共查询到20条相似文献,搜索用时 31 毫秒
1.
Major secondary metabolites produced by two commercial Trichoderma strains active against different phytopathogens 总被引:3,自引:0,他引:3
Vinale F Marra R Scala F Ghisalberti EL Lorito M Sivasithamparam K 《Letters in applied microbiology》2006,43(2):143-148
AIMS: Trichoderma harzianum strains T22 and T39 are two micro-organisms used as active agents in a variety of commercial biopesticides and biofertilizers and widely applied amongst field and greenhouse crops. The production, isolation, biological and chemical characterization of the main secondary metabolites produced by these strains are investigated. METHODS AND RESULTS: Of the three major compounds produced by strain T22, one is a new azaphilone that shows marked in vitro inhibition of Rhizoctonia solani, Pythium ultimum and Gaeumannomyces graminis var. tritici. In turn, filtrates from strain T39 were demonstrated to contain two compounds previously isolated from other T. harzianum strains and a new butenolide. The production of the isolated metabolites was also monitored by liquid chromatography/mass spectrometry during in vitro interaction with R. solani. CONCLUSIONS: This paper reports the isolation and characterization of the main secondary metabolites obtained from culture filtrates of two T. harzianum strains and their production during antagonistic interaction with the pathogen R. solani. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first work on secondary metabolites produced by the commercially applied strains T22 and T39. Our results provide a better understanding of the metabolism of these fungi, which are both widely used as biopesticides and/or biofertilizers in biocontrol. 相似文献
2.
Leobardo Serrano-Carreon Yetrib Hathout Maurice Bensoussan Jean-Marc Belin 《FEMS microbiology letters》1992,93(2):181-187
Abstract Two filamentous fungi, Trichoderma harzianum and Trichoderma viride , were compared for their ability to synthesize lipids on different carbon and nitrogen sources. Three culture media were selected for each strain after preliminary screening. All the test media were nitrogen-deficient (C/N = 60) so as to stimulate lipid accumulation. For both microorganisms the glucose-ammonium sulphate medium was the most conducive to lipid production: a lipid accumulation of 17% (w/w) of biomass dry weight was obtained for T. harzianum and of 32% (w/w) of biomass dry weight for T. viride . In sucrose-sodium nitrate medium T. harzianum was able to accumulate almost 25% (w/w) of its biomass in lipid form. However the small quantity of biomass produced (2 g dry weight/l) limited the quantity of lipid obtained. Neutral lipids, free fatty acids and phospholipids were monitored during 8 days of cultivation of the two fungi. 相似文献
3.
4.
Two filamentous fungi, the white-rot fungus Trametes versicolor and the soil fungus and potential biocontrol organism Trichoderma harzianum, have been grown in pure and mixed cultures on low-N (0.4 mM) and high-N (4 mM) defined synthetic media to determine the activities of selected wood-degrading enzymes such as cellobiase, cellulase, laccase, and peroxidases. Growth characteristics and enzyme activities were examined for potential correlations. Such correlations would allow the use of simple enzyme assays for measuring biomass development and would facilitate predictions about competitiveness of species in mixed fungal cultures. Our results show that while laccase and Poly Red-478 peroxidase activities indicate survival of the decay fungus, none of the monitored extracellular enzymes can serve as a quantitative indicator for biomass accumulation. As expected, the level of available nitrogen affected the production of the enzymes monitored: in low-N media, specific cellobiase, specific cellulase, and peroxidase activities were enhanced, while laccase activities were reduced. Most importantly, laccase activities of Trametes versicolor, and to a smaller extent, cellobiase activities of both fungi, were significantly induced in mixed cultures of Trametes versicolor and Trichoderma harzianum. 相似文献
5.
Culture filtrates of Trichoderma viride and Trichoderma harzianum were inhibitory of Fusarium moniliforme and, to a lesser
extent, Aspergillus flavus. The degree of inhibition was, however, dependent on the carbon or nitrogen source incorporated
into the medium. Scanning electron microscopy revealed the development of abnormal fruiting structures on exposure to some
Trichoderma culture filtrate, while macroscopically, growth restriction and, in the case of A. flavus, altered colony colouration
were observed. Based on the results of inverted colony culture, it would appear that some isolates of Trichoderma produce
inhibitory volatile compounds. The production of possible antibiotics was also demonstrated. The aggressive behaviour (towards
A. flavus and F. moniliforme) demonstrated by Trichoderma spp. may be partly explained by the liberation of extracellular
enzymes by these fungi. An isolate of T. viride exhibited amylolytic, pectinolytic, proteolytic and cellulolytic activity.
