Endophytic Bacillus subtilis P10 from Prunus cerasifera as a biocontrol agent against tomato Verticillium wilt

Abstract Endophytic bacteria serve key roles in the maintenance of plant health and growth. Few studies to date, however, have explored the antagonistic and plant growth-promoting (PGP) properties of Prunus cerasifera endophytes. To that end, we isolated endophytic bacteria from P. cerasifera tissue samples and used a dual culture plate assay to screen these microbes for antagonistic activity against Verticillium dahliae, Botryosphaeria dothidea, Fusarium oxysporum, F. graminearum, and F. moniliforme. Of the 36 strains of isolated bacteria, four (strains P1, P10, P16, and P20) exhibited antagonistic effects against all five model pathogens, and the P10 strain exhibited the strongest antagonistic to five pathogens. This P10 strain was then characterized in-depth via phenotypic assessments, physiological analyses, and 16s rDNA sequencing, revealing it to be a strain of Bacillus subtilis. Application of a P10 cell suspension (1×108 CFU/mL) significantly enhanced the seed germination and seedling growth of tomato in a greenhouse setting. This P10 strain further significantly suppressed tomato Verticillium wilt with much lower disease incidence and disease index scores being observed following P10 treatment relative to untreated plants in pot-based experiments. Tomato plants that had been treated with strain P10 also enhanced defense-related enzymes, peroxidase, superoxide dismutase, and catalase activity upon V. dahliae challenge relative to plants that had not been treated with this endophytic bacterium. The results revealed that the P10 bacterial strain has potential value as a biocontrol agent for use in the prevention of tomato Verticillium wilt.

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Screening of endophytes from rubber trees (hevea brasiliensis) for biological control of Corticium salmonicolor

ENGINEERING AND TECHNOLOGY ◽

10.46223/hcmcoujs.tech.en.8.2.345.2018 ◽

2020 ◽

Vol 8 (2) ◽

pp. 38-44

Author(s):

Nguyen Van Minh ◽

Mai Huu Phuc ◽

Duong Nhat Linh ◽

Tran Thi A Ni ◽

Tran Kien Duc ◽

...

Keyword(s):

Biological Control ◽

Hevea Brasiliensis ◽

Endophytic Bacteria ◽

Rubber Tree ◽

Antagonistic Activity ◽

Ho Chi Minh City ◽

Viet Nam ◽

Dual Culture ◽

Living Tissue ◽

Tissue Samples

28 leaves and living-tissue samples of rubber tree (Hevea brasiliensis) were collected from Ho Chi Minh City, Binh Phuoc province and Binh Duong province (Viet Nam). We isolated and screened endophytes that have potential application as agents for biocontrol of Corticium salmonicolor, the agent of Pink Disease in rubber trees. As a result, 21 strains of endophytic bacteria and 14 strains of endophytic fungi were isolated. Antagonistic activity of the endophytes towards C. salmonicolor was checked by using a dual culture. Testing results showed that: T9, T15 and T16 strains have inhibited C. salmonicolor. T9 and T16 strains showed result that 100% of inhibiting C. salmonicolor at the concentration of 1:1. In the test of ability to kill C. salmonicolor, T9 and T16 strains showed that they could kill C. salmonicolor after 3 sprays of bacterial filtrate. T9 and T6 strains, which were identified by biochemical methods, have similar characteristics to Bacillus thuringiensis.

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Isolation, Identification and Antimicrobial Evaluation of Bactericides Secreting Bacillus subtilis Natto as a Biocontrol Agent

Processes ◽

10.3390/pr8030259 ◽

2020 ◽

Vol 8 (3) ◽

pp. 259 ◽

Cited By ~ 2

Author(s):

Jing Zhang ◽

Muhammad Bilal ◽

Shuai Liu ◽

Jiaheng Zhang ◽

Hedong Lu ◽

...

