Low-cost production of 6G-fructofuranosidase with high value-added astaxanthin by Xanthophyllomyces dendrorhous

► The production of 6G-FFase with value-added astaxanthin was examined. ► Using CSL as nitrogen source significantly reduced the production cost of 6G-FFase. ► The yield of 6G-FFase and the productivity of neo-FOS were relatively high. ► The medium cost reduced 66.3% compared with that before optimization. ► This medium could make the neo-FOS production process waste-free.