Based on the results of the present investigation, Trichoderma spp. are potential candidates for biocontrol of some mycotoxin-producing
fungi, but there exists some doubt as to their osmotolerance within the air-dry seed.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
6.
Antifungal activity of a novel endochitinase gene (chit36) from Trichoderma harzianum Rifai TM 总被引:4,自引:0,他引:4
Ada Viterbo Shoshan Haran Dana Friesem Ofir Ramot Ilan Chet 《FEMS microbiology letters》2001,200(2):169-174
A novel 36-kDa endochitinase named chit36 has been isolated and characterized from Trichoderma harzianum Rifai TM. Partial amino acid sequences from the purified protein were used to clone the fungal cDNA, based on polymerase chain reaction with degenerate primers. The complete open reading frame encodes a 344-amino acid protein which shows 84% similarity to a putative chitinase from Streptomyces coelicolor. Chit36 was overexpressed under the pki1 constitutive promoter from Trichoderma reesei via biolistic transformation of T. harzianum TM. Stable transformants showed expression and endochitinase activity of chit36 in glucose-rich medium. Culture filtrates containing secreted CHIT36 as the sole chitinolytic enzyme completely inhibited the germination of Botrytis cinerea conidia. Growth of Fusarium oxysporum f. sp. melonis and Sclerotium rolfsii were significantly inhibited on agar plates on which the Trichoderma transformants had previously been grown. 相似文献
7.
Isolation and characterization of protease overproducing mutants of Trichoderma harzianum 总被引:2,自引:0,他引:2
Several Trichoderma strains have been reported to be effective in controlling plant diseases, and the action of fungal hydrolytic enzymes is considered as the main mechanism involved in the antagonistic process. Strain Trichoderma harzianum T334 is a potential biocontrol agent against plant pathogenic fungi with the ability to produce low levels of proteases constitutively. To improve its fungal antagonistic capacity, mutagenetic program was undertaken for the construction of protease overproducing derivates. The mutant strains were obtained by means of UV-irradiation and were selected for p-fluorophenyl-alanine resistance or altered colony morphology. It was revealed by means of specific chromogenic protease substrates that both trypsin-like and chymotrypsin-like protease secretion was elevated in most of the mutant strains. The profiles of isoenzymes were different between the mutants and the wild-type strain, when examined by gel filtration chromatography. Certain mutants proved to be better antagonists against plant pathogens in in vitro antagonism experiments. This study suggests the possibility of using mutants with improved constitutive extracellular protease secretion against plant pathogenic fungi. 相似文献
8.
Trichoderma harzianum is a soil-borne filamentous fungus that exhibits biological control properties because it parasitizes a large variety of phytopathogenic fungi. The production of hydrolytic enzymes appears to be a key element in the parasitic process. Among the enzymes released by Trichoderma, the aspartic proteases play a major role. A gene (SA76) encoding an aspartic protease was cloned by 3' rapid amplification of cDNA ends from T. harzianum T88. The coding region of the gene is 1,593 bp long, encoding a polypeptide of 530 amino acids with a predicted molecular mass 55 kDa and a pI of 4.5. The catalytic aspartic residues characteristic of aspartic proteases are conserved with an active-site motif (DSG); however, the DSG in the N-terminal lobe is unusual in that Ser replaced Thr. Northern blot analysis indicated that SA76 was induced in response to different fungal cell walls. Aspartic protease SA76 was expressed in Saccharomyces cerevisiae under control of the GAL1 promoter. The enzyme activity culminates (10.5 U mL(-1)) 72 h after induction with galactose. The temperature optimum of the enzyme was 45 degrees C and its pH optimum was 3.5. The culture supernatant of the S. cerevisiae strain that expressed the aspartic protease SA76 was able to inhibit the growth of five phytopathogenic fungi. The inhibition of mycelial growth varied between 7% and 38%. 相似文献
9.
