Differential induction, purification and characterization of cold active lipase from Yarrowia lipolytica NCIM 3639

Simultaneous mitigation of ochratoxin A and zearalenone by Amano lipase A: conditions and application

Mycotoxins such as ochratoxin A (OTA) and zearalenone (ZEA) are secondary metabolites produced by fungi that exhibit high toxicity and are frequently detected in food and beverages, including beer, the third most consumed beverage worldwide, posing a significant public health concern. The mitigation of these contaminants has become an increasingly urgent priority, particularly in the face of climate change, which is expected to exacerbate their prevalence and concentration throughout the food supply chain. In this context, the development of effective, safe, and food-compatible strategies for reducing mycotoxin levels in complex food matrices is essential to ensure both food quality and consumer safety. Accordingly, this study aimed to evaluate the action of the enzyme Amano lipase A (ALA) in the simultaneous mitigation of OTA and ZEA in model solution and Pilsen type beer. The reaction and kinetic parameters (KM and Vmax) were optimized for this. The application of the enzyme (0.3 U mL-1) in the mitigation of OTA and ZEA in beer was evaluated. Under optimal reaction conditions to ALA in model solution, consisting of 50 mM pH 7 phosphate buffer, 40 ºC and 22 h of incubation, it simultaneously degraded OTA and ZEA by up to 100.0 and 30.6%, respectively. The kinetic parameters KM and Vmax of ALA in the mitigation of OTA and ZEA were 0.03 and 3.14 µM and 6.56 × 10-05 and 19.57 × 10-03 μM min-1, respectively. The enzyme degraded 89.5% OTA and 6.5% ZEA. The enzyme ALA presents as an alternative for controlling these contaminants in beer or food.

Extracellular lipase production by Yarrowia lipolytica under magnetic fields

This study aimed at estimating cultivation conditions to enable Yarrowia lipolytica NNRL Y-1095 to produce extracellular lipase and at evaluating the influence of magnetic fields (MF) on the lipase production and on its catalytic conditions. Culture conditions of carbon sources and surfactant defined to produce extracellular lipase were 10 g L-1 glucose, 15 g L-1 olive oil and 2 g L-1 Triton X-100. The highest lipase activity (34.8 U mL-1) was reached after 144 h when MFs were applied from 72 to 144 h of culture. It corresponds to an increase of 287.5% by comparison with the highest lipase activity in the control culture. MF application from 72 to 144 h did not change the optimal temperature of lipase, which was 37 °C, by comparison with the control. However, the optimal pH of the control was 7.0 while the one of lipase produced with MF was 8.0. Findings highlighted that the presence of MFs led to increase in synthesis of lipase by Y. lipolytica, with changes in the catalytic profile. This is one of the first studies of MF application to Y. lipolytica NRRL Y-1095 cultures to produce lipase.

Extremophilic lipases for industrial applications: A general review

With industrialization and development in modern science enzymes and their applications increased widely. There is always a hunt for new proficient enzymes with novel properties to meet specific needs of various industrial sectors. Along with the high efficiency, the green and eco-friendly side of enzymes attracts human attention, as they form a true answer to counter the hazardous and toxic conventional industrial catalyst. Lipases have always earned industrial attention due to the broad range of hydrolytic and synthetic reactions they catalyse. When these catalytic properties get accompanied by features like temperature stability, pH stability, and solvent stability lipases becomes an appropriate tool for use in many industrial processes. Extremophilic lipases offer the same, thermostable: hot and cold active thermophilic and psychrophilic lipases, acid and alkali resistant and active acidophilic and alkaliphilic lipases, and salt tolerant halophilic lipases form excellent biocatalyst for detergent formulations, biofuel synthesis, ester synthesis, food processing, pharmaceuticals, leather, and paper industry. An interesting application of these lipases is in the bioremediation of lipid waste in harsh environments. The review gives a brief account on various extremophilic lipases with emphasis on thermophilic, psychrophilic, halophilic, alkaliphilic, and acidophilic lipases, their sources, biochemical properties, and potential applications in recent decades.

