scholarly journals Antibiotic Bacillomycin D Affects Iron Acquisition and Biofilm Formation in Bacillus velezensis through a Btr-Mediated FeuABC-Dependent Pathway

Cell Reports ◽  
2019 ◽  
Vol 29 (5) ◽  
pp. 1192-1202.e5 ◽  
Author(s):  
Zhihui Xu ◽  
Ines Mandic-Mulec ◽  
Huihui Zhang ◽  
Yan Liu ◽  
Xinli Sun ◽  
...  
2018 ◽  
Vol 85 (5) ◽  
Author(s):  
Zhihui Xu ◽  
Huihui Zhang ◽  
Xinli Sun ◽  
Yan Liu ◽  
Wuxia Yan ◽  
...  

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.


2019 ◽  
Vol 109 (1) ◽  
pp. 36-43 ◽  
Author(s):  
Zhihui Xu ◽  
Jiyu Xie ◽  
Huihui Zhang ◽  
Dandan Wang ◽  
Qirong Shen ◽  
...  

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.


2020 ◽  
Vol 104 (16) ◽  
pp. 7177-7185
Author(s):  
Qin Xiong ◽  
Di Liu ◽  
Huihui Zhang ◽  
Xiaoyan Dong ◽  
Guishan Zhang ◽  
...  

2018 ◽  
Author(s):  
Yesol Yoo ◽  
Dong-Ho Seo ◽  
Hyunjin Lee ◽  
Young-Do Nam ◽  
Myung-Ji Seo

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.


2012 ◽  
Vol 79 (3) ◽  
pp. 808-815 ◽  
Author(s):  
Zhihui Xu ◽  
Jiahui Shao ◽  
Bing Li ◽  
Xin Yan ◽  
Qirong Shen ◽  
...  

ABSTRACTBacillus amyloliquefaciensstrains are capable of suppressing soilborne pathogens through the secretion of an array of lipopeptides and root colonization, and biofilm formation ability is considered a prerequisite for efficient root colonization. In this study, we report that one of the lipopeptide compounds (bacillomycin D) produced by the rhizosphere strainBacillus amyloliquefaciensSQR9 not only plays a vital role in the antagonistic activity againstFusarium oxysporumbut also affects the expression of the genes involved in biofilm formation. When the bacillomycin D and fengycin synthesis pathways were individually disrupted, mutant SQR9M1, which was deficient in the production of bacillomycin D, only showed minor antagonistic activity againstF. oxysporum, but another mutant, SQR9M2, which was deficient in production of fengycin, showed antagonistic activity equivalent to that of the wild-type strain ofB. amyloliquefaciensSQR9. The results fromin vitro, rootin situ, and quantitative reverse transcription-PCR studies demonstrated that bacillomycin D contributes to the establishment of biofilms. Interestingly, the addition of bacillomycin D could significantly increase the expression levels ofkinCgene, but KinC activation is not triggered by leaking of potassium. These findings suggest that bacillomycin D contributes not only to biocontrol activity but also to biofilm formation in strainB. amyloliquefaciensSQR9.


Marine Drugs ◽  
2021 ◽  
Vol 19 (4) ◽  
pp. 225
Author(s):  
Xiaohui Sun ◽  
Philip Hill ◽  
Jia Liu ◽  
Jing Qian ◽  
Yuting Ma ◽  
...  

Biofilm in dental unit water lines may pose a health risk to patients and dental practitioners. An AdiC-like quorum quenching enzyme, YtnP, was cloned from a deep-sea probiotic Bacillus velezensis, and heterologously expressed in E. coli to examine the application on the improvement of hygiene problems caused by biofilm infection of Pseudomonas aeruginosa in dental units. Pseudomonas bacteria were isolated from dental chair units and used to grow static biofilms in the laboratory. A water filter system was designed to test the antifouling activity of YtnP in Laboratory, to simulate the biofilm contamination on water filter in dental unit water lines. The results demonstrated that the enzyme of YtnP was able to degrade the N-acyl homoserine lactones, significantly inhibited the EPS generation, biofilm formation, and virulence factors production (pyocyanin and rhamnolipid) of P. aeruginosa, and was efficient on the antifouling against P. aeruginosa. The findings in this study indicated the possibility of YtnP as novel disinfectant reagent for hygiene treatment in dental units.


