scholarly journals THE COMPOST, A SOURCE OF PLANT BENEFICIAL BACTERIA WITH BIOCONTROL POTENTIAL

2021 ◽  
Vol 10 (20) ◽  
pp. 32-38
Author(s):  
Oana-Alina Boiu-Sicuia ◽  
Vasilica Stan ◽  
Călina Petruța Cornea
Keyword(s):  
Plant Protection ◽  
Bacterial Load ◽  
Pathogenic Fungi ◽  
Phytopathogenic Fungi ◽  
Microbial Load ◽  
Bacterial Strains ◽  
Beneficial Bacteria ◽  
Lytic Enzymes ◽  
Common Activity ◽  
Biocontrol Potential

Recycling the sewage sludge from treatment plants is a common activity. The resulting compost is usually rich in plant nutrients and beneficial microorganisms. However, compost properties greatly differ depending on the nature of the fermented biomass and fermentation processes. The aim of this study was to analyze the microbial load of three different composts, in order to detect new bacterial strains with plant protection properties. Isolated bacteria were microbiologically characterized and evaluated for their potential to reduce soil-borne phytopathogenic fungi. Results showed a microbial load of approximately 106 CFU/g of compost. In the analyzed samples it was revealed that as bacterial load increases, the fungal amount decreases. Analyzing some newly isolated bacteria obtained from these composts, a good biocontrol potential against soil-borne pathogenic fungi was revealed. Some of the isolated bacterial strains revealed antifungal activity against Rhizoctonia solani and Sclerotinia sclerotiorum. These bacteria showed good colonization capacity and lytic enzymes production, correlated to antimicrobial activity. These compost-originated bacteria reveal high potential in pathogens inhibition. Therefore, the analyzed composts are recommended not only as soil fertility improvers, but also as potential suppressors of soil-borne pathogens. Results revealed these composts as source of plant beneficial bacteria with biological control potential.

scholarly journals Chitinolytic Bacillus subtilis Ege-B-1.19 as a biocontrol agent against mycotoxigenic and phytopathogenic fungi

2018 ◽  
Vol 44 (3) ◽  
pp. 323-331
Author(s):  
Ozlem Oztopuz ◽  
Nermin Sarigul ◽  
Fakhra Liaqat ◽  
Ro-Dong Park ◽  
Rengin Eltem
Keyword(s):  
Molecular Weight ◽  
Bacillus Subtilis ◽  
Biocontrol Agent ◽  
Pathogenic Fungi ◽  
Phytopathogenic Fungi ◽  
Aspergillus Ochraceus ◽  
Lytic Enzyme ◽  
Rrna Gene ◽  
Lytic Enzymes ◽  
16S Rrna Gene Analysis

Abstract Background Biological control of pathogenic fungi is a possible alternate to the chemical control, which is harmful to humans and environment. Soil-borne Bacillus strains can be potential biocontrol agents and a source of lytic enzymes. Aim This study aimed to examine biocontrol potential and lytic enzyme activities of a soil isolate Bacillus subtilis Ege-B-1.19. Materials and methods Strain was identified by biochemical and 16S rRNA gene analysis and its biocontrol activity was investigated against Aspergillus niger EGE-K-213, Aspergillus foetidus EGE-K-211, Aspergillus ochraceus EGE-K-217, Fusarium solani KCTC6328, Rhizoctonia solani KACC40111 and Colletotrichum gloeosporioides KACC40689. Chitinase, chitosanase, N-acetyl-β-hexosaminidase and protease activities of B. subtilis Ege-B-1.19 were also determined. Chitosanase was purified using Sephadex G-150 column and its molecular weight was determined by SDS-PAGE. Chitooligosaccharides production using chitosanase was carried out and analysed by TLC and HPLC. Results Results depicted that B. subtilis Ege-B-1.19 has shown inhibitory effects against all the test fungi. Chitinase, chitosanase, N-acetyl-β-hexosaminidase and protease activities were determined as 2.7 U mL−1, 7.2 U mL−1, 6.2 U mL−1 and 12.2 U mL−1, respectively. Molecular weight of purified chitosanase was 44 kDa. Chitosanase hydrolysed chitosan to glucosamine (GlcN), dimers (GlcN)2 and trimers (GlcN)3. Conclusion Bacillus subtilis Ege-B-1.19 can be anticipated as useful biocontrol agent and its chitosanase can be utilized for enzymatic synthesis of chitooligosaccharides.

