The mutant FOD-Fs are attractive candidates for developing an enzymatic measurement method for
glycated proteins such as glycated albumin in serum. This study will be helpful to establish an easier and rapid clinical
assay system of glycated albumin. 相似文献
7.
8.
A group of Fusarium isolates from slime flux similar to F. aquaeductuum produced unique, strongly curved, aseptate, C-shaped conidia. They were found to be identical to F. splendens nom. nud. Dried specimens from which F. splendens was originally isolated were reexamined and characterized as a new species of Cosmospora. Cosmospora matuoi sp. nov. is proposed for the teleomorph, and Fusarium matuoi sp. nov. is proposed for its anamorph. 相似文献
9.
Twenty six Rhizobium strains isolated from root nodules of Sesbania sesban were studied for chitinase activity on chitin agar plates. Among them, only 12 strains showed chitinase activity. The strain
showing the highest chitinase activity was selected based on maximum clear zone/colony size ratio on chitin agar plates and
chitinase activity in culture filtrate. The strain was identified as Rhizobium sp. which showed a high degree of similarity with Rhizobium radiobacter (= Agrobacterium radiobacter). The cultural and nutritional conditions were optimized for maximum chitinase activity. The Rhizobium sp. exhibited maximum chitinase activity after 36 h of incubation, at neutral pH. Among the different nutritional sources,
arabinose and yeast extract were found to be good inducers for chitinase activity. Rhizobium sp. could degrade and utilize dead mycelia of Aspergillus flavus, Aspergillus niger, Curvularia lunata, Fusarium oxysporum and Fusarium udum. 相似文献
10.
Virulence analysis of 64 isolates of Fusarium oxysporum f. sp. ciceris causing chickpea wilt collected from major chickpea growing states of India on 14 varieties, including 10 international differentials revealed that the isolates from each state were highly variable. Based on the reactions on international differentials, more than one race was found to be prevalent in every state. Majority of the isolates were not matched with the race specific reactions. Therefore, some of the cultivars, namely, GPF 2, DCP 92-3, and KWR 108 should be included as new differentials to obtain clear-cut differential responses. Randomly amplified polymorphic DNA (RAPD), inter-simple sequence repeat (ISSR), and simple sequence repeat (SSR) markers were used to assess the genetic diversity of these isolates. Unweighted paired group method with arithmetic average (UPGMA) cluster analysis was used to divide the isolates into distinct clusters. The clusters generated by RAPD grouped all isolates into three categories at 25% genetic similarity and into two major categories at 30% genetic similarity. ISSR and SSR analyses also grouped all the isolates into two major categories. Majority of the isolates from Punjab and a few from Rajasthan were grouped in one category while the isolates from all other states were grouped in another suggesting the existence of diverse genetic populations of the pathogen at the same location. Some of the RAPD (OPM 6, OPI 9, P 17, OPN 4, OPF 1, P 17, P 21, and SC 1), ISSR (ISSR 7, ISSR 11, and ISSR 12) and SSR (MB 17) markers clearly distinguished area specific isolates. 相似文献
11.
The objective of the present study was to measure the production of cutinase by Fusarium oxysporum in the presence of several carbon and nitrogen sources (glycides, fatty acids and oils, and several organic and inorganic
nitrogen sources), trying to find a cost-effective substitute for cutin in the culture medium as an inducer of cutinase production.
The results were evaluated by the Tukey test, and flaxseed oil was found to give the best results as a cutinase inducer. The
authors optimized the composition of the growth medium employing response surface methodology. The experimental results were
fitted to a second-order polynomial model at a 95% level of significance (p < 0.05). The greatest cutinolytic activity was obtained in a liquid mineral medium supplemented with flaxseed oil, showing
an increase in enzymatic activity from 11 to 22.68 U/mL after 48 h of fermentation. A CCD study of the fermentation conditions
was carried out, and the best production of cutinase was registered with the use of 30 °C and 100 rpm. These results support
the use of flaxseed oil as a substitute for cutin, which is difficult and expensive to obtain, for the production of cutinase
in a larger scale. 相似文献
12.
