Comparison of the biochemical properties of a recombinant lipase extract from Rhizopus oryzae expressed in Pichia pastoris with a native extract

Constitutive Expression in Komagataella phaffii of Mature Rhizopus oryzae Lipase Jointly with Its Truncated Prosequence Improves Production and the Biocatalyst Operational Stability

Rhizopus oryzae lipase (ROL) containing 28 C-terminal amino acids of the prosequence fused to the N-terminal mature sequence in ROL (proROL) was successfully expressed in the methylotrophic yeast Komagataella phaffii (Pichia pastoris) under the constitutive glyceraldehyde-3-phosphate dehydrogenase promoter (PGAP). Although the sequence encoding the mature lipase (rROL) was also transformed, no clones were obtained after three transformation cycles, which highlights the importance of the truncated prosequence to obtain viable transformed clones. Batch cultures of the K. phaffii strain constitutively expressing proROL scarcely influenced growth rate and exhibited a final activity and volumetric productivity more than six times higher than those obtained with proROL from K. phaffii under the methanol-inducible alcohol oxidase 1 promoter (PAOX1). The previous differences were less marked in fed-batch cultures. N-terminal analysis confirmed the presence of the 28 amino acids in proROL. In addition, immobilized proROL exhibited increased tolerance of organic solvents and an operational stability 0.25 and 3 times higher than that of immobilized rROL in biodiesel and ethyl butyrate production, respectively. Therefore, the truncated prosequence enables constitutive proROL production, boosts bioprocess performance and provides a more stable biocatalyst in two reactions in which lipases are mostly used at industrial level, esterification (ethyl butyrate) and transesterification (biodiesel).

Rhizopus oryzae Lipase, a Promising Industrial Enzyme: Biochemical Characteristics, Production and Biocatalytic Applications

Lipases are biocatalysts with a significant potential to enable a shift from current pollutant manufacturing processes to environmentally sustainable approaches. The main reason of this prospect is their catalytic versatility as they carry out several industrially relevant reactions as hydrolysis of fats in water/lipid interface and synthesis reactions in solvent-free or non-aqueous media such as transesterification, interesterification and esterification. Because of the outstanding traits of Rhizopus oryzae lipase (ROL), 1,3-specificity, high enantioselectivity and stability in organic media, its application in energy, food and pharmaceutical industrial sector has been widely studied. Significant advances have been made in the biochemical characterisation of ROL particularly in how its activity and stability are affected by the presence of its prosequence. In addition, native and heterologous production of ROL, the latter in cell factories like Escherichia coli, Saccharomyces cerevisiae and Komagataella phaffii (Pichia pastoris), have been thoroughly described. Therefore, in this review, we summarise the current knowledge about R. oryzae lipase (i) biochemical characteristics, (ii) production strategies and (iii) potential industrial applications.

Truncated Prosequence of Rhizopus oryzae Lipase: Key Factor for Production Improvement and Biocatalyst Stability

Recombinant Rhizopus oryzae lipase (mature sequence, rROL) was modified by adding to its N-terminal 28 additional amino acids from the C-terminal of the prosequence (proROL) to obtain a biocatalyst more suitable for the biodiesel industry. Both enzymes were expressed in Pichia pastoris and compared in terms of production bioprocess parameters, biochemical properties, and stability. Growth kinetics, production, and yields were better for proROL harboring strain than rROL one in batch cultures. When different fed-batch strategies were applied, lipase production and volumetric productivity of proROL-strain were always higher (5.4 and 4.4-fold, respectively) in the best case. rROL and proROL enzymatic activity was dependent on ionic strength and peaked in 200 mM Tris-HCl buffer. The optimum temperature and pH for rROL were influenced by ionic strength, but those for proROL were not. The presence of these amino acids altered lipase substrate specificity and increased proROL stability when different temperature, pH, and methanol/ethanol concentrations were employed. The 28 amino acids were found to be preferably removed by proteases, leading to the transformation of proROL into rROL. Nevertheless, the truncated prosequence enhanced Rhizopus oryzae lipase heterologous production and stability, making it more appropriate as industrial biocatalyst.