Nutrient biomass production from agro-industrial residues using Yarrowia lipolytica: screening and optimization of growing conditions

Abstract The possibility of using agro-industrial residues in bioconversion processes advances with the development of biotechnology and the search for processes in which is possible to add commercial value to previously discarded products. These processes should be low cost, easy to control and chemical-free. The yeast Yarrowia lipolytica (YL) is widely used to produce lipids, enzymes, citric acid, and proteins, among others. This study aimed to evaluate the capacity of this yeast to use agro-industrial residues as a source of carbon without adding extra carbohydrate sources for the development of cells. The study evaluated the production of proteins and lipids from different carbon sources as well as the optimization of the process (agitation, temperature, and nitrogen source). Indeed, YL produced 22.3% of protein and 9.4% of lipids in dry biomass, a 179% of protein and 660% of lipid increase from raw material, respectively, when using cassava residues as a carbon source. However, lipase production was low, indicating that the strain had priority for cell growth.

Molecular characterization of lipase from a psychrotrophic bacterium Pseudomonas sp. CRBC14

Lipases from Pseudomonas species are particularly useful due to their broader biocatalytic applications and temperature activity. In this study, we amplified the gene encoding wild-type cold-active lipase from the genome of psychrotrophic bacterium isolated from the Himalayan glacier. The isolated CRBC14 strain was identified as Pseudomonas sp. based on the 16S rRNA gene sequence. Lipase activity was determined by observing the hydrolysis zone on nutrient agar containing tributyrin (1%, v/v). The sequence analysis of cold-active lipase revealed a protein of 611 amino acids with a calculated molecular mass of 63.71 kDa. The three-dimensional structure of this lipase was generated through template-supported modeling. Distinct techniques stamped the model quality, following which the binding free energies of tributyrin and oleic acid in the complex state with this enzymatic protein were predicted through molecular mechanics generalized born surface area (MMGBSA). A relative comparison of binding free energy values of these substrates indicated tributyrin's comparatively higher binding propensity towards the lipase. Using molecular docking, we evaluated the binding activity of cold-active lipase against tributyrin and oleic acid. Our docking analysis revealed that the lipase had a higher affinity for tributyrin than oleic acid, as evidenced by our measurement of the hydrolysis zone on two media plates. This study will help to understand the bacterial diversity of unexplored Himalayan glaciers and the possible application of their cold-adapted enzymes.

An encapsulated report on enzyme-assisted transesterification with an allusion to lipase

Biodiesel is a renewable, sulfur-free, toxic-free, and low carbon fuel which possesses enhanced lubricity. Transesterification is the easiest method employed for the production of biodiesel, in which the oil is transformed into biodiesel. Biocatalyst-mediated transesterification is more advantageous than chemical process because of its non-toxic nature, the requirement of mild reaction conditions, absence of saponification, easy product recovery, and production of high-quality biodiesel. Lipases are found to be the primary enzymes in enzyme-mediated transesterification process. Currently, researchers are using lipases as biocatalyst for transesterification. Lipases are extracted from various sources such as plants, microbes, and animals. Biocatalyst-based biodiesel production is not yet commercialized due to high-cost of purified enzymes and higher reaction time for the production process. However, research works are growing in the area of various cost-effective techniques for immobilizing lipase to improve its reusability. And further reduction in the production cost of lipases can be achieved by genetic engineering techniques. The reduction in reaction time can be achieved through ultrasonic-assisted biocatalytic transesterification. Biodiesel production by enzymatic transesterification is affected by many factors. Various methods have been developed to control these factors and improve biodiesel production. This report summarizes the various sources of lipase, various production strategies for lipase and the lipase-mediated transesterification. It is fully focused on the lipase enzyme and its role in biodiesel production. It also covers the detailed explanation of various influencing factors, which affect the lipase-mediated transesterification along with the limitations and scope of lipase in biodiesel production.

Cold Active Lipases: Biocatalytic Tools for Greener Technology

Lipases are enzymes that catalyze the ester bond hydrolysis in triglycerides with the release of fatty acids, mono- and diglycerides, and glycerol. The microbial lipases account for $400 million market size in 2017 and it is expected to reach $590 million by 2023. Many biotechnological processes are expedited at high temperatures and hence much research is dealt with thermostable enzymes. Cold active lipases are now gaining importance in the detergent, synthesis of chiral intermediates and frail/fragile compounds, and food and pharmaceutical industries. In addition, they consume less energy since they are active at low temperatures. These cold active lipases have not been commercially exploited so far compared to mesophilic and thermophilc lipases. Cold active lipases are distributed in microbes found at low temperatures. Only a few microbes were studied for the production of these enzymes. These cold-adapted enzymes show increased flexibility of their structures in response to freezing effect of the cold habitats. This review presents an update on cold-active lipases from microbial sources along with some structural features justifying high enzyme activity at low temperature. In addition, recent achievements on their use in various industries will also be discussed.

