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The ISME Journal Mar 2022Trophic interactions play a central role in driving microbial community assembly and function. In gut or soil ecosystems, successful inoculants are always facilitated by...
Trophic interactions play a central role in driving microbial community assembly and function. In gut or soil ecosystems, successful inoculants are always facilitated by efficient colonization; however, the metabolite exchanges between inoculants and resident bacteria are rarely studied, particularly in the rhizosphere. Here, we used bioinformatic, genetic, transcriptomic, and metabonomic analyses to uncover syntrophic cooperation between inoculant (Bacillus velezensis SQR9) and plant-beneficial indigenous Pseudomonas stutzeri in the cucumber rhizosphere. We found that the synergistic interaction of these two species is highly environmental dependent, the emergence of syntrophic cooperation was only evident in a static nutrient-rich niche, such as pellicle biofilm in addition to the rhizosphere. Our results identified branched-chain amino acids (BCAAs) biosynthesis pathways are involved in syntrophic cooperation. Genome-scale metabolic modeling and metabolic profiling also demonstrated metabolic facilitation among the bacterial strains. In addition, biofilm matrix components from Bacillus were essential for the interaction. Importantly, the two-species consortium promoted plant growth and helped plants alleviate salt stress. In summary, we propose a mechanism in which synergic interactions between a biocontrol bacterium and a partner species promote plant health.
Topics: Bacillus; Microbiota; Plant Roots; Pseudomonas stutzeri; Rhizosphere; Soil Microbiology
PubMed: 34593997
DOI: 10.1038/s41396-021-01125-3 -
Cell Host & Microbe Oct 2021Although plant roots encounter a plethora of microorganisms in the surrounding soil, at the rhizosphere, plants exert selective forces on their bacterial colonizers....
Although plant roots encounter a plethora of microorganisms in the surrounding soil, at the rhizosphere, plants exert selective forces on their bacterial colonizers. Unlike immune recognition of pathogenic bacteria, the mechanisms by which beneficial bacteria are selected and how they interact with the plant immune system are not well understood. To better understand this process, we studied the interaction of auxin-producing Bacillus velezensis FZB42 with Arabidopsis roots and found that activation of the plant immune system is necessary for efficient bacterial colonization and auxin secretion. A feedback loop is established in which bacterial colonization triggers an immune reaction and production of reactive oxygen species, which, in turn, stimulate auxin production by the bacteria. Auxin promotes bacterial survival and efficient root colonization, allowing the bacteria to inhibit fungal infection and promote plant health. Thus, a feedback loop between bacteria and the plant immune system promotes the fitness of both partners.
Topics: Arabidopsis; Bacillus; Host Microbial Interactions; Indoleacetic Acids; Plant Immunity; Plant Roots; Reactive Oxygen Species; Rhizosphere
PubMed: 34610294
DOI: 10.1016/j.chom.2021.09.005 -
Biological Chemistry Nov 2020
Topics: Bacillus subtilis; Escherichia coli; Humans
PubMed: 32918804
DOI: 10.1515/hsz-2020-0229 -
Biomolecules Jul 2022Thrombosis has threatened human health in past decades. nattokinase is a potential low-cost thrombolytic drug without side-effects and has been introduced into the... (Review)
Review
Thrombosis has threatened human health in past decades. nattokinase is a potential low-cost thrombolytic drug without side-effects and has been introduced into the consumer market as a functional food or dietary supplement. This review firstly summarizes the biodiversity of sources and the fermentation process of nattokinase, and systematically elucidates the structure, catalytic mechanism and enzymatic properties of nattokinase. In view of the problems of low fermentation yield, insufficient activity and stability of nattokinase, this review discusses the heterologous expression of nattokinase in different microbial hosts and summarizes the protein and genetic engineering progress of nattokinase-producing strains. Finally, this review summarizes the clinical applications of nattokinase.
