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Microbiology Spectrum May 2019The group includes several species with closely related phylogeny. The most well-studied members of the group, , , and , are known for their pathogenic potential.... (Review)
Review
The group includes several species with closely related phylogeny. The most well-studied members of the group, , , and , are known for their pathogenic potential. Here, we present the historical rationale for speciation and discuss shared and unique features of these bacteria. Aspects of cell morphology and physiology, and genome sequence similarity and gene synteny support close evolutionary relationships for these three species. For many strains, distinct differences in virulence factor synthesis provide facile means for species assignment. is the causative agent of anthrax. Some strains are commonly recognized as food poisoning agents, but strains can also cause localized wound and eye infections as well as systemic disease. Certain strains are entomopathogens and have been commercialized for use as biopesticides, while some strains have been reported to cause infection in immunocompromised individuals. In this article we compare and contrast , , and , including ecology, cell structure and development, virulence attributes, gene regulation and genetic exchange systems, and experimental models of disease.
Topics: Animals; Anthrax; Anthrax Vaccines; Bacillus; Bacillus anthracis; Bacillus cereus; Bacillus thuringiensis; Bacterial Toxins; Bacterial Vaccines; Biological Control Agents; DNA, Bacterial; Disease Models, Animal; Ecology; Gastrointestinal Diseases; Gene Expression Regulation, Bacterial; Genes, Bacterial; Genome, Bacterial; Humans; Infections; Invertebrates; Phylogeny; Species Specificity; Spores, Bacterial; Virulence
PubMed: 31111815
DOI: 10.1128/microbiolspec.GPP3-0032-2018 -
Microbiology Spectrum Oct 2014Spores of various Bacillus and Clostridium species are among the most resistant life forms known. Since the spores of some species are causative agents of much food... (Review)
Review
Spores of various Bacillus and Clostridium species are among the most resistant life forms known. Since the spores of some species are causative agents of much food spoilage, food poisoning, and human disease, and the spores of Bacillus anthracis are a major bioweapon, there is much interest in the mechanisms of spore resistance and how these spores can be killed. This article will discuss the factors involved in spore resistance to agents such as wet and dry heat, desiccation, UV and γ-radiation, enzymes that hydrolyze bacterial cell walls, and a variety of toxic chemicals, including genotoxic agents, oxidizing agents, aldehydes, acid, and alkali. These resistance factors include the outer layers of the spore, such as the thick proteinaceous coat that detoxifies reactive chemicals; the relatively impermeable inner spore membrane that restricts access of toxic chemicals to the spore core containing the spore's DNA and most enzymes; the low water content and high level of dipicolinic acid in the spore core that protect core macromolecules from the effects of heat and desiccation; the saturation of spore DNA with a novel group of proteins that protect the DNA against heat, genotoxic chemicals, and radiation; and the repair of radiation damage to DNA when spores germinate and return to life. Despite their extreme resistance, spores can be killed, including by damage to DNA, crucial spore proteins, the spore's inner membrane, and one or more components of the spore germination apparatus.
Topics: Bacillus; Clostridium; Desiccation; Enzymes; Hot Temperature; Inorganic Chemicals; Microbial Viability; Organic Chemicals; Spores, Bacterial
PubMed: 26104355
DOI: 10.1128/microbiolspec.TBS-0003-2012 -
Microbiology Spectrum Dec 2015Despite being resistant to a variety of environmental insults, the bacterial endospore can sense the presence of small molecules and respond by germinating, losing the... (Review)
Review
Despite being resistant to a variety of environmental insults, the bacterial endospore can sense the presence of small molecules and respond by germinating, losing the specialized structures of the dormant spore, and resuming active metabolism, before outgrowing into vegetative cells. Our current level of understanding of the spore germination process in bacilli and clostridia is reviewed, with particular emphasis on the germinant receptors characterized in Bacillus subtilis, Bacillus cereus, and Bacillus anthracis. The recent evidence for a local clustering of receptors in a "germinosome" would begin to explain how signals from different receptors could be integrated. The SpoVA proteins, involved in the uptake of Ca2+-dipicolinic acid into the forespore during sporulation, are also responsible for its release during germination. Lytic enzymes SleB and CwlJ, found in bacilli and some clostridia, hydrolyze the spore cortex: other clostridia use SleC for this purpose. With genome sequencing has come the appreciation that there is considerable diversity in the setting for the germination machinery between bacilli and clostridia.
