Process-integrated engineered resting cells for biocatalytic production of rare natural sugars from sole methanol molecules.

The biocatalytic conversion of green methanol, a promising feedstock, into high value-added products is seen as an attractive way to establish sustainable biomanufacturing. Although natural and engineered microorganisms can utilize methanol, efficiently converting C1 carbon into valuable chemicals in growing cells remains challenging because non-native pathways often suffer from low carbon utilization and limited catalytic stability. Here, we report the integration of an engineered enzyme cascade into resting cells and its coupling with a screened alcohol oxidase enzyme to develop an efficient and stable enzyme-resting cell cascade system for methanol conversion, achieving customizable production of L-erythrulose (C4 sugar) or L-sorbose (C6 sugar). This system shows a stimulated carbon atom economy for L-erythrulose production from methanol and significantly improved stability compared to free enzyme catalysis. By integrating enzyme cascades with durable resting cells, this strategy provides a versatile platform for converting methanol and other C1 substrates into value-added products.