# The Immobilization of Lipases on Porous Support by Adsorption and Hydrophobic Interaction Method
## 3 Porous Carriers Used for the Immobilization of Lipase
### Criteria  
The criteria of the porous support use for lipase immobilization by adsorption and their applications are listed in Table 1. Due to high surface areas, porosity, pore size, and accessibility for binding, _Rhizopus_ _oryze_ lipase immobilized in Lewatit(r) VP OC 1600 or Accurel(r) MP 1000 is presented to have the best performance regarding oleic acid incorporation (mol.%) on tripalmitin [8]. Macroporous Sepabeads have a small pore size (100-200 A), which adsorbs 10-fold more active _Thermomyces lanuginosus_ lipase than mesoporous Purolite C-18 (pore size: 616 A), and are able to be transported with highly viscous reaction media [58]. Thus, the pore size of supports plays a vital role in the modification of oils in solvent-free systems. The treatment of supports with solvents maximizes the adsorption rate and the immobilization yield for lipase B from _Candida antarctica_ (CALB) onto Accurel MP1001 (particle size \(<1000\) um) and styrene-divinylbenzene porous supports (75-150 um) [59; 60]. However, some textural changes on mesoporous carbon beads have less impact on the protein adsorption and catalytic activity of lipases from _Candida antarctica_[71] similar to on immobilized lipase that exhibits a decrease in the specific surface area and pore volume due to the loss of the adsorbed lipase and the comb polymer [73]. The physicochemical properties of macroporous resin NKA matrix supports are crucial for _Burkholderia cepacia_ lipase immobilization, which influences enzyme loading as well as catalytic behavior [69]. A study showed that macroporous supports (5-50 um) provide channels for mass transfer of Phospholipase D and substrates while mesoporous supports (10-50 nm) have high surface areas for enzyme adsorption [37]. Besides, polystyrene macroporous resin (Purolite(r)A109), which has better internal diffusional properties, excellent mechanical stability, high particle diameters (400 um), and robustness, enables the efficient application of immobilized _Candida_ sp. in bioreactors [31]. The optimal mass diffusion of the substrate is achieved by the three-dimensional mesoporous network of ordered mesoporous materials (OMMs), which is useful to immobilize lipase via hydrophobic interaction [74]. Poly(MMA-co-DVB) hydrophobic porous, polymer-encapsulated magnetic microspheres provide an effective system for _Mucor jaanicus_ lipase immobilization that has a 200-fold specific activity increase and reusable cycles of more than 30 times in high-viscosity reaction systems for the solvent-free synthesis of 1,3-diolein [70]. Furthermore, the design of a mesoporous SBA-15 support is tailored to improve enzyme immobilization and have benefits such as hydrophobic character, high surface areas, large pore volumes, and parallel channels [72]. The lamellar structures of mesoporous cuttlebone powder of _Sepia officinalis_ (CBP) also have a large surface area, which is most suitable to entrap more biomolecules on its surface during immobilization [63]. Moreover, the particle size also affects the enzyme immobilization and reaction rates, both of which are influenced by the amount of interfacial area per unit volume [64]. The modified hollow mesoporous silica support (HMSS) exhibits monodisperse, uniform, and spherical morphology with a particle size of 3.8 um. The hydrophobic microenvironment, an appropriate pore size of the HMSS, and a large cavity volume cause a higher catalytic reaction for immobilized _Candida rugosa_ lipase (HMSS-C18-CRL) [75]. The smaller particle size of the support has a larger surface area [66], in which a smaller particle EP400 support has a more abundant surface area for enzyme adsorption and provides substrate access during the hydrolysis reaction better than a larger particle support [64]. A particle size of 300 nm was proven to be the most suitable carrier for both lipases from _Mucor miehei_ and _Rhizopus oryzae_[66].