Modified microassay for the isolation of antimicrobial-producing, spore-forming and nonspore-forming bacteria

Abstract

Antimicrobials are needed to combat antibiotic- and preservative-resistant bacteria. Spore-forming bacteria are prolific producers of antimicrobials. This assay will speed the discovery of antimicrobials from spore-forming bacteria; these new antimicrobials are urgently needed in food and medicinal applications.

Enhancing titre and production stability of paenibacillin from Paenibacillus polymyxa by sequential drug resistance screening

“…After incubation, most cells and spores in the culture were removed by centrifugation at 10 000 g for 7 min. The supernatant was not microfiltered to avoid non‐specific binding between the antimicrobial agent and the filter material (Gerst and Yousef 2018). The remaining cells or spores were eliminated by a lysozyme and heat treatment as summarized later.…”

“…The supernatant was assayed for antimicrobial production in duplicates. The antimicrobial activity of supernatants was measured by a high throughput method as described previously (Gerst and Yousef 2018) with modifications. Briefly, the cell‐free supernatants from each mutant and its two‐fold serial dilutions (150 µl, each) were dispensed into wells of a 96‐well microtitre plate (Corning Incorporated, Corning, NY).…”

Detection and characterization of a rare two‐component lantibiotic, amyloliquecidin GF610 produced by Bacillus velezensis , using a combination of culture, molecular and bioinformatic analyses

“…Although the amyloliquecidin gene cluster is present in the genomes of three different Bacillus spp., the occurrence of the gene cluster among published Bacillus genomes is rare (5% of closest matching genetic sequences). This rarity supports the merits of using the culture-based screening microassay (Gerst & Yousef, 2018) and high-throughput assays to identify bacteria producing uncommon antimicrobials.…”

Draft Genome Sequence of Bacillus velezensis OSY-GA1, Which Encodes Multiple Antimicrobial Metabolites and Expresses Antimicrobial Activity against Foodborne Pathogens

“…produce numerous antimicrobial metabolites (1), some of which are potentially useful in combating preservative-resistant foodborne pathogens. The current work covers B. velezensis OSY-GA1, a bacterium isolated from soil that produces antimicrobials against Escherichia coli and Listeria innocua (2); in the original work, the isolate was designated 8F2 but was renamed OSY-GA1 in the current study. Additionally, B. velezensis OSY-GA1 was found to be antagonistic against L.…”