Biocatalytic esterification of palm oil fatty acids for biodiesel production using glycine-based cross-linked protein coated microcrystalline lipase

Single cell protein and oil production from solid cocoa fatty acid distillates co-fed ethanol

The use of solid lipid sidestreams have been overlooked as a feedstock for the production of microbial biomass for food and feed applications and little to no recent work has examined the utilization of solid fatty acid distillates (FADs), which are a significant residue from vegetable oil processing. Yarrowia lipolytica and Rhodosporidium toruloides cultivated on cocoa fatty acid distillates (CFAD) generated final cell dry weight values > 40 g/L, with strong productivity (3.3 g/L·h) and rich protein (>45%) and lipid content (>25%). Interestingly, microbial oils were > 65% unsaturated fatty acids, compared < 20% unsaturated content in FAD. Importantly, to overcome mass-transfer limitations associated with bioconversion of solid lipid residues, ethanol was applied as a co-substrate to solubilize FAD residues. Here, FAD residues from cocoa deodorization have been demonstrated to be high energy feedstocks that represent an attractive substrate for the production of both single cell protein and oil (SCPO).

Palm oil wastes as feedstock for lipase production by Yarrowia lipolytica and biocatalyst application/reuse

Palm oil production chain generates a greasy residue in the refining stage, the Palm Oil Deodorizer Distillate (PODD), mainly composed of free fatty acids. Palm oil is also used industrially to fry foods, generating a residual frying oil (RFO). In this paper, we aimed to produce lipase from palm agro-industrial wastes using an unconventional yeast. RFO_palm, from a known source, consisted of 0.11% MAG + FFA, 1.5% DAG, and 97.5 TAG, while RFO_commercial, from a commercial restaurant, contained 6.7% of DAG and 93.3% of TAG. All palm oil wastes were useful for extracellular lipase production, especially RFO_commercial that provided the highest activity (4.9 U/mL) and productivity (465 U/L.h) in 75 h of processing time. In 48 h of process, PODD presented 2.3 U/mL of lipase activity and 48.5 U/L.h of productivity. RFO_commercial also showed the highest values for lipase associated to cell debris (843 U/g). This naturally immobilized biocatalyst was tested on hydrolysis reactions to produce Lipolyzed Milk Fat and was quite efficient, with a hydrolysis yield of 13.1% and 3-cycle reuse. Therefore, oily palm residues seem a promising alternative to produce lipases by the non-pathogenic yeast Y. lipolytica and show great potential for industrial applications.

Enzyme-Coated Micro-Crystals: An Almost Forgotten but Very Simple and Elegant Immobilization Strategy

The immobilization of enzymes using protein coated micro-crystals (PCMCs) was reported for the first time in 2001 by Kreiner and coworkers. The strategy is very simple. First, an enzyme solution must be prepared in a concentrated solution of one compound (salt, sugar, amino acid) very soluble in water and poorly soluble in a water-soluble solvent. Then, the enzyme solution is added dropwise to the water soluble solvent under rapid stirring. The components accompanying the enzyme are called the crystal growing agents, the solvent being the dehydrating agent. This strategy permits the rapid dehydration of the enzyme solution drops, resulting in a crystallization of the crystal formation agent, and the enzyme is deposited on this crystal surface. The reaction medium where these biocatalysts can be used is marked by the solubility of the PCMC components, and usually these biocatalysts may be employed in water soluble organic solvents with a maximum of 20% water. The evolution of these PCMC was to chemically crosslink them and further improve their stabilities. Moreover, the PCMC strategy has been used to coimmobilize enzymes or enzymes and cofactors. The immobilization may permit the use of buffers as crystal growth agents, enabling control of the reaction pH in the enzyme environments. Usually, the PCMC biocatalysts are very stable and more active than other biocatalysts of the same enzyme. However, this simple (at least at laboratory scale) immobilization strategy is underutilized even when the publications using it systematically presented a better performance of them in organic solvents than that of many other immobilized biocatalysts. In fact, many possibilities and studies using this technique are lacking. This review tried to outline the possibilities of this useful immobilization strategy.

