True Lipase Research Articles

Lipase and esterase activity in soils from ancient burial vessels

The activity of lipolytic enzymes was assessed using the microplate method using heteromolecular exchange in soils from the bottom of burial vessels, followed by cluster analysis. Groups with a contrasting ratio of lipases C12 - C18 and esterases C4 - C8 were identified in a sample that included 57 burial pots aged two to three thousand years. The total lipolytic activity of soil samples from dishes with the presumptive initial presence of fat-containing food products was above 6% of the maximum value within the sample. Inhibition of esterases in the presence of high concentrations of fatty acids is reflected in the extremely low relative values of esterase activity of the soil microbial community against the background of maximum activity levels of C18 and C12 lipases in two groups of pots. In three groups, esterase activity was observed against the background of high relative activity of C16 lipases, average relative activity of C18 lipases and extremely low activity of true lipases. In the group of pots with high total lipolytic activity (with the exception of certain extreme values of this indicator), the proportion of true lipase activity was 1.7-1.8 times higher compared to the proportion of esterase activity. The grouping of burial vessels by the ratio of lipase and esterase activity reflects the characteristics of the funeral food, while the absolute values of enzyme activity among selected vessels with the highest total lipolytic activity are grouped according to the type of burial.

Investigation of amino acids related to Staphylococcus saprophyticus AG1 EstAG1 carboxylesterase catalytic function revealed a new family of bacterial lipolytic enzymes

Most of the lipolytic enzymes (carboxylesterases, EC 3.1.1.1 and triacylglycerol acylhydrolases, EC 3.1.1.3) originate from bacteria and form a large group of functionally important enzymes that are also well known for their use in multiple biotechnology sectors. Rapid and increasing amount of bacterial lipolytic enzymes being discovered and characterized led to a necessity to classify them. More than twenty years ago bacterial lipolytic enzymes were originally classified into eight families and six true lipase sub-families based on the differences in their amino acid sequences and biochemical properties. Later, this classification was comprehensively updated to 19 families with eight subfamilies, and more recently, employing deeper comparative analysis methods, classification expanded to 35 families and 11 subfamilies. Bacterial lipolytic enzymes that cannot be classified into currently existing families are still being discovered. This work provides site-directed mutagenesis and differential scanning fluorimetry based investigation of catalytic function-related amino acids of previously discovered and characterized EstAG1 carboxylesterase from Staphylococcus saprophyticus AG1. Experimental results obtained in this work revealed that EstAG1 carboxylesterase can be placed into a new family of bacterial lipolytic enzymes.

Identification of a Novel Lipase with AHSMG Pentapeptide in Hypocreales and Glomerellales Filamentous Fungi.

Lipases are enzymes that hydrolyze triglycerides to fatty acids and glycerol. A typical element in lipases is a conserved motif of five amino acids (the pentapeptide), most commonly G-X-S-X-G. Lipases with the pentapeptide A-X-S-X-G are present in species of Bacillus, Paucimonas lemoignei, and the yeast Trichosporon asahii; they are usually thermotolerant and solvent resistant. Recently, while searching for true lipases in the Trichoderma harzianum genome, one lipase containing the pentapeptide AHSMG was identified. In this study, we cloned from T. harzianum strain B13-1 the lipase ID135964, renamed here as ThaL, which is 97.65% identical with the reference. We found that ThaL is a lid-containing true lipase of cluster III that belongs to a large family comprising highly conserved proteins in filamentous fungi in the orders Hypocreales and Glomerellales, in which predominantly pathogenic fungi are found. ThaL was expressed in conidia, as well as in T. harzianum mycelium, where it was cultured in liquid minimal medium. These results—together with the amino acid composition, absence of a signal peptide, mitochondrial sorting prediction, disordered regions in the protein, and lineage-specific phylogenetic distribution of its homologs—suggest that ThaL is a non-canonical effector. In summary, AHSMG-lipase is a novel lipase family in filamentous fungi, and is probably involved in pathogenicity.

