title: Use of ceramic-based cell immobilization to produce 1,3-propanediol from biodiesel-derived waste glycerol with Klebsiella pneumoniae.
abstract: OBJECTIVE
  The feasibility of the continuous production of a valuable bioplastic raw material, namely 1,3-propanediol (1,3-PDO) from biodiesel by-product glycerol, using immobilized cells was investigated. In addition, the effect of hydraulic retention time (HRT) was also analysed.
  
  
  RESULTS
  Ceramic balls and ceramic rings were used for the immobilization of a locally isolated strain; Klebsiella pneumoniae (GenBank no. 27F HM063413). HRT of 1 h is the best one in terms of volumetric production rate (g 1,3-PDO l(-1) h(-1)). The results indicated that ceramic-based cell immobilization achieved a 2-fold higher production rate (10 g 1,3-PDO l(-1) h(-1)) in comparison with suspended cell system (4·9 g 1,3-PDO l(-1) h(-1)).
  
  
  CONCLUSIONS
  Continuous cultures with immobilized cells revealed that 1,3-PDO production was more effective and more stable than suspended culture systems. Furthermore, cell immobilization had also obvious benefits especially for resistance of the production for extreme conditions (high organic loading rates, cell washouts). The results were important for understanding the significance of continuous immobilization process among other well-known 1,3-PDO fermentation processes.
  
  
  CONCLUSIONS
  This work is a promising process for further studies, as the immobilized micro-organism was able to reach high volumetric production rates at short HRT, it has an important role in tolerating and converting glycerol during fermentation. Therefore, HRT is a very significant operational parameter (P value <0·05) directly affecting the bioreactor performance and production rate.
authors: Department of Bioengineering, Faculty of Engineering, Ege University, Bornova, Izmir, Turkey.
authors: M
authors: M
authors: Gungormusler
authors: C
authors: C
authors: Gonen
authors: N
authors: N
authors: Azbar
mesh_terms: D056804:Biofuels; D019149:Bioreactors; D018914:Cells, Immobilized; D002516:Ceramics; D005285:Fermentation; D005990:Glycerol / Q000378:metabolism*; D007218:Industrial Microbiology; D007711:Klebsiella pneumoniae / Q000378:metabolism*; D011409:Propylene Glycols / Q000378:metabolism*
chemical_list: D056804:Biofuels; D011409:Propylene Glycols; C041787:1,3-propanediol; D005990:Glycerol