Phylogenomic and biochemical analysis reassesses temperate marine yeast Yarrowia lipolytica NCIM 3590 to be Yarrowia bubula

Yarrowia clade contains yeast species morphologically, ecologically, physiologically and genetically diverse in nature. Yarrowia lipolytica NCIM 3590 (NCIM 3590), a biotechnologically important strain, isolated from Scottish sea waters was reinvestigated for its phenotypic, biochemical, molecular and genomic properties as it exhibited characteristics unlike Y. lipolytica, namely, absence of extracellular lipolytic activity, growth at lower temperatures (less than 20 °C) and in high salt concentrations (10% NaCl). Molecular identification using ITS and D1/D2 sequences suggested NCIM 3590 to be 100% identical with reference strain Yarrowia bubula CBS 12934 rather than Y. lipolytica CBS 6124 (87% identity) while phylogenetic analysis revealed that it clustered with Y. bubula under a separate clade. Further, whole genome sequencing of NCIM 3590 was performed using Illumina NextSeq technology and the draft reported here. The overall genome relatedness values obtained by dDDH (94.1%), ANIb/ANIm (99.41/99.42%) and OrthoANI (99.47%) indicated proximity between NCIM 3590 and CBS 12934 as compared to the reference strain Y. lipolytica. No extracellular lipase activity could be detected in NCIM 3590 while LIP2 gene TBLASTN analysis suggests a low 42% identity with e value 2 e-77 and 62% coverage. Hence molecular, phylogenetic, genomics, biochemical and microbial analyses suggests it belongs to Yarrowia bubula.

Purification and characterization of a thermoalkaliphilic esterase from Bacillus cereus WZZ006 for enantioselective resolution of indoxacarb intermediate

An intracellular esterase (BCE) from Bacillus cereus WZZ006 was purified to homogeneity with an 89.5-fold purification, specific activity of 1.79 U/mg, and 26.7% recovery. The estimated molecular weight of BCE was 96 kDa which was analyzed by SDS-PAGE and MALDI-TOF-MS. Activity staining denotes that BCE has an unexplored new carboxyl esterase characteristic. BCE enzyme activity was maximum at pH 8.5 and also at 50 °C with pNP-caproate as a substrate. This indicates that the studied BCE as a thermoalkaliphilic esterase. The kinetic properties like K_m, V_max, kcat and kcat/K_m value for BCE was found to be 0.98 mM, 0.03 mM/min, 69.47 min^-1 and 70.89 mM^-1 min^-1, respectively. Synthesis of (S)-5-chloro-1-oxo-2,3-dihydro-2-hydroxy-1H-indole-2-carboxylic acid methyl ester ((S)-CODHCM) by BCE can be shortened to 3 h compared to 36 h with whole-cell catalysis. The e.e._s achieved was 93.83%, and conversion around 52.78% with E being 39.95. These features render BCE as a promising biocatalyst for the synthesis of a key chiral intermediate for indoxacarb.

Synthesis of flavor esters by a novel lipase from Aspergillus niger in a soybean-solvent system

To find a lipase for synthesis of flavor esters in food processing, a total of 35 putative lipases from Aspergillus niger F0215 were heterologously expressed and their esterification properties in crude preparations were examined. One of them, named An-lipase with the highest esterification rate (23.1%) was selected for further study. The purified An-lipase had the maximal activity at 20 °C and pH 6.5 and the specific activity of 1293 U/mg. Sixty percent of the activity was maintained in a range of temperatures of 0-30 °C and pHs of 3.0-8.5. The highest hydrolysis activity of An-lipase was towards pNPC (C8), followed by pNPB (C4) and pNPA (C2), then pNPL (C12). K _m, V _max, k _cat, and k _cat/K _m towards pNPC were 26.7 mmol/L, 129.9 mmol/(L h), 23.2 s^-1, and 0.8/mM/s, respectively. The ethyl lactate, butyl butyrate, and ethyl caprylate flavor esters were produced by esterification of the corresponding acids with conversion efficiencies of 15.8, 37.5, and 24.7%, respectively, in a soybean-oil-based solvent system. In conclusion, An lipase identified in this study significantly mediated synthesis of predominant flavor esters (ethyl lactate, butyl butyrate, and ethyl caprylate) in a soybean-oil-lacking other toxic organic solvents, which has potential application in food industries.

