In the present study, benzaldehyde was converted by both the free cells Saccharomyces cerevisiae (ATCC 834) and those immobilized in the calcium alginate liquid-core capsule into L-PAC during anaerobic fermentation in a medium containing benzaldehyde. In a free cells survey, skipping aerobic adaptation before anaerobic fermentation caused all of benzaldehyde to be converted by 220 g (wet weight) of cells in 100 mL of the medium even at a higher concentration of 8 g/L benzaldehyde. The yield of L-PAC based on the moles of converted benzaldehyde increased as the amount of benzaldehyde dose was increased. The encapsulation protected cells effectively from the toxicity of benzaldehyde. Even a small quantity, 1.1 g (dry weight), of encapsulated cells in 100 mL of the medium containing 0.6% benzaldehyde converted more than 95% of the benzaldehyde, and the corresponding yield of L-PAC was about 40%. The production of L-PAC by the encapsulated cells depended on the pH of the medium. The conversion of benzaldehyde decreased slightly, but yield of L-PAC increased as the pH of the broth solution was fixed at a lower value. Biotransformation in a small side reactor of the batch system caused higher yield of L-PAC than that in the batch reactor containing the same quantity of encapsulated cells during the first 4 hours of fermentation.

L-phenylacetylcarbinol L-PAC Benzaldehyde Saccharomyces cerevisiae

Agarwal SC, Basu SK, Vora VV, Mason JR, Pirt SJ, Biotechnol. Bioeng., 29, 783 (1987) 
Astrup A, Breum L, Toubro S, Hein P, Quaade F, J. Obesity, 16, 269 (1992)
Astrup A, Buemann B, Christensen NJ, Toubro S, Thoeb G, Victor OJ, Quaade F, Metabolism, 41, 686 (1992) 
Buchholz K, "Characterization of Immobilized Biocatalsis. In: Dechema Monographs," Verlag Chmie, Veinheim, 84 (1979)
Chang HN, Seong GH, Yoo IK, Park JK, Seo JH, Biotechnol. Bioeng., 51(2), 157 (1996) 
Chang HN, Seong GH, Yoo IK, Park JK, Seo JH, "Method for Immobilization of Whole Microbial Cells in Calcium Alginate Capsules," US Patent, 5766907 (1998)
Cheong SH, Park JK, Chang HN, HWAHAK KONGHAK, 31(6), 788 (1993)
Cheong SH, Park JK, Kim BS, Chang HN, Biotechnol. Tech., 7, 879 (1993) 
Culic J, Netrval J, Ulbrecht S, Souhrada J, Vojtisek V, Vodnansky M, "Method of the Cost Production in the Production of D(-)-1-phenyl-1-phenyl-1-hydroxy-2-propanone for the preparation of L-(-)ephedrine," Czech Patent, 222941 (1984)
Kurosawa H, Nomura N, Tanaka H, Biotechnol. Bioeng., 33, 716 (1989) 
Lee JW, Yoo YJ, Korean J. Chem. Eng., 11(2), 119 (1994)
Long A, Ward OP, Biotechnol. Bioeng., 34, 933 (1989) 
Mahmoud WM, El-Sayed AMM, Coughlin RW, Biotechnol. Bioeng., 36, 47 (1990) 
Mahmoud WM, El-Sayed AMM, Coughlin RW, Biotechnol. Bioeng., 36, 55 (1990) 
Neuberg C, Lieberman L, Biochem. Z., 121, 311 (1921)
Nikolova P, Ward OP, Biotechnol. Lett., 16(1), 7 (1994) 
Oh CY, Park JK, Bioprocess Eng., 19, 419 (1998)
Rogers PL, Shin HS, Wang B, Adv. Biochem. Eng. Biotechnol., 56, 33 (1997)
Seely RJ, Hageman RV, Yarus MJ, Sullivan SA, "Process for Producing L-PAC. An Immobilized Cell Mass for Us in the Process and Method for Preparing Cell Mass," US Patent, 89, 64421 (1989)
Tripathi CKM, Basu SK, Vara VC, Mason JR, Pirt SJ, Biotechnol. Lett., 10, 635 (1988) 
Vojtisek V, Netrval J, Folia Microbiol., 27, 173 (1982)
Wang B, Shin HS, Rogers PL, "Microbial and Enzymatic Biotransformation of Benzaldehyde to L-Phenylacetylcarbinol(L-PAC). In: Better Living through Innovative Biochemical Engineering," Continental Press, Singapore (1994)
Yeom SH, Yoo YJ, Korean J. Chem. Eng., 14(3), 204 (1997)