Antibiotics from predatory bacteria

Abstract

SummaryBacteria, which prey on other microorganisms, are commonly found in the environment. While some of these organisms act as solitary hunters, others band together in large consortia before they attack their prey. Anecdotal reports suggest that bacteria practicing such a wolfpack strategy utilize antibiotics as predatory weapons. Consistent with this hypothesis, genome sequencing revealed that these micropredators possess impressive capacities for natural product biosynthesis. Here, we will present the results from recent chemical investigations of this bacterial group, compare the biosynthetic potential with that of non-predatory bacteria and discuss the link between predation and secondary metabolism.

A non-canonical peptide synthetase adenylates 3-methyl-2-oxovaleric acid for auriculamide biosynthesis

“…Recently, the dipeptide auriculamide ( 1 , Fig. 1), and the diterpene O -methylkolavelool were observed in cultures of H. aurantiacus 114-95 T , providing initial evidence for the assumed secondary metabolome of this species [4–6]. Within the entire genus, 1 is only the second PKS/NRPS-derived molecule to be described, following the report on siphonazole ( 2 , Fig.…”

Bacillus licheniformis escapes from Myxococcus xanthus predation by deactivating myxovirescin A through enzymatic glucosylation

“…The biological significance of secondary metabolite productions by M. xanthus is to allow for more efficient killing and extracellular digestion of prey into small nutrient molecules (Xiao et al, 2011;Korp et al, 2016). The deletion of M. xanthus genes involved in TA production has been demonstrated to cause a major delay in E. coli killing compared with the wild-type strain (Xiao et al, 2011).…”

“…During the predation, M. xanthus cells employ chemosensory systems and surface motility systems to search for the microbial prey, subsequently killing and consuming prey cells by delivering hydrolytic enzymes and active secondary metabolites mediated by outer membrane vesicles (Evans et al ., ; Keane and Berleman, ; Lloyd and Whitworth, ; Livingstone et al ., ). The large genome of M. xanthus harbours a high number of encoding genes that enable it to produce a wide range of secondary metabolites with many biological activities (Goldman et al ., ; Weissman and Müller, ; Korp et al ., ), among which myxovirescin A (TA, a.k.a. antibiotic TA), myxalamids, cittilin and myxoprincomide have been shown to be involved in the predatory killing of some prey (Berleman et al ., ; Keane and Berleman, ).…”

Is “Wolf‐Pack” Predation by Antimicrobial Bacteria Cooperative? Cell Behaviour and Predatory Mechanisms Indicate Profound Selfishness, Even when Working Alongside Kin

“…and myxobacteria, are able to kill a broad range of prey, including Gram‐negative bacteria, Gram‐positive bacteria, and fungi . Such broad range predation involves the secretion of toxic materials (hydrolytic enzymes and secondary metabolites) into the extracellular milieu, which can, therefore, be considered public goods—a shared resource produced communally . This mechanism of predation is therefore often referred to as “wolf‐pack” predation, as it apparently requires high densities of predatory cells, and is social—i.e., all predators contribute to the same public goods …”

“…[4][5][6] Such broad range predation involves the secretion of toxic materials (hydrolytic enzymes and secondary metabolites) into the extracellular milieu, which can, therefore, be considered public goods-a shared resource produced communally. [7][8][9] This mechanism of predation is therefore often referred to as "wolf-pack" predation, as it apparently requires high densities of predatory cells, and is sociali.e., all predators contribute to the same public goods. [10] Nevertheless, the molecular mechanisms of social predation are relatively poorly understood in myxobacteria and other microbial wolf-pack hunters.…”