Bacillus subtilisimpact on plant growth, soil health and environment: Dr. Jekyll and Mr. Hyde

Abstract

The increased dependence of farmers on chemical fertilizers poses a risk to soil fertility and ecosystem stability. Plant growth‐promoting rhizobacteria (PGPR) are at the forefront of sustainable agriculture, providing multiple benefits for the enhancement of crop production and soil health. Bacillus subtilis is a common PGPR in soil that plays a key role in conferring biotic and abiotic stress tolerance to plants by induced systemic resistance (ISR), biofilm formation and lipopeptide production. As a part of bioremediating technologies, Bacillus spp. can purify metal contaminated soil. It acts as a potent denitrifying agent in agroecosystems while improving the carbon sequestration process when applied in a regulated concentration. Although it harbours several antibiotic resistance genes (ARGs), it can reduce the horizontal transfer of ARGs during manure composting by modifying the genetic makeup of existing microbiota. In some instances, it affects the beneficial microbes of the rhizosphere. External inoculation of B. subtilis has both positive and negative impacts on the endophytic and semi‐synthetic microbial community. Soil texture, type, pH and bacterial concentration play a crucial role in the regulation of all these processes. Soil amendments and microbial consortia of Bacillus produced by microbial engineering could be used to lessen the negative effect on soil microbial diversity. The complex plant–microbe interactions could be decoded using transcriptomics, proteomics, metabolomics and epigenomics strategies which would be beneficial for both crop productivity and the well‐being of soil microbiota. Bacillus subtilis has more positive attributes similar to the character of Dr. Jekyll and some negative attributes on plant growth, soil health and the environment akin to the character of Mr. Hyde.

Optimization of industrial (3000 L) production of Bacillus subtilis CW-S and its novel application for minituber and industrial-grade potato cultivation

“…In an in-vitro seedling assay, this strain promoted plant growth by significantly increasing the vegetative growth parameters of wheat seedlings. The plant probiotic activity of this strain was comparable to that described in past studies, which showed that Bacillus subtilis is a rhizospheric bacteria with numerous favorable effects on crops and plants 2 , 29 , 30 .…”

“…The majority of the researchers cited did not mention root length, stolon number, or transplanted plantlet survival rates, and there was no evidence of the use of plant probiotics in aeroponics such as Bacillus subtilis 46 – 49 . Bacillus subtilis CW-S performed well in aeroponic because it offered plants biotic and abiotic stress tolerance via induced systemic resistance (ISR), biofilm growth, and lipopeptide production 30 , 50 .…”

Preinoculation with Endophytic fungus Phomopsis liquidambaris reduced rice bakanae disease caused by Fusarium proliferatum via enhanced plant resistance

“…However, the use of chemical agents can result in easily cause resistance to pathogens and environmental pollution and, thus, provides a challenging control method (Henkler & Luch, 2011). Beneficial plant micro‐organisms are recommended as biological control agents (BCAs) in agricultural production due to their safety and environmental friendliness (Li et al, 2014; Mahapatra et al, 2022). At present, the use of beneficial micro‐organisms to improve crop health, and alleviate and protect plants from stress has become a research priority (Sahoo et al, 2013; Yao et al, 2021).…”

Model Study for Interaction of Sublethal Doses of Zinc Oxide Nanoparticles with Environmentally Beneficial Bacteria Bacillus thuringiensis and Bacillus megaterium

“…Bacillus species produce various enzymes, antibiotics, vitamins, amino acids, organic acids and other substances, performing important functions in the natural environment as well as in the biotechnological industry [ 11 , 12 , 13 ]. Various Bacillus species have the potential to support plant growth, limit or fight plant pathogens and mitigate the effects of stress, e.g., salt stress, by colonizing the roots and regulating physiological and molecular processes in plants [ 11 , 12 , 13 , 14 , 15 , 16 ]. Bacillus sp.…”

“…Bacillus sp. colonize the soil environment and directly influence soil quality and the condition of plants, as they are involved in processes such as nutrient cycling, organic matter decomposition and symbiotic relations with plants [ 15 ]. Some Bacillus species benefit plants by supplying them with minerals via reduction of atmospheric nitrogen to forms available to plants.…”