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Lipases are enzymes that hydrolyze long-chain carboxylic esters, and in the presence of organic solvents, they catalyze organic synthesis reactions. However, the use of solvents in these processes often results in enzyme denaturation, leading to a reduction in enzymatic activity. Consequently, there is significant interest in identifying new lipases that are resistant to denaturing conditions, with extremozymes emerging as promising candidates for this purpose. Lip7, a lipase from Geobacillus sp. ID17, a thermophilic microorganism isolated from Deception Island, Antarctica, was recombinantly expressed in E. coli C41 (DE3) in functional soluble form. Its purification was achieved with 96% purity and 23% yield. Enzymatic characterization revealed Lip7 to be a thermo-alkaline enzyme, reaching a maximum rate of 3350 U mg−1 at 50 °C and pH 11.0, using p-nitrophenyl laurate substrate. Notably, its kinetics displayed a sigmoidal behavior, with a higher kinetic efficiency (kcat/Km) for substrates of 12-carbon atom chain. In terms of thermal stability, Lip7 demonstrates stability up to 60 °C at pH 8.0 and up to 50 °C at pH 11.0. Remarkably, it showed high stability in the presence of organic solvents, and under certain conditions even exhibited enzymatic activation, reaching up to 2.5-fold and 1.35-fold after incubation in 50% v/v ethanol and 70% v/v isopropanol, respectively. Lip7 represents one of the first lipases from the bacterial subfamily I.5 and genus Geobacillus with activity and stability at pH 11.0. Its compatibility with organic solvents makes it a compelling candidate for future research in biocatalysis and various biotechnological applications. [ABSTRACT FROM AUTHOR]

The present study aimed to screen and optimize lipase production by the Antarctic strain Acinetobacter johnsonii Ant12 for lipid-rich wastewater treatment. Lipase production was successfully enhanced threefold through optimization of culture conditions. The optimum crude lipase activity was observed at 50 °C with high stability in a wide temperature range. The lipase also exhibited high activity and stability in the presence of solvents, metal ions, and surfactants. The crude lipase was used for the treatment of lipid-rich wastewater, which poses a significant challenge, as traditional removal methods are often inefficient or non-eco-friendly. In this study, bioaugmentation with Ant12 resulted in substantial lipid reduction in synthetic as well as real-world wastewater. Multiple linear regression analysis showed that lipid concentration and time were the most significant factors influencing lipid degradation. Bioaugmentation of real-world wastewater with Ant12 cells resulted in 84% removal of lipids in 72 h, while its crude lipase degraded 73.7% of lipids after 24 h. Thus, the specific rate of lipid degradation was higher for crude lipase (0.095/h) than the whole cell treatment (0.031/h). Economic analysis revealed that crude lipase production was much cheaper, faster and more eco-friendly than purified or partially purified lipase production, which justifies its use in wastewater treatment. The high activity of enzyme also implicates its application as a detergent additive. In our knowledge, it is the first study to establish A. johnsonii isolate from Antarctica for lipid-rich wastewater treatment. [ABSTRACT FROM AUTHOR]

The catalytic performance of various biocatalysts obtained by the adsorption of lipase B from Candida antarctica (CaL-B) onto and into polyvinyl alcohol (PVA) and polylactic acid (PLA) nanofibers were tested in the kinetic resolution of racemic 1-benzo[b]thiophen-2-yl-ethanol by transesterification. Best performance regarding reaction velocity and selectivity was registered for CaL-B adsorbed onto PLA nanofibers. The high operational stability of this biocatalyst was confirmed in recycling experiments, after 5 cycles the biocatalyst maintained 86.6% of its initial activity. The optimal process parameters in continuous flow mode also were established. [ABSTRACT FROM AUTHOR]

