A mutant capable of producing 1,4-butanediol and a method of preparing 1,4-butanediol using the same are provided. The mutant microorganism is prepared by introducing and amplifying genes encoding enzymes converting succinate into 4-hydroxybutyrate and 4-hydroxybutyrate into 1,4-butanediol in a microorganism capable of producing succinate. The method includes culturing the mutant in a medium containing carbohydrate and obtaining 1,4-butanediol from the culture. Thus, 1,4-butanediol, which is essential in chemical industry, can be prepared in a biological process.

A genetically engineered strain of Escherichia coli Nissle 1917 (EcN) with a modified genome designed to enhance the production of short-chain fatty acids (SCFAs) is provided. The engineered genome includes the atoB gene from E. coli K-12, responsible for encoding acetyl-CoA acetyltransferase, a crt-bcd-etfA-etfB-BHBD gene cluster from E. C. butyricum that encodes enzymes involved in the synthesis of SCFAs, specifically enoyl-CoA hydratase, butyryl-CoA dehydrogenase, and electron transfer flavoproteins, and the ptb-buk gene from C. acetobutyricum, which encodes phosphotransbutyrylase and butyrate kinase. Additionally, key genes associated with competing metabolic pathwaysldhA, frdABCD, adhE, ackA, and ptaare deleted to optimize SCFA production, particularly butyrate. This strain is intended for use in therapeutic applications where enhanced SCFA production is beneficial, such as in the treatment of coronary heart disease.