scholarly journals Multitrait Pseudomonas spp. Isolated from Monocropped Wheat (Triticum aestivum) Suppress Fusarium Root and Crown Rot

2020 ◽  
Vol 110 (3) ◽  
pp. 582-592 ◽  
Author(s):  
Habib Ullah ◽  
Humaira Yasmin ◽  
Saqib Mumtaz ◽  
Zahra Jabeen ◽  
Rabia Naz ◽  
...  
Keyword(s):  
Plant Growth ◽  
Pathogenic Fungi ◽  
Endophytic Bacterium ◽  
Crown Rot ◽  
Common Disease ◽  
Arid Zones ◽  
Bacterial Strains ◽  
Beneficial Bacteria ◽  
Wheat Varieties ◽  
Root And Crown Rot

Fusarium root and crown rot is the most common disease of wheat, especially wheat grown in arid zones where drought is a common issue. The development of environmentally safe approaches to manage diseases of food crops is important for humans. The monocropping system recruits beneficial bacteria that promote plant growth through nutrient solubilization and pathogen suppression. In this study, a field where wheat was monocropped for 5 successive years under rainfed conditions was identified. A total of 29 bacterial isolates were obtained from the rhizosphere, endosphere, and phyllosphere of wheat at its harvesting stage. The Gram-negative bacteria were less prevalent (41%) but the majority (75%) exhibited plant growth-promoting traits. The ability of strains to solubilize nutrients (solubilization index = 2.3 to 4), inhibit pathogenic fungi (25 to 56%), and produce antifungal compounds was highly variable. The rhizobacteria significantly promoted the growth and disease resistance of wheat varieties such as Pirsbak-2015 and Galaxy-2013 by inducing antioxidant enzyme activity (0.2- to 2.1-fold). The bacterial strains were identified as Ochrobactrum spp., Acinetobacter spp., and Pseudomonas mediterranea by 16S rRNA and rpoD sequence analysis. The endophytic bacterium P. mediterranea HU-9 exhibited maximum biocontrol efficacy against wheat root and crown rot diseases with a disease score/disease index from 1.8 to 3.1. The monocropping systems of rainfed agriculture are an ideal source of beneficial bacteria to use as bioinoculants for different crops.

scholarly journals Identification and Characterization of a Hexapeptide with Activity Against Phytopathogenic Fungi That Cause Postharvest Decay in Fruits

2000 ◽  
Vol 13 (8) ◽  
pp. 837-846 ◽  
Author(s):  
Belén López-García ◽  
Luis González-Candelas ◽  
Enrique Pérez-Payá ◽  
Jose F. Marcos
Keyword(s):  
Antimicrobial Activity ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Plant Protection ◽  
Phytopathogenic Fungi ◽  
Bacterial Strains ◽  
General Sequence ◽  
Postharvest Decay ◽  
Structure Conservation

A hexapeptide of amino acid sequence Ac-Arg-Lys-Thr-Trp-Phe-Trp-NH 2 was demonstrated to have antimicrobial activity against selected phytopathogenic fungi that cause postharvest decay in fruits. The peptide synthesized with either all D- or all L-amino acids inhibited the in vitro growth of strains of Penicillium italicum, P. digitatum, and Botrytis cinerea, with MICs of 60 to 80 μM and 50% inhibitory concentration (IC50) of 30 to 40 μM. The inhibitory activity of the peptide was both sequence- and fungus-specific since (i) sequence-related peptides lacked activity (including one with five residues identical to the active sequence), (ii) other filamentous fungi (including some that belong to the genus Penicillium) were insensitive to the peptide's antifungal action, and (iii) the peptide did not inhibit the growth of several yeast and bacterial strains assayed. Experiments on P. digitatum identified conidial germination as particularly sensitive to inhibition although mycelial growth was also affected. Our findings suggest that the inhibitory effect is initially driven by the electrostatic interaction of the peptide with fungal components. The antifungal peptide retarded the blue and green mold diseases of citrus fruits and the gray mold of tomato fruits under controlled inoculation conditions, thus providing evidence for the feasibility of using very short peptides in plant protection. This and previous studies with related peptides indicate some degree of peptide amino acid sequence and structure conservation associated with the antimicrobial activity, and suggest a general sequence layout for short antifungal peptides, consisting of one or two positively charged residues combined with aromatic amino acid residues.

