scholarly journals Genomic Analysis and Secondary Metabolites Production of the Endophytic Bacillus velezensis Bvel1: A Biocontrol Agent against Botrytis cinerea Causing Bunch Rot in Post-Harvest Table Grapes

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1716
Author(s):  
Kallimachos Nifakos ◽  
Polina C. Tsalgatidou ◽  
Eirini-Evangelia Thomloudi ◽  
Aggeliki Skagia ◽  
Dimitrios Kotopoulis ◽  
...  
Keyword(s):  
Cell Culture ◽  
Botrytis Cinerea ◽  
Biological Control Agent ◽  
Gene Clusters ◽  
Bacillus Velezensis ◽  
Post Harvest ◽  
Grape Berries ◽  
Table Grapes ◽  
Bunch Rot

Botrytis bunch rot caused by Botrytis cinerea is one of the most economically significant post-harvest diseases of grapes. In the present study, we showed that the bacterial strain Bvel1 is phylogenetically affiliated to Bacillus velezensis species. The strain Bvel1 and its secreted metabolites exerted an antifungal activity, under in vitro conditions, against B. cinerea. UHPLC–HRMS chemical analysis revealed that iturin A2, surfactin-C13 and -C15, oxydifficidin, bacillibactin, L-dihydroanticapsin, and azelaic acid were among the metabolites secreted by Bvel1. Treatment of wounded grape berries with Bacillus sp. Bvel1 cell culture was effective for controlling grey mold ingress and expansion in vivo. The effectiveness of this biological control agent was a function of the cell culture concentration of the antagonist applied, while preventive treatment proved to be more effective compared to curative. The strain Bvel1 exhibited an adequate colonization efficiency in wounded grapes. The whole-genome phylogeny, combined with ANI and dDDH analyses, provided compelling evidence that the strain Bvel1 should be taxonomically classified as Bacillus velezensis. Genome mining approaches showed that the strain Bvel1 harbors 13 antimicrobial biosynthetic gene clusters, including iturin A, fengycin, surfactin, bacilysin, difficidin, bacillaene, and bacillibactin. The results provide new insights into the understanding of the endophytic Bacillus velezensis Bvel1 biocontrol mechanism against post-harvest fungal pathogens, including bunch rot disease in grape berries.

scholarly journals Bacillus velezensis 83 a bacterial strain from mango phyllosphere, useful for biological control and plant growth promotion

AMB Express ◽  
2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Karina A. Balderas-Ruíz ◽  
Patricia Bustos ◽  
Rosa I. Santamaria ◽  
Víctor González ◽  
Sergio Andrés Cristiano-Fajardo ◽  
...  
Keyword(s):  
Biological Control ◽  
Plant Growth ◽  
Biological Control Agent ◽  
Gene Clusters ◽  
In Vitro Assays ◽  
Shoot Biomass ◽  
Plant Growth Promoting Bacteria ◽  
Bacillus Velezensis

Abstract Bacillus velezensis 83 was isolated from mango tree phyllosphere of orchards located in El Rosario, Sinaloa, México. The assessment of this strain as BCA (biological control agent), as well as PGPB (plant growth-promoting bacteria), were demonstrated through in vivo and in vitro assays. In vivo assays showed that B. velezensis 83 was able to control anthracnose (Kent mangoes) as efficiently as chemical treatment with Captan 50 PH™ or Cupravit hidro™. The inoculation of B. velezensis 83 to the roots of maize seedlings yielded an increase of 12% in height and 45% of root biomass, as compared with uninoculated seedlings. In vitro co-culture assays showed that B. velezensis 83 promoted Arabidopsis thaliana growth (root and shoot biomass) while, under the same experimental conditions, B. velezensis FZB42 (reference strain) had a suppressive effect on plant growth. In order to characterize the isolated strain, the complete genome sequence of B. velezensis 83 is reported. Its circular genome consists of 3,997,902 bp coding to 3949 predicted genes. The assembly and annotation of this genome revealed gene clusters related with plant-bacteria interaction and sporulation, as well as ten secondary metabolites biosynthetic gene clusters implicated in the biological control of phytopathogens. Despite the high genomic identity (> 98%) between B. velezensis 83 and B. velezensis FZB42, they are phenotypically different. Indeed, in vitro production of compounds such as surfactin and bacillomycin D (biocontrol activity) and γ-PGA (biofilm component) is significantly different between both strains.

scholarly journals Identification of epiphytic yeasts and bacteria with potential for biocontrol of grey mold disease on table grapes caused by Botrytis cinerea

