Current analysis on 1,3-propanediol production from glycerol via pure wild strain fermentation

Bioproduction of 1,3-propanediol (1,3-PDO), a ubiquitous green chemical, has received great attention due to its wide range of applications, coupled with the abundance of crude glycerol from biodiesel industry. To commercialize this product, the bottlenecks of low yield and productivity of 1,3-PDO should be addressed. Herein, the present review carefully analyses the state-of-the-art performance of a myriad of wild-type 1,3-PDO-producing genera over the past decade. The effects of fermentation modes, aeration conditions, substrate tolerance ability, and extent of metabolite inhibition on the synthesis of 1,3-PDO by different bacterial strains are discussed comprehensively to realize the efficient utilization of the industrial wastes in harvesting the high valued chemical commodity. Among the various cultivation method, continuous mode fermentation possesses certain robustness over the others in terms of yield and productivity. Strict anaerobes are regarded as the best microbe than other aerotolerant anaerobes and facultative anaerobes because of the outstanding fermentation performance at anaerobic conditions. The responses of various microbes to high initial substrate and impurities in crude glycerol have concluded that the discovery of osmotolerant microbe is crucial. Moreover, the 1,3-PDO-producing bacteria with minimum generation of byproducts along with appreciable tolerance towards the metabolites is a determining factor of commercializing 1,3-PDO bioproduction.