10.
11.
Cloning and heterologous expression of SS10, a subtilisin-like protease displaying antifungal activity from Trichoderma harzianum 总被引:1,自引:0,他引:1
Trichoderma harzianum parasitizes a large variety of phytopathogenic fungi. Trichoderma harzianum mycoparasitic activity depends on the secretion of complex mixtures of hydrolytic enzymes able to degrade the host cell wall. A gene ( SS10 ) encoding a subtilisin-like protease was cloned from T. harzianum T88, a biocontrol agent effective against soil-borne fungal pathogens. The full-length cDNA was isolated by 5' and 3' rapid amplification of the cDNA ends. The coding region of the gene is 1302 bp long, encoding 433 amino acids of a predicted protein with a molecular mass of 45 kDa and a pI of 6.1. Analysis of the deduced amino acid sequence revealed that this protein had homology to the serine proteases of the subtilisin-like superfamily (subtilases) (EC 3.4.21.) and had a predicted active site made up of the catalytic residues Asp 187, His 218 and Ser 376. Northern experiments demonstrated that SS10 was induced in response to different fungal cell walls. Subtilisin-like protease gene SS10 was expressed in Saccharomyces cerevisiae under control of the GAL1 promoter. The enzyme activity culminates (17.8 U mL−1 ) 60 h after induction with galactose. The optimal enzyme reaction temperature was 50 °C and the optimal pH was 8. The subtilisin-like protease exerted broad-spectrum antifungal activity against Alternaria alternata, Fusarium oxysporum, Rhizoctonia solani, Sclerotinia sclerotiorum and Cytospora chrysosperma . 相似文献
12.
AIMS: To clone and characterize the gene coding for BGN16.3, a beta-1,6-glucanase putatively implicated in mycoparasitism by Trichoderma harzianum, a biocontrol agent used against plant pathogenic fungi. METHODS AND RESULTS: Using degenerate primed PCR and cDNA library screening, we have cloned the cDNA coding BGN16.3. bgn16.3 showed a significant sequence identity (50%) to bgn16.1; however, they both have low identity to the previously cloned bgn16.2, allowing the identification of amino acid sequences putatively involved in the common catalytic activity of the three proteins. bgn16.3 is a single-copy gene and highly homologous sequences are present in all tested Trichoderma species. bgn16.3 expression pattern is analysed by Northern blot, finding that it is expressed during the interaction of T. harzianum CECT 2413 with Botrytis cinerea, supporting the implication of the enzyme in the mycoparasitic process. CONCLUSIONS: The cloned bgn16.3 completes the knowledge on the beta-1,6-glucanase isozyme system from T. harzianum CECT 2413. A highly homologous gene is present in all analysed Trichoderma strains. bgn16.3 is expressed under few specific conditions, including the mycoparasitic process. SIGNIFICANCE AND IMPACT OF THE STUDY: This study contributes to the knowledge of beta-1,6-glucanases. It implicates this group of enzymes in the mycoparasitism by some biocontrol agents such as T. harzianum. 相似文献
13.
Biological control of phytopathogenic fungi through lytic action of Trichoderma species 总被引:2,自引:0,他引:2
Abstract The antagonistic effect of Trichoderma reesei and Trichoderma harzianum was studied towards a range of phytopathogenic fungi; Alternia solani, Botrytis fabae, Cladosporium cucumerinum, Fusarium oxysporum, Fusarium tricintum . Coculture of the phytopathogens and Trichodema under laboratory conditions clearly showed dominance of the Trichoderma species. In all cases, Trichoderma overgrew the phytopathogens and subsequently developed a conidial lawn over the surface. In these studies the lytic action of the pathogen was clearly apparent and the inhibition of growth appears directly related to its ability to hydrolyze the cell walls of the tested microorganisms rather than through the inhibitory action of antibiotics or toxins. Proteinase, mannanase, laminarinase and chitinase activities were determined in the extracellular fluid of Trichoderma . Glucose and laminaribiose were detected after the in vitro hydrolysis of the cell walls of the phytopathogens. The data imply that the nature of T. reesei and T. harzianum antagonism is based on mycoparasitism (lysis) and appears to optimalize with contact between the mycelia. 相似文献
14.