Topics: Bacillus; Bacterial Proteins; Gene Expression Regulation, Bacterial; Spores, Bacterial
PubMed: 27337279
DOI: 10.1128/microbiolspec.TBS-0014-2012 -
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 Mar 2012Species of Bacillus and related genera have long been troublesome to food producers on account of their resistant endospores. These organisms have undergone huge... (Review)
Review
Species of Bacillus and related genera have long been troublesome to food producers on account of their resistant endospores. These organisms have undergone huge taxonomic changes in the last 30 years, with numbers of genera and species now standing at 56 and over 545, respectively. Despite this expansion, relatively few new species have been isolated from infections, few are associated with food and no important new agents of foodborne illness have been reported. What has changed is our knowledge of the established agents. Bacillus cereus is well known as a cause of food poisoning, and much more is now understood about its toxins and their involvement in infections and intoxications. Also, although B. licheniformis, B. subtilis and B. pumilus have occasionally been isolated from cases of food-associated illness, their roles were usually uncertain. Much more is now known about the toxins that strains of these species may produce, so that their significances in such episodes are clearer; however, it is still unclear why such cases are so rarely reported. Another important development is the use of aerobic endosporeformers as probiotics, as the potentials of such organisms to cause illness or to be sources of antibiotic resistance need to be borne in mind.
Topics: Bacillus; Food Microbiology; Foodborne Diseases; Probiotics; Spores, Bacterial
PubMed: 22121830
DOI: 10.1111/j.1365-2672.2011.05204.x -
Journal of the American Mosquito... 2007Since the discovery of Bacillus thuringiensis (Berliner) serovariety israelensis de Barjac (Bti) and efficacious isolates of Bacillus sphaericus Neide, formulations of... (Review)
Review
Since the discovery of Bacillus thuringiensis (Berliner) serovariety israelensis de Barjac (Bti) and efficacious isolates of Bacillus sphaericus Neide, formulations of these bacteria have become the predominant non-chemical means employed for control of mosquito larvae at several locations in the United States and other countries. An overview of developments in the past 20 years is presented in this chapter regarding the toxins of Bti and B. sphaericus, their modes of action, efficacy and factors that affect larvicidal activity, development of resistance, safety, and their roles in integrated mosquito control. The efficacy of Bti formulations has been demonstrated in a variety of habitats against a multitude of species of mosquitoes. B. sphaericus formulations have been utilized predominantly in organically enriched habitats against Culex species, but they are also active in a variety of habitats having low organic enrichment, against numerous species, and across several genera. Stegomyia spp. are not susceptible to practical doses of B. sphaericus formulations. B. sphaericus has been shown to persist longer than Bti in polluted habitats and, under certain circumstances, can recycle in larval cadavers. A disadvantage of B. sphaericus has been the development of resistance in certain populations of Cx. quinquefasciatus Say and Cx. pipiens Linnaeus. Biotic and abiotic factors that influence the larvicidal activity of Bti and B. sphaericus include species of mosquito and their respective feeding strategies, rate of ingestion, age and density of larvae, habitat factors (temperature, solar radiation, depth of water, turbidity, tannin and organic content, presence of vegetation, etc.), formulation factors (type of formulation, toxin content, how effectively the material reaches the target, and settling rate), storage conditions, production factors, means of application and frequency of treatments. Due to their efficacy and relative specificity, both Bti and B. sphaericus can be ideal control agents in integrated programs especially where other biological control agents, environmental management, personal protection and the judicious use of insecticides are combined.
Topics: Animals; Bacillus; Culicidae; Mosquito Control; Pest Control, Biological
PubMed: 17853604
DOI: 10.2987/8756-971X(2007)23[133:BTSIAB]2.0.CO;2 -
Molecules (Basel, Switzerland) Nov 2018Microbial solubilization applies the natural ability of a microorganism to liberate phosphorus from unavailable structures. The main mechanism recognized to be...
Microbial solubilization applies the natural ability of a microorganism to liberate phosphorus from unavailable structures. The main mechanism recognized to be responsible for the solubilization of phosphorus is the production of different types of organic acids. Three kinds of species and three types of raw materials (poultry bones, fish bones, and ash) were tested for solubilization. The following parameters were compared for all discussed cases: pH, specific growth rate, solubilization factor, released phosphorus concentration, and total and individual concentration of organic acids. Utilization of ash brought about the highest specific and maximum specific growth rates. A decrease in pH was observed in most of the discussed cases with the exception of fish bones. At the same time, fish bones had the highest concentration of released P₂O₅ and the highest total concentration of produced organic acids (gluconic, lactic, acetic, succinic, and propionic) in all discussed cases. The tested species produced the mentioned acids with the exception of , where propionic acid was not present. The lactic and acetic acids were those produced in the highest amount. The kind of raw materials and type of species used in solubilization had a strong influence on the kind of organic acids that were detected in the broth culture and its total concentration, which had a direct influence on the amount of released phosphorus. The combination of with the fish bones at 5 g/L is proposed as the pair that gives the highest concentration of released phosphorus (483 ± 5 mg/L).
Topics: Bacillus; Bacillus cereus; Bacillus megaterium; Bacillus subtilis; Phosphorus; Solubility
PubMed: 30404208
DOI: 10.3390/molecules23112897 -
Journal of Applied Microbiology Jun 2010To identify the diversity of pigmented aerobic spore formers found in the environment and to characterize the chemical nature of this pigmentation.
AIMS
To identify the diversity of pigmented aerobic spore formers found in the environment and to characterize the chemical nature of this pigmentation.