scholarly journals Study on antifungal activity of silver/bentonite nanomaterials on soybean phytopathogenic fungi

2018 ◽  
Vol 15 (2) ◽  
pp. 349-357
Author(s):  
Nguyễn Hoài Châu ◽  
Nguyễn Thị Thúy ◽  
Đào Trọng Hiền ◽  
Hoàng Thị Mai ◽  
Nguyễn Văn Quang ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antifungal Activity ◽  
Plant Protection ◽  
Chemical Reduction ◽  
Pathogenic Fungi ◽  
Phytopathogenic Fungi ◽  
Soybean Plant ◽  
Subsequent Formation ◽  
Inhibition Effect ◽  
Sclerotial Germination

In the present study, silver nanoparticles were synthesized by chemical reduction method route into the lamellar space of bentonite (Ag/CTS/Bentonite). Silver nitrate (AgNO3) was taken as a metal precursor, sodium borohydride (NaBH4) as a reducing agent, reduction of Ag+ ions and the subsequent formation of Ag nanoparticles, chitosan as a natural polymeric stabilizer and was sticked silver nanoparticles to the surface of bentonite particles, respectively. Manipulating the size and shape of Ag/CTS/Bentonite nanomaterial was characterized using transmission electron microscopy (TEM), spherical silver nanoparticles, as depicted by TEM, were found to have a wide particle size distribution from 5 nm to 90 nm. Meanwhile, the X-Ray flourescence (XRF) spectrum indicated the presence of silver on bentonite particles. Antifungal activity of the synthesized Ag/CTS/Bentonite nanomaterial was investigated against crop pathogenic fungi (Fusarium oxysporium (F. oxysporium) and Rhizoctonia solani (R. solani)) isolated from infected soybean plant in Bac Ninh province by the Plant Protection Research Institute. The assessment of fungicidal activity of the Ag/CTS/Bentonite nanomaterial showed that this product exhibited strong antifungal activity towards soybean pathogenic fungi. At highest nanosilver concentration of the Ag/CTS/Bentonite nanocomposite (400 ppm) sclerotial germination of F. oxysporum was almost inhibited, after 7 days the inhibition effect on sclerotial germination attained 66.70%. For the case of R. solani, after 2 days at 400 ppm silver nanoparticles concentration the inhibition effect on sclerotial germination attained 92.82%. The obtained results suggested that the synthesized Ag/CTS/Bentonite nanomaterial acts as an effective antifungal agent. Thus, it could be used in developing novel antifungal agents for potential applications in agriculture.

scholarly journals IN VITRO FORMATION OF ASSOCIATED BIOFILMS BY TRICHODERMA SPP. AND PLANT GROWTH PROMOTING BACTERIA (PGPB)

ÈKOBIOTEH ◽  
2020 ◽  
Vol 3 (3) ◽  
pp. 324-330
Author(s):  
N.F. Galimzianova ◽  
◽  
G.E. Aktuganov ◽  
T.F. Boyko ◽  
E.A. Gilavnova ◽  
...  
Keyword(s):  
Plant Protection ◽  
Phytopathogenic Fungi ◽  
Plant Residues ◽  
Fungal Mycelium ◽  
Plant Growth Promoting Bacteria ◽  
Bacterial Strains ◽  
Trichoderma Spp ◽  
Yield Increase ◽  
Plant Growth Promoting

The capability to formation of combined biofilms by the fungi from Trichoderma genus and several PGP-bacteria including Pseudomonas extremaustralis, P. koreensis, P. mandelii and Advenella kashmirensis has been demonstrated. The strains of Trichoderma used in the experiment not only exert antagonism to phytopathogenic fungi, but also accelerate the decomposition of plant residues. It was found that microscopic fungi whose mycelial structure offers advantages in reaching and assimilating of nutrient substrates, during their growth can favor to directional moving of bacteria cells. The explored bacterial strains moved along the fungal mycelium on the surface of the medium, and in areas where the medium was absent, the bacteria moved inside the hyphae, leaving them when the mycelium reached the substrate. The findings evidence the potential of considered microorganisms for developing of a new generation multifunctional biopreparation for agriculture, contributing not only to crop yield increase and plant protection against phytopathogenic fungi, but also maintaining soil fertility.