2018 ◽  
Vol 16 (1) ◽  
pp. e1002 ◽  
Author(s):  
Kazem Kasfi ◽  
Parissa Taheri ◽  
Behrooz Jafarpour ◽  
Saeed Tarighi
Keyword(s):  
Botrytis Cinerea ◽  
Disease Incidence ◽  
Gray Mold ◽  
Antagonistic Activity ◽  
Antagonistic Effect ◽  
Bacterial Isolates ◽  
Thompson Seedless ◽  
Grape Berries ◽  
Table Grapes

The objective of this study was to identify grapevine epiphytic yeasts and bacteria for biocontrol of Botrytis cinerea on grapes. Antagonistic yeasts and bacteria were isolated from the epiphytic flora associated with grape berries and leaves cv. ‘Thompson seedless’ from vineyards in Iran and identified by sequencing the conserved genomic regions. A total of 130 yeast and bacterial isolates from the surface of grapevine were screened in vitro for determining their antagonistic effect against B. cinerea and used to control postharvest gray mold. Among the 130 isolates, five yeasts and four bacterial isolates showed the greatest antagonistic activity in vitro against B. cinerea. Two yeasts species including Meyerozyma guilliermondii and Candida membranifaciens had high antagonistic capability against the pathogen. Also, 4 bacterial isolates belonging to Bacillus sp. and Ralstonia sp. showed significant biocontrol effect against B. cinerea. The isolates were capable of producing volatile and non-volatile substances, which suppressed the pathogen growth. The antagonistic activity of selected yeasts and bacteria against the pathogen was investigated on wounded berries of ‘Thompson seedless’. On small clusters with intact berries, all of the antagonistic isolates considerably reduced the decay on grape berries and inhibition of gray mold incidence on fruits treated by these isolates was less than 50%, except for the isolate N1, which had higher capability in inhibiting the disease incidence. These results suggest that antagonist yeasts and bacteria with potential to control B. cinerea on grape can be found in the microflora of grape berries and leaves.

scholarly journals Diffusible Compounds Produced by Hanseniaspora osmophila and Gluconobacter cerinus Help to Control the Causal Agents of Gray Rot and Summer Bunch Rot of Table Grapes

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 664
Author(s):  
Matías Olivera ◽  
Ninoska Delgado ◽  
Fabiola Cádiz ◽  
Natalia Riquelme ◽  
Iván Montenegro ◽  
...  
Keyword(s):  
Mycelial Growth ◽  
Inhibitory Effect ◽  
Biocontrol Agents ◽  
Environmental Cost ◽  
Antifungal Compounds ◽  
Table Grapes ◽  
Dual Cultures ◽  
Bunch Rot ◽  
Direct Bioautography

Gray and summer bunch rot are important diseases of table grapes due to the high economic and environmental cost of their control with synthetic fungicides. The ability to produce antifungal compounds against the causal agents Botrytis, Aspergillus, Penicillium, and Rhizopus of two microorganisms isolated from table grapes and identified as Hanseniaspora osmophila and Gluconobacter cerinus was evaluated. In dual cultures, both biocontrol agents (together and separately) inhibited in vitro mycelial growth of these pathogens. To identify the compounds responsible for the inhibitory effect, extractions were carried out with organic solvents from biocontrol agents separately. Through dual cultures with pathogens and pure extracts, only the hexane extract from H. osmophila showed an inhibitory effect against Botrytis cinerea. To further identify these compounds, the direct bioautography technique was used. This technique made it possible to determine the band displaying antifungal activity at Rf = 0.05–0.2. The compounds present in this band were identified by GC-MS and compared to the NIST library. The most abundant compounds, not previously reported, corresponded to alkanes, ketones, alcohols, and terpenoids. H. osmophila and G. cerinus have the potential to control the causal agents of gray and summer bunch rot of table grapes.

scholarly journals Germination and Establishment of Infection on Grape Berries by Single Airborne Conidia of Botrytis cinerea

Plant Disease ◽  
2001 ◽  
Vol 85 (6) ◽  
pp. 668-677 ◽  
Author(s):  
S. Coertze ◽  
G. Holz ◽  
A. Sadie
Keyword(s):  
Botrytis Cinerea ◽  
Incubation Period ◽  
Skin Penetration ◽  
Grape Berry ◽  
High Rate ◽  
Disease Symptoms ◽  
Surface Colonization ◽  
Grape Berries ◽  
Table Grapes ◽  
Infection Mode

