Production of Phenylacetylcarbinol in a Stand Still Condition Using Two Phase System by Applying Yeast Cells Capable of Fermenting Dried Ephedra Extract and Molass as Biocatalysts

Abstract

Microbial Biotransformation of benzaldehyde to L Phenylacetylcarbinol (L-PAC) as a key intermediate for L-ephedrine synthesis has been evaluated using immobilized Hansenula polymorpha. The cultivation of 10 ml Hansenula anomala inoculum for 48 h in the cultivation medium with glucose as a sole carbon source resulted in the highest ethanol concentration of 10.6 ± 0.53 g/l. This was followed by Hansenula polymorpha (4.06 ± 0.20 g/l) and Brettanomyces lambicus (2.94 ± 0.15 g/l), respectively. The cultivation using 100 ml dried Ephedra  extract and molass in 1:1 ratio as a sole carbon source showed that microbes with ability to consume glucose, fructose and sucrose released high level of ethanol (g/l) included Hansenula polymorpha (43.4 ± 4.0), (41.8 ± 1.2) and Hansenula anomala (38.1 ± 2.5). A biotransformation experiment was conducted using wet biomass of 3.06 g/l dry biomass equivalent from the medium with dried Ephedra extract and molass in 1:1 ratio as carbon source. After the two phase system was stood aside for 24 h, Hansenula polymorpha generated an overall R-phenylacetylcarbinol (PAC) concentration of 3.97 and 3.72 mM at 4 ^OC and 35^OC which was followed by Hansenula polymorpha (3.04 and 3.73 mM), Brettanomyces lambicus (1.24 and 2.98 mM) as well as Hansenula anomala (0.86 and 0.07 mM).