True lipase activity and in vitro digestibility of potential lipid sources for the spiny lobster Panulirus argus feeds

Spiny lobster aquaculture has increased during the past decades, attended to the lobster high demand and commercial value. However, the absence of cost-effective and nutritionally adequate formulated feeds remains as one of the drawbacks for the sustainable expansion of this activity. Despite lipids are important nutrients and energy sources for these crustaceans, lipid digestion remains poorly understood. In this study, the pH-Stat method was used for studying in vitro the lipolytic activity in the digestive gland of the spiny lobster Panulirus argus and the digestibility of 18 oils from animal, plant and microalgae origin. We complemented these analyses by evaluating the effects of several emulsifiers (non-ionic surfactants and phospholipids) on lipid digestion, and by making a partial characterization of enzymes with lipolytic activity in this species. Results demonstrate for the first time the presence of true digestive lipases in spiny lobsters, and also that P. argus has the ability to efficiently hydrolyzed both animal and vegetable oils. Fish oils are highly digestible but algae oils and plant derived oils such as rapeseed oil, should be also taken into account in feed formulation for P. argus. In addition, results indicate that hydrolyzed soy lecithin presents the greatest potential to be used as an emulsifier ingredient in lobsters' feeds, for which optimal inclusion level in feed needs to be determined. This study increases our understanding on lipid digestion in lobsters and may assist in selecting appropriated oils and emulsifiers for P. argus feeds.

Artificial Neural Networks and Response Surface Methodology Approach for Optimization of an Eco-Friendly and Detergent-Stable Lipase Production from Actinomadura Keratinilytica Strain Cpt29

This work mainly focused on the production of an efficient, economical, and eco-friendly lipase (AKL29) from Actinomadura keratinilytica strain Cpt29 isolated from poultry compost in north east of Algeria, for use in detergent industries. AKL29 shows a significant lipase activity (45 U/mL) towards hydrolyzed triacylglycerols, indicating that it is a true lipase. For maximum lipase production the modeling and optimization of potential culture parameters such as incubation temperature, cultivation time, and Tween 80 (v/v) were built using RSM and ANN approaches. The results show that both the two models provided good quality predictions, yet the ANN showed a clear superiority over RSM for both data fitting and estimation capabilities. A 4.1-fold increase in lipase production was recorded under the following optimal condition: incubation temperature (37.9 °C), cultivation time (111 h), and Tween 80 (3.27%, v/v). Furthermore, the partially purified lipase showed good stability, high compatibility, and significant wash performance with various commercial laundry detergents, making this novel lipase a promising potential candidate for detergent industries.

CLONING AND in silico STUDIES OF LIPASE GENE OF A THERMOPHILIC BACTERIA ISOLATED FROM THE HYDROTHERMAL VENT AREA OF KAWIO, NORTH SULAWESI

Underwater volcano is an example of a natural habitat of thermophilic bacteria, such as hydrothermal vent Kawio in North Sulawesi. The focus of this research was to screen the bacterial isolates originally from hydrothermal vent Kawio for the production of thermostable lipase. In this study, the lipase gene from the selected isolate was cloned, sequenced, and in silico analysis was performed to predict the characteristics of the lipase protein. One of three isolates examined, showed a positive reaction. Phylogenetic analysis of 16S rRNA gene showed that the isolate was a novel bacteria closely related to Bacillus safensis strain FO-26b with 96,87% homology. Amino acid sequence analysis of the lipase showed similarity between lipase of Bacillus pumilus strain B106 with 98% homology. Further analysis at the protein level indicated that the lipase isolated from marine water was a member of family I.4 of ‘true lipase’ group.