Table grapes (cv. Dauphine) at different phenological stages were dusted in a settling tower with dry conidia of Botrytis cinerea. The berries were incubated for periods of 3 to 96 h at high relative humidity (RH; ±93% RH, moist berries), or were covered with a film of water (wet berries). Germination of the solitary conidia, appressorium formation, stilbene and suberin induction by germlings, and germling viability were examined by fluorescence microscopy after each incubation period. Isolation and freezing studies were conducted to determine surface colonization (berries left unsterile) and penetration (surface-disinfested berries). Symptoms were determined on berries incubated at a specific wetness regime, kept dry for 10 days, and then incubated for 4 days at high RH. Microscopic observations indicated that germination was delayed on immature berries, but proceeded at a high rate on mature berries. Growth was invariably restricted on moist berries. Attempted penetration was always direct. Stilbene and suberin were generally induced early and were intense on berries at the pea-size and bunch closure stages. Dieback of conidia and germlings occurred at a significantly higher rate on wet than moist berries, and was more pronounced on immature than on mature berries. The segment isolation and freezing studies showed that infections in grape berry cheeks established by this infection mode were few. Extended incubation periods did not lead to substantially higher rates of surface colonization and skin penetration. Disease symptoms did not develop during the 14-day period on the berries transferred to dry perspex chambers, irrespective of phenological stage, incubation period, or wetness regime. According to these findings, this mode of infection should not contribute to a gradual build-up of secondary inoculum in the vineyard, and to B. cinerea epiphytotics.

scholarly journals Biocontrol Ability and Mechanism of a Broad-Spectrum Antifungal Strain Bacillus safensis sp. QN1NO-4 Against Strawberry Anthracnose Caused by Colletotrichum fragariae

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaojuan Li ◽  
Miaoyi Zhang ◽  
Dengfeng Qi ◽  
Dengbo Zhou ◽  
Chunlin Qi ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Broad Spectrum ◽  
Gene Clusters ◽  
Morinda Citrifolia ◽  
Gas Chromatography Mass Spectrometry ◽  
Post Harvest ◽  
Bacillus Safensis ◽  
Strawberry Anthracnose ◽  
Colletotrichum Fragariae

Strawberry is a very popular fruit with a special taste, color, and nutritional value. Anthracnose caused by Colletotrichum fragariae severely limits fruit shelf life during post-harvest storage. Use of traditional chemical fungicides leads to serious environment pollution and threatens food safety. Biocontrol is considered as a promising strategy to manage the post-harvest fruit diseases. Here, strain QN1NO-4 isolated from noni (Morinda citrifolia L.) fruit exhibited a high antifungal activity against C. fragariae. Based on its physicochemical profiles and phylogenetic tree of the 16S rRNA sequence, strain QN1NO-4 belonged to the genus Bacillus. The average nucleotide identity (ANI) calculated by comparing two standard strain genomes was below 95–96%, suggesting that the strain might be a novel species of the genus Bacillus and named as Bacillus safensis sp. QN1NO-4. Its extract effectively reduced the incidence of strawberry anthracnose of harvested fruit. Fruit weight and TSS contents were also maintained significantly. The antifungal mechanism assays indicated that the extract of the test antagonist inhibited mycelial growth and spore germination of C. fragariae in vitro. Cells of strain QN1NO-4 demonstrated the cytoplasmic heterogeneity, disappeared organelles, and ruptured ultrastructure. Notably, the strain extract also had a broad-spectrum antifungal activity. Compared with the whole genome of strain QN1NO-4, several functional gene clusters involved in the biosynthesis of active secondary metabolites were observed. Fifteen compounds were identified by gas chromatography–mass spectrometry (GC-MS). Hence, the fruit endophyte B. safensis sp. QN1NO-4 is a potential bio-agent identified for the management of post-harvest disease of strawberry fruit.

scholarly journals Comparison of efficacy and modes of action of two high-potential biocontrol Bacillus strains and commercial biocontrol products against Botrytis cinerea in table grapes

OENO One ◽  
2021 ◽  
Vol 55 (3) ◽  
pp. 228-243
Author(s):  
Héctor Calvo ◽  
Jean Roudet ◽  
Ana Pilar Gracia ◽  
María Eugenia Venturini ◽  
Marc Fermaud
Keyword(s):  
Botrytis Cinerea ◽  
Culture Medium ◽  
Biological Control Agent ◽  
Living Cells ◽  
High Potential ◽  
Main Mode ◽  
Culture Form ◽  
Table Grapes ◽  
New Findings ◽  
Disease Reduction

