Recovery of Acinetobacter radioresistens Lipase by Hydrophobic Adsorption to n‐Hexadecane Coated on Nonwoven Fabric

Abstract

A simple and clean adsorption/desorption process was proposed for recovering Acinetobacter radioresistens lipase from fermentation broth. The adsorbent used was n-hexadecane coated on a hydrophobic nonwoven fabric (NWF). n-Hexadecane has a melting point of 16-18 degrees C, and its affinity for lipase decreases markedly from liquid to solid state. Accordingly, performing the adsorption and desorption above and below, respectively, the melting point would need no extraneous materials for separation. The adsorption isotherms at various temperatures were found to follow the Langmuir model. Simulation of the batch adsorption/desorption process showed that there exists an optimal amount of adsorbent for both concentration factor and enzyme recovery; the process is restrained by equilibrium. The performance of column adsorption/desorption could also be simulated using the adsorption isotherm, and it was shown that the concentration factor was proportional to the amount of adsorbent used. The benefits of this process include easy preparation of adsorbent, low operational cost, no extraneous materials needed, negligible enzyme denaturation, high efficiency, and simple process simulation.

Acinetobacter lipases: molecular biology, biochemical properties and biotechnological potential

“…Molecular mass reports vary ( Table 2), but DNA sequence data [45,77] predict mature proteins approximating 32 kDa, characteristic of the family [3]. Most are highly hydrophobic in nature, even in comparison with other bacterial lipases, as evidenced by the number of purification and recovery methods that exploit this characteristic [10,31,45,52,75,84].…”

“…Enzyme characteristics that may affect activity, stability, and yield under various fermentation conditions include strong affinity toward organic-aqueous interfaces, polymers, and solid adsorbents [51,52,58,84], inactivation by various inhibitors or foaming [85], and susceptibility to proteolytic degradation [47,58,85]. Optimized lipase production is further complicated by choice of medium to include carbon source(s) [54], addition of inert compounds and hydrophobic adsorbents [51,58,73,84], detergents and emulsifiers [45,47,54,58,73] or fermentation mode (batch, semicontinuous, or continuous) [51,73,85]. Low operational cost, high efficiency, process simplicity, environmental friendly productions are important considerations in commercial operations.…”

“…The differential affinity of A. radioresistens lipase for n-hexadecane-coated fabric with temperature was further explored as a low cost strategy to enhance recovery [84]. The lipase was adsorbed to hexadecane immobilized on fabric in batch cultures at 25°C and effectively desorbed from columns packed with fabric by lowering the temperature to 4°C.…”

Theoretical and experimental study of volumetric change rate during phase change process

“…Generally, the temperature of the thermocline varies from 5 to 301C. The phase transition temperature of hexadecane is between 16 and 181C [13]. Hexadecane is chosen as the PCM because of the suitable melting point, low cost and stable performance.…”

Reconfigurable microfluidic pump enabled by opto-electrical-thermal transduction

“…The phase transition temperature of the OERM working medium of hexadecane (C 16 H 34 ) is not a fixed temperature and occurs in the temperature range of 16-18 C. 20,21 This melting temperature range is suitable for operation at room temperature. In addition, hexadecane has a low latent heat (184 kJ/L) compared to water (332 kJ/L).…”