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The traditional way of dealing with plant diseases has been the use of chemical products, but these harm the environment and are incompatible with the global effort for sustainable development. The use of Bacillus and related species in the biological control of plant diseases is a trend in green agriculture. Many studies report the positive effect of these bacteria, but a synthesis is still necessary. So, the objective of this work is to perform a meta-analysis of Bacillus biocontrol potential and identify factors that drive its efficacy. Data were compiled from articles published in journals listed in two of the main scientific databases between 2000 and 2021. Among 6159 articles retrieved, 399 research papers met the inclusion criteria for a systematic review. Overall, Bacilli biocontrol agents reduced disease by 60% compared to control groups. Furthermore, experimental tests with higher concentrations show a strong protective effect, unlike low and single concentration essays. Biocontrol efficacy also increased when used as a protective inoculation rather than therapeutic inoculation. Inoculation directly in the fruit has a greater effect than soil drenching. The size of the effect of Bacillus-based commercial products is lower than the newly tested strains. The findings presented in this study confirm the power of Bacillus-based bioinoculants and provide valuable guidance for practitioners, researchers, and policymakers seeking effective and sustainable solutions in plant disease management.Highlights: Bacillus biological control agents significantly reduced disease by 60% when compared to negative control groups; The concentration of the inoculum drives the protection effect of Bacillus inoculation; Protective inoculation has a greater effect than therapeutic inoculation; Inoculation directly in the fruit has a greater effect than soil drenching; In comparison with test strains, commercial bioproducts have a lower protective effect. [ABSTRACT FROM AUTHOR]

Bacillus sp. PHP1601 (Bacillales: Bacillaceae), a member of the B. subtilissensu lato, possesses an interesting ability to antagonise fly larvae. Blowflies are considered occupational nuisances and recognised as vectors of disease. A study was undertaken to evaluate the biocontrol potential of Bacillus sp. PHP1601 against Lucilia cuprina (Wiedemann) (Diptera, Calliphoridae) larvae. Bioassays were established to determine the biocontrol efficacy of various treatment formulations, i.e., vegetative cell (102–1010 cells g−1), endospore (102–1010 endospores g−1), cell-free supernatant (1–30% v w−1) and crude biosurfactant extract (5–1000 μg g−1) against second instar L. cuprina fly larvae reared on milk agar medium. All treatments demonstrated a dose-dependent larvicidal response over a 240 h period. Even at the lowest cell and endospore concentrations tested (i.e., 102 cells/endospores g−1) the pupation stage was inhibited, effectively interrupting the fly reproduction cycle. Larvae antagonism elicited by partially purified biosurfactant extracts indicated the likely contribution of bioactive lipopeptide compounds to the mechanism of inhibition. Larvae cadavers recovered from these treatments displayed substantial physiological discolouration and lacked structural integrity. PHP1601 was confirmed to be a strain of B. velezensis based on multiple-locus sequence analysis of 16S rRNA, gyrA, rpoB and dnaJ housekeeping genes. This study constitutes the first report of a strain of B. velezensis demonstrating a larvicidal response towards a member of the suborder Brachycera. [ABSTRACT FROM AUTHOR]

For a long time, the genus Bacillus has been known and considered among the most applicable genera in several fields. Recent taxonomical developments resulted in the identification of more species in Bacillus-related genera, particularly in the order Bacillales (earlier heterotypic synonym: Caryophanales), with potential application for biotechnological and industrial purposes such as biofuels, bioactive agents, biopolymers, and enzymes. Therefore, a thorough understanding of the taxonomy, growth requirements and physiology, genomics, and metabolic pathways in the highly diverse bacterial order, Bacillales, will facilitate a more robust designing and sustainable production of strain lines relevant to a circular economy. This paper is focused principally on less-known genera and their potential in the order Bacillales for promising applications in the industry and addresses the taxonomical complexities of this order. Moreover, it emphasizes the biotechnological usage of some engineered strains of the order Bacillales. The elucidation of novel taxa, their metabolic pathways, and growth conditions would make it possible to drive industrial processes toward an upgraded functionality based on the microbial nature. [ABSTRACT FROM AUTHOR]

Biological soil crusts (biocrusts) account for a substantial portion of primary production in dryland ecosystems. They successionally mature to deliver a suite of ecosystem services, such as carbon sequestration, water retention and nutrient cycling, and climate regulation. Biocrust assemblages are extremely well adapted to survive desiccation and to rapidly take advantage of the periodic precipitation events typical of arid ecosystems. Here we focus on the wetting response of incipient cyanobacterial crusts as they mature from "light" to "dark." We sampled a cyanobacterial biocrust chronosequence before (dry) and temporally following a controlled wetting event and used high-throughput 16S rRNA and rRNA gene sequencing to monitor the dynamics of microbial response. Overall, shorter-term changes in phylogenetic beta diversity attributable to periodic wetting were as large as those attributable to biocrust successional stage. Notably, more mature crusts showed significantly higher resistance to precipitation disturbance. A large bloom of a few taxa within the Firmicutes, primarily in the order Bacillales, emerged 18 h after wetting, while filamentous crust-forming cyanobacteria showed variable responses to wet-up across the successional gradient, with populations collapsing in less-developed light crusts but increasing in later-successional-stage dark crusts. Overall, the consistent Bacillales bloom accompanied by the variable collapse of pioneer cyanobacteria of the Oscillatoriales order across the successional gradient suggests that the strong response of few organisms to a hydration pulse with the mortality of the autotroph might have important implications for carbon (C) balance in semiarid ecosystems.IMPORTANCE Desert biological soil crusts are terrestrial topsoil microbial communities common to arid regions that comprise 40% of Earth's terrestrial surface. They successionally develop over years to decades to deliver a suite of ecosystem services of local and global significance. Ecosystem succession toward maturity has been associated with both resistance and resilience to disturbance. Recent work has shown that the impacts of both climate change and physical disturbance on biocrusts increase the potential for successional resetting. A larger proportion of biocrusts are expected to be at an early developmental stage, hence increasing susceptibility to changes in precipitation frequencies. Therefore, it is essential to characterize how biocrusts respond to wetting across early developmental stages. In this study, we document the wetting response of microbial communities from a biocrust chronosequence. Overall, our results suggest that the cumulative effects of altered precipitation frequencies on the stability of biocrusts will depend on biocrust maturity.