Engineering a modular pectin-to-lipids bioconversion system using two Kluyveromyces marxianus strains

Pectin production by processing renewable feedstocks is an appealing and sustainable approach. However, microbial valorization of pectin remains underdeveloped and necessitates efficient expression of key enzymes. In this study, we developed a novel two-stage microbial consortium for pectin valorization through modular utilization of engineered Kluyveromyces marxianus strains. CRISPR-mediated integration of PGU1 in strain YKM1013 significantly increased endoPG production, enabling efficient pectin hydrolysis and achieving a 65% improvement in hydrolysis degree. Meanwhile, strain YKM1015, engineered with a synthetic D-galacturonic acid (D-galUA) metabolic pathway, demonstrated efficient utilization of available D-galUA components. The established bioprocess achieved remarkable lipids productivity, yielding 19-fold and 6-fold increases in medium-chain fatty acid (MCFA) and long-chain fatty acid (LCFA) production, respectively, thereby establishing the microbial platform for direct pectin-to-lipids bioconversion. Collectively, these advances provided a feasible bioconversion route for valorizing pectin-rich biomass into high-value chemicals via microbial cell factory platform construction.