METHODS FOR PRODUCING ISOPRENE AND BY-PRODUCT

摘要

PROBLEM TO BE SOLVED: To provide methods for producing isoprene and a by-product such as ethanol, 1,3-propanediol or hydrogen by using cultured cells.SOLUTION: The invention provides a recombinant host cell comprising: (a) a heterologous nucleic acid encoding an isoprene synthase polypeptide; (b) a nucleic acid encoding an isopentenyl-diphosphate delta-isomerase (IDI) polypeptide; (c) a nucleic acid encoding 1-deoxyxylulose-5-phosphate synthase (DXS) polypeptide and/or one or more polypeptides of mevalonate (MVA) pathway; and (d) a heterologous nucleic acid encoding one or more polypeptides participating in ethanol fermentation, wherein the cell simultaneously generates isoprene and ethanol under such oxygen-limited culture conditions that the oxygen transfer rate (OTR) is less than the oxygen uptake rate (OUR). Also provided is a method for obtaining isoprene and by-products by culturing the cell under anaerobic (low oxygen) conditions.