scholarly journals Metabolism of the Flavonoid Epicatechin by Laccase of Colletotrichum gloeosporioides and Its Effect on Pathogenicity on Avocado Fruits

2005 ◽  
Vol 95 (11) ◽  
pp. 1341-1348 ◽  
Author(s):  
R. Guetsky ◽  
I. Kobiler ◽  
X. Wang ◽  
N. Perlman ◽  
N. Gollop ◽  
...  
Keyword(s):  
Colletotrichum Gloeosporioides ◽  
Laccase Activity ◽  
Thioglycolic Acid ◽  
Culture Media ◽  
Antifungal Compounds ◽  
Symptom Development ◽  
Fungal Attack ◽  
Avocado Fruit ◽  
Laccase Enzyme ◽  
Unripe Fruits

During avocado fruit ripening, decreasing levels of the flavonoid epicatechin have been reported to modulate the metabolism of preformed antifungal compounds and the activation of quiescent Colletotrichum gloeosporioides infections. Epicatechin levels decreased as well when C. gloeosporioides was grown in the presence of epicatechin in culture. Extracts of laccase enzyme obtained from decayed tissue and culture media fully metabolized the epicatechin substrate within 4 and 20 h, respectively. Purified laccase protein from C. gloeosporioides showed an apparent MW of 60,000, an isoelectric point at pH 3.9, and maximal epicatechin degradation at pH 5.6. Inhibitors of fungal laccase such as EDTA and thioglycolic acid reduced C. gloeosporioides symptom development when applied to ripening susceptible fruits. Isolates of C. gloeosporioides with reduced laccase activity and no capability to metabolize epicatechin showed reduced pathogenicity on ripening fruits. On the contrary, Mexican isolates with increasing capabilities to metabolize epicatechin showed early symptoms of disease in unripe fruits. Transcript levels of cglac1, encoding C. gloeosporioides laccase, were enhanced during fungal development in the presence of epicatechin at pH 6.0, where avocado fruits are susceptible to fungal attack. But transcript increase was not detected at pH 5.0, where the fruit is resistant to fungal attack. The present results suggest that biotransformation of epicatechin by C. gloeosporioides in ripening fruits is followed by the decline of the preformed antifungal diene compound, resulting in the activation of quiescent infections.

scholarly journals Development of Colletotrichum gloeosporioides Restriction Enzyme-Mediated Integration Mutants as Biocontrol Agents Against Anthracnose Disease in Avocado Fruits

2001 ◽  
Vol 91 (2) ◽  
pp. 143-148 ◽  
Author(s):  
N. Yakoby ◽  
R. Zhou ◽  
I. Kobiler ◽  
A. Dinoor ◽  
D. Prusky
Keyword(s):  
Restriction Enzyme ◽  
Insertional Mutagenesis ◽  
Colletotrichum Gloeosporioides ◽  
Fungal Genome ◽  
Symptom Development ◽  
Wild Type ◽  
Fresh Weight ◽  
Type Isolate ◽  
Avocado Fruit ◽  
Virulence Assay

Reduced-pathogenicity mutants of the avocado fruit pathogen Colletotrichum gloeosporioides isolate Cg-14 (teleomorph: Glomerella cingulata) were generated by insertional mutagenesis by restriction enzyme-mediated integration (REMI) transformation. Following seven transformations, 3,500 hygromycin-resistant isolates were subjected to a virulence assay by inoculation on mesocarp and pericarp of cv. Fuerte avocado fruits. Fourteen isolates showed a reduced degree of virulence relative compared with wild-type Cg-14. Two isolates, Cg-M-142 and Cg-M-1150, were further characterized. Cg-M-142 produced appressoria on avocado pericarp similar to Cg-14, but caused reduced symptom development on the fruit's pericarp and mesocarp. Isolate Cg-M-1150 did not produce appressoria; it caused much reduced maceration on the mesocarp and no symptoms on the pericarp. Southern blot analysis of Cg-M-142 and Cg-M-1150 showed REMI at different XbaI sites of the fungal genome. Pre-inoculation of avocado fruit with Cg-M-142 delayed symptom development by the wild-type isolate. Induced resistance was accompanied by an increase in the levels of preformed antifungal diene, from 760 to 1,200 μg/g fresh weight 9 days after inoculation, whereas pre-inoculation with Cg-M-1150 did not affect the level of antifungal diene, nor did it delay the appearance of decay symptoms. The results presented here show that reduced-pathogenicity isolates can be used for the biological control of anthracnose caused by C. gloeosporioides attack.

