Psychrophiles as a source of novel antimicrobials

Abstract

Cold environments such as Arctic and Antarctic regions and the deep sea are richly populated by microbes which encounter the same selective pressures and/or even more than their counterparts from moderate or warm environments. Microbes from moderate and warm environments have been extensively studied for their ability to produce antimicrobial compounds, and new results are scarce. Taking into account the rapid emergence of antimicrobial resistance, we need to look for new sources of antimicrobials. Here in this review, we summarise the knowledge of new antimicrobials or antimicrobial activity from microorganisms from different cold environments to date. A special focus due to their richness in bioactive compounds is given to marine environments; nonetheless, compounds from other sources are mentioned. The later-described compounds all display some kind of beneficial antimicrobial activity and are part of many different chemical classes of antimicrobial compounds (lantibiotics, spirotetronates, microcins, synoxazolidinones, indole alkaloids, monanchocidins, etc.). Furthermore, studies which identified antimicrobial producers but did not identify the actual produced compound are mentioned, and promising sources for future bioprospecting are discussed.