Application of commercial and non-commercial immobilized lipases for biocatalytic production of ethyl lactate in organic solvents

This study explores the potential for enhancing the production of ethyl lactate (EL), a green solvent, through enzymatic esterification. Different solvents were compared as organic media for conversion of lactate and ethanol into EL, catalyzed by Novozym 435. Chloroform and hexane were the most effective in low acid concentrations (0.01-0.1M) exhibiting maximum EL yields of 88% and 75% respectively. The yield of EL improved as the solvent's LogP increased up to a value of 2. Non-commercial immobilized biocatalysts consisting heterologous Rhizopous oryzae (rROL) and Candida rugosa (CRL) lipases immobilized on hydrophobic supports were compared to commercial biocatalysts clarifying that Novozym 435 and Lipozyme RM IM could be efficiently applied. Operational stability tests were conducted using Novozym 435, which retained higher activity in chloroform as compared to hexane. Although non-commercial biocatalysts were not competitive in esterification, they exhibited significant activity towards hydrolysis constituting a valuable alternative to higher-cost options.

Solid-surface activated recombinant Rhizopous oryzae lipase expressed in Pichia pastoris and chemically modified variants as efficient catalysts in the synthesis of hydroxy monodeprotected glycals

A highly active, specific and regioselective heterogeneous lipase biocatalyst was developed for the monodeprotection of peracetylated glycals.

Cloning, expression, and characterization of Aureobasidium melanogenum lipase in Pichia pastoris

cDNA of Aureobasidium melanogenum lipase comprises 1254 bp encoding 417 amino acids, whereas genomic DNA of lipase comprises 1311 bp with one intron (57 bp). The lipase gene contains a putative signal peptide encoding 26 amino acids. The A. melanogenum lipase gene was successfully expressed in Pichia pastoris. Recombinant lipase in an inducible expression system showed the highest lipase activity of 3.8 U/mL after six days of 2% v/v methanol induction. The molecular mass of purified recombinant lipase was estimated as 39 kDa using SDS-PAGE. Optimal lipase activity was observed at 35–37 °C and pH 7.0 using p-nitrophenyl laurate as the substrate. Lipase activity was enhanced by Mg2+, Mn2+, Li+, Ca2+, Ni2+, CHAPS, DTT, and EDTA and inhibited by Hg2+, Ag+, SDS, Tween 20, and Triton X-100. The addition of 10% v/v acetone, DMSO, p-xylene, and octanol increased lipase activity, whereas that of propanol and butanol strongly inhibited it.

Biodiesel production from crude Jatropha oil catalyzed by non-commercial immobilized heterologous Rhizopus oryzae and Carica papaya lipases

The aim of this study was to evaluate the feasibility of biodiesel production by transesterification of Jatropha oil with methanol, catalyzed by non-commercial sn-1,3-regioselective lipases. Using these lipases, fatty acid methyl esters (FAME) and monoacylglycerols are produced, avoiding the formation of glycerol as byproduct. Heterologous Rhizopus oryzae lipase (rROL) immobilized on different synthetic resins and Carica papaya lipase (rCPL) immobilized on Lewatit VP OC 1600 were tested. Reactions were performed at 30°C, with seven stepwise methanol additions. For all biocatalysts, 51-65% FAME (theoretical maximum=67%, w/w) was obtained after 4h transesterification. Stability tests were performed in 8 or 10 successive 4h-batches, either with or without rehydration of the biocatalyst between each two consecutive batches. Activity loss was much faster when biocatalysts were rehydrated. For rROL, half-life times varied from 16 to 579h. rROL on Lewatit VPOC 1600 was more stable than for rCPL on the same support.

Heterologous overexpression and biochemical characterization of the (galactophospho)lipase from Fusarium solani in Pichia pastoris that is expressed in planta

High-level extracellular production of Fusarium solani (galactophospho)lipase, named FSL, was achieved using a Pichia pastoris X33 expression system. The (galactophospho) lipase encoding gene was cloned into pGAPZαA with the Saccharomyces cerevisiae α-factor signal sequence by two different ways. The two constructs consist of an additional sequence of a (His)6-tag of the vector fused to the N-terminus of this enzyme (tFSL) while the other expression vector was constructed without any additional sequence (rFSL). Compared to the native enzyme (nFSL) (18.75 mg/L), a high level secretion of rFSL (310 mg/L) and tFSL (240 mg/L) was achieved providing an important improvement in enzyme production. Biochemical characterization showed that pure recombinant proteins (rFSL and tFSL) presented similar behaviour towards triglycerides, phospholipid and galactolipid. Like the nFSL, rFSL and tFSL are active at high concentration of bile salts (4mM) and calcium ions enhanced lipase activity. During plant infection, transcripts of this fungal lipase gene were detected 3, 7 and 10 days post infection.

