Abstract: This disclosure is in the technical field of synthetic biology and metabolic engineering. The disclosure provides engineered viable bacteria having a reduced or abolished synthesis of poly-N-acetyl-glucosamine (PNAG), Enterobacterial Common Antigen (ECA), cellulose, colanic acid, core oligosaccharides, Osmoregulated Periplasmic Glucans and Glucosylglycerol (O), glycan, and trebalose. The disclosure further provides methods for the production of bioproduct by the viable bacteria and uses thereof. Furthermore, the disclosure is in the technical field of fermentation of metabolically engineered microorganisms producing bioproduct.