Gene cloning, heterologous expression, and partial characterization of a novel cold-adapted subfamily I.3 lipase from Pseudomonas fluorescence KE38

A novel cold-active true lipase from Pseudomonas sp. KE38 was cloned, sequencing and expressed in E. coli by degenerate PCR and genome walking technique. The open reading frame of the cloned gene encoded a polypeptide chain of 617 amino acids with a confirmed molecular weight of 64 kD. Phylogenetic analysis of the deduced amino acid sequence of the lipase indicated that it had high similarity with lipases of subfamily Ι.3 of bacterial lipases. Recombinant lipase was purified in denatured form as inclusion bodies, which were then renatured by urea followed by dialysis. Lipase activity was determined titrimetrically using olive oil as substrate. The enzyme showed optimal activity at 25 °C, pH 8.5 and was highly stable in the presence of various metal ions and organic solvents. Low optimal temperature and high activity in the presence of methanol and ethanol make this lipase a potential candidate for transesterification reactions and biodiesel production.

Characterization of novel metagenomic–derived lipase from Indian hot spring

Extreme environments are the main source of industrially suitable biocatalysts. The non-cultivable approach of searching enzymes is known to provide ample scope to accomplish novelty for their industrial applications. Lip479 clone out of seven lipase-producing clones obtained from Taptapani hot spring was found to be optimally active at pH 8.0 and temperature 65 °C. The recombinant Lip479 was highly stable in organic solvents, methanol, DMF, DMSO, acetone, and dichloromethane. Lip479 lipase activity was enhanced in the presence of K+, Mn2+, Na+, Zn2+, and Ca2+ except for Fe3+. The ability of Lip479 lipase to act on long carbon chain of 4-nitrophenyl myristate suggests it might be a true lipase. Lip479 clone was found to have ORF of 1251 bp encoding 416 amino acid residues of 42.57 KDa size (theoretically calculated). The presence of conserved motif Ala-His-Ser-Gln-Gly and Zn2+-binding consensus sequence (GAAHAAKH) of the clone assigns the protein to lipase family 1.5. Phylogenetic lineage of the protein sequence of Lip479 was traced to family 1.5 as it was clubbed up with those of reported lipases of the same family. The above biochemical features indicated that Lip479 lipase can be a potential biocatalyst for its use in various industries.

Structure solution and analyses of the first true lipase obtained from metagenomics indicate potential for increased thermostability

Metagenomics is a modern approach to discovery of new enzymes with novel properties. This article reports the structure of a new lipase, belonging to family I.1, obtained by means of metagenomics. Its structure presents a fold typical of α/β hydrolases, with the lid in closed conformation. The protein was previously shown to present high thermostability and to be stable in aqueous solutions of polar organic solvents at high concentrations [30% (V/V)]. Molecular dynamics studies showed that the protein maintains its structure well in organic solvents. They also suggested that its thermostability might be enhanced if it were mutated to present a disulfide bond similar to that typically found in lipase family I.2. These findings identify this lipase as a good candidate for further improvement through protein engineering.

In vitro digestibility of oils used in feed for Macrobrachium tenellum, Macrobrachium americanum and Litopenaeus vannamei adults

The objective of this work was to determine in vitro digestibility of some used or potentially used oils in feed for adult organisms of Macrobrachium tenellum, M. americanum, and Litopenaeus vannamei. For this purpose different feed oils were assessed, eight animal oils (shark liver, fish, sardine, salmon, tuna orbit, red crab, cod liver, and krill); 12 vegetable oils (chia, soya, macadamia, corn, sesame, safflower, coconut, wheat germ, olive, peanut, pumpkin seed, and canola); and two feed grade triglycerides (tripalmitin and tributyrin). In the in vitro digestibility analyses of these feed oils, the digestive enzymes of the three species in study were used with the pH Stat method. The digestion speed results were analyzed according to origin (animal, vegetable), types of oils (crustacean, fish, gramineae, leguminosae, and other types of vegetables), and ingredients for each species and among them. The three crustacean species assessed have the capability of hydrolyzing oils with heterogeneous fatty acids indicating the presence of triacylglycerol lipases in their hepatopancreas for lipid digestion. The fastest digestion speed for the studied species was observed in crustacean oils, possibly due to the balance between the proportion of their saturated and unsaturated fatty acids, which was 1:1.4. Likewise, high values of tributyrinase were found in these organisms, suggesting an important role of this activity as part of their lipolytic capacity and reinforcing the idea of true lipase participation in triglyceride hydrolysis with both short and long chain fatty acids. This information allows knowing the level of maximum digestion and potential use of oils in feed formulation for these species. Hence, this study can be the basis for more research on ingredients, fatty acid profiles, in vivo digestibility, and their effects on the productive parameters of the organisms under rearing conditions.

