Surfactin Production, Biofilm Formation and Antagonistic Activity Against Phytopathogens by Bacillus velezensis

ABSTRACTRhizosphere colonization by plant growth-promoting rhizobacteria (PGPR) along plant roots facilitates the ability of PGPR to promote plant growth and health. Thus, an understanding of the molecular mechanisms of the root colonization process by plant-beneficialBacillusstrains is essential for the use of these strains in agriculture. Here, we observed that ansfpgene mutant of the plant growth-promoting rhizobacteriumBacillus velezensisSQR9 was unable to form normal biofilm architecture, and differential protein expression was observed by proteomic analysis. A minor wall teichoic acid (WTA) biosynthetic protein, GgaA, was decreased over 4-fold in the Δsfpmutant, and impairment of theggaAgene postponed biofilm formation and decreased cucumber root colonization capabilities. In addition, we provide evidence that the major WTA biosynthetic enzyme GtaB is involved in both biofilm formation and root colonization. The deficiency in biofilm formation of the ΔgtaBmutant may be due to an absence of UDP-glucose, which is necessary for the synthesis of biofilm matrix exopolysaccharides (EPS). These observations provide insights into the root colonization process by a plant-beneficialBacillusstrain, which will help improve its application as a biofertilizer.IMPORTANCEBacillus velezensisis a Gram-positive plant-beneficial bacterium which is widely used in agriculture. Additionally,Bacillusspp. are some of the model organisms used in the study of biofilms, and as such, the molecular networks and regulation systems of biofilm formation are well characterized. However, the molecular processes involved in root colonization by plant-beneficialBacillusstrains remain largely unknown. Here, we showed that WTAs play important roles in the plant root colonization process. The loss of thegtaBgene affects the ability ofB. velezensisSQR9 to sense plant polysaccharides, which are important environmental cues that trigger biofilm formation and colonization in the rhizosphere. This knowledge provides new insights into theBacillusroot colonization process and can help improve our understanding of plant-rhizobacterium interactions.

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Efficacy of the Combination of Tobramycin and a Macrolide in an InVitroPseudomonas aeruginosa Mature Biofilm Model

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00372-10 ◽

2010 ◽

Vol 54 (10) ◽

pp. 4409-4415 ◽

Cited By ~ 33

Author(s):

Marie Tré-Hardy ◽

Carole Nagant ◽

Naïma El Manssouri ◽

Francis Vanderbist ◽

Hamidou Traore ◽

...

Keyword(s):

Biofilm Formation ◽

Chronic Infection ◽

Laboratory Strain ◽

Antagonistic Activity ◽

Local Administration ◽

Pulmonary Infections ◽

Strain Pao1 ◽

Biofilm Model ◽

Effective Combination

ABSTRACT Respiratory disease is the main cause of morbidity and mortality in patients with cystic fibrosis (CF). In particular, patients suffer from chronic infection due to biofilm formation by opportunistic Pseudomonas aeruginosa (32). Therefore, there is an urgent need to develop alternative ways to treat biofilm-associated clinical infections. The aim of this study was to compare the antimicrobial effects in vitro of the combinations tobramycin-clarithromycin and tobramycin-azithromycin against five P. aeruginosa biofilms and to establish the most effective combination. We performed a kinetic study over a period of 28 days of a twice-daily coadministration of the combinations tobramycin-clarithromycin and tobramycin-azithromycin on 12-day-old, mature P. aeruginosa biofilms formed on microplate pegs for 4 clinical isolates and one laboratory strain (PAO1) to simulate the treatment of CF patients with tobramycin inhalation solution (TOBI) through aerosolization. A synergy between tobramycin and clarithromycin was recorded for 3/5 biofilms, with a bacterial decrease of more than 5 log. Conversely, we found an antagonistic activity when 4 μg/ml tobramycin was administered with azithromycin at 2 μg/ml for P. aeruginosa PAO1 and with azithromycin at 2, 20, 50, 100, and 200 μg/ml for P. aeruginosa PYO1. Treatment with tobramycin at 4 μg/ml combined with clarithromycin at 200 μg/ml eradicated all five biofilms, while tobramycin-azithromycin at the same concentrations eradicated only three biofilms. Results of this study suggest that local administration of tobramycin and clarithromycin into the respiratory tract represents a better strategy than the combination tobramycin-azithromycin for the treatment of P. aeruginosa-associated pulmonary infections.

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Enhanced Control of Plant Wilt Disease by a Xylose-Inducible degQ Gene Engineered into Bacillus velezensis Strain SQR9XYQ

Phytopathology ◽

10.1094/phyto-02-18-0048-r ◽

2019 ◽

Vol 109 (1) ◽

pp. 36-43 ◽

Cited By ~ 3

Author(s):

Zhihui Xu ◽

Jiyu Xie ◽

Huihui Zhang ◽

Dandan Wang ◽

Qirong Shen ◽

...