Keyword(s):

Bacillus Subtilis ◽

Column Chromatography ◽

High Performance ◽

Biocontrol Agent ◽

Mass Spectral ◽

13C Nuclear Magnetic Resonance ◽

Rdna Sequencing ◽

Bacillus Subtilis Natto ◽

Antimicrobial Evaluation ◽

Inhibitory Potential

Herein, a bactericide-secreting Bacillus strain, potentially useful as a biocontrol agent, was isolated from the commercial Yanjing Natto food. Following the biochemical and physiological evaluation, the molecular identification was performed using 16S rDNA sequencing of polymerase chain reaction-amplified DNA that confirmed the natto isolate as Bacillus subtilis natto (B. subtilis natto). The biocontrol (microbial inhibitory) capability of B. subtilis natto was investigated against Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, and yeast (Yarrowia lipolytica) and recorded. The antimicrobial activity of B. subtilis natto was further enhanced by optimizing the growth medium for optimal bactericides secretion. Under optimized conditions, B. subtilis natto exhibited much higher inhibitory activity against S. aureus with a zone of inhibition diameter up to 27 mm. After 48 h incubation, the optimally yielded B. subtilis natto broth was used to extract and purify the responsible bactericides by silica gel column chromatography, gel column chromatography, and semi-preparative high-performance liquid chromatography. Structural identification of purified bactericides (designated as NT-5, NT-6, and NT-7) from B. subtilis natto was performed by 13C-nuclear magnetic resonance (NMR) and mass spectral analyses. The NMR comparison also revealed that NT-5, NT-6, and NT-7 had identical structures, except for the fatty chain. In summary, the present study suggests the improved biocontrol and/or microbial inhibitory potential of newly isolated bactericides secreting B. subtilis natto.

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Fusarium wilt biocontrol and tomato growth stimulation, using endophytic bacteria naturally associated with Solanum sodomaeum and S. bonariense plants

Egyptian Journal of Biological Pest Control ◽

10.1186/s41938-020-00313-1 ◽

2020 ◽

Vol 30 (1) ◽

Author(s):

Rania Aydi-Ben-Abdallah ◽

Hayfa Jabnoun-Khiareddine ◽

Mejda Daami-Remadi

Keyword(s):

Fusarium Wilt ◽

Endophytic Bacteria ◽

Biochemical Characterization ◽

Growth Parameters ◽

Disease Incidence ◽

Main Body ◽

Safe Alternative ◽

Rdna Sequencing ◽

Tomato Growth

Abstract Background Fusarium wilt biocontrol using endophytic microorganisms may represent a potentially attractive and environmentally safe alternative since endophytes could better limit disease incidence and severity through inhibition of the systemic fungus progress. Main body of the abstract Twenty-three endophytic bacterial isolates, naturally associated with Solanum sodomaeum and Solanum bonariense, were evaluated for their ability to control Fusarium wilt of tomato induced by Fusarium oxysporum f. sp. lycopersici (FOL) and to promote plant growth. Selected endophytic isolates were screened in vivo, using the root dipping and the culture substrate drenching methods. The most bioactive isolates were subjected to morphological and biochemical characterization and subsequent identification through 16S rDNA sequencing genes. Seven isolates (Stenotrophomonas maltophilia S23, S24, S26 and S28; Bacillus sp. SV81; Azotobacter chroococcum S11; and Serratia marcescens S14) were found to be the most efficient in reducing disease severity by 82–96% over control. Treatments with these isolates led to a significant enhancement in growth parameters, estimated at 45.5–61 and 24.2–70.5% than the control, in tomato plants infected or not with FOL, respectively. Diffusible and volatile metabolites released from bacterial cultures had significantly limited FOL radial growth. All isolates were positive for indole-3-acetic acid (IAA) production. S. marcescens S14, S. maltophilia S28, and Bacillus sp. SV81 exhibited a positive phosphate solubilization activity. Production of chitinase, protease, pectinase, and hydrogen cyanide were also investigated. Short conclusion This study clearly demonstrated that endophytic bacteria recovered from these 2 Solanum species can be explored as promising biocontrol agents active against FOL and are able to enhance tomato growth.

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Biocontrol Potential of Endophytic Bacteria Isolated from Healthy Rice Plant against Rice Blast Disease (Pyricularia oryzae Cav.)

