John Bosley

Bio: John Bosley is an academic researcher. The author has contributed to research in topics: Lipase & Bovine serum albumin. The author has an hindex of 2, co-authored 2 publications receiving 30 citations.

Immobilization of Lipases for Use in Non-Aqueous Reaction Systems

Abstract: Although the natural function of lipases is to hydrolyse fats and oils it has been shown that, under very low water conditions, the reverse reaction dominates and the lipases can be utilised for the catalysis of esterification and transesterification reactions. Although crude suspensions of enzyme powders have successfully been used for these reactions [1] their effectiveness (efficiency) is, in general, much lower than for immobilized lipase biocatalysts. In order to fully exploit lipases under these essentially nonaqueous (microaqueous) conditions the use of immobilization technology offers a number of important benefits, including; enzyme re-use, easy separation of product from enzyme and the potential to run continuous processes via packed-bed reactors. In some cases the activity and stability of the enzyme is also improved [2].

Preparation of immobilized lipase by adsorption of lipase and a non-lipase protein on a support

Abstract: Lipase is supported on a carrier material, which may hydrophobic or formed of an ion-exchange resin, by adsorbing to the carrier the lipase and a substantial coating of a non-lipase protein such as ovalbumin, bovine serum albumin or sodium caseinate. The protein is applied simultaneous with or prior to the lipase. The protein coating improves the activity of the enzyme especially with respect to its use in esterification and inter-esterification reactions.

Marine Extremophiles: A Source of Hydrolases for Biotechnological Applications

Abstract: The marine environment covers almost three quarters of the planet and is where evolution took its first steps. Extremophile microorganisms are found in several extreme marine environments, such as hydrothermal vents, hot springs, salty lakes and deep-sea floors. The ability of these microorganisms to support extremes of temperature, salinity and pressure demonstrates their great potential for biotechnological processes. Hydrolases including amylases, cellulases, peptidases and lipases from hyperthermophiles, psychrophiles, halophiles and piezophiles have been investigated for these reasons. Extremozymes are adapted to work in harsh physical-chemical conditions and their use in various industrial applications such as the biofuel, pharmaceutical, fine chemicals and food industries has increased. The understanding of the specific factors that confer the ability to withstand extreme habitats on such enzymes has become a priority for their biotechnological use. The most studied marine extremophiles are prokaryotes and in this review, we present the most studied archaea and bacteria extremophiles and their hydrolases, and discuss their use for industrial applications.

Production and use of immobilized lipases in/on nanomaterials: A review from the waste to biodiesel production

Abstract: As a highly efficient and environmentally friendly biocatalyst, immobilized lipase has received incredible interest among the biotechnology community for the production of biodiesel. Nanomaterials possess high enzyme loading, low mass transfer limitation, and good dispersibility, making them suitable biocatalytic supports for biodiesel production. In addition to traditional nanomaterials such as nano‑silicon, magnetic nanoparticles and nano metal particles, novel nanostructured forms such as nanoflowers, carbon nanotubes, nanofibers and metal-organic frameworks (MOFs) have also been studied for biodiesel production in the recent years. However, some problems still exist that need to be overcome in achieving large-scale biodiesel production using immobilized lipase on/in nanomaterials. This article mainly presents an overview of the current and state-of-the-art research on biodiesel production by immobilized lipases in/on nanomaterials. Various immobilization strategies of lipase on various advanced nanomaterial supports and its applications in biodiesel production are highlighted. Influential factors such as source of lipase, immobilization methods, feedstocks, and production process are also critically discussed. Finally, the current challenges and future directions in developing immobilized lipase-based biocatalytic systems for high-level production of biodiesel from waste resources are also recommended.

Nanomaterials as Matrices for Enzyme Immobilization

Abstract: Nanomaterials constitute novel and interesting matrices for enzyme immobilization. While their high surface to volume ratio is an obvious advantage, their Brownian motion can impact the behavior of enzymes immobilized on these matrices. Carbon nanotubes, superparamagnetic nanoparticles, and mesoporous materials constitute some important classes of matrices. Such immobilized enzyme systems have been used in both aqueous and low water media for biocatalysis and resolution of racemates. This overview examines the behavior of enzymes immobilized on nanomaterials and discusses the results reported with such biocatalyst preparations.

Lactose hydrolysis by Lactozym™ immobilized on cellulose beads in batch and fluidized bed modes

Abstract: LactozymTM is a commercially available preparation of b-galactosida se from Kluyveromyces fragilis. It has valid generally recognized as safe (GRAS) status for whey hydrolysis and production of low lactose milk. Immobilized b-galactosidase from K. fragilis has been less studied. In this work, LactozymTM was immobilized on cellulose beads via epichlorohydrin coupling chemistry. The optimized preparation was characterized in terms of its kinetic parameters. The fluidized bed hydrolyzed whey lactose ( > 90% conversion) in 5 h as compared to 48 h taken by the same enzyme in continuous batch mode. The immobilized enzyme could be reused three times without any change in the performance of the fluidized bed reactor. The fluidized bed could also hydrolyze milk lactose up to 60% within 5 h. The above data show that this enzyme from a GRAS status source can also be used to develop a process for lactose hydrolysis for whey utilization as well as production of low lactose milk.

Enhancement of lipase activity in non-aqueous media upon immobilization on multi-walled carbon nanotubes.

Abstract: Immobilization of biologically active proteins on nanosized surfaces is a key process in bionanofabrication. Carbon nanotubes with their high surface areas, as well as useful electronic, thermal and mechanical properties, constitute important building blocks in the fabrication of novel functional materials. Lipases from Candida rugosa (CRL) were found to be adsorbed on the multiwalled carbon nanotubes with very high retention of their biological activity (97%). The immobilized biocatalyst showed 2.2- and 14-fold increases in the initial rates of transesterification activity in nearly anhydrous hexane and water immiscible ionic liquid [Bmim] [PF6] respectively, as compared to the lyophilized powdered enzyme. It is presumed that the interaction with the hydrophobic surface of the nanotubes resulted in conformational changes leading to the 'open lid' structure of CRL. The immobilized enzyme was found to give 64% conversion over 24 h (as opposed to 14% with free enzyme) in the formation of butylbutyrate in nearly anhydrous hexane. Similarly, with ionic liquid [Bmim] [PF6], the immobilized enzyme allowed 71% conversion as compared to 16% with the free enzyme. The immobilized lipase also showed high enantioselectivity as determined by kinetic resolution of (±) 1-phenylethanol in [Bmim] [PF6]. While free CRL gave only 5% conversion after 36 h, the immobilized enzyme resulted in 37% conversion with > 99% enantiomeric excess. TEM studies on the immobilized biocatalyst showed that the enzyme is attached to the multiwalled nanotubes. Successful immobilization of enzymes on nanosized carriers could pave the way for reduced reactor volumes required for biotransformations, as well as having a use in the construction of miniaturized biosensensor devices.