Enzymatic biodiesel synthesis from yeast oil using immobilized recombinant Rhizopus oryzae lipase

The recombinant Rhizopus oryzae lipase (1-3 positional selective), immobilized on Relizyme OD403, has been applied to the production of biodiesel using single cell oil from Candida sp. LEB-M3 growing on glycerol from biodiesel process. The composition of microbial oil is quite similar in terms of saponifiable lipids than olive oil, although with a higher amount of saturated fatty acids. The reaction was carried out in a solvent system, and n-hexane showed the best performance in terms of yield and easy recovery. The strategy selected for acyl acceptor addition was a stepwise methanol addition using crude and neutralized single cell oil, olive oil and oleic acid as substrates. A FAMEs yield of 40.6% was obtained with microbial oils lower than olive oil 54.3%. Finally in terms of stability, only a lost about 30% after 6 reutilizations were achieved.

Role of Met93 and Thr96 in the lid hinge region of Rhizopus chinensis lipase

We engineered Rhizopus chinensis lipase to study its critical amino acid role in catalytic properties. Based on the amino acid sequence and three-dimensional model of the lipase, residues located in its lid hinge region (Met93 and Thr96) were replaced with corresponding amino acid residues (Ile93 and Asn96) found in the lid hinge region of Rhizopus oryzae lipase. The substitutions in the lid hinge region affected not only substrate specificity but also the thermostability of the lipase. Both lipases preferred p-nitrophenyl laurate and glyceryl trilaurate (C12). However, the variant S4-3O showed a slight decline in activity toward long-chain fatty acid (C16-C18). When enzymes activities decreased by half, the temperature of the variant (45 °C) was 22 °C lower than the parent (67 °C), probably substantially destabilized the structure of the lid region. The interfacial kinetic analysis of S4-3O suggested that the lower catalytic efficiency was due to a higher K m* value. According to the lipase structure investigated, Ile93Met played a role of narrowing the size of the hydrophobic patch, which affected the substrate binding affinity, and Asn96Thr destabilized the structure of the lipase by disrupting the H-bond interaction in the lid region.

Biochemical diversity of carboxyl esterases and lipases from Lake Arreo (Spain): a metagenomic approach

The esterases and lipases from the α/β hydrolase superfamily exhibit an enormous sequence diversity, fold plasticity, and activities. Here, we present the comprehensive sequence and biochemical analyses of seven distinct esterases and lipases from the metagenome of Lake Arreo, an evaporite karstic lake in Spain (42°46'N, 2°59'W; altitude, 655 m). Together with oligonucleotide usage patterns and BLASTP analysis, our study of esterases/lipases mined from Lake Arreo suggests that its sediment contains moderately halophilic and cold-adapted proteobacteria containing DNA fragments of distantly related plasmids or chromosomal genomic islands of plasmid and phage origins. This metagenome encodes esterases/lipases with broad substrate profiles (tested over a set of 101 structurally diverse esters) and habitat-specific characteristics, as they exhibit maximal activity at alkaline pH (8.0 to 8.5) and temperature of 16 to 40°C, and they are stimulated (1.5 to 2.2 times) by chloride ions (0.1 to 1.2 M), reflecting an adaptation to environmental conditions. Our work provides further insights into the potential significance of the Lake Arreo esterases/lipases for biotechnology processes (i.e., production of enantiomers and sugar esters), because these enzymes are salt tolerant and are active at low temperatures and against a broad range of substrates. As an example, the ability of a single protein to hydrolyze triacylglycerols, (non)halogenated alkyl and aryl esters, cinnamoyl and carbohydrate esters, lactones, and chiral epoxides to a similar extent was demonstrated.