Comparison of Two Natural 1,3-Propanediol Producers in Regards to the Effect of Glucose Usage as a Co-substrate

WOS: 000358302100011Biodiesel production, in which glycerol is produced as a by-product, has increased significantly and now vast amounts of glycerol have been considered as a waste product. Biotechnological conversion of glycerol into a valuable bioplastic raw material, namely, 1,3-propanediol (1,3-PDO) seems to be very promising. In this study, locally isolated Klebsiella pneumoniae and Clostridium beijerinckii NRRL B593 were comparatively studied for their 1,3-PDO production potential with the addition of different concentrations of glucose together with glycerol. Addition of a co-substrate enhanced the molar yields of 1,3-PDO by 11% only for K. pneumoniae with an addition of 1 g/L of glucose.TUBITAK-CAYDAGTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [109Y150]; EBILTEMEge University [2008BIL032]The authors gratefully acknowledge TUBITAK-CAYDAG (Grant No. 109Y150) and EBILTEM (Grant No. 2008BIL032) for the support. The data presented in this article were produced within the projects above; however, it is only the authors of this article who are responsible for the results and discussions made herein

Reduced catabolic protein expression in Clostridium butyricum DSM 10702 correlate with reduced 1,3-propanediol synthesis at high glycerol loading

WOS: 000358064700001PubMed ID: 25401066Higher initial glycerol loadings (620 mM) have a negative effect on growth and 1,3-propanediol (1,3-PDO) synthesis in Clostridium butyricum DSM 10702 relative to lower initial glycerol concentrations (170 mM). To help understand metabolic shifts associated with elevated glycerol, protein expression levels were quantified by LC/MS/MS analyses. Thirty one (31) proteins involved in conversion of glycerol to 1,3-PDO and other by-products were analyzed by multiple reaction monitoring (MRM). The analyses revealed that high glycerol concentrations reduced cell growth. The expression levels of most proteins in glycerol catabolism pathways were down-regulated, consistent with the slower growth rates observed. However, at high initial glycerol concentrations, some of the proteins involved in the butyrate synthesis pathways such as a putative ethanol dehydrogenase (CBY_3753) and a 3-hydroxybutyryl-CoA dehydrogenase (CBY_3045) were up-regulated in both exponential and stationary growth phases. Expression levels of proteins (CBY_0500, CBY_0501 and CBY_0502) involved in the reductive pathway of glycerol to 1,3-PDO were consistent with glycerol consumption and product concentrations observed during fermentation at both glycerol concentrations, and the molar yields of 1,3-PDO were similar in both cultures. This is the first report that correlates expression levels of glycerol catabolism enzymes with synthesis of 1,3-PDO in C. butyricum. The results revealed that significant differences in the expression of a small subset of proteins were observed between exponential and stationary growth phases at both low and high glycerol concentrations.Scientific And Technological Research Council Of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [BIDEB 2214]; Scientific And Technological Research Council Of Turkey (CAYDAG Project)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [109Y150]; Genome CanadaGenome Canada; Province of ManitobaThe authors would like to acknowledge Prof. Dr. Nuri Azbar for his valuable contribution and insightful discussions. The authors would like to thank Dr. Graham Alvare for his technical assistance with bioinformatics. This work was funded by The Scientific And Technological Research Council Of Turkey (TUBITAK, BIDEB 2214 and CAYDAG Project No: 109Y150), by Genome Canada, through the Applied Genomics Research in Bioproducts or Crops (ABC) program for the grant titled, "Microbial Genomics for Biofuels and CoProducts from Biorefining Processes", and by the Province of Manitoba, through the Manitoba Research Innovation Fund (MRIF)