KnE Life Sciences ◽

10.18502/kls.v2i6.1051 ◽

2017 ◽

Vol 2 (6) ◽

pp. 287 ◽

Cited By ~ 1

Author(s):

Fitri Widiantini ◽

Andri Herdiansyah ◽

Endah Yulia

Keyword(s):

Endophytic Bacteria ◽

Rice Blast ◽

Biocontrol Agent ◽

Pyricularia Oryzae ◽

Rice Blast Disease ◽

Blast Disease ◽

Dual Culture ◽

Biocontrol Activity ◽

Dual Culture Assay ◽

Biocontrol Potential

Isolation was attempted to collect endophytic bacteria as potential biocontrol agents against rice blast disease (Pyricularia oryzae Cav.). The disease is one of major threats in rice production as it can cause 100% yield loss. Concern on the environment and human health has led to the searching of alternative controlling method to replace the commonly used pesticide-based method. Endophytic bacteria are bacteria that have intimate relationship with their host without inducing any pathogenic symptom. The use of endophytic microbial as biocontrol agent has its own advantages as the microbes are more easily to adapt to the environment needed by the host plant. We evaluated endophytic bacteria isolated from healthy rice plants and tested for their potential biocontrol activity using dual culture assay. Ten isolates were found to inhibit the growth of P. oryzae of more than 50%. Microscopic observation showed that they were able to cause the mycelia malformation of P. oryzae. Further work is currently in progress to determine their effectiveness in the pot trial. Keywords: Endophytic bacteria; Pyricularia oryzae; biocontrol.

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Potential Bacterial Antagonists for the Control of Charcoal Rot (Macrophomina phaseolina) in Strawberry

Horticulturae ◽

10.3390/horticulturae7110457 ◽

2021 ◽

Vol 7 (11) ◽

pp. 457

Author(s):

Josefina Viejobueno ◽

Natalia Rodríguez-Berbel ◽

Luis Miranda ◽

Berta de los Santos ◽

María Camacho

Keyword(s):

Disease Incidence ◽

Hydrolytic Enzymes ◽

Macrophomina Phaseolina ◽

Field Trials ◽

Dry Mass ◽

Dual Culture ◽

Plant Mortality ◽

Charcoal Rot ◽

Rdna Sequencing

The effect of antagonistic bacteria to control Macrophomina phaseolina was evaluated under in vitro, growth chamber, greenhouse and field conditions. A total of 177 bacteria, isolated from Athrocaulon macrostachyum rhizosphere of the Lebrija marsh, were screened for their potential against M. phaseolina (causes charcoal rot in strawberry) by dual culture assay. Of these isolates, 14 most promising strains were molecularly identified by the 16S rDNA sequencing method using the EzBioCloud database. These strains were tested for in vitro hydrolytic enzymes, HCN production, and biocontrol against M. phaseolina in strawberry plants. All the 14 strains produced, at least, one hydrolytic enzymatic activity and one of them, which belongs to Brevibacterium genus (Hvs8), showed the lowest records of disease incidence (20%) and severity (0.4). With these results, greenhouse and field trials were carried out with the Hvs8 strain, compared to non-treated control. In the greenhouse assays, Hvs8 strain increased root dry mass by 30%, over the control. In the field trials, production and fruit quality were not significantly different between Hvs8 treatment and non-treated control, but plant mortality and plant mortality associated to M. phaseolina decreased by more than 24% and 65% respectively, in Hvs8 treatment. This study suggests that Brevibacterium sp. Hvs8 strain could be a candidate for controlling charcoal rot in strawberry.

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Amylolytic activity and its parametric optimization of an endophytic bacterium Bacillus subtilis with an ethno-medicinal origin

Biologia ◽

10.1515/biolog-2015-0047 ◽

2015 ◽

Vol 70 (3) ◽

Cited By ~ 3

Author(s):

Dina Barman ◽

Mamtaz Sahana Dkhar

Keyword(s):

Bacillus Subtilis ◽

Endophytic Bacteria ◽

Endophytic Bacterium ◽

Amylolytic Activity ◽

Amylolytic Enzymes ◽

Bacterium Bacillus Subtilis ◽

Bacterium Bacillus ◽

Blue Background ◽

Positive Results ◽

Subtilis Subsp

AbstractAmylolytic enzymes are a starch hydrolyzing important group of industrial enzymes with a multi-dimensional utility. In the present study, endophytic bacteria were isolated from Potentilla fulgens Wall. and screened for their amylolytic activity. Out of total 13 endophytic bacteria isolated, 3 of them showed positive results for amylolytic activity, i.e. production of halo zone against blue background in starch-containing media. The most promising isolate was identified as Bacillus subtilis subsp. inaquosorum PR

