Microbiology: Digging for antibiotics

Soil-dwelling bacteria may represent an untapped source of new antibiotics and other pharmaceutical compounds, a study published online in Nature this week suggests.

Jillian Banfield and colleagues decoded the draft genomes of hundreds of uncultivated and largely unstudied micro-organisms from a northern Californian grassland soil ecosystem. They identified more than a thousand biosynthetic gene clusters, inferred to synthesize a range of molecules, including various peptides, anti-bacterial toxins and other metabolites of unclear function. Expression of these genes varied depending on the depth and location of the soil sample taken, suggesting a biological response to varying environmental conditions.

Soil-dwelling microbes are known to produce a variety of useful secondary metabolites, including antibiotics, antifungals and immunosuppressants, yet most of these molecules are derived from just a few cultured microbial groups. This study broadens the range of potential sources, and even highlights two previously unknown bacterial species that have unusually large biosynthetic capabilities. In addition, the work raises the possibility that soil microbes may use this complicated chemical language to communicate with one another.

doi: 10.1038/s41586-018-0207-y

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