A proposed update for the classification and description of bacterial lipolytic enzymes.

Bacterial lipolytic enzymes represent an important class of proteins: they provide their host species with access to additional resources and have multiple applications within the biotechnology sector. Since the formalisation of lipolytic enzymes into families and subfamilies, advances in molecular biology have led to the discovery of lipolytic enzymes unable to be classified via the existing system. Utilising sequence-based comparison methods, we have integrated these novel families within the classification system so that it now consists of 35 families and 11 true lipase subfamilies. Representative sequences for each family and subfamily have been defined as well as methodology for accurate comparison of novel sequences against the reference proteins, facilitating the future assignment of novel proteins. Both the code and protein sequences required for integration of additional families are available at: https://github.com/thh32/Lipase_reclassification.

N-terminal domain replacement changes an archaeal monoacylglycerol lipase into a triacylglycerol lipase

BackgroundLipolytic enzymes of hyperthermophilic archaea generally prefer small carbon chain fatty acid esters (C2–C12) and are categorized as esterases. However, a few have shown activity with long-chain fatty acid esters, but none of them have been classified as a true lipase except a lipolytic enzyme AFL from Archaeglobus fulgidus. Thus, our main objective is to engineer an archaeal esterase into a true thermostable lipase for industrial applications. Lipases which hydrolyze long-chain fatty acid esters display an interfacial activation mediated by the lid domain which lies over active site and switches to open conformation at the oil–water interface. Lid domains modulate enzyme activities, substrate specificities, and stabilities which have been shown by protein engineering and mutational analyses. Here, we report engineering of an uncharacterized monoacylglycerol lipase (TON-LPL) from an archaeon Thermococcus onnurineus (strain NA1) into a triacylglycerol lipase (rc-TGL) by replacing its 61 N-terminus amino acid residues with 118 residues carrying lid domain of a thermophilic fungal lipase—Thermomyces lanuginosus (TLIP).ResultsTON-LPL and rc-TGL were cloned and overexpressed in E. coli, and the proteins were purified by Ni–NTA affinity chromatography for biochemical studies. Both enzymes were capable of hydrolyzing various monoglycerides and shared the same optimum pH of 7.0. However, rc-TGL showed a significant decrease of 10 °C in its optimum temperature (Topt). The far UV–CD spectrums were consistent with a well-folded α/β-hydrolase fold for both proteins, but gel filtration chromatography revealed a change in quaternary structure from trimer (TON-LPL) to monomer (rc-TGL). Seemingly, the difference in the oligomeric state of rc-TGL may be linked to a decrease in temperature optimum. Nonetheless, rc-TGL hydrolyzed triglycerides and castor oil, while TON-LPL was not active with these substrates.ConclusionsHere, we have confirmed the predicted esterase activity of TON-LPL and also performed the lid engineering on TON-LPL which effectively expanded its substrate specificity from monoglycerides to triglycerides. This approach provides a way to engineer other hyperthermophilic esterases into industrially suitable lipases by employing N-terminal domain replacement. The immobilized preparation of rc-TGL has shown significant activity with castor oil and has a potential application in castor oil biorefinery to obtain value-added chemicals.

