Is essential for L-lactate degradation and allows cells to grow with lactate as the sole carbon source. May also allow cells to utilize an alternative carbon source during biofilm formation, since it contributes to the formation of architecturally complex communities when lactate is present. Is under the dual control of the transcriptional repressors LutR and SinR, which allows the lutABC operon to be induced during both growth in liquid culture and biofilm formation. Is induced by L-lactate, which relieves LutR repression. Cells lacking this gene are unable to grow on minimal medium with L-lactate as the sole carbon source. Cells lacking the lutABC operon exhibit little or no defect in biofilm formation on MSgg medium, but form small colonies that almost completely lacked surface architecture when glycerol is replaced with L-lactate in the MSgg medium. Belongs to the LutC/YkgG family.