Pepper Bacterial Spot Control by Bacillus velezensis: Bioprocess Solution

Abstract

Pepper bacterial spot is one of the most severe plant diseases in terms of infection persistence and economic losses when it comes to fresh pepper fruits used in nutrition and industrial processing. In this study, Bacillus velezensis IP22 isolated from fresh cheese was used as a biocontrol agent of pepper bacterial spot, whose main causal agent is the cosmopolitan pathogen Xanthomonas euvesicatoria. After optimization of the cultivation medium composition aimed at maximizing of the antimicrobial activity against X. euvesicatoria and validation of the optimized medium at the scale of a laboratory bioreactor, in planta tests were performed. The results have showed significant suppression of bacterial spot symptoms in pepper plants by the produced biocontrol agent, as well as reduction of disease spreading on the healthy (uninoculated) pepper leaves. Furthermore, HPLC-MS (high pressure liquid chromatography–mass spectrometry) analysis was employed to examine antimicrobial metabolites produced by B. velezensis IP22, where lipopeptides were found with similar m/z values compared to lipopeptides from fengycin and locillomycin families. The bioprocess solution developed at the laboratory scale investigated in this study represents a promising strategy for production of pepper bacterial spot biocontrol agent based on B. velezensis IP22, a food isolate with a great perspective for application in plant protection.

Modeling and Optimization of Gas Sparging-Assisted Bacterial Cultivation Broth Microfiltration by Response Surface Methodology and Genetic Algorithm

“…Bacillus velezensis IP22, the strain used as an active component of microbial biopesticide, was isolated from fresh cheese and previously identified using 16S rRNA gene sequencing [ 11 ]. Preparation of inoculum, i.e., a sufficient amount of a liquid pure culture, was performed by transferring Bacillus velezensis IP22 biomass to Erlenmayer flasks containing sterile liquid medium—nutrient broth (HiMedia, Mumbai, India), followed by cultivation on a laboratory shaker at 28 °C, 150 rpm and under spontaneous aeration for 48 h. The obtained inoculum was used to inoculate the medium in the bioreactor (Biostat ® Aplus, Sartorius AG, Göttingen, Germany), while inoculum volume corresponded to 10% ( v / v ) of the bioreactor working volume (2 L).…”

“…Bacillus velezensis has been investigated in biological control of different plant diseases considering the ability of Bacillus velezensis strains to produce antimicrobial compounds and express mechanisms related to plant growth promotion [ 9 , 10 ]. Bacillus velezensis IP22 is a novel biocontrol agent, which expresses several mechanisms of antimicrobial action against plant pathogens, including competition for growth space and nutrients, as well as production of lipopeptides [ 11 , 12 ]. Sustainable, environment-friendly, and cost-effective production of biopesticides significantly depends on the method of cultivation broth downstream processing [ 13 ].…”

Draft Genome Sequence of Bacillus velezensis Strain Marseille-Q1230, Isolated from a Stool Sample from a Severely Malnourished Child

“… Bacillus velezensis was first isolated by Ruiz-García et al from the Vélez River in Malaga, Spain ( 2 ), and possesses bactericidal ( 3 , 4 ) and fungicidal ( 5 ) abilities, thus promoting plant growth and controlling wheat diseases ( 6 ). No previous studies have reported its presence in the human microbiome, as this species has been isolated only from plants or environmental samples ( 7 , 8 ). Here, we present the genome sequence of a B. velezensis strain that was isolated from a human sample collected as part of a childhood malnutrition study in Mali; the study was approved by the Malian ethical committee (approval number 2014/46/CE/FMPOS).…”

Dynamic Modeling Using Artificial Neural Network of Bacillus Velezensis Broth Cross-Flow Microfiltration Enhanced by Air-Sparging and Turbulence Promoter

“…Relative importance of the input variables effect to permeate flux, as the output variable, was calculated using Garson's equation (Equation (6)…”

“…Bacillus velezensis, a species of the genus Bacillus [1], has been extensively studied in recent years due to its remarkable biocontrol qualities against different plant pathogenic bacteria and fungi [2]. Besides an ability to produce large number of metabolites responsible for its antibacterial and antifungal activity, such as lipopeptides [3], enzymes [4] and volatile organic compounds [5], biomass of Bacillus velezensis could also be successfully utilized as a biocontrol agent [6,7]. Since multiplication of bacterial biomass is predominantly performed in a liquid culture, separation of bacterial biomass from the cultivation broth is of a great importance.…”