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Lysis and biological control of Aspergillus niger by Bacillus subtilis AF 1

Canadian Journal of Microbiology ◽

10.1139/m96-072 ◽

1996 ◽

Vol 42 (6) ◽

pp. 533-538 ◽

Cited By ~ 64

Author(s):

A. R. Podile ◽

A. P. Prakash

Keyword(s):

Biological Control ◽

Bacillus Subtilis ◽

Aspergillus Niger ◽

Fungal Growth ◽

Dry Weight ◽

Crown Rot ◽

Fungal Mycelium ◽

Infested Soil ◽

Dual Culture ◽

Bacterial Cells

A biocontrol rhizobacterial strain of Bacillus subtilis AF 1 grown for 6 h was coinoculated with Aspergillus niger at different time intervals and microscopic observations revealed adherence of bacterial cells to the fungal mycelium. Bacterial cells multiplied in situ and colonized the mycelial surface. Growth of AF 1 resulted in damage to the cell wall, followed by lysis. AF 1 inoculation into media containing A. niger at 0, 6, and 12 h suppressed >90% fungal growth, while in 18- and 24-h cultures fungal growth inhibition was 70 and 56%, respectively, in terms of dry weight. In dual culture the fungal growth was not accompanied by formation of spores. The mycelial preparation of A. niger as principal carbon source supported the growth of B. subtilis, as much as chitin. Extracellular protein precipitate from B. subtilis culture filtrate had a significant growth-retarding effect on A. niger. Groundnut seeds bacterized with B. subtilis showed a reduced incidence of crown rot in A. niger infested soil, suggesting a possible role of B. subtilis in biological control of A. niger.Key words: mycolytic bacteria, Bacillus subtilis, Aspergillus niger, biological control.

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Combined Application of Rhizosphere Bacteria with Endophytic Bacteria Suppresses Root Diseases and Increases Productivity of Black Pepper (Piper nigrum L.)

Agriculture ◽

10.3390/agriculture11010015 ◽

2020 ◽

Vol 11 (1) ◽

pp. 15

Author(s):

Sy Dinh Nguyen ◽

Thi Huyen Trang Trinh ◽

Trung Dzung Tran ◽

Tinh Van Nguyen ◽

Hoang Van Chuyen ◽

...

Keyword(s):

Bacillus Subtilis ◽

Endophytic Bacteria ◽

Growth Promotion ◽

Black Pepper ◽

Rhizosphere Bacteria ◽

Growth And Yield ◽

Piper Nigrum ◽

Bacillus Velezensis ◽

Root Knot Nematode ◽

Central Highland

Black pepper (Piper nigrum L.) is one of the most important crops and global demand continues to increase, giving it a high export value. However, black pepper cultivation has been seriously affected by a number of pathogenic diseases. Among them, “quick wilt” caused by Phytophthora sp., “slow decline” caused by Fusarium sp., and root-knot nematode Meloidogyne sp. have a serious negative effect on black pepper growth and productivity. There have been different chemical and biological methods applied to control these diseases, but their effectiveness has been limited. The aim of this research was to evaluate different combinations of rhizosphere bacteria and endophytic bacteria isolated from black pepper farms in the Central Highland of Vietnam for their ability to suppress pathogens and promote black pepper growth and yield. Formula 6, containing the strains Bacillus velezensis KN12, Bacillus amyloliquefaciens DL1, Bacillus velezensis DS29, Bacillus subtilis BH15, Bacillus subtilis V1.21 and Bacillus cereus CS30 exhibited the largest effect against Phytophthora and Fusarium in the soil and in the roots of black pepper. These bio-products also increased chlorophyll a and b contents, which led to a 1.5-fold increase of the photosynthetic intensity than the control formula and a 4.5% increase in the peppercorn yield (3.45 vs. 3.30 tons per hectare for the control). Our results suggest that the application of rhizosphere and endophytic bacteria is a promising method for disease control and growth-promotion of black pepper.

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