MATERIALS AND RESULTS
Sampling of heat-resistant bacterial counts from soil, sea water and the human gastrointestinal tract. Phylogenetic profiling using analysis of 16S rRNA sequences to define species. Pigment profiling using high-performance liquid chromatography-photo diode array analysis.
CONCLUSIONS
The most commonly found pigments were yellow, orange and pink. Isolates were nearly always members of the Bacillus genus and in most cases were related with known species such as Bacillus marisflavi, Bacillus indicus, Bacillus firmus, Bacillus altitudinis and Bacillus safensis. Three types of carotenoids were found with absorption maxima at 455, 467 and 492 nm, corresponding to the visible colours yellow, orange and pink, respectively. Although the presence of other carotenoids cannot be ruled out, these three predominant carotenoids appear to account for the pigments obtained in most pigmented bacilli, and our analysis reveals the existence of a C30 biosynthetic pathway. Interestingly, we report the presence of a water-soluble pigment that may also be a carotenoid. The function of carotenoids is photoprotection, and carotenoid-containing spores exhibited significantly higher levels of resistance to UV radiation than non-carotenoid-containing Bacillus species.
SIGNIFICANCE AND IMPACT OF THE STUDY
This study demonstrates that pigmented bacilli are ubiquitous and contain new carotenoid biosynthetic pathways that may have industrial importance.
Topics: Bacillus; Carotenoids; Gastrointestinal Tract; Humans; Phylogeny; Pigmentation; RNA, Ribosomal, 16S; Seawater; Soil Microbiology; Spores, Bacterial; Water Microbiology
PubMed: 19878522
DOI: 10.1111/j.1365-2672.2009.04590.x -
Journal of Applied Microbiology Feb 2019To investigate effects of fluoride ion (F ) on, and kinetics of its movement into and out of, spores and growing cells of Bacillus species.
AIMS
To investigate effects of fluoride ion (F ) on, and kinetics of its movement into and out of, spores and growing cells of Bacillus species.
METHODS AND RESULTS
Effects of F on Bacillus cell growth, spore germination and outgrowth and heat resistance were investigated, as well as F movement into and out of spores using F-NMR. F inhibited Bacillus subtilis spore germination and outgrowth, and YhdU, now named FluC, was crucial to prevent F accumulation in growing cells and to minimize F inhibition of spore germination. Dormant wild-type, yhdU and coat defective B. subtilis spores, and Bacillus cereus spores incubated in 40 mmol l NaF for 48 h accumulated 2-2·6 mol l F and its movement into Bacillus spores was highest at low pH. Bacillus subtilis spores lacking Ca-dipicolinic acid accumulated higher F levels than wild-type spores.
CONCLUSIONS
These results are consistent with F incorporation into the dormant spore core, and as HF and/or NaF, but not CaF . YhdU played no significant role in F uptake or efflux in dormant spores, but assisted in F export early in spore germination.
SIGNIFICANCE AND IMPACT OF STUDY
This knowledge provides new insight into effects of F on Bacillus cells and spores and how this anion moves into, and out of spores.
Topics: Bacillus; Bacillus subtilis; Biological Transport; Fluorides; Hot Temperature; Picolinic Acids; Spores, Bacterial
PubMed: 30430725
DOI: 10.1111/jam.14155 -
Journal of Bacteriology Apr 2014Spores of Bacillus species can remain in their dormant and resistant states for years, but exposure to agents such as specific nutrients can cause spores' return to life... (Review)
Review
Spores of Bacillus species can remain in their dormant and resistant states for years, but exposure to agents such as specific nutrients can cause spores' return to life within minutes in the process of germination. This process requires a number of spore-specific proteins, most of which are in or associated with the inner spore membrane (IM). These proteins include the (i) germinant receptors (GRs) that respond to nutrient germinants, (ii) GerD protein, which is essential for GR-dependent germination, (iii) SpoVA proteins that form a channel in spores' IM through which the spore core's huge depot of dipicolinic acid is released during germination, and (iv) cortex-lytic enzymes (CLEs) that degrade the large peptidoglycan cortex layer, allowing the spore core to take up much water and swell, thus completing spore germination. While much has been learned about nutrient germination, major questions remain unanswered, including the following. (i) How do nutrient germinants penetrate through spores' outer layers to access GRs in the IM? (ii) What happens during the highly variable and often long lag period between the exposure of spores to nutrient germinants and the commitment of spores to germinate? (iii) What do GRs and GerD do, and how do these proteins interact? (iv) What is the structure of the SpoVA channel in spores' IM, and how is this channel gated? (v) What is the precise state of the spore IM, which has a number of novel properties even though its lipid composition is very similar to that of growing cells? (vi) How is CLE activity regulated such that these enzymes act only when germination has been initiated? (vii) And finally, how does the germination of spores of clostridia compare with that of spores of bacilli?
Topics: Bacillus; Bacterial Proteins; Gene Expression Regulation, Bacterial; Spores, Bacterial
PubMed: 24488313
DOI: 10.1128/JB.01455-13