Influence of selected physical parameters on the biodegradation of acrylamide by immobilized cells of Rhodococcus sp.

Citation
Ms. Nawaz et al., Influence of selected physical parameters on the biodegradation of acrylamide by immobilized cells of Rhodococcus sp., BIODEGRADAT, 9(5), 1998, pp. 381-387
Citations number
22
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biotecnology & Applied Microbiology
Journal title
BIODEGRADATION
ISSN journal
0923-9820 → ACNP
Volume
9
Issue
5
Year of publication
1998
Pages
381 - 387
Database
ISI
SICI code
0923-9820(1998)9:5<381:IOSPPO>2.0.ZU;2-5
Abstract
The influences of concentration of acrylamide, pH, temperature, duration of storage of encapsulated cells and presence of different metals and chelato rs on the ability of immobilized cells of a Rhodococcus sp, to degrade acry lamide were evaluated. Immobilized cells (3 g) rapidly degraded 64 and 128 mM acrylamide in 3 and 5 h, respectively, whereas free cells took more than 24 h to degrade 64 mM acrylamide. An acrylamide concentration of 128 mM in hibited the growth of the free cells. Immobilized bacteria were slow to deg rade acrylamide at 10 degrees C. Less than 60% of acrylamide was degraded i n 4 h. However, 100% of the compound was degraded in less than 3 h at 28 de grees C and 45 degrees C. The optimum pH for the degradation of acrylamide by encapsulated cells was pH 7.0. Less than 10% of acrylamide was degraded at pH 6.0, while ca. 60% of acrylamide was degraded at pH 8.0 and 8.5. Copp er and nickel inhibited the degradation, suggesting the presence of sulfhyd ryl (-SH) groups in the active sites of the acrylamide degrading amidase. T ron enhanced the rates of degradation and chelators (EDTA and 1,10 phenanth roline) reduced the rates of degradation suggesting the involvement of iron in its active site(s) of the acrylamide-degrading-amidase. Immobilized cel ls could be stored up to Iq days without any detectable loss of acrylamide- degrading activity.