The one health concept focuses on the interconnectedness of all living organisms, specifically considering the health aspects. Human health is linked to the health of plants, animals, and living soil microorganisms that form the basis of life for all the rest. Soil is a source of a diversity of microorganisms on which plant growth and prosperity depend. Plants interact with microorganisms from the rhizosphere, the area of soil immediately adjacent to the root, which is richest in microbial abundance. Bacillus species account for up to 95% of the Gram-positive bacterial communities present in the soil and rhizosphere, making them a dominant genus. Bacillus belongs to one of the types of bacteria that may improve plants condition by: - Facilitated nutrient uptake and assimilation, including NPK, - Growth promotion, - Hormone regulation, - Stress control, - Pathogen suppression, - Facilitated seed germination, - Detoxification of pesticides and contaminants. Positive effects on animals and humans consisting of: - Improving animal microbiomes, - Providing endosymbionts for insects, - Being food for animals, - Natural allergy remediation, - Detoxification of contaminated food   and feed (e.g. aflatoxin B1), - Provision of secondary metabolites. As a result of excessive urbanization, chemical pollution and landscape degradation, the amount of soil microorganisms, including positive bacteria like Bacillus may decrease. The harmful effects of urbanization and pollution can be reduced by monitoring of native microbiome and/or applying some beneficial strains such as Bacillus spp. for environment remediation projects.

Antibiotics have been added to animal feed since the 1950s. They have helped to quickly increase the muscle mass and size of livestock, and thus produce more meat. In addition, using them was supposed to prevent diseases. The use of antibiotics in the meat industry carries with it several negative impacts on human, animal, and ecosystem health, such as: • Increase in antibiotic-resistant bacteria that can infect humans and animals, • Change in the composition of the intestinal microbiota of farm animals, • More frequent inflammation, • Reducing the usefulness of antibiotics. The makeshift use of antibiotics is slowly being abandoned for healthy livestock. A pure feed with only probiotic admixture, devoid of agents that stimulate rapid muscle mass gain, gives much better results in maintaining the overall health of poultry farming and other animal species. The positive effects of Bacillus subtilis are based on • Reduction of colonization of Salmonella typhimurium bacteria, • Reduction of gut pathogens, • Optimizing Gut Function, • Better absorption of nutrients, • Increasing the number and length of intestinal microvilli.

Crops are exposed to various environmental stresses that inhibit their growth and diminish crop productivity globally. Plant biostimulants are substances/microorganisms adjusted to plants to improve their ability to absorb nutrients, withstand extreme conditions, and enhance crop quality traits. Benefits of using microbial formulas containing Bacillus spp.: - have metabolic and genetic diversity for significant adaptation to environmental conditions, - more effectively produce metabolites and form resilient spores, - develop tolerance to abiotic stresses, - fast growth rate and facilitated colonisation in the rhizosphere. Mechanisms of Bacillus plant growth promotion: - improvement of the availability of nutrients, - effect on the release of root exudates, such as ACC deaminase, - effect on plant growth-stimulating phytohormones metabolism, - release of antimicrobial compounds, hydrolytic enzymes, and siderophores, - reduced toxicity of the soil pollutants, - improvement of natural defence against pathogens. The incorporation of Bacillus spp. in cropping systems is an effective and environmentally friendly strategy for sustainable agriculture.

Spores are robust, dormant, and non-reproducing forms of Bacteria that allow them to survive adverse environmental conditions. The process of endospore formation, known as sporulation, begins when the bacterial cell detects unfavorable conditions, that trigger a series of morphological and physiological changes. Bacillus endospores are resistant to a wide range of stress factors, compared to growing vegetative cells. Cryo-electron microscopy analyses of Bacillus endospores contribute to a better understanding of the structural basis underlying their remarkable resilience to environmental conditions. The unique resistance properties of endospores are associated with: -> maintenance of low water content, -> protective layer of peptidoglican cortex, -> presence of DPA- dipicolinic acid, -> crystalline nucleotide (increased stability of circular DNA structure). The endospore formation process consists of the following stages: 1) Initiation by detecting unfavorable environmental conditions. 2) Asymmetric division into a smaller forespore and a larger mother cell. 3) Forming of a double membrane-bound structure. 4) Spore coat synthesis around the forespore by the mother cell. 5) DNA condensation and packaging within the forespore. 6) The mother cell lyses and releases the mature endospore into the environment. Bacterial endospores have several industrial uses, including: biofertilizers with extended shelf life, microbial-based biostimulant formulas and plant growth enhancers, composting and manure enrichment, land and water bioremediation, soil health improvement. The properties resulting from the structure of Bacillus endospores make them possible to use them for a variety of purposes, from improving animal and human health to providing benefits for plants and soil.

A prevalent challenge in swine production is postweaning diarrhea caused by Escherichia coli. Newly weaned pigs lack adequate immune protection, being highly susceptible to gastrointestinal issues leading to diarrhea, growth retardation, and early death. The use of appropriate probiotics can be an effective strategy in reducing the frequency and intensity of diarrhea, consequently enhancing the growth of nursery pigs. It has been demonstrated that appropriate dietary supplementation with probiotics based on Bacillus strains can contribute to: - Reduced incidence and severity of diarrheas, - Improved early postweaning growth, - Increased activity of digestive enzymes, - Higher blood glucose levels, - Increased levels of short-chain fatty acids, which play important roles in gut integrity, nutrient absorption, and gut microbiome balance. The application of Bacillus as probiotics in piglets can be considered an efficient way of reducing the effects of pathogenic Escherichia coli. It also improves pigs ‘health in a safe and eco-friendly way without using antibiotics that are widely used in nursery pig diets can lead to problems with antibiotic-resistant bacteria.

