Bacterial heterozygosity promotes survival under multidrug selection.

Although bacterial cells typically contain a single chromosome, some species are naturally polyploid and carry multiple copies of their chromosome. Polyploid chromosomes can be identical or heterogeneous, the latter giving rise to bacterial heterozygosity. Although the benefits of heterozygosity are well studied in eukaryotes, its consequences in bacteria are less understood.

Phenotypic heterogeneity in Streptomyces colonies.

Streptomyces are a large genus of multicellular bacteria best known for their prolific production of bioactive natural products. In addition, they play key roles in the mineralisation of insoluble resources, such as chitin and cellulose. Because of their multicellular mode of growth, colonies of interconnected hyphae extend over a large area that may experience different conditions in different parts of the colony.

Ecological drivers of division of labour in Streptomyces.

Division of labour occurs when different individuals, cells or tissues become specialised to perform complementary tasks that benefit the whole organism or social group. Although long studied in multicellular organisms and colonies of social insects, several recent studies have established that division of labour is common in microorganisms. We review recent work on the division of labour in unicellular and multicellular bacteria, with a particular focus on reproductive and metabolic divisions of labour in actinomycetes.