Assessment of the Morphological, Biochemical, and Kinetic Properties forCandida rugosaLipase Immobilized on Hydrous Niobium Oxide to Be Used in the Biodiesel Synthesis

Abstract

Lipase from Candida rugosa (CRL) was immobilized by covalent attachment on hydrous niobium oxide. The matrix could effectively be attached to the enzyme with high retention of activity and prevent its leakage. Following immobilization, CRL exhibited improved storage stability and performed better at higher incubation temperatures. In addition, the enzyme retained most of its catalytic efficiency after successive operational cycles. The immobilized derivative was also fully characterized with respect to its morphological properties: particle size, surface specific area, and pore size distribution. Structural integrity and conformational changes, such as surface cavities in the support, set by the lipase procedure, were observed by Scanning Electron Microscopy. Additionally, a comparative study between free and immobilized lipases was provided in terms of pH, temperature, and thermal stability. CRL derivative was evaluated for the synthesis of biodiesel employing babassu oil and short chain alcohols. The process was feasible only for oil and butanol reaction system.

Sustainable production of the emulsifier methyl oleate by Candida rugosa lipase nanoconjugates

“…In this study, immobilization onto F-MWCNTs has been observed to improve the catalytic properties of CRL due to the thermostability of MWCNTs at high temperatures while providing a robust environment for CRL linkage (Raghavendra et al, 2010), in concurrence with a previous work reported by Min et al (2012). Apart from conserving the structure of the CRL as well as preventing enzyme degradation during long reaction periods at high temperature (Ramos et al, 2014), the use of MWCNTs is providing a hydrophobic microenvironment suitable for CRL activity (Miranda et al, 2011). However, the decrease of conversion rate of the CRL-MWCNTs after 11 h could be attributed to the adverse alteration on the conformation of lipase active site and reduced lipase activity (Ramos et al, 2014).…”

Modelling and optimization ofCandida rugosananobioconjugates catalysed synthesis of methyl oleate by response surface methodology

“…Higher reaction temperatures tend to promote propensity of enzyme inactivation, due to conformational changes in the enzyme tertiary structure. [45,46] The study found that by increasing the reaction temperature up to 56 C, higher yields of methyl oleate were possible, albeit by also increasing the reaction time. From an economic point of view, it is more desirable for the esterification process to be executed at a much lower reaction temperature, because less energy is required to operate the large bioreactors.…”

“…The F-MWCNTs allowed for a robust setting for the CRL enzyme linkage [32,44] and improved the hydrophobicity of the microenvironment. [45,46] Nonetheless, the concentration of the formed ester declined at temperatures exceeding 50 C, which was probably caused by the partial inactivation of the CRLMWCNTs. This outcome was somewhat anticipated as the reaction temperature (T > 50 C) had exceeded the optimal temperature of the enzyme.…”

Candida rugosa Lipase Immobilized onto Acid-Functionalized Multi-walled Carbon Nanotubes for Sustainable Production of Methyl Oleate

“…Meanwhile, the delayed decline in methyl oleate production observable in the reactions catalyzed by the CRLMWCNTs can be attributed to the more rigid structure of the CRL resulting from an additional multipoint interaction between the lipase and matrix, thereby delaying enzyme deactivation. Such improved properties of the CRL-MWCNTs can be due to the highly thermostable carbon nanotube supports that provided a robust setting for the CRL enzyme linkage [34] and improved hydrophobicity of the microenvironment [42]. It has been described that lipase activity is activated by hydrophobic interactions between the surface of the matrix and the active structure of the lipase [42].…”

“…Such improved properties of the CRL-MWCNTs can be due to the highly thermostable carbon nanotube supports that provided a robust setting for the CRL enzyme linkage [34] and improved hydrophobicity of the microenvironment [42]. It has been described that lipase activity is activated by hydrophobic interactions between the surface of the matrix and the active structure of the lipase [42]. Under these favorable conditions, such an efficient biocatalysis was promoted and the catalytically active reaction duration for the CRL-MWCNTs was extended for a longer period of time.…”