Bacillus subtilis strain IB exhibiting inhibitory activity against the Fusarium head blight disease fungus Fusarium graminearum was isolated and identified. The major inhibitory compound was purified from the culture broth through anion exchange, hydrophobic
interaction, and reverse phase high-performance liquid chromatography (RP-HPLC) steps. It was a 1,463-Da lipopeptide and had
an amino acid composition consisting of Ala, Glx, Ile, Orn, Pro, Thr, and Tyr at a molar ratio of 1:3:1:1:1:1:2. Electrospray
ionization mass spectrometry/mass spectrometry (ESI MS/MS) analyses of the natural and the ring-opened peptides showed the
antagonist was fengycin, a kind of macrolactone molecule with antifungal activity produced by several Bacillus strains. Fluorescence microscopic analysis indicated this peptide permeabilized and disrupted F. graminearum hyphae. 相似文献
13.
Fusarium solani degraded methyl tert-butyl ether (MTBE) and other oxygenated compounds from gasoline including tert-butyl alcohol (TBA). The maximum degradation rate of MTBE was 16 mg protein h and 46 mg/g protein h for TBA. The culture
transformed 77% of the total carbon to 14CO2. The estimated yield for MTBE was 0.18 g dry wt/g MTBE. 相似文献
14.
Srinivasachary Gosman N Steed A Simmonds J Leverington-Waite M Wang Y Snape J Nicholson P 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2008,116(8):1145-1153
Fusarium head blight (FHB) is an important disease of wheat worldwide. The cultivar Spark is more resistant than most other UK winter
wheat varieties but the genetic basis for this is not known. A mapping population from a cross between Spark and the FHB susceptible
variety Rialto was used to identify quantitative trait loci (QTL) associated with resistance. QTL analysis across environments
revealed nine QTL for FHB resistance and four QTL for plant height (PH). One FHB QTL was coincident with the Rht-1D locus and accounted for up to 51% of the phenotypic variance. The enhanced FHB susceptibility associated with Rht-D1b is not an effect of PH per se as other QTL for height segregating in this population have no influence on susceptibility.
Experiments with near-isogenic lines supported the association between susceptibility and the Rht-D1b allele conferring the semi-dwarf habit. Our results demonstrate that lines carrying the Rht-1Db semi-dwarfing allele are compromised in resistance to initial infection (type I resistance) while being unaffected in resistance
to spread within the spike (type II resistance). 相似文献
15.
O. K. Strunnikova V. Yu. Shakhnazarova N. A. Vishnevskaya V. K. Chebotar’ I. A. Tikhonovich 《Microbiology》2007,76(5):596-602
The development of Fusarium culmorum and Pseudomonas fluorescens in soil, and the relations between them, were studied using membrane filters containing the fungus, the bacterium, or both microorganisms; the filters were incubated in soil. F. culmorum was identified by indirect immunofluorescence; the GUS-labeled strain was used to visualize P. fluorescens. It was found that F. culmorum introduced in soil can develop as a saprotroph, with the formation of mycelium, macroconidia, and a small amount of chlamydospores. Introduction of glucose and cellulose resulted in increased density of the F. culmorum mycelium and macroconidia. P. fluorescens suppressed the development of the F. culmorum mycelium in soil, but stimulated chlamydospore formation. Decreased mycelial density in the presence of P. fluorescens was more pronounced in soil without additions and less pronounced in the case of introduction of glucose or cellulose. F. culmorum had no effect on P. fluorescens growth in soil. 相似文献
16.
Environmental manipulation or conservation is one among several approaches evolved for harnessing the potentiality of entomopathogens
in an integrated pest management. Cultural manipulation can permit the pathogen to reproduce more than usual or can preserve
or enhance those already present. Among the key pest of chilli thrips, Scirtothrips dorsalis Hood (Thripidae: Thysanoptera) and broad mite, Polyphagotarsonemus latus [Banks] (Tarsonemoidea: Acari) are reported to cause the leaf curl in the leaves of chilli. Fusarium semitectum has infected the thrips and mites. The effectiveness of the mycopathogen, F. semitectum is chiefly influenced by the environmental conditions. Enhancing the microclimate the mycopathogen can be able to develop
and buildup further. Chilli has been grown as sole crop, however companion crops such as sorghum, cotton, red gram, castor
and maize were grown to understand the cropping system effect. Chilli-sorghum, chilli-cotton-chilli and chilli-red gram were
the best cropping systems in terms of total chilli yield. The chilli-cotton-chilli cropping system ranked second with respect
to benefit-cost ratio of 1:1 where as chilli-sorghum cropping system claimed the highest as 1.125:1. Interestingly, sorghum
is not grown as a companion crop with chilli in Karnataka under rain fed conditions, where as chilli-cotton combination is
a practice in many places of the state. 相似文献
17.
