Characterization and genomic profiling of Klebsiella pneumoniae 2e, a newly isolated 1,3-propanediol-producing strain, revealed its adaptability to crude glycerol.

In this study, Klebsiella pneumoniae 2e was newly isolated for the conversion of crude glycerol into 1,3-PDO. Batch fermentation analysis confirmed that crude glycerol and its main impurities had slight impacts on the growth, key enzyme activity and 1,3-PDO production of K. pneumoniae 2e. The 1,3-PDO yield from crude glycerol by K. pneumoniae 2e reached 0.62 mol1,3-PDO/molglycerol, which was higher than that of most reported 1,3-PDO-producing Klebsiella strains. Genomic profiling revealed that K. pneumoniae 2e possesses 30 genes involved in glycerol anaerobic metabolism and 1,3-PDO biosynthesis. Quantitative real-time PCR analysis of these genes showed that the majority of the genes encoding the key enzymes for glycerol metabolism and 1,3-PDO biosynthesis were significantly up-regulated during culture in crude glycerol relative to pure glycerol. Further comparative genomic analysis revealed a higher number of stress response proteins and a novel glycerol uptake facilitator protein in K. pneumoniae 2e compared to other Klebsiella strains. This work confirms the adaptability of a newly isolated 1,3-PDO-producing strain, K. pneumoniae 2e, to crude glycerol and provide insights into the molecular mechanisms involved in its crude glycerol tolerance, which is valuable for industrial 1,3-PDO production from crude glycerol.IMPORTANCE The rapid development of biodiesel industry leads to tremendous of crude glycerol generation. Due to the presence of complex impurities, crude glycerol ...
Source: Applied and Environmental Microbiology - Category: Microbiology Authors: Tags: Appl Environ Microbiol Source Type: research