New Recombinant Cold-Adapted and Organic Solvent Tolerant Lipase from Psychrophilic Pseudomonas sp. LSK25, Isolated from Signy Island Antarctica

In recent years, studies on psychrophilic lipases have become an emerging area of research in the field of enzymology. The study described here focuses on the cold-adapted organic solvent tolerant lipase strain Pseudomonas sp. LSK25 isolated from Signy Station, South Orkney Islands, maritime Antarctic. Strain LSK25 lipase was successfully cloned, sequenced, and over-expressed in an Escherichia coli system. Sequence analysis revealed that the lipase gene of Pseudomonas sp. LSK25 consists of 1432 bp, lacks an N-terminal signal peptide and encodes a mature protein consisting of 476 amino acids. The recombinant LSK25 lipase was purified by single-step purification using Ni-Sepharose affinity chromatography and had a molecular mass of approximately 65 kDa. The final recovery and purification fold were 44% and 1.3, respectively. The LSK25 lipase was optimally active at 30 °C and at pH 6. Stable lipolytic activity was reported between temperatures of 5–30 °C and at pH 6–8. A significant enhancement of lipolytic activity was observed in the presence of Ca²⁺ ions, the organic lipids of rice bran oil and coconut oil, a synthetic C12 ester and a wide range of water immiscible organic solvents. Overall, lipase strain LSK25 is a potentially desirable candidate for biotechnological application, due to its stability at low temperatures, across a range of pH and in organic solvents.

Integration process of fermentation and liquid biphasic flotation for lipase separation from Burkholderia cepacia

Liquid Biphasic Flotation (LBF) is an advanced recovery method that has been effectively applied for biomolecules extraction. The objective of this investigation is to incorporate the fermentation and extraction process of lipase from Burkholderia cepacia using flotation system. Initial study was conducted to compare the performance of bacteria growth and lipase production using flotation and shaker system. From the results obtained, bacteria shows quicker growth and high lipase yield via flotation system. Integration process for lipase separation was investigated and the result showed high efficiency reaching 92.29% and yield of 95.73%. Upscaling of the flotation system exhibited consistent result with the lab-scale which are 89.53% efficiency and 93.82% yield. The combination of upstream and downstream processes in a single system enables the acceleration of product formation, improves the product yield and facilitates downstream processing. This integration system demonstrated its potential for biomolecules fermentation and separation that possibly open new opportunities for industrial production.

Valorization of papaya fruit waste through low-cost fractionation and microbial conversion of both juice and seed lipids

Seed oil from papaya waste was validated as a novel carbon substrate for Yarrowia lipolytica to produce high-value products.

Biodiesel production from lipid of carbon dioxide sequestrating bacterium and lipase of psychrotolerant Pseudomonas sp. ISTPL3 immobilized on biochar

An extracellular lipase was purified and characterized from psychrotolerant bacterium Pseudomonas sp. ISTPL3 isolated from Pangong lake. Lipase was purified by sequential methods of ammonium sulphate precipitation, dialysis, DEAE-cellulose ion exchange chromatography and Sephadex G-100 gel filtration chromatography, resulting in a purification fold of 6.53 and yield of 5.45%. The molecular weight was approximately 31kDa. The purified lipase was used for transesterification of lipids produced by oleaginous chemolithotrophic bacterium Serratia sp. ISTD04 for production of biodiesel. Upon biochemical characterization, lipase was found to be alkalophilc, thermostable, active in organic polar solvents and sensitive to detergents. Further, lipase was immobilized on activated biochar to assess its transesterification efficiency during biodiesel production. Immobilized lipase gave the highest yield of fatty acid methyl esters (FAMEs) (92.23%)>unimmobilized lipase>NaOH. The immobilized lipase was assessed for its reusability and retained 75.11% of its activity after 3 cycles of biodiesel production.

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.