In table grapes (cv. Thomson Seedless), the antifungal activity against Botrytis cinerea was further analysed and compared between two high potential bacterial biological control agent (BCA) strains, Bacillus velezensis BUZ-14 and B. ginsengihumi S38. Two commercial biocontrol products (BPs), served as standards of comparison, Amylo-X® and Serenade Max®, also based on Bacillus BCA strains. The main mode of action quantified for all the strains was antibiosis due to hydrosoluble and volatile metabolites and their combinations. The BUZ-14 strain was the most active BCA strain, demonstrating significant disease reduction exceeding 60 % when used in the culture form grown in 863 medium, including living cells (LCs) and cell-free supernatant (CFS). Both BPs exhibited significantly reduced efficacy of their CFS fraction (< 10 %) compared with that of the two BCA strains, confirming their high antibiosis potential. The novel methodology allowed us to demonstrate the significant effect of the BCA culture medium on volatilome (VOC) antagonist efficacy. The S38 strain achieved the highest disease reduction (90 %) owing to the greatest production of VOCs in the richest MOLP (Medium Optimum Lipopetide Production) culture medium, whereas grape juice was the least favourable medium for VOC efficacy for both bacterial strains (BUZ14 and S38). The overall poor activity of living Bacillus cells in all the BCA and BPs tested is discussed based on the low capacity of the BCA strains to grow in the berry. Then, the presence of living cells is also discussed with the possibility that these cells are not required in field applications of such BCA strains in this genus. Moreover, different environmental suboptimal conditions, including temperature (22 and 27 °C) and relative humidity (RH) (100 and 85–95 %), were tested, and BUZ-14 exhibited the highest Botrytis reduction at both temperatures and RH values. However, no significant differences were observed between temperatures or RH values for the same BCA. Further studies in vineyard conditions and applications, such as biofumigation or active packaging, will be performed to confirm the new findings reported in this investigation.

scholarly journals Bacillus amyloliquefaciens ALB65 Inhibits the Growth of Listeria monocytogenes on Cantaloupe Melons

2020 ◽  
Vol 87 (1) ◽  
Author(s):  
Thao D. Tran ◽  
Celia Del Cid ◽  
Robert Hnasko ◽  
Lisa Gorski ◽  
Jeffery A. McGarvey
Keyword(s):  
United States ◽  
Biological Control ◽  
Listeria Monocytogenes ◽  
Bacillus Amyloliquefaciens ◽  
Biological Control Agent ◽  
Gene Clusters ◽  
The United States ◽  
Control Agent ◽  
Content Type

ABSTRACT Listeria monocytogenes is a foodborne pathogen that causes high rates of hospitalization and mortality in people infected. Contamination of fresh, ready to eat produce by this pathogen is especially troubling because of the ability of this bacterium to grow on produce under refrigeration temperatures. In this study, we created a library of over 8,000 plant phyllosphere-associated bacteria and screened them for the ability to inhibit the growth of L. monocytogenes in an in vitro fluorescence-based assay. One isolate, later identified as Bacillus amyloliquefaciens ALB65, was able to inhibit the fluorescence of L. monocytogenes by >30-fold in vitro. B. amyloliquefaciens ALB65 was also able to grow, persist, and reduce the growth of L. monocytogenes by >1.5 log CFU on cantaloupe melon rinds inoculated with 5 × 103 CFU at 30°C and was able to completely inhibit its growth at temperatures below 8°C. DNA sequence analysis of the B. amyloliquefaciens ALB65 genome revealed six gene clusters that are predicted to encode genes for antibiotic production; however, no plant or human virulence factors were identified. These data suggest that B. amyloliquefaciens ALB65 is an effective and safe biological control agent for the reduction of L. monocytogenes growth on intact cantaloupe melons and possibly other types of produce. IMPORTANCE Listeria monocytogenes is estimated by the Centers for Disease Control and Prevention and the U.S. Food and Drug Administration to cause disease in approximately 1,600 to 2,500 people in the United States every year. The largest known outbreak of listeriosis in the United States was associated with intact cantaloupe melons in 2011, resulting in 147 hospitalizations and 33 deaths. In this study, we demonstrated that Bacillus amyloliquefaciens ALB65 is an effective biological control agent for the reduction of L. monocytogenes growth on intact cantaloupe melons under both pre- and postharvest conditions. Furthermore, we demonstrated that B. amyloliquefaciens ALB65 can completely inhibit the growth of L. monocytogenes during cold storage (<8°C).

scholarly journals Draft Genome Sequence of Bacillus velezensis Strain E68, Isolated from an Oil Battery

2020 ◽  
Vol 9 (24) ◽  
Author(s):  
Nathan Liang ◽  
Suha Jabaji
Keyword(s):  
Biological Control ◽  
Fungal Pathogens ◽  
Biological Control Agent ◽  
Draft Genome ◽  
Gene Clusters ◽  
Control Agent ◽  
Biosynthetic Gene ◽  
Bacillus Velezensis ◽  
Biosynthetic Gene Clusters ◽  
Content Type

ABSTRACT Bacillus velezensis strain E68 is a biosurfactant-producing bacterium isolated from an oil battery near Chauvin, Alberta, Canada. Strain E68 exhibited antimicrobial activity against fungal pathogens and could potentially serve as a biological control agent. Its genome was sequenced and annotated, revealing the presence of multiple lipopeptide biosynthetic gene clusters.

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