Purification and characterization of an organic solvent-tolerant and detergent-stable lipase from Haloferax mediterranei CNCMM 50101

The present study investigates the purification and biochemical characterization of an extracellular lipase (HML) from Haloarchaea Haloferax mediterranei strain ATS1, isolated from the Sebkha (Medea, Algeria). The pure protein was obtained with ammonium sulfate precipitation (40–70%)-dialysis and UNO Q-6 FPLC, and characterized biochemically. Matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF/MS) analysis revealed that the purified enzyme was a monomer, with a molecular mass of 45,011.09 Da. It showed optimum lipase activity at pH 7 and 60 °C. HML showed a higher specific activity on triacylglycerols with long-chains fatty acids, indicating that HML is a true lipase. This enzyme was completely inhibited by phenylmethanesulfonyl fluoride (PMSF) and diiodopropyl fluorophosphates (DFP), which suggested its belonging to the serine lipase family. The Km and Vmax for HML toward olive oil were 1.01 mM and 1195 U/mg, respectively. Compared to Lipolase, HML displayed an elevated organic solvent tolerance, an outstanding stability to surfactants, oxidizing, and auxiliary agents, a considerable compatibility with various commercialized laundry detergents, and wash performance analysis revealed that it could remove oil-stains effectively. Overall, HML has a number of attractive properties that make it a potential promising candidate for the synthesis of non-aqueous peptides and detergent formulations.

Fungal Screening on Olive Oil for Extracellular Triacylglycerol Lipases: Selection of a Trichoderma harzianum Strain and Genome Wide Search for the Genes.

A lipolytic screening with fungal strains isolated from lignocellulosic waste collected in banana plantation dumps was carried out. A Trichoderma harzianum strain (B13-1) showed good extracellular lipolytic activity (205 UmL−1). Subsequently, functional screening of the lipolytic activity on Rhodamine B enriched with olive oil as the only carbon source was performed. The successful growth of the strain allows us to suggest that a true lipase is responsible for the lipolytic activity in the B13-1 strain. In order to identify the gene(s) encoding the protein responsible for the lipolytic activity, in silico identification and characterization of triacylglycerol lipases from T. harzianum is reported for the first time. A survey in the genome of this fungus retrieved 50 lipases; however, bioinformatic analyses and putative functional descriptions in different databases allowed us to choose seven lipases as candidates. Suitability of the bioinformatic screening to select the candidates was confirmed by reverse transcription polymerase chain reaction (RT-PCR). The gene codifying 526309 was expressed when the fungus grew in a medium with olive oil as carbon source. This protein shares homology with commercial lipases, making it a candidate for further applications. The success in identifying a lipase gene inducible with olive oil and the suitability of the functional screening and bioinformatic survey carried out herein, support the premise that the strategy can be used in other microorganisms with sequenced genomes to search for true lipases, or other enzymes belonging to large protein families.

New lipases by mining of Pleurotus ostreatus genome.

The analysis of Pleurotus ostreatus genome reveals the presence of automatically annotated 53 lipase and 34 carboxylesterase putative coding-genes. Since no biochemical or physiological data are available so far, a functional approach was applied to identify lipases from P. ostreatus. In the tested growth conditions, four lipases were found expressed, with different patterns depending on the used C source. Two of the four identified proteins (PleoLip241 and PleoLip369), expressed in both analysed conditions, were chosen for further studies, such as an in silico analysis and their molecular characterization. To overcome limits linked to native production, a recombinant expression approach in the yeast Pichia pastoris was applied. Different expression levels were obtained: PleoLip241 reached a maximum activity of 4000 U/L, whereas PleoLip369 reached a maximum activity of 700 U/L. Despite their sequence similarity, these enzymes exhibited different substrate specificity and diverse stability at pH, temperature, and presence of metals, detergents and organic solvents. The obtained data allowed classifying PleoLip241 as belonging to the “true lipase” family. Indeed, by phylogenetic analysis the two proteins fall in different clusters. PleoLip241 was used to remove the hydrophobic layer from wool surface in order to improve its dyeability. The encouraging results obtained with lipase treated wool led to forecast PleoLip241 applicability in this field.

