Plant pathogens are the main threat for profitable agricultural productivity. Currently, chemical-based pesticides are thought to be an effective and reliable agricultural management measure for controlling pests. Chemical pesticides are highly effective and convenient to use but they are a potential threat for the environment and all kinds of life on earth. Therefore, the use of biological control agents for the management of plant pathogens is considered as a safer and sustainable strategy for safe and profitable agricultural productivity. Bacillus-based biocontrol agents play a fundamental role in the field of biopesticides. Many Bacillus species have proved to be effective against a broad range of plant pathogens. They have been reported as plant growth promoter, systemic resistance inducer, and used for production of a broad range of antimicrobial compounds (lipopeptides, antibiotics and enzymes) and competitors for growth factors (space and nutrients) with other pathogenic microorganisms thr...

https://tandfonline.com/doi/pdf/10.1080/13102818.2017.1286950

Bacillus species as versatile weapons for plant pathogens: a review

Biological control of plant pathogens by Bacillus species

Qualified presumption of safety (QPS) was developed to provide a generic safety evaluation for biological agents to support EFSA's Scientific Panels. The taxonomic identity, body of knowledge, safety concerns and antimicrobial resistance are assessed. Safety concerns identified for a taxonomic unit (TU) are where possible to be confirmed at strain or product level, reflected by 'qualifications'. No new information was found that would change the previously recommended QPS TUs and their qualifications. The list of microorganisms notified to EFSA was updated with 54 biological agents, received between April and September 2019; 23 already had QPS status, 14 were excluded from the QPS exercise (7 filamentous fungi, 6 Escherichia coli, Sphingomonas paucimobilis which was already evaluated). Seventeen, corresponding to 16 TUs, were evaluated for possible QPS status, fourteen of these for the first time, and Protaminobacter rubrum, evaluated previously, was excluded because it is not a valid species. Eight TUs are recommended for QPS status. Lactobacillus parafarraginis and Zygosaccharomyces rouxii are recommended to be included in the QPS list. Parageobacillus thermoglucosidasius and Paenibacillus illinoisensis can be recommended for the QPS list with the qualification 'for production purposes only' and absence of toxigenic potential. Bacillus velezensis can be recommended for the QPS list with the qualification 'absence of toxigenic potential and the absence of aminoglycoside production ability'. Cupriavidus necator, Aurantiochytrium limacinum and Tetraselmis chuii can be recommended for the QPS list with the qualification 'production purposes only'. Pantoea ananatis is not recommended for the QPS list due to lack of body of knowledge in relation to its pathogenicity potential for plants. Corynebacterium stationis, Hamamotoa singularis, Rhodococcus aetherivorans and Rhodococcus ruber cannot be recommended for the QPS list due to lack of body of knowledge. Kodamaea ohmeri cannot be recommended for the QPS list due to safety concerns.

https://efsa.onlinelibrary.wiley.com/doi/pdf/10.2903/j.efsa.2020.5965

Update of the list of QPS-recommended biological agents intentionally added to food or feed as notified to EFSA 13: suitability of taxonomic units notified to EFSA until September 2020.

Over the last seven decades, applications using members of the Bacillus subtilis group have emerged in both food processes and crop protection industries. Their ability to form survival endospores and the plethora of antimicrobial compounds they produce has generated an increased industrial interest as food preservatives, therapeutic agents and biopesticides. In the growing context of food biopreservation and biological crop protection, this review suggests a comprehensive way to visualize the antimicrobial spectrum described within the B. subtilis group, including volatile compounds. This classification distinguishes the bioactive metabolites based on their biosynthetic pathways and chemical nature: i.e., ribosomal peptides (RPs), volatile compounds, polyketides (PKs), non-ribosomal peptides (NRPs), and hybrids between PKs and NRPs. For each clade, the chemical structure, biosynthesis and antimicrobial activity are described and exemplified. This review aims at constituting a convenient and updated classification of antimicrobial metabolites from the B. subtilis group, whose complex phylogeny is prone to further development.

/pdf/overview-of-the-antimicrobial-compounds-produced-by-members-h9zmgur7c5.pdf

Overview of the Antimicrobial Compounds Produced by Members of the Bacillus subtilis Group.