Ceramides are sphingolipid compounds that are very attractive as active components in both the pharmaceutical and the cosmetic industries. In this study, the synthesis of 1-O,3-N-diacyl 3-amino-1,2-propanediol-type pseudo-ceramides was developed at the semi-pilot scale, starting from a two-step continuous enzymatic process with immobilized Candida antarctica lipase B (Novozym® 435) in a packedbed bioreactor, previously optimized at the laboratory scale. This process involved the selective N-acylation of 3-amino-1,2-propanediol (step 1), followed by the selective O-acylation of the N-acyl 3-amino-1,2-propanediol synthesized in the first step, with various fatty acids as acyl donors, to produce N,O-diacyl 3-amino-1,2-propanediol-type pseudo-ceramides (step 2). Under partially optimized operating conditions, high synthesis yields and production rates were obtained, within the ranges 76-92% and 3.7-4.6 g h-1 (step 1), or 23-36% and 1-1.4 g h-1 (step 2), respectively, depending on the fatty acids used as acyl donors. The overall synthesis yields varied from 20 to 33%: the best yield was obtained using palmitic acid and lauric acid as first and second acyl donors, respectively. Together with the high production rates also obtained with these acyl donors, this confirms that this two-step process has great potential for the production of differently functionalized 1-O,3-N-diacyl 3-amino-1,2-propanediol-type pseudo-ceramides on an industrial scale. [ABSTRACT FROM AUTHOR]

An extracellular cold active lipase-producing psychrotrophic bacterium (BRI 8) was isolated from the Antarctic sea water sample. The 16s rRNA sequence study revealed that the isolate belongs to the genus Halomonas (929 bp). The present paper reports optimization of fermentation conditions for production of lipase (EC 3.1.1.3) from Halomonas sp. BRI 8. Highest lipase production was observed in the medium containing olive oil and peptone. The optimum pH and temperature for enzyme catalysis were 7.0 and 10°C respectively. The enzyme was relatively more stable in acidic pH range and retained 50% activity when incubated at 30°C for 1 h. The enzyme was stable in various organic solvents and showed more than 100% activity in presence of isoamyl alcohol. Significant enzyme activity was also observed in the presence of metal ions and detergents. The molecular mass of partially purified lipase was found to be around 66 kD. [ABSTRACT FROM AUTHOR]

The aim of the present study was to investigate the taxonomic identity of yeasts isolated from the Antarctic continent and to evaluate their ability to produce enzymes (lipase, protease and xylanase) at low and moderate temperatures. A total of 97 yeast strains were recovered from marine and terrestrial samples collected in the Antarctica. The highest amount of yeast strains was obtained from marine sediments, followed by lichens, ornithogenic soils, sea stars, Salpa sp., algae, sea urchin, sea squirt, stone with lichens, Nacella concinna, sea sponge, sea isopod and sea snail. Data from polyphasic taxonomy revealed the presence of 21 yeast species, distributed in the phylum Ascomycota ( n = 8) and Basidiomycota ( n = 13). Representatives of encapsulated yeasts, belonging to genera Rhodotorula and Cryptococcus were recovered from 7 different Antarctic samples. Moreover, Candida glaebosa, Cryptococcus victoriae, Meyerozyma (Pichia) guilliermondii, Rhodotorula mucilaginosa and R. laryngis were the most abundant yeast species recovered. This is the first report of the occurrence of some species of yeasts recovered from Antarctic marine invertebrates. Additionally, results from enzymes production at low/moderate temperatures revealed that the Antarctic environment contains metabolically diverse cultivable yeasts, which could be considered as a target for biotechnological applications. Among the evaluated yeasts in the present study 46.39, 37.11 and 14.43 % were able to produce lipase (at 15 °C), xylanase (at 15 °C) and protease (at 25 °C), respectively. The majority of lipolytic, proteolytic and xylanolytic strains were distributed in the phylum Basidiomycota and were mainly recovered from sea stars, lichens, sea urchin and marine sediments. [ABSTRACT FROM AUTHOR]