Keyword(s):

Plant Growth ◽

Biofilm Formation ◽

Antibiotic Production ◽

Genetically Engineered ◽

Flagellar Motility ◽

Bacillus Velezensis ◽

Tomato Root ◽

Bacillus Spp ◽

Plant Growth Promoting

Bacillus velezensis SQR9 (former B. amyloliquefaciens SQR9) is a plant-growth-promoting rhizobacterium (PGPR) that promotes plant growth and health. The colonization of PGPR strains along plant roots is a prerequisite for them to execute their specific functions. However, one problem of microbial introduction in practice is that the applied PGPR strains do not always successfully colonize the rhizosphere. In Bacillus spp., two-component signal transduction system (TCS) DegS/U regulates flagellar motility, biofilm formation and antibiotic production. Phosphorylation of DegU by DegS is positively affected by DegQ protein. In this study, we constructed a xylose-inducible degQ genetically engineered strain SQR9XYQ to improve the biocontrol activity. The results from in vitro, root in situ, greenhouse experiments and RT-qPCR studies demonstrate that (i) the phosphorylation of DegU in SQR9XYQ can be gradually activated by xylose, which is a component of both cucumber and tomato root exudates, and (ii) biofilm formation, antibiotic expression, colonization activity, and biocontrol efficiency were improved in SQR9XYQ compared with the wild-type strain SQR9. These results suggest that colonization trait is important to biocontrol strains for maintenance of plant health.

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Insight into the surfactin production of Bacillus velezensis B006 through metabolomics analysis

Journal of Industrial Microbiology & Biotechnology ◽

10.1007/s10295-018-2076-7 ◽

2018 ◽

Vol 45 (12) ◽

pp. 1033-1044 ◽

Cited By ~ 7

Author(s):

Junqiang Wang ◽

Rongjun Guo ◽

Wenchao Wang ◽

Guizhen Ma ◽

Shidong Li

Keyword(s):

Bacillus Velezensis ◽

Surfactin Production ◽

Insight Into ◽

Metabolomics Analysis

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Genome Shuffling of Bacillus velezensis for Enhanced Surfactin Production and Variation Analysis

Current Microbiology ◽

10.1007/s00284-019-01807-4 ◽

2019 ◽

Vol 77 (1) ◽

pp. 71-78 ◽

Cited By ~ 1

Author(s):

Liang Chen ◽

Xing-yu Chong ◽

Ying-Ying Zhang ◽

Yang-yong Lv ◽

Yuan-Sen Hu

Keyword(s):

Genome Shuffling ◽

Variation Analysis ◽

Bacillus Velezensis ◽

Surfactin Production

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Quorum sensing signal autoinducer-2 promotes root colonization of Bacillus velezensis SQR9 by affecting biofilm formation and motility

Applied Microbiology and Biotechnology ◽

10.1007/s00253-020-10713-w ◽

2020 ◽

Vol 104 (16) ◽

pp. 7177-7185

Author(s):

Qin Xiong ◽

Di Liu ◽

Huihui Zhang ◽

Xiaoyan Dong ◽

Guishan Zhang ◽

...

Keyword(s):

Quorum Sensing ◽

Biofilm Formation ◽

Root Colonization ◽

Bacillus Velezensis ◽

Autoinducer 2

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Complete Genome Sequence of Bacillus velezensis L-1, Which Has Antagonistic Activity against Pear Diseases

Genome Announcements ◽

10.1128/genomea.01271-17 ◽

2017 ◽

Vol 5 (48) ◽

Author(s):

Pingping Sun ◽

Jianchao Cui ◽

Xiaohui Jia ◽

Wenhui Wang

Keyword(s):

Secondary Metabolites ◽

Genome Sequence ◽

Complete Genome Sequence ◽

Complete Genome ◽

Biocontrol Agent ◽

Antagonistic Activity ◽

Bacillus Velezensis ◽

Content Type

ABSTRACT Bacillus velezensis L-1 is an effective biocontrol agent against pear diseases. Here, we report the complete genome sequence of B. velezensis L-1 in which clusters related to the biosynthesis of secondary metabolites were predicted. This genome provides insights into the possible biocontrol mechanisms and furthers application of this specific bacterium.

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Bacillus velezensis as Antagonist towards Penicillium roqueforti s.l. in Silage: in vitro and in vivo Evaluation

10.20944/preprints201801.0273.v1 ◽

2018 ◽

Cited By ~ 1

Author(s):

Eva Wambacq ◽

Kris Audenaert ◽

Monica Höfte ◽

Sarah De Saeger ◽

Geert Haesaert

Keyword(s):

Cell Suspension ◽

Antagonistic Activity ◽

Antagonistic Effect ◽

Corn Silage ◽

Penicillium Roqueforti ◽

Bacillus Velezensis ◽

Toxigenic Fungi ◽

The Impact

In Belgium, silages are often infected by Penicillium roqueforti sensu lato (s.l.). These toxigenic fungi are well adapted to silage conditions, and their prevention during feed-out is difficult. Bacillus velezensis strain NRRL B-23189 has been reported to inhibit P. roqueforti s.s. conidiospore germination in vitro by the production of lipopeptides. In the present study, the antagonistic effect of this B. velezensis strain towards P. roqueforti s.l. was evaluated in vitro and in vivo. In vitro, corn silage conditions were simulated, and the impact of B. velezensis culture supernatant or cell suspension on P. roqueforti s.l. growth, conidiospore germination and survival and roquefortine C production was evaluated. The antagonism was promising, but growth of B. velezensis in corn silage infusion was poor. An in vivo experiment with microsilos containing a mixture of perennial ryegrass and white clover artificially contaminated with P. roqueforti s.l. was carried out to determine if B. velezensis cell suspension could be used as an antagonistic silage inoculant. The B. velezensis cell suspension applied was unsuccessful in reducing P. roqueforti s.l. numbers at desiling after 56 days compared to no additive application. However, feed-out of the silage was not simulated, so it remains elusive whether or not B. velezensis exerts antagonistic activity during this phase. 

