Immobilization of aPleurotus ostreatusLaccase Mixture on Perlite and Its Application to Dye Decolourisation

Abstract

In the present study, a crude laccase preparation from Pleurotus ostreatus was successfully immobilized on perlite, a cheap porous silica material, and tested for Remazol Brilliant Blue R (RBBR) decolourisation in a fluidized bed recycle reactor. Results showed that RBBR decolourisation is mainly due to enzyme action despite the occurrence of dye adsorption-related enzyme inhibition. Fine tuning of immobilization conditions allowed balancing the immobilization yield and the resulting rate of decolourisation, with the adsorption capacity of the solid biocatalyst. In the continuous lab scale reactor, a maximum conversion degree of 56.1% was achieved at reactor space-time of 4.2 h. Stability and catalytic parameters of the immobilized laccases were also assessed in comparison with the soluble counterparts, revealing an increase in stability, despite a reduction of the catalytic performances. Both effects are most likely ascribable to the occurrence of multipoint attachment phenomena.

Sucrose Hydrolysis in a Bespoke Capillary Wall-Coated Microreactor

“…These catalytic behavior deviations upon immobilization are usually assigned to: (i) the stabilization of the tertiary structure of the enzyme that result from the attachment to the immobilization carrier, leading to a decrease in structure flexibility [40]; and (ii) alterations of enzyme microenvironment that improves the retention of activity at extreme pH values [41].…”

“…immobilization carrier, leading to a decrease in structure flexibility [40]; and (ii) alterations of enzyme microenvironment that improves the retention of activity at extreme pH values [41]. …”

Upgrading Laccase Production and Biochemical Properties: Strategies and Challenges

“…The immobilization of enzymes also provides clear advantages compared to the conventional industrial processes, where for example, continuous flow reactors make the use of laccase more cost effective. Apart from the fact that immobilized enzymes are used in the same applications as free enzymes, and with even better results, with the use of these technologies, novel application are more likely to be developed . The inconveniences experienced with the use of free enzymes have led to scientists to focus their efforts in developing new enzyme immobilization techniques whether by chemical modification or genetic modification or a mixture of these technologies .…”

The comparative study of a laccase-natural clinoptilolite-based catalyst activity and free laccase activity on model compounds

“…LCBB was 25 times less expensive than a biocatalyst made by linking a laccase to Celite 633 through a two step reaction [14], and its activity was twice higher than Celite-based catalyst. Relatively to other supports, such as chitosan [16] and, very recently, Perlite [36], the price of LCBB results to be more convenient. By considering this, it was concluded that LCBB was active enough for further testing, especially because various possibilities exist to improve the specific activity of LCBB.…”