Purification and Characterization of a Novel Cold-Active Lipase from the Yeast Candida zeylanoides

Cold-active lipases have attracted attention in recent years due to their potential applications in reactions requiring lower temperatures. Both bacterial and fungal lipases have been investigated, each having distinct advantages for particular applications. Among yeasts, cold-active lipases from the genera Candida, Yarrowia, Rhodotorula, and Pichia have been reported. In this paper, biosynthesis and properties of a novel cold-active lipase from Candida zeylanoides isolated from refrigerated poultry meat are described. Heat-sterilized olive oil was found to be the best lipase biosynthesis inducer, while nonionic detergents were not effective. The enzyme was purified to homogeneity using hydrophobic chromatography and its enzymatic properties were tested. Pure enzyme activity at 7 °C was about 60% of the maximal activity at 27 °C. The enzyme had rather good activity at higher temperatures, as well. Optimal pH of pure lipase was between 7.3 and 8.2, while the enzyme from the crude extract had an optimum pH of about 9.0. The enzyme was sensitive to high ionic strength and lost most of its activity at high salt concentrations. Due to the described properties, cold-active C. zeylanoides lipase has comparative advantages to most similar enzymes with technological applications and may have potential to become an industrially important enzyme.

Expression and characterization of a novel 1,3-regioselective cold-adapted lipase from Rhizomucor endophyticus suitable for biodiesel synthesis

BACKGROUND

The biodiesel production can be carried out by transesterification using either chemical or enzymatic process. The enzymatic transesterification is more promising as it offers an environmental friendly option compared to the chemical process, where the lipases with high catalytic efficiency and good stability play a key role. Hence, it is of great value to identify novel lipases which are suitable for biodiesel production.

RESULTS

A lipase gene (ReLipA) from Rhizomucor endophyticus was cloned and heterologously expressed in Pichia pastoris. ReLipA shared the highest identity of 61 % with the lipases from Rhizopus delemar, Rhizopus oryzae, and Saccharomyces cerevisiae. The recombinant lipase (ReLipA) was secreted as an active protein with the highest activity of 1961 U mL(-1) in a 5-L fermentor by high cell-density fermentation. ReLipA was purified to homogeneity with a recovery yield of 75.7 %. The purified enzyme was most active at pH 6.0 and 40 °C, respectively, and it was stable up to 55 °C. ReLipA displayed 75 % of its maximal activity at 0 °C, indicating that it is a cold-adapted lipase. It exhibited broad substrate specificity toward various p-nitrophenyl esters and triglycerides. ReLipA hydrolyzed triolein to release mainly 1,2-diolein without the formation of 1,3-diolein, suggesting that it is a sn-1,3 regiospecific lipase. Furthermore, ReLipA synthesized different types of oleates by esterification using oleic acid and short chain alcohols (e.g., methanol, ethanol, and butanol) as the substrates with the highest conversion yield of 82.2 %. Therefore, the cold-adapted lipase may be a good biocatalyst in ester synthesis in biodiesel industry.

CONCLUSIONS

A novel cold-adapted lipase was identified and characterized. The high yield and excellent properties may confer the enzyme with great potential for biodiesel production in bioenergy industry. This is the first report on a cold-adapted lipase from Rhizomucor species.

Expression, purification and characterization of a functional, recombinant, cold-active lipase (LipA) from psychrotrophic Yersinia enterocolitica

A novel cold-active lipase gene encoding 294 amino acid residues was obtained from the Yersinia enterocolitica strain KM1. Sequence alignment and phylogenetic analysis revealed that this novel lipase is a new member of the bacterial lipase family I.1. The lipase shares the conserved GXSXG motif and catalytic triad Ser85-Asp239-His261. The recombinant protein LipA was solubly and heterogeneously expressed in Escherichia coli, purified by Ni-affinity chromatography, and then characterized. LipA was active over a broad range spanning 15-60°C with an optimum activity at 25°C and across a wide pH range from 5.0 to 11.0 with an optimum activity at pH 7.5. The molecular weight was estimated to be 34.2 KDa. The lipase could be activated by Mg(2+) and a low concentration (10%) of ethanol, dimethyl sulfoxide, methanol and acetonitrile, whereas it was strongly inhibited by Zn(2+), Cu(2+) and Mn(2+). This cold-active lipase may be a good candidate for detergents and biocatalysts at low temperature.