Purification and Characterization of an Alkali-Thermostable Lipase from Thermophilic Anoxybacillus flavithermus HBB 134.

An intracellular lipase from Anoxybacillus flavithermus HBB 134 was purified to 7.4-fold. The molecular mass of the enzyme was found to be about 64 kDa. The maximum activity of the enzyme was at pH 9.0 and 50°C. The enzyme was stable between pH 6.0 and 11.0 at 25°C, 40°C, and 50°C for 24 h. The Km and Vmax of the enzyme for pNPL substrate were determined as 0.084 mM and 500 U/mg, respectively. Glycerol, sorbitol, and mannitol enhanced the enzyme thermostability. The enzyme was found to be highly stable against acetone, ethyl acetate, and diethyl ether. The presence of PMSF, NBS, DTT and β-mercaptoethanol inhibited the enzyme activity. Hg(2+), Fe(3+), Pb(2+), Al(3+), and Zn(2+) strongly inhibited the enzyme whereas Li(+), Na(+), K(+), and NH4(+) slightly activated it. At least 60% of the enzyme activity and stability were retained against sodium deoxycholate, sodium taurocholate, n-octyl-β-D-glucopyranoside, and CHAPS. The presence of 1% Triton X-100 caused about 34% increase in the enzyme activity. The enzyme is thought to be a true lipase since it has preferred the long-chain triacylglycerols. The lipase of HBB 134 cleaved triolein at the 1- or 3-position.

Analysis of Comparative Sequence and Genomic Data to Verify Phylogenetic Relationship and Explore a New Subfamily of Bacterial Lipases

Thermostable and organic solvent-tolerant enzymes have significant potential in a wide range of synthetic reactions in industry due to their inherent stability at high temperatures and their ability to endure harsh organic solvents. In this study, a novel gene encoding a true lipase was isolated by construction of a genomic DNA library of thermophilic Aneurinibacillus thermoaerophilus strain HZ into Escherichia coli plasmid vector. Sequence analysis revealed that HZ lipase had 62% identity to putative lipase from Bacillus pseudomycoides. The closely characterized lipases to the HZ lipase gene are from thermostable Bacillus and Geobacillus lipases belonging to the subfamily I.5 with ≤ 57% identity. The amino acid sequence analysis of HZ lipase determined a conserved pentapeptide containing the active serine, GHSMG and a Ca2+-binding motif, GCYGSD in the enzyme. Protein structure modeling showed that HZ lipase consisted of an α/β hydrolase fold and a lid domain. Protein sequence alignment, conserved regions analysis, clustal distance matrix and amino acid composition illustrated differences between HZ lipase and other thermostable lipases. Phylogenetic analysis revealed that this lipase represented a new subfamily of family I of bacterial true lipases, classified as family I.9. The HZ lipase was expressed under promoter Plac using IPTG and was characterized. The recombinant enzyme showed optimal activity at 65°C and retained ≥ 97% activity after incubation at 50°C for 1h. The HZ lipase was stable in various polar and non-polar organic solvents.

Immobilization and characterization of a new regioselective and enantioselective lipase obtained from a metagenomic library.