Background Fermented soybean products are consumed in many Asian countries and are one of the potential sources of bioactive peptides. Soybean is fermented using bacteria (Bacillus subtilis and lactic acid bacteria) and fungi (Mucor spp., Aspergillus spp. and Rhizopus spp.), resulting in different types of fermented products. Scope and approach This review article is focused on production of bioactive peptides in fermented soybean products and their role in prevention and treatment of several metabolic diseases. Studies on novel bioactive peptides having specific health benefits can lead to their application in the development of functional foods and pharmaceuticals with the aim replace synthetic drugs that have several side effects. Key findings and conclusions Peptides in fermented soybean products are either released by the hydrolysis of soybean proteins during fermentation or produced by the microorganisms associated with fermentation. During soybean fermentation specific bioactive peptides are produced as a result of hydrolysis of soybean proteins (Glycinin and β-conglycinin). Individual microbial strains contribute in the formation of specific bioactive peptides with respective health benefits depending on the sequence and composition of amino acids. Such bioactive peptides may act like regulatory compounds and exhibit bioactive properties such as anti-hypertensive, antimicrobial, antioxidant, anti-diabetic and anticancer activities. Studies in future, on application of specific strains for soybean fermentation can lead in to the formation of novel bioactive peptides with potential health benefits.

Production of bioactive peptides during soybean fermentation and their potential health benefits

The rapid onset of resistance reduces the efficacy of most conventional antimicrobial drugs and is a general cause of concern for human well-being. Thus, there is great demand for a continuous supply of novel antibiotics to combat this problem. Bacteria-derived antimicrobial peptides (AMPs) have long been used as food preservatives; moreover, prior to the development of conventional antibiotics, these AMPs served as an efficient source of antibiotics. Recently, peptides produced by members of the genus Bacillus were shown to have a broad spectrum of antimicrobial activity against pathogenic microbes. Bacillus-derived AMPs can be synthesized both ribosomally and nonribosomally and can be classified according to peptide biosynthesis, structure, and molecular weight. The precise mechanism of action of these AMPs is not yet clear; however, one proposed mechanism is that these AMPs kill bacteria by forming channels in and (or) disrupting the bacterial cell wall. Bacillus-derived AMPs have potential in the pharmaceutical industry, as well as the food and agricultural sectors. Here, we focus on Bacillus-derived AMPs as a novel alternative approach to antibacterial drug development. We also provide an overview of the biosynthesis, mechanisms of action, applications, and effectiveness of different AMPs produced by members of the Bacillus genus, including several recently identified novel AMPs.

Antimicrobial peptides of the genus Bacillus: a new era for antibiotics.

Isolation and characterization of a novel analyte from Bacillus subtilis SC-8 antagonistic to Bacillus cereus.

Narrow antagonistic activity of antimicrobial peptide from Bacillus subtilis SCK-2 against Bacillus cereus.

Bacillus subtilis SC-8 is a Gram-positive bacterium displaying narrow antagonistic activity for the Bacillus cereus group. B. subtilis SC-8 was isolated from Korean traditional fermented-soybean food. Here we report the draft genome sequence of B. subtilis SC-8, including biosynthetic genes for antibiotics that may have beneficial effects for control of food-borne pathogens.

Genome Sequencing of Bacillus subtilis SC-8, Antagonistic to the Bacillus cereus Group, Isolated from Traditional Korean Fermented-Soybean Food

The o-succinylbenzoate synthase (OSBS) family is part of the functionally diverse enolase superfamily. Many proteins in one branch of the OSBS family catalyze both OSBS and N-succinylamino acid racemization in the same active site. In some promiscuous NSAR/OSBS enzymes, NSAR activity is biologically significant in addition to or instead of OSBS activity. Identifying important residues for each reaction could provide insight into how proteins evolve new functions. We have made a series of mutations in Amycolatopsis sp. T-1-60 NSAR/OSBS in an active site loop, referred to as the 20s loop. This loop affects substrate specificity in many members of the enolase superfamily but is poorly conserved within the OSBS family. Deletion of this loop decreased OSBS and NSAR catalytic efficiency by 4500-fold and 25,000-fold, respectively, showing that it is essential. Most point mutations had small effects, changing the efficiency of both NSAR and OSBS activities <10-fold compared to that of the wild type. An exception ...

In-Cheol Yeo

Papers

Antimicrobial peptides of the genus Bacillus: a new era for antibiotics.

Isolation and characterization of a novel analyte from Bacillus subtilis SC-8 antagonistic to Bacillus cereus.

Narrow antagonistic activity of antimicrobial peptide from Bacillus subtilis SCK-2 against Bacillus cereus.

Genome Sequencing of Bacillus subtilis SC-8, Antagonistic to the Bacillus cereus Group, Isolated from Traditional Korean Fermented-Soybean Food

Role of an Active Site Loop in the Promiscuous Activities of Amycolatopsis sp. T-1-60 NSAR/OSBS