Bioprospecting for antimicrobials at the end of the world

DELGADO O.D.; SANCHEZ L. A

Helsinor

Congreso; Microbial secondary metabolites in microbiomes 2019; 2019

Center for Microbial Secundary Metabolites; Danish National Research Foundation

Research and development of novel antimicrobial compounds are a worldwide priority owing to several factors such as increasing resistance in bacterial pathogens, caused by inappropriate use of antibiotics; the emergence of new pathogens and the shortage of pharmaceutical companies involved in drug discovery. Also, resistant bacteria such as methicillin-resistant Staphylococcus aureus, penicillin-resistant Streptococcus pneumoniae, and beta-lactam-resistant Pseudomonas aeruginosa causes high mortality rates and economic losses in health institutions. Cold environments are a suitable source of microorganisms with the ability to produce cold-active antimicrobial compounds with potential use in biotechnology. Because of their harsh conditions, Argentinean environments such as Patagonia, Sub-Antarctic, and Antarctic regions are valuable sources for microbial bioprospecting and natural compounds discovery. Here some findings are presented on antibacterial and antifungal producer strains isolated during sub-Antarctic and Antarctic campaigns. The isolates were biochemically characterized and molecularly identified as Serratia proteamaculans 136 and 137; Burkholderia gladioli RSZ, Halomonas titanicae and Pseudomonas yamanorum 8H1 sp. nov. The strains showed wide-inhibition spectra against common food-spoilage bacteria and also against pathogenic and phytopathogenic bacteria tested. On the other hand, antifungal activities were also observed by S. proteamaculans 137 and B. gladioli RSZ when they were evaluated against phytopathogenic fungal strains like Penicillium digitatum, Penicillium italicum, Geotrichum sp., Macrophomina phaseolina and Phomopsis citri which are involved in post-harvest fruit diseases, affecting the agronomic industry and significant production losses. This work suggests that the environments exposed to low temperatures represent a valuable source of cold-active antimicrobials for their potential use in the food industry, pharmaceutical or as a biocontrol agent of post-harvest diseases during cold storage in the agriculture industry. However, the purification grade and molecular identification for each antimicrobial compound are different, at the moment and more studies involving, i.e., Mass Spectrometry or NMR structure elucidation are necessary to inquire into their mode of action.