Production and characterization of biomass and exopolysaccharides obtained in submerged culture under different initial pHs used in the cultivation of Colletotrichum gloeosporioides and Rhizopus stolonifer

2020 ◽  
pp. 628
Author(s):  
Juan Diego Valenzuela Cobos ◽  
René Oscar Rodríguez-Grimón ◽  
Ana Grijalva-Endara ◽  
Raúl Marcillo-Vallejo ◽  
Onay Adonys Mercader-Camejo
Keyword(s):  
Yeast Extract ◽  
Submerged Culture ◽  
Liquid Culture ◽  
Colletotrichum Gloeosporioides ◽  
Culture Media ◽  
Mycelial Biomass ◽  
Rhizopus Stolonifer

Colletotrichum gloeosporioides (GC003) and Rhizopus stolonifer (RS001) were cultivated in two different liquid culture media: LC1 (glucose 40 g L-1, yeast extract 3 g L-1 and tryptone peptone 2 g L-1) and LC2 (glucose 40 g L-1, yeast extract 3 g L-1 and tryptone peptone 10 g L-1) for the production of mycelial biomass and exopolysaccharides (EPS). By using the liquid culture (LC2) under pH of 4.5 presented the highest biomass content (15.73 g L-1) in the propagation of Rhizopus stolonifer. The highest production of exopolysaccharides (1.74 g L-1) was obtained by the liquid culture (LC2) under pH of 4.5 in the cultivation of Colletotrichum gloeosporioides. The results presented that the production of biomass and exopolysaccharides (EPS) is directly related with the pHs values and the strain used in the cultivation.

scholarly journals Biological Control of Thielaviopsis paradoxa and Colletotrichum gloeosporioides by the Extracellular Enzymes of Wickerhamomyces anomalus

Agriculture ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 325
Author(s):  
Luis Fernando Zepeda-Giraud ◽  
Dario Rafael Olicón-Hernández ◽  
Juan Pablo Pardo ◽  
Minerva Georgina Araiza Villanueva ◽  
Guadalupe Guerra-Sánchez
Keyword(s):  
Extracellular Enzymes ◽  
Colletotrichum Gloeosporioides ◽  
Culture Media ◽  
Crop Protection ◽  
Fungal Growth ◽  
Antagonistic Effect ◽  
Economic Losses ◽  
Post Harvest ◽  
Wickerhamomyces Anomalus ◽  
Yeast Peptone Dextrose

An alternative to chemical fungicides in post-harvest diseases are the use of biocontrol agents and their extracellular products against phytopathogens. Two relevant agents in post-harvest infections are Thielaviopsis paradoxa and Colletotrichum gloeosporioides, causing large economic losses in cacao, pineapple, and avocado during storage. In this work, we evaluated the effect of Wickerhamomyces anomalus, an effective biocontrol agent, against these filamentous fungi, focusing on the production of extracellular enzymes and their effect on fungal growth and germination. Moreover, we evaluated the use of inactivated fungal biomass as an inducer in complete (Potato Dextrose Agar and Yeast Peptone Dextrose) and minimal culture media. The antagonistic effect of W anomalus on the growth of both phytopathogens was also studied. The extracellular enzymes in YPD cultures, using T. paradoxa inactivated biomass as the best inducer, were capable of inhibiting the germination of both phytopathogens. In minimal media, only the production of a 30 kDa glucanase with activity against laminarin was observed. The enzyme was effective against the spore germination of T. paradoxa. In post-harvest crop protection tests, growth inhibition of T. paradoxa was observed using the cell-free enzyme extract, which is a promising system to protect cocoa fruits from T. paradoxa during post-harvest.

Susceptibility of Fuerte avocado fruit at various stages of growth, to infection by anthracnose and stem end rot fungi

1978 ◽  
Vol 18 (90) ◽  
pp. 158 ◽  
Author(s):  
RA Peterson
Keyword(s):  
Field Experiments ◽  
Colletotrichum Gloeosporioides ◽  
Natural Infection ◽  
Persea Americana ◽  
Glomerella Cingulata ◽  
Stages Of Growth ◽  
Small Fruit ◽  
Avocado Fruit ◽  
Time Of Infection

In a series of field experiments, Fuerte avocado fruit (Persea americana) were susceptible to infection by Glomerella cingulata var. minor (Colletotrichum gloeosporioides var, minor) and Dothiorella aromatics, from set until harvest. Natural infection was detected from December to May and field inoculations demonstrated that small fruit in October were also susceptible. The time of infection varied with the season and was related to rainfall incidence. The significance of this finding is discussed.

scholarly journals Differential Activation of Ammonium Transporters During the Accumulation of Ammonia by Colletotrichum gloeosporioides and Its Effect on Appressoria Formation and Pathogenicity

