Reprogramming a Hgt-family Kluyveromyces marxianus sugar transporter by site-directed mutagenesis to enable co-consumption of glucose and xylose.

Engineering a Kluyveromyces marxianus sugar transporter enabled co-consumption of glucose and xylose, reducing glucose affinity by 20-fold and increasing xylose affinity threefold.

• Why it matters: Efficient utilization of lignocellulosic hydrolysates in biorefineries depends on simultaneous sugar consumption, but native transporters favor glucose, causing inefficient xylose use and diauxic growth.
• What they did: Researchers characterized native xylose transporters and used structural modelling to create a mutant transporter (N325V) that altered sugar affinity, then expressed it in yeast strains to test co-consumption.
• The result: The engineered transporter allowed yeast to consume ~90% of xylose within 45 hours in bioreactors, enabling simultaneous sugar uptake and increased biomass, advancing biofuel production strategies.