Aquaculture is the practice of cultivating, breeding, and harvesting aquatic organisms under controlled conditions, typically for commercial purposes. It involves the farming of various species of fish, crustaceans and mollusks. Aquaculture is also one of the drivers of pollution in both fresh and salt water because of: - use of feeds for animals and fertilizers - metabolic wastes - Fish mortalities because of disease and poor water condition - Oil spillage because of the use of machines like generators, automated feeders, water pumps and other - antibiotics and chemicals used for the pond preparation, disease treatment and growth promotion. The breeding of aquatic organisms requires clean water, but at the same time is a source of pollutants that greatly reduce breeding efficiency. Methods of treating water from pollution: - Water replacement and biofilters, which is a very expensive method, - Chemicals, that can be accumulated by animals and thus dangerous for humans, - Beneficial microorganisms, such as Bacillus. Bacillus is a safe and efficient way to purify water. It was demonstrated that Bacillus inhibits the growth of pathogens, provides nutrients and has more advantages, including producing spores and metabolites that is more effective against a wide range of pathogenic microbes than other probiotics. This bacterium is also capable of changing water parameters for the better by: - Decrease in heavy metals load, - Modulation of water hardness, - Remediation of spilled oil, - Removal of phosphates, - Modulation of pH, - Removal of nitrogenous waste, - Removal of organic matter. Understanding the positive effects of Bacillus in aquaculture can help not only this field, but also the entire water ecosystem and human health.

Horizontal gene transfer (HGT) is the exchange of genetic information between microorganisms, a process that can include the spread of antibiotic-resistance genes among bacteria. Exchange of mobile genetic elements (including PLASMIDS - small circular, double-stranded DNA molecules in bacteria) generally contributes to the plasticity of bacterial genomes, allowing them to rapidly adapt to changing environments, acquire new traits, and evolve over time. Plasmid-transferring bacteria are capable of transferring genetic material (when in competent stage), specifically plasmids, to other bacteria, facilitating the exchange of genetic information. Bacillus, a genus of bacteria, is generally considered a safe group as it does not actively exchange DNA with other bacteria through plasmid transfer, as they do not reach a competent state. This characteristic makes Bacillus strains a suitable choice for various applications, including animal feed, plant growth enhancers, probiotics, and water treatment.

Modern agriculture relies on substantial quantities of chemical fertilizers. Overfertilization may often lead to disbalance in beneficial crop microbiome and this increased susceptibility to plant diseases, especially in case of monoculture crop systems. It was demonstrated that certain Bacillus species show the efficiency in suppresing plant pathogens by: Antibiosis - synthesis of secondary metabolities for inhibition of plant pathogens Competition - microorganisms in plant rhizosphere compete with pathogens for niches and nutrients Induced systematic resistance (ISR) - Bacillus stimulates ISR. This improves the plant’s resistance against pathogenic bacteria, fungi and viruses. Reshaping of the soil microbiome - Bacillus regulate rhizosphere microbiome to raise plant disease suppression and antifungal activity. Bacillus genera contain a range of species that are are natural plant allies, helping to improve their natural resistance and promote crop field performence by: DIRECT EFFECTS - siderophore production, nitrogen fixation, phytohormone production and nutrient solubilization, INIDRECT EFFECTS - production of exopolysaccharides (EPS), biofilm formation, and release of lytic enzymes. The practical application of Bacillus in agricultural fields is usually challenging due to varying environmental conditions. To improve biocontrol efficiency specific measures can be introduced by: development biofertilizers and biostimulants based on specific Bacillus inocula, use of antagonistic metabolities instead of/mixed with biocontrol agents, novel formulas acting as combination of specific bacterial isolates and chemical agents. Source: Zhang et al. 2023; DOI: 10.1111/1751-7915.14348

The structural elements of bacterial cells and their functionalities are important for their adaptability to specific environments. STRUCTURE Cell Membrane - Acts as a selectively permeable barrier, allowing nutrients to enter and waste products to exit. Cell Wall -  Provides structural support, shape, and protection against environmental stresses. Capsule (in some bacteria) - A protective layer outside the bacterial cell wall, composed of polysaccharides. METABOLISM Cytoplasm - gel-like matrix composed of water, enzymes, nutrients, wastes, and gases. Mesosomes - Invaginations of the cell membrane that play a role in cell division and membrane organization. Vacuoles (in some bacteria): membrane-bound structures that store nutrients and mediate in cell turgor maintenance. Ribosomes - cellular structures composed of RNA and protein, responsible for protein synthesis. GENETIC MATERIAL Nucleoid - Contains the bacterial DNA, essential for governing cellular functions and reproduction. Plasmids - Small, circular DNA molecules that can be transferred between bacterial cells, contributing to genetic diversity. MOVEMENT Pili - Hair-like appendages facilitating adhesion to surfaces. Can also play a role in communication between bacterial cells. Flagella - Whip-like structures responsible for bacterial movement. Enable cells to navigate towards nutrients or away from threats. Understanding these intricacies opens doors to harnessing the power of bacteria for various applications, from medicine to environmental solutions. If your field of professional activity involves the application of the beneficial properties of bacteria, especially from the Bacillus genus, please contact us and we will be happy to advise you.