2004 ◽  
Vol 72 (12) ◽  
pp. 6836-6845 ◽  
Author(s):  
Shwu-Jen Liaw ◽  
Hsin-Chih Lai ◽  
Won-Bo Wang

ABSTRACT After sensing external signals, Proteus mirabilis undergoes a multicellular behavior called swarming which is coordinately regulated with the expression of virulence factors. Here we report that exogenously added fatty acids could act as signals to regulate swarming in P. mirabilis. Specifically, while oleic acid enhanced swarming, some saturated fatty acids, such as lauric acid, myristic acid, palmitic acid, and stearic acid, inhibited swarming. We also found that expression of hemolysin, which has been shown to be coordinately regulated with swarming, was also inhibited by the above saturated fatty acids. Previously we identified a gene, rsbA, which may encode a histidine-containing phosphotransmitter of the bacterial two-component signaling system and act as a repressor of swarming and virulence factor expression in P. mirabilis. We found that while myristic acid, lauric acid, and palmitic acid exerted their inhibitory effect on swarming and hemolysin expression through an RsbA-dependent pathway, the inhibition by stearic acid was mediated through an RsbA-independent pathway. Biofilm formation and extracellular polysaccharide (EPS) production play an important role in P. mirabilis infection. We found that RsbA may act as a positive regulator of biofilm formation and EPS production. Myristic acid was found to slightly stimulate biofilm formation and EPS production, and this stimulation was mediated through an RsbA-dependent pathway. Together, these data suggest that fatty acids may act as environmental cues to regulate swarming and virulence in P. mirabilis and that RsbA may play an important role in this process.


2021 ◽  
Vol 2 (4) ◽  
pp. 531-553
Author(s):  
Nataliia Tkachuk ◽  
Liubov Zelena

This paper tackles bacteria of the genus Bacillus as both biodamaging/biodegrading and biocontrolling agents. The article addresses the said bacteria’s ability to form biofilms and corrosive, antimicrobial and antibiofilm proactive compounds, primarily, siderophores. Their role depends on the species, microorganism strain, production of antimicrobial substances, biofilm formation, and the type of damaged material. The bacteria under analysis have demonstrated the ability to cause as well as inhibit biodamage. The involvement of bacteria of the genus Bacillus in microbiologically influenced corrosion processes is determined by the production of corrosive metabolites and the impact of certain bioelectrochemical mechanisms. Lipopeptides generated by Bacillus subtilis (surfactin, iturin and fengycin) are capable of modifying surfaces’ hydrophobic properties and impacting the microbes’ adhesion to surfaces. Produced by Bacillus velezensis, the siderophore bacillibactin at a high concentration is capable of inhibiting the formation of bacterial biofilms, thus slowing down the degradation of materials. Further study of siderophores as green inhibitors of microbiologically influenced corrosion may be promising as the said compounds possess antibiofilm-forming properties and high-intensity inhibitory capabilities.


2019 ◽  
Author(s):  
Sagarika Devi ◽  
Heiko T. Kiesewalter ◽  
Renátó Kovács ◽  
Jens Christian Frisvad ◽  
Tilmann Weber ◽  
...  

ABSTRACTFor a safe and sustainable environment, effective microbes as biocontrol agents are in high demand. We have isolated a new Bacillus velezensis strain DTU001, investigated its antifungal spectrum, sequenced its genome, and uncovered the production of lipopeptides in HPLC-HRMS analysis. To test the antifungal efficacy, extracts of B. velezensis DTU001 was tested against a range of twenty human or plant pathogenic fungi. We demonstrate that inhibitory potential of B. velezensis DTU001 against selected fungi is superior in comparison to single lipopeptide, either iturin or fengycin. The isolate showed analogous biofilm formation to other closely related Bacilli. To further support the biocontrol properties of the isolate, coculture with Candida albicans demonstrated that B. velezensis DTU001 exhibited excellent antiproliferation effect against C. albicans. In summary, the described isolate is a potential antifungal agent with a broad antifungal spectrum that might assist our aims to avoid hazardous pathogenic fungi and provide alternative to toxicity caused by chemicals.


Sign in / Sign up

Export Citation Format

Share Document