Biodegradation of cyanide in cassava wastewater using a novel thermodynamically-stable immobilized rhodanese
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Date
2020-11-18
Journal Title
Journal ISSN
Volume Title
Publisher
Taylor and Francis Online
Abstract
Extracellular rhodanese obtained from Aureobasidium pullulans was employed in both free and
immobilized forms for the biodegradation of cyanide present in cassava processing mill effluent
(CPME). Crosslinking with glutaraldehyde (at an optimum concentration of 5% v/v) before entrapment
in alginate beads resulted in the highest immobilization yield of 94.5% and reduced enzyme
leakage of 1.8%. Rhodanese immobilized by cross-linking before entrapment (cbe) retained about
46% of its initial activity after eight cycles of catalysis compared to the entrapment in alginate
alone (eaa) which lost more than 79% after the fifth catalytic cycle. A cross-examination of
thermodynamic (DG
d, DS
d, DH
d) kinetic (kd, t1=2, D and z values) parameters at 30–70 C
showed that cbe displayed a higher resistance to thermal inactivation when compared to the free
enzyme (fe) and (eaa). The efficiency of cyanide biodegradation from the CPME by the fe, eaa and
cbe were 55, 62, and 74% respectively after 6 h. Biodegradation of cyanide using the cbe was
monitored using FTIR spectroscopy. Rhodanese immobilized via cbe had a higher resistance to
thermal denaturation over other enzyme forms. Hence, this makes cbe adaptable for large-scale
detoxification of cyanide from CPME.
Description
Staff Publication
Keywords
Aureobasidium pullulans;, immobilization;, kinetics;, rhodanese;, thermodynamics
Citation
Adedeji Nelson Ademakinwa , Mayowa Oladele Agunbiade & Oladapo Fagbohun (2020): Biodegradation of cyanide in cassava wastewater using a novel thermodynamically-stable immobilized rhodanese, Preparative Biochemistry & Biotechnology, DOI: 10.1080/10826068.2020.1846053