Cryotolerance in microorganisms from polar regions provides their survival through alternating freezing and thawing cycles. Our research was aimed at biodiversity analysis of culturable bacteria from the King George Island near Antarctica including their antibiotic resistance and cold-adaptive enzymes. Average bacterial density was estimated as 3 × 106 cells/mL but the number of colony-forming units (CFU) was essentially lower - (3.2–9.2)x103 cells/mL. Totally, 83 stable strains were isolated and identified using phylogenetic analysis of 16S rRNA gene nucleotide sequences and phenotypic traits. Main groups were the Gram-negative Pseudomonas and Duganella species as well as Gram-positive Arthrobacter spp. Besides, eubacteria Psychrobacter , Flavobacterium , Clavibacter , Aquaspirillum , Polaromonas , Actinibacterium, Shewanella, Kocuria and families Comamonadacea, Actinobacteridae were found. Genetic diversity of the bacteria was elevated with plasmids of different lengths in 33 strains but no correlation between the plasmids content and antibiotic resistance was found. Among cold-adapted enzymes antioxidant catalases (91.5%), peroxidases (57.5%), alkaline phosphatases (42.2%) prevailed; unspecific exonucleases were revealed in 16.9% strains and restriction endonucleases of type II - in 8.4% strains only. Lypases were detected in 24 strains (28.9%) and could facilitate membrane fluidity at low temperatures. Despite the antibiotic resistance the Antarctic cultivable eubacteria are mainly not pathogenic and may serve as sources of plasmids and cold-adapted enzymes for biotechnology. [Display omitted] [ABSTRACT FROM AUTHOR]

Highlights: [•] LipG7, an enantioselective, cold-adapted lipase was purified. [•] LipG7 retains 100% of initial activity after thermal denaturation. [•] LipG7 effectively catalysed the enantioselective transesterification of a secondary alcohol. [•] Low coverage, high throughput transcriptome sequencing identified the LipG7 gene. [•] Heterologously expressed LipG7 retains its thermostability characteristics. [Copyright &y& Elsevier]

Abstract: The suitability of two different imidazolium-based families of ionic liquids (ILs) involving alkylsulfate and alkylsulfonate anions to act as solvents in an aqueous biphasic system for the extraction of lipase A from Candida antarctica has been investigated. Both high charge–density salts and aminoacids have been studied in order to evaluate both their potential as two-phase forming agents and as stabilizers of the active conformation of the enzyme. Extraction with 1-ethyl-3-methylimidazolium butyl sulfate [C2MIM][C4SO4] with ammonium sulfate affords an enzyme recovery of 99%. The structural conformation of the enzyme was analyzed by Fourier transform infrared data. [Copyright &y& Elsevier]

Abstract: Enzyme-catalyzed degradation of PCL films with embedded Candida antarctica Lipase B (CALB, 1.6%-by-wt) under continuous fluid exchange (flow) conditions and in controlled humidity desiccators were determined. At 0.2 mL/min flow rate, film weight loss reached 85% in 3 d relative to bulk-no flow incubations where 70% degradation occurred in 9 days. This increase in rate under flow conditions is attributed to more efficient removal of degradation products that can act as competitive inhibitors. However, further increase in flow rate from 0.2 to 0.5 mL/min results in slower weight loss (7 days, 70%) as increased flow rate appears to negatively influence enzyme stability. Another intriguing discovery is that, by using flow in place of bulk-no flow conditions, removal of degradation products is more efficient leading to formation of a porous matrix where SEM cross sectional images show larger better defined pores. The unusual phenomenon of high porosity matrices resulting from enzyme-catalyzed hydrolysis is unique to embedded enzyme systems. Studies were also conducted where 1.6% CALB-embedded PCL films were incubated in desiccators set at 20, 75 and 95% relative humidity (RH). Water-uptake and molecular weight change at 20% RH were insignificant. However, at 75 and 95% RH, by 28 days, %-water content increased to 0.30 and 0.82, and film M n decreased by 25% to 59,300 and 58% to 33,900, respectively. While stability under controlled low-humidity environments demonstrates options for safe storage, applications are envisioned where the unique degradation properties of enzyme-embedded bioresorbable films will be exploited for release of actives ranging from fragrances, flavors and therapeutic agents. [Copyright &y& Elsevier]

