MIT researchers have engineered living bacterial circuits that function as biological transistors and logic gates, capable of performing computation on growth media. By modifying Pantoea agglomerans bacteria with 5 strains (2 transistor types + 3 relay types), they created self-growing circuit boards that process logic operations and signal routing—demonstrated through adders and demultiplexers with 24-colony networks. While proof-of-concept shows promise for future agricultural sensors, the 8-hour processing time and lab-scale limitations mean practical SME applications are still distant.