Starving bacteria can hook onto other bacterial species to share their nutrients.

Marie-Thérèse Giudici-Orticoni of Aix-Marseille University, France, and her colleagues cultured Clostridium acetobutylicum, which uses glucose to grow, and Desulfovibrio vulgaris, which uses lactate and sulfate, in a medium containing only glucose. Desulfovibrio vulgaris attached itself to C. acetobutylicum, allowing it to share the other bacterium's cytoplasm and proteins. This altered the metabolism of D. vulgaris, allowing it to grow with only glucose.

In a separate study, Christian Kost of the Max Planck Institute for Chemical Ecology in Jena, Germany, and his colleagues mutated Escherichia coli and Acinetobacter baylyi so that they could not produce certain essential amino acids. When grown in a medium lacking the amino acid it required, E. coli formed nanotubes up to 14 micrometres long to connect with and share the cytoplasm of nearby A. baylyi, which was producing the amino acid. In return, E. coli provided A. baylyi with the amino acid it needed. These bacteria function as interconnected entities rather than individuals, the authors suggest.

Nature Commun. 6, 6283; 6238 (2015)