Enzyme-catalyzed degradation of poly(trimethylene carbonate) homo-polymer (PTMC) and poly(trimethy-lene carbonate-co-glycolide) co-polymer (PTGA) was investigated in the presence of lipases from Candida antarctica and Hog pancreas. Degradation was monitored by gravimetry, size-exclusion chromatography (SEC), nuclear magnetic resonance (NMR), tensiometry and environmental scanning electron microscopy (ESEM). PTMC can be rapidly degraded by Candida antarctica lipase with 98% mass loss after 9 days, while degradation by Hog pancreas lipase leads to 27% mass loss. Introduction of 16% glycolide units in PTMC chains strongly affects the enzymatic degradation. Hog pancreas lipase becomes more effective to PTGA co-polymer with a mass loss of 58% after 9 days, while Candida antarctica lipase seems not able to degrade PTGA. Bimodal molecular weight distributions are observed during enzymatic degradation of both PTMC and PTGA, which can be assigned to the fact that the surface is largely degraded while the internal part remains intact. The composition of the PTGA co-polymer remains constant, and ESEM shows that the polymers are homogeneously eroded during enzymatic degradation. Contact angle measurements confirm the enzymatic degradation mechanism, i.e., enzyme adsorption on the polymer surface followed by enzyme-catalyzed chain cleavage. [ABSTRACT FROM AUTHOR]

Abstract: Candida antarctica lipase B (CalB) is one of the most widely used biocatalysts in organic synthesis. The traditional method for purification of CalB is a multi-step, high cost and low recovery procedure. Biomimetic affinity purification had high efficiency purification. We selected 298 ligand columns from a 700-member library of synthetic ligands to screen Pichia pastoris protein extract. Of the 298, three columns (named as A9-14, A9-10, and A11-33) had one-step purification effect, and A9-14 of these affinity ligands, had both high purification and recovery. The one-step recovery of CalB reached 73% and the purification reached 91% upon purification. The active groups of A9-14 were cyclohexylamine and propenylamine. Furthermore, both A9-14 and A9-10 had the same R1 active group of cyclohexylamine which might act the main binding role for CalB. The synthetic ligand A9-14 had a binding capacity of 0.4mg/mL and had no negative effects on its hydrolytic activity. Unlike a natural affinity ligand, this synthetic ligand is highly stable to resist 1M NaOH, and thus has great potential for industrial scale production of CalB. [Copyright &y& Elsevier]

Antarctic bacteria producing extracellular lipolytic enzymes with activity at low temperature were isolated, and the most promising strain, named G, was identified as a Psychrobacter species based on 16S rDNA sequence alignment. The genomic DNA of this bacterium was used to construct its plasmid genomic library into pUC118 plasmid vectors, and to screen the cold-active lipolytic enzyme genes. Two genes encoding for cold-active lipolytic enzymes, Lip-1452 (with an open reading frame of 1452 bp in length) and Lip-948 (with an open reading frame of 948 bp in length), were screened. The primary structure of the two lipases deduced from the nucleotide sequence showed a consensus pentapeptide containing the active serine ( Lip-1452, GDSAG, and Lip-948, GNSMG) and a conserved His-Gly dipeptide in the N-terminal part of the enzyme. Protein sequence alignment and conserved regions analysis indicated that the two lipases probably belonged to family IV and family V of the bacterial lipolytic enzymes, respectively. The upstream and downstream sequences of the two lipolytic lipases were also obtained. The two lipase genes were cloned into the expression vector pCold III and integrated into Escherichia coli BL21 (DE3). The functional expression of both lipase genes by E. coli BL21 (DE3) cells was observed as the formation of clear haloes around colonies on a 1% (vol/vol) tributyrin plate upon induction with isopropyl-β--thiogalactopyranoside at 5°C. A lipase activity assay showed that the specific activity of the pCold III+ Lip-948 expression system was up to 3.7 U ml, whereas that of pCold III+ Lip-1452 was very low. [ABSTRACT FROM AUTHOR]