scholarly journals Potential Role of Phospholipases in Virulence and Fungal Pathogenesis

2000 ◽  
Vol 13 (1) ◽  
pp. 122-143 ◽  
Author(s):  
Mahmoud A. Ghannoum
Keyword(s):  
Virulence Factor ◽  
Cell Damage ◽  
Pathogenic Fungi ◽  
Microbial Pathogens ◽  
Immunogold Electron Microscopy ◽  
Lytic Enzymes ◽  
Fungal Virulence ◽  
Phospholipase B ◽  
Genes Encoding

SUMMARY Microbial pathogens use a number of genetic strategies to invade the host and cause infection. These common themes are found throughout microbial systems. Secretion of enzymes, such as phospholipase, has been proposed as one of these themes that are used by bacteria, parasites, and pathogenic fungi. The role of extracellular phospholipase as a potential virulence factor in pathogenic fungi, including Candida albicans, Cryptococcus neoformans, and Aspergillus, has gained credence recently. In this review, data implicating phospholipase as a virulence factor in C. albicans, Candida glabrata, C. neoformans, and A. fumigatus are presented. A detailed description of the molecular and biochemical approaches used to more definitively delineate the role of phospholipase in the virulence of C. albicans is also covered. These approaches resulted in cloning of three genes encoding candidal phospholipases (caPLP1, caPLB2, and PLD). By using targeted gene disruption, C. albicans null mutants that failed to secrete phospholipase B, encoded by caPLB1, were constructed. When these isogenic strain pairs were tested in two clinically relevant murine models of candidiasis, deletion of caPLB1 was shown to lead to attenuation of candidal virulence. Importantly, immunogold electron microscopy studies showed that C. albicans secretes this enzyme during the infectious process. These data indicate that phospholipase B is essential for candidal virulence. Although the mechanism(s) through which phospholipase modulates fungal virulence is still under investigations, early data suggest that direct host cell damage and lysis are the main mechanisms contributing to fungal virulence. Since the importance of phospholipases in fungal virulence is already known, the next challenge will be to utilize these lytic enzymes as therapeutic and diagnostic targets.

scholarly journals Biocontrol potential of Streptomyces sp. CACIS-1.5CA against phytopathogenic fungi causing postharvest fruit diseases

2020 ◽  
Vol 30 (1) ◽  
Author(s):  
Zahaed Evangelista-Martínez ◽  
Erika Anahí Contreras-Leal ◽  
Luis Fernando Corona-Pedraza ◽  
Élida Gastélum-Martínez
Keyword(s):  
Pathogenic Fungi ◽  
Phytopathogenic Fungi ◽  
Antagonistic Activity ◽  
Fruit Rot ◽  
Main Body ◽  
Type I ◽  
Tropical Fruit ◽  
Habanero Pepper ◽  
Antagonistic Microorganisms

Abstract Background Fungi are one of the microorganisms that cause most damage to fruits worldwide, affecting their quality and consumption. Chemical controls with pesticides are used to diminish postharvest losses of fruits. However, biological control with microorganisms or natural compounds is an increasing alternative to protect fruits and vegetables. In this study, the antifungal effect of Streptomyces sp. CACIS-1.5CA on phytopathogenic fungi that cause postharvest tropical fruit rot was investigated. Main body Antagonistic activity was evaluated in vitro by the dual confrontation over fungal isolates obtained from grape, mango, tomato, habanero pepper, papaya, sweet orange, and banana. The results showed that antagonistic activity of the isolate CACIS-1.5CA was similar to the commercial strain Streptomyces lydicus WYEC 108 against the pathogenic fungi Colletotrichum sp., Alternaria sp., Aspergillus sp., Botrytis sp., Rhizoctonia sp., and Rhizopus sp. with percentages ranging from 30 to 63%. The bioactive extract obtained from CACIS-1.5 showed a strong inhibition of fungal spore germination, with percentages ranging from 92 to 100%. Morphological effects as irregular membrane border, deformation, shrinkage, and collapsed conidia were observed on the conidia. Molecularly, the biosynthetic clusters of genes for the polyketide synthase (PKS) type I, PKS type II, and NRPS were detected in the genome of Streptomyces sp. CACIS-1.5CA. Conclusions This study presented a novel Streptomyces strain as a natural alternative to the use of synthetic fungicides or other commercial products having antagonistic microorganisms that were used in the postharvest control of phytopathogenic fungi affecting fruits.