【目的】对蔬菜大棚土壤中和阿魏菇腐烂的菌盖上分离的两株木霉菌进行分类鉴定。【方法】结合形态学分类特征和ITS序列分析的方法进行鉴定。【结果】从蔬菜大棚的土壤中和阿魏菇腐烂的菌盖上分离的两株木霉菌分别为Trichoderma pleuroticola和T.pleurotum。T.pleuroticola的形态特征与T.harzianum相似,但其分生孢子显著大于T.harzianum的分生孢子,且在PDA上产生黑褐色的色素以及黄色的结晶物。T.pleurotum典型特征是分生孢子梗单生,有时匍匐,分枝散生,初级分枝和分生孢子梗顶端聚生,类似粘帚霉。【结论】分离的两株木霉分别是T.pleuroticola和T.pleurotum,为木霉菌中国新纪录种。 相似文献
15.
AIMS: To inhibit xylitol dehydrogenase (XDH) in Trichoderma reesei by antisense inhibition strategy and construct novel strains capable of accumulating xylitol. METHODS AND RESULTS: The xdh1 antisense expression plasmid pGTA-xdh was constructed by inserting xdh1 DNA fragment inversely between the gpdA promoter and the trpC terminator from Aspergillus nidulans into a pUC19 plasmid backbone. Trichoderma reesei protoplasts were co-transformated with pGTA-xdh and hygromycin B resistance plasmid pAN7-1. Of 20 transformants screened from the selective medium, one transformant with the highest xylitol accumulation, designated ZY15, showed a distinct reduction (c. 52%) in XDH activity compared with the original strain Rut-C30. The results of Southern hybridization and PCR assay showed that the antisense expression cassette of xdh1 was integrated into the genome of T. reesei. The RT-PCR analysis proved that antisense RNA effectively inhibited XDH expression (c. 65%). Xylitol accumulation (2.37 mg ml(-1)) of ZY15 was five times higher than that (0.46 mg ml(-1)) of the original strain Rut-C30. CONCLUSIONS: Strain ZY15 successfully downregulated XDH production and exhibited xylitol accumulation in xylose liquid medium. SIGNIFICANCE AND IMPACT OF THE STUDY: This study contributed to the budding field of fungal genetics in two points. First, it confirmed that antisense RNA strategy could be used as a means of reducing gene expression in the filamentous fungus T. reesei. Secondly, it verified that the strategy appears most promising for creating novel filamentous fungi strains capable of accumulating intermediary metabolites. 相似文献
16.
Prabavathy VR Mathivanan N Sagadevan E Murugesan K Lalithakumari D 《Bioresource technology》2006,97(18):2330-2334
Protoplasts were isolated from Trichoderma harzianum strain PTh18 using lysing enzymes and self-fusion of T. harzianum protoplasts was carried out using polyethylene glycol in STC buffer. The fused protoplasts of T. harzianum were regenerated and 15 self-fusants were selected to study the chitinase production and biocontrol activity. High chitinase activity was measured in the culture filtrates of most of the self-fusants (87%) than the parent. Among the fusants, the strain SFTh8 produced maximum chitinase with a two-fold increase as compared to the parent strain. All the self-fusants exhibited increased antagonistic activity against Rhizoctonia solani than the parent. The crude chitinase preparation of SFTh8 lysed the mycelia of T. harzianum, Trichoderma viride and Trichoderma reesei and released the protoplasts in higher number than the crude chitinase preparation of parent strain PTh18. 相似文献
17.
A beta-1,3-glucanase, from culture filtrates of Trichoderma harzianum, was purified in sequential steps by gel filtration, hydrophobic interaction and ion exchange chromatography. A typical procedure provided 69-fold purification with 0.32% yield. The molecular mass of the protein was found to be approximately 29 kDa, as estimated by SDS-PAGE on a 10% slab gel. The K(M) and V(max) values for beta-1,3-glucanase, using laminarin as substrate, were 1. 72 mg ml(-1) and 3.10 U ml(-1), respectively. The pH optimum for the enzyme was pH 4.4 and maximum activity was obtained at 50 degrees C. The enzyme was strongly inhibited by HgCl(2) and SDS. These results suggest that each beta-1,3-glucanase produced by T. harzianum is different and is probably encoded by different genes. 相似文献
18.