During the summer 2005/06, an oceanographic cruise was carried out in the Ross Sea, from Cape Adare, through the Terra Nova Bay polynya to the eastern edge of the Ross Ice Shelf. We analysed microbial activities (prokaryotic carbon production, protease, phosphatase, beta-glucosidase and lipase activity) and bacterial community structure (using Denaturing Gradient Gel Electrophoresis - DGGE) in order to establish if differences in bacterioplankton assemblages and their metabolic requirements occur within the five Ross Sea water masses: Antarctic Surface Waters (AASW), High Salinity Shelf Water (HSSW), Ice Shelf Water (ISW), Antarctic Bottom Water (AABW), Circumpolar Deep Water (CDW). Differences in activities were found between the highly active AASW and all the other water bodies. A Principal Component Analysis highlighted two main gradients: in the Cape Adare area (AASWn, CDW and AABW) higher phosphatase, lipase and glycolytic activities, increasing towards the surface, were identified, whereas in the southern sector of the basin [AASWs and (m)HSSW] higher leucine uptake and polypeptide degradation characterized the second gradient. DGGE fingerprinting showed for the first time that different water masses harboured diverse bacterial communities, highlighting the high specificity of deep water assemblages. Alpha- and Gammaproteobacteria represented the main phylogenetic groupings in all samples and no substantial difference in the phylogenetic composition of assemblages was found between different water masses. [ABSTRACT FROM AUTHOR]

Background: The Lipase Engineering Database (LED) integrates information on sequence, structure and function of lipases, esterases and related proteins with the α/β hydrolase fold. A new superfamily for Candida antarctica lipase A (CALA) was introduced including the recently published crystal structure of CALA. Since CALA has a highly divergent sequence in comparison to other α/β hydrolases, the Lipase Engineering Database was used to classify CALA in the frame of the already established classification system. This involved the comparison of CALA to similar structures as well as sequence-based comparisons against the content of the LED. Results: The new release 3.0 (December 2009) of the Lipase Engineering Database contains 24783 sequence entries for 18585 proteins as well as 656 experimentally determined protein structures, including the structure of CALA. In comparison to the previous release [1] with 4322 protein and 167 structure entries this update represents a significant increase in data volume. By comparing CALA to representative structures from all superfamilies, a structure from the deacetylase superfamily was found to be most similar to the structure of CALA. While the α/β hydrolase fold is conserved in both proteins, the major difference is found in the cap region. Sequence alignments between both proteins show a sequence similarity of only 15%. A multisequence alignment of both protein families was used to create hidden Markov models for the cap region of CALA and showed that the cap region of CALA is unique among all other proteins of the α/β hydrolase fold. By specifically comparing the substrate binding pocket of CALA to other binding pockets of α/β hydrolases, the binding pocket of Candida rugosa lipase was identified as being highly similar. This similarity also applied to the lid of Candida rugosa lipase in comparison to the potential lid of CALA. Conclusion: The LED serves as a valuable tool for the systematic analysis of single proteins or protein families. The updated release 3.0 was used for the evaluation of α/β hydrolases. The HTML version of the database with new features is available at http://www.led.uni-stuttgart.de and provides sequences, structures and a set of analysis tools including phylogenetic trees and HMM profiles [ABSTRACT FROM AUTHOR]

Abstract: Enzymatic syntheses of biodiesel via alcoholysis of different vegetable oils (sunflower, borage, olive and soybean) have been studied. Loss of lipase activity induced by the nucleophile is greater with methanol than with ethanol, and is greater for Lipozyme® TL IM than for Novozym® 435. The optimum volume of ethanol depends on the loading of solid biocatalyst and is higher for preparations of Novozym® 435 than for Lipozyme® TL IM. Maximum rates were obtained with Lipozyme® TL IM, for a molar ratio of alcohol to FA residues of 0.33. By contrast, Novozym® 435 requires at least a 2:1 ratio. Alcoholysis of the vegetable oils is faster with Lipozyme® TL IM than with Novozym® 435. Use of a high loading of Novozym® 435 (50% w/w) and a large molar excess of ethanol are required to obtain an initial rate similar to that obtained with Lipozyme® TL IM at a lower enzyme loading (10% w/w) and an equimolar ratio of ethanol and FA residues. Novozym® 435 produces quantitative conversions in only 7h at 25°C, but complete conversions are not obtained with Lipozyme® TL IM. Three stage stepwise addition of ethanol yields 84% conversion to ethyl esters for Lipozyme® TL IM. Hence use of Novozym® 435 is preferred. After nine cycles in a batch reactor Novozym® 435 retained 85% of its initial activity. [Copyright &y& Elsevier]