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Inhibitory Effect ofBacillus velezensison Biofilm Formation byStreptococcus mutans

10.1101/313965 ◽

2018 ◽

Cited By ~ 1

Author(s):

Yesol Yoo ◽

Dong-Ho Seo ◽

Hyunjin Lee ◽

Young-Do Nam ◽

Myung-Ji Seo

Keyword(s):

Dental Caries ◽

Streptococcus Mutans ◽

Biofilm Formation ◽

Culture Medium ◽

Focal Point ◽

Cell Surface Hydrophobicity ◽

Surface Hydrophobicity ◽

Inhibitory Effect ◽

Fermented Foods ◽

Bacillus Velezensis

ABSTRACTStreptococcus mutansplays a key role in the development of dental caries and promotes the formation of oral biofilm produced by glucosyltransferases (GTFs).Bacillus velezensisK68 was isolated from traditional fermented foods and inhibits biofilm formation mediated byS. mutans. Gene amplification results demonstrated thatB. velezensisK68 contained genes for the biosynthesis of 1-deoxynojirimycin (1-DNJ), a known GTF expression inhibitor. The presence of the GabT1, Yktc1, and GutB1 genes required for 1-DNJ synthesis inB. velezensisK68 was confirmed. Supernatant fromB. velezensisK68 culture medium inhibited biofilm formation by 84% whenS. mutanswas cultured for 48 h, and inhibited it maximally when 1% glucose was added to theS. mutansculture medium as a GTF substrate. In addition, supernatant fromB. velezensisK68 medium containing 3 ppb 1- DNJ decreasedS. mutanscell surface hydrophobicity by 79.0 ± 0.8% compared with that of untreated control. The supernatant containing 1-DNJ decreasedS. mutansadherence by 99.97% and 98.83% under sugar-dependent and sugar-independent conditions, respectively.S. mutanstreated with the supernatant exhibited significantly reduced expression of the essential GTF genesgtfB,gtfC,andgtfDcompared to that in the untreated group. Thus,B. velezensisinhibits the biofilm formation, adhesion, and GTF gene expression ofS. mutansthrough 1- DNJ production.IMPORTANCEDental caries is among the most common infectious diseases worldwide, and its development is closely associated with physiological factors of bacteria, such as the biofilm formation and glucosyltransferase production ofStreptococcus mutans.Biofilms are difficult to remove once they have formed due to the exopolysaccharide matrix produced by the microorganisms residing in them; thus, inhibiting biofilm formation is a current focal point of research into prevention of dental caries. This study describes the inhibitory properties ofBacillus velezensisK68, an organism isolated from traditional Korean fermented foods, against biofilm formation byS. mutans. Herein, we show thatB. velezensisinhibits the biofilm formation, adherence to surfaces, and glucosyltransferase production ofS. mutans.

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Genome Sequence Resource of Bacillus velezensis EB14, a native endophytic bacterial strain with biocontrol potential against the poplar stem canker causative pathogen, Sphaerulina musiva

Phytopathology ◽

10.1094/phyto-09-20-0433-a ◽

2020 ◽

Author(s):

Sachin Naik ◽

Adrian Tsang ◽

Uma Shaanker Ramanan ◽

Selvadurai Dayanandan

Keyword(s):

Genome Sequence ◽

Gene Clusters ◽

Stem Canker ◽

Antagonistic Activity ◽

Comparative Genomic ◽

Plant Interactions ◽

Bacillus Velezensis ◽

Hybrid Poplars ◽

Leaf Spots ◽

Underlying Basis

Bacillus velezensis EB14, isolated from a leaf of Populus  jackii, possesses antagonistic activity against Sphaerulina musiva, a fungal pathogen of Populus sp. that causes leaf spots and stem cankers on Poplars limiting the utility of hybrid poplars as plantation trees. We sequenced the genome of B. velezensis EB14 to gain insights into the underlying basis of its antagonistic activity. Here, we report the complete genome sequence of B. velezensis EB14, a gram-positive bacterium of the family Bacillaceae. Through antiSMASH analysis, we predicted several gene clusters coding for the biosynthesis of antimicrobial compounds, and several genes involved in plant bacterial interactions. These findings support the potential of developing B. velezensis EB14 as a biocontrol agent against S. musiva in poplar plantations. The genome of B. velezensis EB14 along with genome sequences of closely related B. velezensis species are invaluable for comparative genomic analyses to gain insights into bacterial, fungal and host plant interactions.

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