scholarly journals Double Gamers—Can Modified Natural Regulators of Higher Plants Act as Antagonists against Phytopathogens? The Case of Jasmonic Acid Derivatives

2020 ◽  
Vol 21 (22) ◽  
pp. 8681
Author(s):  
Nicolò Orsoni ◽  
Francesca Degola ◽  
Luca Nerva ◽  
Franco Bisceglie ◽  
Giorgio Spadola ◽  
...  
Keyword(s):  
Jasmonic Acid ◽  
Plant Pathogens ◽  
Higher Plants ◽  
Fungal Growth ◽  
Pathogenic Fungi ◽  
Inhibitory Effect ◽  
Fungal Species ◽  
Phytopathogenic Fungi ◽  
Phaeomoniella Chlamydospora ◽  
Horticultural Crops

As key players in biotic stress response of plants, jasmonic acid (JA) and its derivatives cover a specific and prominent role in pathogens-mediated signaling and hence are promising candidates for a sustainable management of phytopathogenic fungi. Recently, JA directed antimicrobial effects on plant pathogens has been suggested, supporting the theory of oxylipins as double gamers in plant-pathogen interaction. Based on these premises, six derivatives (dihydrojasmone and cis-jasmone, two thiosemicarbazonic derivatives and their corresponding complexes with copper) have been evaluated against 13 fungal species affecting various economically important herbaceous and woody crops, such as cereals, grapes and horticultural crops: Phaeoacremonium minimum, Neofusicoccum parvum, Phaeomoniella chlamydospora, Fomitiporia mediterranea, Fusarium poae, F. culmorum, F. graminearum, F. oxysporum f. sp. lactucae,F. sporotrichioides, Aspergillus flavus, Rhizoctonia solani,Sclerotinia spp. and Verticillium dahliae. The biological activity of these compounds was assessed in terms of growth inhibition and, for the two mycotoxigenic species A. flavus and F. sporotrichioides, also in terms of toxin containment. As expected, the inhibitory effect of molecules greatly varied amongst both genera and species; cis-jasmone thiosemicarbazone in particular has shown the wider range of effectiveness. However, our results show that thiosemicarbazones derivatives are more effective than the parent ketones in limiting fungal growth and mycotoxins production, supporting possible applications for the control of pathogenic fungi.

Thymol and its Derivatives for Management of Phytopathogenic fungi of maize

2021 ◽  
Vol 18 ◽  
Author(s):  
Jyoti Gaba ◽  
Sunita Sharma ◽  
Harleen Kaur ◽  
Pardeep Kaur
Keyword(s):  
Pathogenic Fungi ◽  
Bioactive Compound ◽  
Mannich Bases ◽  
Phytopathogenic Fungi ◽  
Leaf Blight ◽  
Significant Control ◽  
Thymol Derivatives ◽  
Potential Alternative ◽  
Blight Disease

Background: Thymol is a bioactive compound having many pharmacological activities. Objective: The present study was carried out to evaluate the fungi toxic effects of thymol and derivatives against phytopathogenic fungi of maize. Method: Thymol was derivatized to get formylated thymol, Mannich bases, and imine derivatives. All the synthesized thymol derivatives were characterized by their physical and spectral properties. Synthesized thymol derivatives were screened for their in vitro antifungal effects using poisoned food technique against three maize pathogenic fungi namely Fusarium moniliforme, Rhizoctonia solani and Dreschlera maydis. Results: Thymol and formylated thymol showed promising results for control of D. maydis with ED50 values less than standard carbendazim and comparable to standard mancozeb. These two compounds were further evaluated for control of D. maydis causative maydis leaf blight disease on maize plants grown in the field during the Kharif season (June to October) 2018. Conclusion: Thymol exhibited significant control of maydis leaf blight disease of maize and emerged as a potential alternative to synthetic fungicides used in cereal crops.

Sign in / Sign up

Export Citation Format

Share Document