Abstract: Both enantiomers of 6-methyl-ε-caprolactone (6-MeCL) are obtained in high enantiomeric excess by the combination of an enzymatic ring opening of racemic 6-methyl-ε-caprolactone and subsequent enzymatic ring closure. Immobilized Candida antarctica lipase B (Novozym 435) was selected as the biocatalyst for both the ring-opening and the ring-closing reaction. This route provides ready access to enantiopure (S)-6-MeCL (ee=99.6%) and (R)-6-MeCL (ee=98.8%). [Copyright &y& Elsevier]

Abstract: Candida antarctica lipase-catalyzed hydrolysis of O-butyryl-BINOL [(±)-3] or O-butyryl-6,6′-dibromo-BINOL [(±)-5] yielded optically active BINOL [(R)-1] or 6,6′-dibromo-BINOL [(R)-4] with high enantiomeric excess at 80°C. Reaction temperature and acyl group of substrate had a great influence on the reactivity and enantioselectivity, respectively, of lipase-catalyzed hydrolysis for chiral binaphthol synthesis. [Copyright &y& Elsevier]

A single-step acylation of rutin and naringin, catalyzed by immobilized Candida antarctica lipase B in 2-methyl-2-butanol, occurred preferentially on the primary hydroxyl group. Using palmitic methyl ester as acyl donor, the acylation rate of naringin was 10-fold higher than that of rutin. Under optimal conditions, i.e. a molar ratio acyl donor/naringin of 7:1 and 200 mbar, 92% naringin was acylated. [ABSTRACT FROM AUTHOR]

Antarctic fishes of the suborder Notothenioidei characteristically possess large stores of neutral lipids that have been shown to be important both in conferring buoyant lift and as a caloric resource for energy metabolism. Previous work has established that the aerobic energy metabolism of Antarctic fish is fueled predominantly by the catabolism of fatty acids, with the catabolic machinery displaying a preference for the oxidation of unsaturated fatty acids. The composition of the fatty acids released from adipose tissue of Antarctic fish during lipolysis, however, has not previously been demonstrated. Employing a substrate competition assay, we have characterized the substrate specificity of hormone-sensitive lipase (HSL) from adipose tissue of the Antarctic fish Trematomus newnesi. Rates of oleic acid release from radiolabeled triolein were quantified in the presence and absence of a nonradiolabeled cosubstrate. Polyunsaturated species of triacylglycerols (TAGs) containing 18:2 or 20:4 depressed rates of oleate release by 70-75% below control values. Most of the molecular species of TAG containing monoenoic fatty acids (i.e. those containing 14:1, 16:1 or 20:1) had no significant effect on rates of oleate release. By contrast, oleate release from triolein was actually stimulated (by 2-4-fold) by both saturated species of TAG (i.e. those containing 14:0, 16:0 and 18:0) and those possessing long-chain (22:1 and 24:1) monoenes (by 1.2-1.5-fold). Thus, the rank order of substrate preference for adipose tissue HSL was: polyunsaturates > monoenes > saturates. Degree of fatty acid unsaturation had a more marked effect on rates of hydrolysis than did fatty acid chain length. In addition, the enzyme displayed a preference for the hydrolysis of sn1,2 rather than sn-1,3 diacylglycerols. These data indicate that the substrate specificity of adipose tissue HSL may be an important factor in determining which fatty acids are mobilized during stimulated lipolysis and which are made available for catabolism by other tissues of Antarctic fishes. Our data further suggest that TAGs containing some saturated fatty acids may be sufficiently poor substrates for catabolism by HSL to explain their disproportionate accumulation in adipose tissue. Such a mechanism could also contribute to the ontogenetic accumulation of fats that has been reported as an underlying basis for the positive correlation of buoyancy with increasing body mass in this group. [ABSTRACT FROM AUTHOR]