Topics: Bacillus; Bacillus subtilis; Bioengineering; Biotechnology; Humans; Subtilisins
PubMed: 35883536
DOI: 10.3390/biom12070980 -
Journal of Applied Microbiology Jan 2022Bacillus cytotoxicus is a member of the Bacillus cereus group with the ability to grow at high temperatures (up to 52℃) and to synthesize cytotoxin K-1, a... (Review)
Review
Bacillus cytotoxicus is a member of the Bacillus cereus group with the ability to grow at high temperatures (up to 52℃) and to synthesize cytotoxin K-1, a diarrhoeagenic cytotoxin, which appears to be unique to this species and more cytotoxic than the cytotoxin K-2 produced by other members of this group. Only a few isolates of this species have been characterized with regard to their cytotoxic effects, and the role of cytotoxin K-1 as a causative agent of food poisoning remains largely unclear. Bacillus cytotoxicus was initially isolated from a food-borne outbreak, which led to three deaths, and the organism has since been linked to other outbreaks all involving plant-based food matrices. Other studies, as well as food-borne incidents reported to the UK Food Standards Agency, detected B. cytotoxicus in insect-related products and in dried food products. With insect-related food becoming increasingly popular, the association with this pathogen is concerning, requiring further investigation and evidence to protect public health. This review summarizes the current knowledge around B. cytotoxicus and highlights gaps in the literature from a food safety perspective.
Topics: Bacillus; Bacillus cereus; Enterotoxins; Food Microbiology; Food Safety; Foodborne Diseases; Humans
PubMed: 34260791
DOI: 10.1111/jam.15214 -
Brazilian Journal of Microbiology :... Mar 2023Bacillus spp. are widely marketed and used in agricultural systems as antagonists to various phytopathogens, but it can also benefit the plant as plant growth promoters....
Bacillus spp. are widely marketed and used in agricultural systems as antagonists to various phytopathogens, but it can also benefit the plant as plant growth promoters. Therefore, the longer presence of the bacterium in the rhizosphere would result in a prolonged growth-promoting benefit, but little is yet known about its persistence in the rhizosphere after seed coating. The objectives of this study were to evaluate the tomato growth promotion mediated by Bacillus licheniformis FMCH001 and Bacillus subtilis FMCH002 and the survival rate of these bacteria both in shoots and in the rhizosphere. The Bacillus strains used throughout this study were obtained from Quartzo® produced by Chr. Hansen. The application of a mixture of B. subtilis and B. licheniformis (Quartzo®) at concentrations 1 × 10, 1 × 10, and 1 × 10 CFU mL, as well as the application of B. subtilis and B. licheniformis individually at concentration 1 × 10 CFU mL, increased fresh and dry masses of shoot and root system, volume of root system, and length of roots of tomato plants when compared to control. Both Bacillus strains produced IAA after 48 h of in vitro. Bacillus colonies obtained from plant sap were morphologically similar to colonies of B. subtilis and B. licheniformis strains and were detected in inoculated on plants and not detected in control ones. A similar pattern was obtained through DNA-based detection (qPCR). Therefore, B. subtilis and B. licheniformis were able to produce auxin, promote tomato growth, and colonize and persist in the rhizosphere.
Topics: Bacillus subtilis; Bacillus licheniformis; Solanum lycopersicum; Bacillus; Agriculture; Plant Roots; Rhizosphere
PubMed: 36422850
DOI: 10.1007/s42770-022-00874-3 -
Journal of Applied Microbiology Oct 2022Recently, the clustered regularly interspaced short palindromic repeats (CRISPR) system has been developed into a precise and efficient genome editing tool. Since its... (Review)
Review
Recently, the clustered regularly interspaced short palindromic repeats (CRISPR) system has been developed into a precise and efficient genome editing tool. Since its discovery as an adaptive immune system in prokaryotes, it has been applied in many different research fields including biotechnology and medical sciences. The high demand for rapid, highly efficient and versatile genetic tools to thrive in bacteria-based cell factories accelerates this process. This review mainly focuses on significant advancements of the CRISPR system in Bacillus subtilis, including the achievements in gene editing, and on problems still remaining. Next, we comprehensively summarize this genetic tool's up-to-date development and utilization in other Bacillus species, including B. licheniformis, B. methanolicus, B. anthracis, B. cereus, B. smithii and B. thuringiensis. Furthermore, we describe the current application of CRISPR tools in phages to increase Bacillus hosts' resistance to virulent phages and phage genetic modification. Finally, we suggest potential strategies to further improve this advanced technique and provide insights into future directions of CRISPR technologies for rendering Bacillus species cell factories more effective and more powerful.
