Streptomyces strains producing mitochondriotoxic antimycin A found in cereal grains

Abstract

Reasons for mammalian cell toxicity observed in barley and spring wheat grains were sought. Streptomyces sp. isolates from wheat and barley produced heat-stable methanol-soluble substances which inhibited the motility of exposed porcine spermatozoa used as a toxicity indicator. Several barley isolates produced antimycin A (2 to 5 ng/mg wet wt of biomass), a macrolide antibiotic known to block oxygen utilization in mitochondria. The antimycin-producing isolates were members of the Streptomyces albidoflavus group. In in vitro assays with porcine kidney tubular epithelial cells, the specific toxicity of antimycin A towards mitochondria was higher than that of the mycotoxin enniatin B but lower than that of the mitochondriotoxins cereulide and paenilide, produced by food-related Bacillus cereus and Paenibacillus tundrae, respectively. The toxic wheat isolates, related to Streptomyces sedi, did not produce antimycin A and or any other known toxin. Our results suggest that the presence of toxin-producing streptomycetes in stored cereal grains may pose a thus far unrecognized threat for food and feed safety.

The Toxicity of Wiped Dust and Airborne Microbes in Individual Classrooms Increase the Risk of Teachers’ Work-Related Symptoms: A Cross-Sectional Study

“…Transient receptor potential (TRP) channels in the chemosensory trigeminal C-fibers innervating the nasal cavity, throat, and conjunctiva and in the vagal C-fibers innervating the lower respiratory tract can sense irritating and toxic chemicals [87,88]. The sperm-toxic microbial toxin antimycin A has been shown to cause mitochondrial dysfunction, mtROS production, and C-fiber activation via TRP channels in experimental mice models [89][90][91]. When exposed to mtROS-even non-toxic concentrations of chemicals, LPS, or inflammatory mediatorsthis chemosensory system can induce neurogenic inflammation via neuropeptide secretion and mast cell degranulation [90,[92][93][94][95][96][97][98].…”

Cloning and Expression of the Chitinase Encoded by ChiKJ406136 from Streptomyces Sampsonii (Millard & Burr) Waksman KJ40 and Its Antifungal Effect

“…In the purified components, soil isolates of S. sampsonii can produce heptaene polyene antibiotics [18,27], In addition, S. sampsonii has been shown to produce hydrolytic enzymes, such as amylase, chitinase, protease, and lipase [19]. Studies at the molecular level have focused on strain identification and the phylogenesis of related species [28][29][30][31][32][33][34][35]. The complete genome sequence of Streptomyces sampsonii KJ40 was recently described by our lab [36], resulting in the discovery of a large number of gene encoding chitinases and enzymes involved in secondary metabolite production.…”

Current and Future Technologies for Microbiological Decontamination of Cereal Grains

“…Numerous bacteria belonging to Streptomyces genus were recently found on barley and spring wheat grains. The authors also reported the presence of antimycin A toxin‐producing strains in barley, which is the first report of antimycin A in a food substance (Rasimus‐sahari, Mikkola, Andersson, Jestoi, & Salkinoja‐salonen, ).…”