Seed Treatment with Trichoderma Species for Control of Damping-off of Cowpea Caused by Macrophomina phaseolina 总被引:1,自引:0,他引:1
A. T. Adekunle K. F. Cardwell D. A. Florini T. Ikotun 《Biocontrol Science and Technology》2001,11(4):449-457
Cowpea seeds treated with three Trichoderma spp. at four inoculum doses, and at four exposure times in three different formulations were planted in soils amended with Macrophomina phaseolin a, and assessed for stand establishment and post-emergence damping off. The highest percentage plant stands at 21 days after planting were 66% for T. koningii and T. harzianum , and 51% for Trichoderma sp., at 6.8 ×10 7 , 2.0 ×10 10 , and 1.0 ×10 7 colony forming units (CFUs) ml -1 , respectively. Across sampling dates and irrespective of time of exposure to the formulations, the T. harzianum and T. koningii formulations resulted in significantly greater percentage plant stands than the seeds treated with a Trichoderma sp. and the controls. Seed treatment formulations with Trichoderma spp. were derived from propagule suspensions at the most effective inoculum dose in Tween 80, in suspension with cooked cassava starch as an adhesive, or in a slurry with uncooked cassava starch. At 21 days, the suspensions with Tween 80 and cooked starch resulted in significantly higher percentage plant stands than the control, while stands from seeds treated in a slurry formulation and starch solutions were not different. Seed exposure to the different formulations for 10, 20, 30, or 40 min, provided mixed results. Seeds treated with benomyl at 0.5 g a.i/50 g resulted in 95 and 100% stands for the two sets of experiments, respectively. 相似文献
19.
Chitinase gene expression during mycoparasitic interaction of Trichoderma harzianum with its host. 总被引:9,自引:0,他引:9
S Zeilinger C Galhaup K Payer S L Woo R L Mach C Fekete M Lorito C P Kubicek 《Fungal genetics and biology : FG & B》1999,26(2):131-140
For monitoring chitinase expression during mycoparasitism of Trichoderma harzianum in situ, we constructed strains containing fusions of green fluorescent protein (GFP) to the 5'-regulatory sequences of the T. harzianum nag1 (N-acetyl-beta-d-glucosaminidase-encoding) and ech42 (42-kDa endochitinase-encoding) genes. Confronting these strains with Rhizoctonia solani led to induction of gene expression before (ech42) or after (nag1) physical contact. A 12-kDa cut-off membrane separating the two fungi abolished ech42 expression, indicating that macromolecules are involved in its precontact activation. No ech42 expression was triggered by culture filtrates of R. solani or by placing T. harzianum onto plates previously colonized by R. solani. Instead, high expression occurred upon incubation of T. harzianum with the supernatant of R. solani cell walls digested with culture filtrates or purified endochitinase 42 (CHIT42, encoded by ech42) from T. harzianum. The chitinase inhibitor allosamidin blocked ech42 expression and reduced inhibition of R. solani growth during confrontation. The results indicate that ech42 is expressed before contact of T. harzianum with R. solani and its induction is triggered by soluble chitooligosaccharides produced by constitutive activity of CHIT42 and/or other chitinolytic enzymes. 相似文献
20.
The effect of carbon sources on the level of beta-1,3-glucanases in the culture filtrates of Trichoderma harzianum (Tc) was investigated. Enzyme activity was detected in all carbon sources, but highest levels were found when laminarin and purified cell walls were used. Three isoforms of beta-1,3-glucanase were produced during growth of the fungus on purified cell walls. Two isoforms were produced on chitin, chitosan, N-acetylglucosamine and laminarin, while only one was detected when the fungus was grown on cellulose and glucose. A 36-kDa beta-1,3-glucanase (GLU36) was secreted from T. harzianum (Tc) grown on all carbon sources tested as demonstrated by Western blot analysis. We found that a significant increase in the level of GLU36 in the culture filtrate follows glucose exhaustion, suggesting that this enzyme is controlled by carbon catabolite repression. 相似文献