Characterization of an acidic cold-adapted cutinase from Thielavia terrestris and its application in flavor ester synthesis

An acidic cutinase (TtcutB) from Thielavia terrestris CAU709 was purified to apparent homogeneity with 983 Um g(-1) specific activity. The molecular mass of the enzyme was estimated to be 27.3 and 27.9 kDa by SDS-PAGE and gel filtration, respectively. A peptide sequence homology search revealed no homologous cutinases from T. terrestris, except for one putative cutinase gene (XP003656017.1), indicating that TtcutB is a novel enzyme. TtcutB exhibited an acidic pH optimum of 4.0, and stability at pH 2.5-10.5. Optimal activity was at 55 °C, it was stable up to 65 °C, and retained over 30% activity at 0 °C. Km values toward p-nitrophenyl (pNP) acetate, pNP-butyrate and pNP-caproate were 8.3, 1.1 and 0.88 mM, respectively. The cutinase exhibited strong synthetic activity on flavor ester butyl butyrate under non-aqueous environment, and the highest esterification efficiency of 95% was observed under the optimized reaction conditions. The enzyme's unique biochemical properties suggest great potential in flavor esters-producing industries.

Purification and characterization of an extracellular cold-adapted alkaline lipase produced by psychrotrophic bacterium Yersinia enterocolitica strain KM1

An extracellular cold-adapted alkaline lipase from the psychrotrophic Yersinia enterocolitica strain KM1 was purified 26-fold to homogeneity. The enzyme was active over a broad range spanning 0-60 °C with an optimum activity at 37 °C, and it was found to be alkaline-preferring with an optimum activity at pH 9.0. The molecular weight was estimated to be 34.3 KDa and monomeric. The lipase could be activated by Ca(2+) and low concentration (10%) of ethanol, dimethyl sulphoxide, methanol, and acetonitrile, whereas it was strongly inhibited by Zn(2+), Cu(2+), SDS, EDTA, and PMSF. Using p-nitrophenyl butyrate as a substrate at 37 °C, the Km and Vmax of the enzyme were found to be 16.58 mM and 5.24 × 10(5)  μM · min(-1), respectively. This extracellular cold-adapted alkaline lipase may be a good candidate for detergents and biocatalysts at low temperature.

Yarrowia lipolytica and its multiple applications in the biotechnological industry

Yarrowia lipolytica is a nonpathogenic dimorphic aerobic yeast that stands out due to its ability to grow in hydrophobic environments. This property allowed this yeast to develop an ability to metabolize triglycerides and fatty acids as carbon sources. This feature enables using this species in the bioremediation of environments contaminated with oil spill. In addition, Y. lipolytica has been calling the interest of researchers due to its huge biotechnological potential, associated with the production of several types of metabolites, such as bio-surfactants, γ-decalactone, citric acid, and intracellular lipids and lipase. The production of a metabolite rather than another is influenced by the growing conditions to which Y. lipolytica is subjected. The choice of carbon and nitrogen sources to be used, as well as their concentrations in the growth medium, and the careful determination of fermentation parameters, pH, temperature, and agitation (oxygenation), are essential for efficient metabolites production. This review discusses the biotechnological potential of Y. lipolytica and the best growing conditions for production of some metabolites of biotechnological interest.

Screening, purification and characterization of a novel cold-active and organic solvent-tolerant lipase from Stenotrophomonas maltophilia CGMCC 4254

An extracellular organic solvent-tolerant and cold-active lipase producing bacterium was isolated from oil-contaminated soil samples, and identified taxonomically as Stenotrophomonas maltophilia. The lipase from S. maltophilia CGMCC 4254 (SML) was purified 60.5-fold to homogeneity with 38.9 U/mg specific activity. Partially purified SML displayed remarkable stability in 50% and 100% (v/v) hydrophobic organic solvents after incubation for 7 days. The enzyme also retained more than 50% of its residual activity in several pure hydrophilic organic solvents after incubation for 7 days. SML showed 57% maximum activity at 5°C, and had optimal activity at 35°C. These unique properties of SML make it promising as a biocatalyst for industrial processes.

Efficient lipase purification using reverse micellar extraction

Reverse micellar extraction (RME) of enzyme provides an attractive option for conventional method with the potential to achieve purification and concentration in a single step with high yield. This study presents a methodology for optimization of RME with Pseudomonas lipase as model system. Fold-purification, percent recovery and extraction time were the objective functions while the type and concentration of surfactant, contact time, pH, ionic strength, and the ratio of organic to aqueous phase were the decision variables. Under optimized conditions, the AOT (Aerosol OT (bis 2-ethylhexyl) sodium sulfosuccinate)-isooctane system gave a 15-fold purification, 80% recovery and 2.5-fold concentration of the Pseudomonas lipase with process time of 45 min.