2013 ◽  
Vol 26 (3) ◽  
pp. 345-355 ◽  
Author(s):  
Chen Shnaiderman ◽  
Itay Miyara ◽  
Ilana Kobiler ◽  
Amir Sherman ◽  
Dov Prusky
Keyword(s):  
Gene Disruption ◽  
Colletotrichum Gloeosporioides ◽  
Ammonium Transporter ◽  
Ammonium Transport ◽  
Wild Type ◽  
Ammonia Accumulation ◽  
Ammonium Transporters ◽  
Avocado Fruit ◽  
Appressoria Formation ◽  
Encoding Genes

Ammonium secreted by the post-harvest pathogen Colletotrichum gloeosporioides during host colonization accumulates in the host environment due to enhanced fungal nitrogen metabolism. Two types of ammonium transporter-encoding genes, AMET and MEP, are expressed during pathogenicity. Gene disruption of AMET, a gene modulating ammonia secretion, showed twofold reduced ammonia secretion and 45% less colonization on avocado fruit, suggesting a contribution to pathogenicity. MEPB, a gene modulating ammonium transport, is expressed by C. gloeosporioides during pathogenicity and starvation conditions in culture. Gene disruption of MEPB, the most highly expressed gene of the MEP family, resulted in twofold overexpression of MEPA and MEPC but reduced colonization, suggesting MEPB expression's contribution to pathogenicity. Analysis of internal and external ammonia accumulation by ΔmepB strains in mycelia and germinated spores showed rapid uptake and accumulation, and reduced secretion of ammonia in the mutant versus wild-type (WT) strains. Ammonia uptake by the WT germinating spores but not by the ΔmepB strain with compromised ammonium transport activated cAMP and transcription of PKA subunits PKAR and PKA2. ΔmepB mutants showed 75% less appressorium formation and colonization than the WT, which was partially restored by 10 mM exogenous ammonia. Thus, whereas both AMET and MEPB genes modulate ammonia secretion, only MEPB contributes to ammonia accumulation by mycelia and germinating spores that activate the cAMP pathways, inducing the morphogenetic processes contributing to C. gloeosporioides pathogenicity.

Antifungal compounds from immature avocado fruit peel

1992 ◽  
Vol 31 (1) ◽  
pp. 93-96 ◽  
Author(s):  
N.K.B. Adikaram ◽  
D.F. Ewing ◽  
A.M. Karunaratne ◽  
E.M.K. Wijeratne
Keyword(s):  
Antifungal Compounds ◽  
Fruit Peel ◽  
Avocado Fruit

scholarly journals Produksi dan karakterisasi lakase Omphalina sp. Production and characterization of Omphalina sp. laccase

2016 ◽  
Vol 75 (2) ◽  
Author(s):  
. SISWANTO ◽  
. SUHARYANTO ◽  
Rossy FITRIA
Keyword(s):  
Oil Palm ◽  
Laccase Activity ◽  
Research Result ◽  
White Rot Fungi ◽  
White Rot ◽  
Partial Purification ◽  
Empty Fruit Bunches ◽  
Optimum Ph ◽  
Laccase Enzyme

SummaryOmphalina sp. a white-rot fungi (WRF)originated from oil palm plantation has abilityto degrade empty fruit bunches of oil palm(EFBOP) so that it is expected to producelaccase with high activity. The ability ofOmphalina sp. to produce laccase enzyme onliquid fermentation will be studied. The enzymewill also be partially purified andcharacterized. The research result showed thatthe highest enzyme activity (1.162 U/mL) wasobtained using glucose malt yeast (GMY)medium at room temperature for four days.The addition of 2,5-xylidine as an inducerproduced laccase earlier i.e two days, but theactivity of laccase was less active afterprolonged incubation compared to that ofcontrol. The laccase produced on mediumcontaining 2% EFBOP reached optimumactivity as much as 0.38 U/mL after 10 th daysof incubation. Partial purification of laccaseon Sephacryl S-200 HR column resulted58.23% of yield recovery with twice purity thanbefore. The optimum pH of laccase was 4.5.Laccase activity was stable even after heatedon 50 o C for 30 minutes, but then decreasedwhen heated until 60 o C. The laccase has K Mand V max as much as 0.15 mM and 0.56 U/mLrespectively.RingkasanOmphalina sp., adalah fungi pelapuk putih(FPP) hasil isolasi dari kebun kelapa sawityang diketahui mampu mendegradasi tandankosong kelapa sawit (TKKS) dengan cepatsehingga diharapkan mampu menghasilkanlakase dengan aktivitas tinggi. KemampuanOmphalina sp. menghasilkan enzim lakasepada fermentasi cair akan dipelajari. Selain itu,lakase yang dihasilkan akan dimurnikan secaraparsial serta dilakukan karakterisasi pH, suhu,dan konsentrasi substrat optimum. Hasilpenelitian menunjukkan bahwa Omphalina sp.menghasilkan lakase dengan aktivitas tertinggi(1,162 U/mL) pada medium glucose malt yeast(GMY) yang diinkubasikan pada suhu ruangselama empat hari. Penambahan 2,5-xilidinsebagai induser mempercepat produksi lakaselebih awal yaitu dalam waktu dua hari, namunaktivitasnya masih lebih rendah dibandingkandengan kontrol pada inkubasi lebih lanjut.Lakase dari Omphalina sp. juga dapatdiproduksi pada medium yang mengandung2% TKKS dan aktivitasnya mencapai0,38 U/mL yang diinkubasi dalam suhu ruangselama 10 hari. Pemurnian parsial pada kolomSephacryl S-200 HR menghasilkan rendemensebesar 58,23% dengan kemurnian dua kalinya.Aktivitas lakase optimum pada pH 4,5 dantetap stabil setelah pemanasan selama 30 menitpada suhu ruang hingga 50 o C dan menuruntajam pada suhu 60 o C. Lakase Omphalina sp.menghasilkan nilai K M dan V maks masing-masing sebesar 0,15 mM dan 0,56 U/mL.