In previous work, a new lipase and its cognate foldase were identified and isolated from a metagenomic library constructed from soil samples contaminated with fat. This new lipase, called LipG9, is a true lipase that shows specific activities that are comparable to those of well-known industrially-used lipases with high activity against long-chain triglycerides. In the present work, LipG9 was co-expressed and co-immobilized with its foldase, on an inert hydrophobic support (Accurel MP1000). We studied the performance of this immobilized LipG9 (Im-LipG9) in organic media, in order to evaluate its potential for use in biocatalysis. Im-LipG9 showed good stability, maintaining a residual activity of more than 70% at 50°C after incubation in n-heptane (log P 4.0) for 8 h. It was also stable in polar organic solvents such as ethanol (log P -0.23) and acetone (log P -0.31), maintaining more than 80% of its original activity after 8 h incubation at 30°C. The synthesis of ethyl esters was tested with fatty acids of different chain lengths in n-heptane at 30 °C. The best conversions (90% in 3 h) were obtained for medium and long chain saturated fatty acids (C8, C14 and C16), with the maximum specific activity, 29 U per gram of immobilized preparation, being obtained with palmitic acid (C16). Im-LipG9 was sn-1,3-specific. In the transesterification of the alcohol (R,S)-1-phenylethanol with vinyl acetate and the hydrolysis of the analogous ester, (R,S)-1-phenylethyl acetate, Im-LipG9 showed excellent enantioselectivity for the R-isomer of both substrates (E> 200), giving an enantiomeric excess (ee) of higher than 95% for the products at 49% conversion. The results obtained in this work provide the basis for the development of applications of LipG9 in biocatalysis.

Biochemical characterization of Yarrowia lipolytica LIP8, a secreted lipase with a cleavable C-terminal region

Yarrowia lipolytica is a lipolytic yeast possessing 16 paralog genes coding for lipases. Little information on these lipases has been obtained and only the major secreted lipase, namely YLLIP2, had been biochemically and structurally characterized. Another secreted lipase, YLLIP8, was isolated from Y. lipolytica culture medium and compared with the recombinant enzyme produced in Pichia pastoris. N-terminal sequencing showed that YLLIP8 is produced in its active form after the cleavage of a signal peptide. Mass spectrometry analysis revealed that YLLIP8 recovered from culture medium lacks a C-terminal part of 33 amino acids which are present in the coding sequence. A 3D model of YLLIP8 built from the X-ray structure of the homologous YLLIP2 lipase shows that these truncated amino acids in YLLIP8 belong to an additional C-terminal region predicted to be mainly helical. Western blot analysis shows that YLLIP8 C-tail is rapidly cleaved upon enzyme secretion since both cell-bound and culture supernatant lipases lack this extension. Mature recombinant YLLIP8 displays a true lipase activity on short-, medium- and long-chain triacylglycerols (TAG), with an optimum activity at alkaline pH on medium chain TAG. It has no apparent regioselectivity in TAG hydrolysis, thus generating glycerol and FFAs as final lipolysis products. YLLIP8 properties are distinct from those of the 1,3-regioselective YLLIP2, acting optimally at acidic pH. These lipases are tailored for complementary roles in fatty acid uptake by Y. lipolytica.

Lipase production by Botryosphaeria ribis EC-01 on soybean meal supplemented with amino acids, and some physicochemical properties of the enzyme

The amino acids that form the chemical structure of several lipase catalytic triads (serine, histidine, glutamic or aspartic acid), as well as glycine, were added to soybean meal in distilled water as nutrient for Botryosphaeria ribis EC-01 to produce lipase under submerged fermentation. The addition of glutamic acid at 0.01% concentration increased lipase activity by 60% (2,684 U/gss), while at 0.1% the increase was 80% (3,039 U/gss) by comparison with the control (1,690 U/gss). Glycine also stimulated lipase production on this medium increasing the enzyme production by 31 % (25 UmL -1 ) by comparison to the control (19 UmL -1 ). The optimal pH of this lipase was 8.0 in phosphate buffer, and was stable in the pH range (3–10), while the optimal temperature was 55°C. The fungal lipase remained active in methanol, ethanol and glycerol at concentrations of 25, 10 and 50% (v/v), respectively. The addition of the cations Ba 2+ , Mg 2+ and Mn 2+ increased lipase activity, while Fe 3 , Cu 2+ and Hg 2+ partially inhibited the enzyme. Some kinetic properties demonstrated that B. ribis EC-01 lipase was a true lipase preferring long chain fatty acyl esters as substrates . These properties make B. ribis EC-01 lipase attractive for use in the production of biodiesel.