Topics: Bacillus; Bacillus Phages; Bacillus anthracis; Bacillus subtilis; CRISPR-Cas Systems; Gene Editing
PubMed: 35797344
DOI: 10.1111/jam.15704 -
Transcription Aug 2021The low G + C Gram-positive bacteria represent some of the most medically and industrially important microorganisms. They are relied on for the production of food and... (Review)
Review
The low G + C Gram-positive bacteria represent some of the most medically and industrially important microorganisms. They are relied on for the production of food and dietary supplements, enzymes and antibiotics, as well as being responsible for the majority of nosocomial infections and serving as a reservoir for antibiotic resistance. Control of gene expression in this group is more highly studied than in any bacteria other than the Gram-negative model Escherichia coli, yet until recently no structural information on RNA polymerase (RNAP) from this group was available. This review will summarize recent reports on the high-resolution structure of RNAP from the model low G + C representative Bacillus subtilis, including the role of auxiliary subunits and , and outline approaches for the development of antimicrobials to target RNAP from this group.
Topics: Bacillus subtilis; Bacterial Proteins; DNA-Directed RNA Polymerases; Gram-Positive Bacteria; Transcription, Genetic
PubMed: 34403307
DOI: 10.1080/21541264.2021.1964328 -
Trends in Microbiology Aug 2023Bacillus and Pseudomonas ubiquitously occur in natural environments and are two of the most intensively studied bacterial genera in the soil. They are often coisolated... (Review)
Review
Bacillus and Pseudomonas ubiquitously occur in natural environments and are two of the most intensively studied bacterial genera in the soil. They are often coisolated from environmental samples, and as a result, several studies have experimentally cocultured bacilli and pseudomonads to obtain emergent properties. Even so, the general interaction between members of these genera is virtually unknown. In the past decade, data on interspecies interactions between natural isolates of Bacillus and Pseudomonas has become more detailed, and now, molecular studies permit mapping of the mechanisms behind their pairwise ecology. This review addresses the current knowledge about microbe-microbe interactions between strains of Bacillus and Pseudomonas and discusses how we can attempt to generalize the interaction on a taxonomic and molecular level.
Topics: Pseudomonas; Bacillus; Soil; Soil Microbiology; Bacteria
PubMed: 36878770
DOI: 10.1016/j.tim.2023.02.003 -
Nature Communications Apr 2020Bacteria can produce membranous nanotubes that mediate contact-dependent exchange of molecules among bacterial cells. However, it is unclear how nanotubes cross the cell...
Bacteria can produce membranous nanotubes that mediate contact-dependent exchange of molecules among bacterial cells. However, it is unclear how nanotubes cross the cell wall to emerge from the donor or to penetrate into the recipient cell. Here, we report that Bacillus subtilis utilizes cell wall remodeling enzymes, the LytC amidase and its enhancer LytB, for efficient nanotube extrusion and penetration. Nanotube production is reduced in a lytBC mutant, and the few nanotubes formed appear deficient in penetrating into target cells. Donor-derived LytB molecules localize along nanotubes and on the surface of nanotube-connected neighbouring cells, primarily at sites of nanotube penetration. Furthermore, LytB from donor B. subtilis can activate LytC of recipient bacteria from diverse species, facilitating cell wall hydrolysis to establish nanotube connection. Our data provide a mechanistic view of how intercellular connecting devices can be formed among neighbouring bacteria.
Topics: Amidohydrolases; Bacillus subtilis; Bacterial Proteins; Cell Surface Extensions; Cell Wall; Conjugation, Genetic; Protein Transport
PubMed: 32321911
DOI: 10.1038/s41467-020-15605-1