Tailoring enzyme microenvironment: State-of-the-art strategy to fulfill the quest for efficient bio-catalysis

Enzymes as green industrial biocatalysts have become a powerful norm that offers several advantages over traditional catalytic agents with regard to process efficiency, reusability, sustainability, and overall cost-effective ratio. However, enzymes obtained from natural origins are often engineered/tailored since their native forms do not fulfill the acute need for the industrial application. Revolutionary developments in protein engineering provide excellent opportunities for designing and constructing novel industrial biocatalysts with improved functional properties including catalytic activity, stability, substrate specificity, and reaction product inhibition. Momentum in enzyme immobilization has enabled robustness and optimal functions in extreme industrial environments, such as high temperature or organic solvents. The emergence of multi-enzyme catalytic cascade based on a combination of biocatalysts presents multifarious opportunities in biosynthesis, biocatalysis, and biotransformation. This review focuses on the emerging and state-of-the-art enzyme engineering trends and approaches to constructing innovative nano- and microstructured biocatalysts with enhanced catalytic activity and stability features requisite for industrial exploitation. Continuous key developments in this direction together with protein engineering in unique ways might offer ever-increasing opportunities for future biocatalysis-based industrial bioprocesses.

Protein-Coated Microcrystals, Combi-Protein-Coated Microcrystals, and Cross-Linked Protein-Coated Microcrystals of Enzymes for Use in Low-Water Media

Protein-coated microcrystals (PCMC) are a high-activity preparation of enzymes for use in low-water media. The protocols for the preparation of PCMCs of Subtilisin Carlsberg and Candida antarctica lipase B (CAL B) are described. The combi-PCMC concept is useful both for cascade and non-cascade reactions. It can also be beneficial to combine two different specificities of a lipase when the substrate requires it. Combi-PCMC of CALB and Palatase used for the conversion of coffee oil present in spent coffee grounds to biodiesel is described. Cross-linked protein-coated microcrystals (CL-PCMC) in some cases can give better results than PCMC. Protocols for the CLPCMC of Subtilisin Carlsberg and Candida antarctica lipase B (CAL B) are described. A discussion of their applications is also provided.

Study on the spectrophotometric detection of free fatty acids in palm oil utilizing enzymatic reactions

In this paper, a comprehensive study has been made on the detection of free fatty acids (FFAs) in palm oil via an optical technique based on enzymatic aminolysis reactions. FFAs in crude palm oil (CPO) were converted into fatty hydroxamic acids (FHAs) in a biphasic lipid/aqueous medium in the presence of immobilized lipase. The colored compound formed after complexation between FHA and vanadium (V) ion solution was proportional to the FFA content in the CPO samples and was analyzed using a spectrophotometric method. In order to develop a rapid detection system, the parameters involved in the aminolysis process were studied. The utilization of immobilized lipase as catalyst during the aminolysis process offers simplicity in the product isolation and the possibility of conducting the process under extreme reaction conditions. A good agreement was found between the developed method using immobilized Thermomyces lanuginose lipase as catalyst for the aminolysis process and the Malaysian Palm Oil Board (MPOB) standard titration method (R² = 0.9453).

A novel chemoenzymatic synthesis of propyl caffeate using lipase-catalyzed transesterification in ionic liquid

Propyl caffeate has the highest antioxidant capacity in the caffeate alkyl esters family, but industrial production of propyl caffeate is hindered by low yields using either the chemical or enzymatic catalysis method. To set up a high-yield process for obtaining propyl caffeate, a novel chemoenzymatic synthesis method using lipase-catalyzed transesterification of an intermediate methyl caffeate or ethyl caffeate and 1-propanol in ionic liquid was established. The maximum propyl caffeate yield of 98.5% was obtained using lipase-catalyzed transesterification under the following optimal conditions: Novozym 435 as a biocatalyst, [Bmim][CF3SO3] as a medium, a molar ratio of methyl caffeate to 1-propanol of 1:5, a mass ratio of methyl caffeate to lipase of 1:20, and a reaction temperature of 60°C. The two-step conversion of caffeic acid to propyl caffeate via methyl caffeate is an efficient way to prepare propyl caffeate with an overall yield of 82.7%.