scholarly journals Activity of Laccase Enzyme Present in the Phenol-Contaminated Sediments of the Marilao-Meycauayan-Obando River System, Philippines

2021 ◽  
Vol 37 (1) ◽  
pp. 162-168
Author(s):  
King Dave G. Martin ◽  
Maria Fatima T. Astrero ◽  
Laurence Anthony N. Mallari ◽  
Roland M. Hipol
Keyword(s):  
Sulfonic Acid ◽  
Laccase Activity ◽  
River System ◽  
Contaminated Sediments ◽  
Phenol Concentration ◽  
Sampling Area ◽  
The Family ◽  
Bacteria And Fungi ◽  
Laccase Enzyme ◽  
Collection Sites

Laccases are enzymes produced by different microbes like bacteria and fungi. These enzymes are members of the family of oxidases and are capable of oxidizing phenolics into non-toxic forms. Sediments were collected from the Marilao-Meycauayan-Obando River System, specifically from the sampling area connected to leather tanneries, which directly dump their effluents into the river. This study aimed to determine the presence of laccase activity of sediments of Meycauayan River where effluents of leather factories and tanneries are directly dumped. Concentration of the phenolic compounds from five collection sites were measured. Collected phenol - contaminated sediments were tested for laccase activity using ABTS (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)). Laccase was extracted from the collected sediments and used for the degradation of phenol. Reduction of phenol concentration by the extracted laccase reached 79.82% to as high as90.84%with a starting phenol concentration of 27.5 mmol per sample. Three strains of phenol-degrading ligninolytic bacteria closely related to Lysinibacillus xylanilyticus, Lysinibacillus fusiformisss, and Lysinibacillus sphaericuswere identified to be present in the river’s sediment which could produce laccase and facilitate degradation of phenol.

scholarly journals Sorption of Zinc by exopolysaccharides produced by liquid media of phytopatogenic fungi

2021 ◽  
Vol 26 (1) ◽  
pp. 2312-2317
Author(s):  
JUAN DIEGO VALENZUELA-COBOS ◽  
ANA GRIJALVA-ENDARA
Keyword(s):  
Yeast Extract ◽  
Liquid Culture ◽  
Culture Medium ◽  
Colletotrichum Gloeosporioides ◽  
Culture Media ◽  
Phytopathogenic Fungi ◽  
Mycelial Biomass ◽  
Rhizopus Stolonifer ◽  
Liquid Media ◽  
Liquid Culture Medium

Phytopathogenic fungi such as: Colletotrichum gloeosporioides and Rhizopus stolonifer were cultivated in three different liquid culture media: LCC (glucose 40 g L-1 , yeast extract 3 g L-1 ), LC2 (glucose 40 g L-1 , yeast extract 3 g L-1 and tryptone peptone 2 g L-1 ) and LC3 (glucose 40 g L-1 , yeast extract 3 g L-1 and tryptone peptone 10 g L-1 ) under pH of 5.5 for the production of mycelial biomass and exopolysaccharides (EPS). The liquid culture medium (LC3) used in cultivation of Colletotrichum gloeosporioides showed the highest production of biomass (15.40 g L-1 ) and exopolysaccharides (3.40 g L-1 ). Exopolysaccharides (EPS) obtained from the liquid culture medium (LC3) of Colletotrichum gloeosporioides presented the highest absorption content of Zinc (56 mg g-1 ). The results presented that the exopolysaccharides (EPS) produced by Colletotrichum gloeosporioides showed the greatest biosorbent capacity of Zinc (Zn) using the culture medium with the highest amount of tryptone peptone.

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