Scale up of biopolymer (PHB) fermentation from 500Ml shake flasks to 2L stirred tank fermentor

• Main Author: Aimi Salma, Awalludin
• Format: Undergraduates Project Papers
• Language: English
• Published: 2009
• Subjects: TP Chemical technology
• Online Access: http://umpir.ump.edu.my/id/eprint/696/1/Aimi_Salma_Awalludin.pdf; http://umpir.ump.edu.my/id/eprint/696/
• Institution: Universiti Malaysia Pahang

This study is about the scale up of biopolymer fermentation from 500 mL shake flasks to 2L fermentor. The purpose of this project is to determine air flow rate at 2L fermentor which gives the same kLa and kap as produced in shake flasks. The rationale of using the kLa value is to ensure a certain mass transfer capability in order to cope with the oxygen demand of the culture, thus being an important scale-up factor. Both values were derived by fitting the dissolved oxygen tension (DOT) versus time data into The Fibonacci Min Search (Fminsearch) method. Two values, which are 0.2960 for volumetric mass transfer coefficient for oxygen (kLa) and 0.0220 for the electrode mass transfer coefficient (kap) were obtained at small scale. These values are required to be duplicated in the larger scale. It was done by using a fixed agitation rate of 200 rpm and a manipulated aeration rate which is 1L/min,1.5L/min,2L/min and 1.75L/min. The most comparable kLa and kap values obtained from the trial are at 1.75L/min. This aeration rate will be used in the 2L fermentor in order to investigate the production of poly-β-hydroxybutyrate (PHB). Fermentation is run at both scales to compare the glucose, biomass and PHB profile. From the experiment and calculation, the maximum concentration of PHB is achieve at the 36th hours, which is 1.415g/L for 500 mL shake flasks, and 2.17g/L for 2L fermentor. The cell dry mass obtained at the optimum harvesting time is 6.065 g/L for both scales.-Author-