Electronic Journal of Biotechnology ISSN: 0717-3458
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Vol. 6 No. 2, Issue of August 15, 2003 |
© 2003 by Pontificia Universidad Católica
de Valparaíso -- Chile |
Received November 13, 2002 / Accepted April 25, 2003 |
Biotransformation of (L)-citronellal to (L)-citronellol by free
and immobilized Rhodotorula minuta
Harshad
Ravindra Velankar*
The
Kelkar Education Trust's Scientific Research Center
Mithagar Road, Mulund (E) Mumbai-400081, India
Tel: 91 22 5900392/93
Fax: 91 22 5647334
E-mail: hvela2000@yahoo.com
Mohan
Ram Heble
The
Kelkar Education Trust's Scientific Research Center
Mithagar Road, Mulund (E) Mumbai-400081, India
Tel: 91 22 5900392/93
Fax: 91 22 5647334
E-mail: kelkar_src@vsnl.net
*
Corresponding author
Keywords: alginate
immobilization, bioconversion, monoterpene, yeast.
This
paper reports biotransformation of (L)-citronellal to (L)-citronellol
using free and immobilized cells of Rhodotorula minuta. The
culture preparation variables such as pH, temperature
and incubation period for obtaining maximum cell growth of R. minuta
were optimized. The optimized culture conditions for
free and immobilized cells of R. minuta. have
been compared for (L)-citronellal biotransformation.
The various factors such as the optimum substrate concentration
and the time of substrate addition at varying cell concentrations
during the growth of yeast culture were also
studied. Highest (L)-citronellol concentration of 3.5 gl-1
was obtained with free cell catalyzed biotransformation at pH 5.5,
27ºC and 150 rpm after 8 hrs using initial (L)-citronellal concentration
of 4.47 gl-1. Alginate immobilized R. minuta cells
could optimally biotransform similar substrate concentration to 3.3
gl-1 (L)-citronellol at pH 6, 27ºC and 150 rpm after 8
hrs. Immobilized cells could be reused twice after the first run and
the product concentrations of 2.63 gl-1 and 1.52 gl-1
were obtained during the first and the second reuse.
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