We successfully isolated a lipase gene (designated lipPA) directly from the genomic DNA of an Antarctic isolate of Penicillium allii using PCR and a suite of degenerate primers specifically designed to target two conserved regions of fungal lipase genes. We applied the biolistic transformation system to successfully integrate the lipPA gene into a heterologous fungal host, Trichoderma reesei, one of the most powerful secretors of extracellular proteins, and induced the transformant to secrete an active lipase into the growth medium. The recombinant lipase had a temperature optimum of 25 °C at pH 7.9 and retained greater than 50% of the maximum activity from 10 °C to 35 °C and over a pH range from 4.0 to 8.5. [ABSTRACT FROM AUTHOR]

The activity of the lipolytic enzyme, triacylglycerol lipase (TAG lipase; E.C. 3.1.1.3) was measured in heart ventricle, liver, oxidative skeletal muscle, and adipose tissue of four species of Antarctic fishes (Chaenocephalus aceratus, Notothenia coriiceps, Trematomus newnesi, Gobionotothen gibberifrons). Estimates of weight-specific activities at 0°C in tissues of the Antarctic fishes were broadly comparable to those reported for temperate-zone fish species assayed at their physiological temperature. Within each species, liver tissue displayed the highest weight-specific activity of TAG lipase in C. aceratus, T. newnesi, and G. gibberifrons, while adipose tissue of N. coriiceps showed the highest activity within that species. Combining these estimates with carefully measured somatic indices of the tissues, permitted assessment of the relative importance of different tissues to overall lipolytic capacity on an organismal level. On this basis, liver tissue displays the greatest capacity of TAG lipase per 100 g body weight in each of the species studied. [ABSTRACT FROM AUTHOR]

Candida antarctica B lipase-catalysed alcoholysis of 2′, 3′, 5′-tri-O-hexanoyluridine (1a), 2′, 3′, 5′-tri-O-dodecanoyluridine (1b), 2′, 3′, 5′-tri-O-hexanoylinosine (1c) and 2′, 3′, 5′-tri-O-dodecanoylinosine (1d) proceeded regioselectively to produce the corresponding 2′, 3′-di-O-acylribonucleosides 2a–d, providing a simple and efficient access to these new lipophilic compounds. Contrasting to the alcoholysis, enzymatic hydrolysis of 1a–d using different enzymes and experimental conditions did not proceed regioselectively. [ABSTRACT FROM AUTHOR]

The activities of four immobilized lipases for glycerolysis of a commercially available fish oil (TG500) rich in eicosapentaenoic residues (>58%, w/w) have been characterized in solvent-free systems. The effects of the mole ratio of TG500 to glycerol and temperature have been investigated. The highest conversion was obtained at 60 °C with a Candida antarctica fraction B lipase (Chirazyme L-2) and a mole ratio of TG500 (based on fatty acid equivalents) to glycerol of 1.5 to 1. [ABSTRACT FROM AUTHOR]

The search for microbial enzymes from extreme environments may result in the discovery of biomolecules with different properties. In this sense, the aim of this study was to evaluate and optimize the conditions for lipase production by the marine-derived Antarctic yeast Leucosporidium scottii CRM 728 using an experimental design with different sources of carbon and nitrogen. The applied strategy was composed of three steps, including Plackett-Burman, Central Composite Design (CCD), and validation assay. Among nine variables applied, corn steep liquor, olive oil, and soybean oil showed a positive effect in the lipase production, while urea showed a negative effect. The production of lipase increased 9-fold in comparison to the basal activity when olive oil and corn steep liquor were used as nutrient sources. On the other hand, there was an increase of 4.8-fold when soybean oil and corn steep liquor were used as nutrient sources. The highest amounts of lipase were achieved in non-saline conditions and at 20.0 °C. In this study, the lipase production by the marine-derived psychrotolerant yeast L. scottii was for the first time reported, providing new knowledgement in the field of enzymatic production by extremophilic and marine microbial resource. [Display omitted] • Lipase production by L. scottii CRM 728 was optimized using a mathematical model. • Corn steep liquor was used as the only nitrogen source. • Lipase production increased 9-fold using olive oil and corn steep liquor. • The best conditions were achieved in a non-saline medium and at 20 °C. [ABSTRACT FROM AUTHOR]