The maT clade of transposons is a group of transposable elements intermediate in sequence and predicted protein structure to mariner and Tc transposons, with a distribution thus far limited to a few invertebrate species. We present evidence, based on searches of publicly available databases, that the nematode Caenorhabditis briggsae has several maT-like transposons, which we have designated as CbmaT elements, dispersed throughout its genome. We also describe two additional transposon sequences that probably share their evolutionary history with the CbmaT transposons. One resembles a fold back variant of a CbmaT element, with long (380-bp) inverted terminal repeats (ITRs) that show a high degree (71%) of identity to CbmaT1. The other, which shares only the 26-bp ITR sequences with one of the CbmaT variants, is present in eight nearly identical copies, but does not have a transposase gene and may therefore be cross mobilised by a CbmaT transposase. Using PCR-based mobility assays, we show that CbmaT1 transposons are capable of excising from the C. briggsae genome. CbmaT1 excised approximately 500 times less frequently than Tcb1 in the reference strain AF16, but both CbmaT1 and Tcb1 excised at extremely high frequencies in the HK105 strain. The HK105 strain also exhibited a high frequency of spontaneous induction of unc-22 mutants, suggesting that it may be a mutator strain of C. briggsae. 相似文献
18.
The present study aimed to analyze the growth kinetics and morphogenesis of toxigenic Fusarium verticillioides strains. Growth curves based on mycelial dry weight measured after 24, 48, and 96 h and every 4 days for a period of 60 days
were obtained for each strain. The morphogenesis of this fungus was studied during its developmental stages through the fluorescent
method Fluorecein Diacetate-FDA and Ethidium Bromide-EB. The growth curves of the strains usually followed a homogeneous pattern
comparable to the ideal growth curve. Using the fluorescence method, non-viable cells showed a light bright red coloration
and viable cells presented green fluorescence with three fluorescent patterns. The present results showed that the morphogenesis
of F. verticillioides is an asynchronous process characterized by the presence of a wide variety of fungal forms until 50 days of culture. The
method is very useful to demonstrate the F. verticillioides growth stages as well as the perfect differentiation between viable and non-viable cell. 相似文献
19.
Although resistance of microorganisms to Hg(II) salts has been widely investigated and resistant strains have been reported
from many eubacterial genera, there are few reports of mercuric ion resistance in extremophilic microorganisms. Moderately
thermophilic mercury resistant bacteria were selected by growth at 62 °C on Luria agar containing HgCl2. Sequence analysis of 16S rRNA genes of two isolates showed the closest matches to be with Bacillus pallidus and Ureibacillus thermosphaericus. Minimum inhibitory concentration (MIC) values for HgCl2 were 80 μg/ml and 30 μg/ml for these isolates, respectively, compared to 10 μg/ml for B. pallidus H12 DSM3670, a mercury-sensitive control. The best-characterised mercury-resistant Bacillus strain, B. cereus RC607, had an MIC of 60 μg/ml. The new isolates had negligible mercuric reductase activity but removed Hg from the medium
by the formation of a black precipitate, identified as HgS by X-ray powder diffraction analysis. No volatile H2S was detected in the headspace of cultures in the absence or presence of Hg2+, and it is suggested that a new mechanism of Hg tolerance, based on the production of non-volatile thiol species, may have
potential for decontamination of solutions containing Hg2+ without production of toxic volatile H2S. 相似文献
20.
A d -lactonohydrolase gene of about 1.1 kb was cloned from Fusarium moniliforme. The ORF sequence predicted a protein of 382 amino acids with a molecular mass of about 40 kDa. An expression plasmid carrying the gene under the control of the triose phosphate isomerase gene promotor was introduced into Saccharomyces cerevisiae, and the d -lactonohydrolase gene was successfully expressed in the recombinant strains.Revisions requested 10 September 2004; Revisions received 15 October 2004The nucleotide sequence data reported in this paper has been assigned accession number AY728018 in the GeneBank database. 相似文献