Organic Solvent-tolerant Lipase Research Articles

Expression and characterization of an organic solvent tolerant recombinant lipase from Staphylococcus capitis SH6 for food wastewater treatment

The study illustrated here aims on an organic solvent tolerant lipase from Staphylococcus capitis (SCL). The gene part, encoding the mature lipase, was cloned and sequenced. The concluded polypeptide sequence, equivalent to the protein, consist of 388 amino acid residues with a molecular mass of about 45 kDa. A structure-based alignment of the SCL amino acid sequence shows high identities with those many staphylococcal lipases. From this alignment of sequences, the catalytic triad (Ser 117, Asp 308 and His 347) of SCL could be identified. The mature part of the SCL was expressed in Escherichia coli and the recombinant lipase (r-SCL) was purified to homogeneity. The purified r-SCL presented a quite interesting stability at low temperatures (< 30 °C) and the enzyme was found to be highly stable in polar organic solvent and at a pH ranging from 3 to 12. After that, we have demonstrated that the recombinant enzyme may be implicated in the biodegradability of oily wastewater from effluents of fast-food restaurants; the maximum conversion yield into fatty acids obtained at 30 °C, was 65%.

A thermostable organic solvent-tolerant lipase from Brevibacillus sp.: production and integrated downstream processing using an alcohol-salt-based aqueous two-phase system.

Lipases are used for the synthesis of different compounds in the chemical, pharmaceutical, and food industries. Most of the reactions are carried out in non-aqueous media and often at elevated temperature, requiring the use of organic solvent-tolerant thermostable lipases. However, most known lipases are not stable in the presence of organic solvents and at elevated temperature. In this study, an organic solvent-tolerant thermostable lipase was obtained from Brevibacillus sp. SHI-160, a moderate thermophile isolated from a hot spring in the East African Rift Valley. The enzyme was optimally active at 65°C and retained over 90% of its activity after 1 h of incubation at 70°C. High lipase activity was measured in the pH range of 6.5 to 9.0 with an optimum pH of 8.5. The enzyme was stable in the presence of both polar and non-polar organic solvents. The stability of the enzyme in the presence of polar organic solvents allowed the development of an efficient downstream processing using an alcohol-salt-based aqueous two-phase system (ATPS). Thus, in the presence of 2% salt, over 98% of the enzyme partitioned to the alcohol phase. The ATPS-recovered enzyme was directly immobilized on a solid support through adsorption and successfully used to catalyze a transesterification reaction between paranitrophenyl palmitate and short-chain alcohols in non-aqueous media. This shows the potential of lipase SHI-160 to catalyze reactions in non-aqueous media for the synthesis of valuable compounds. The integrated approach developed for enzyme production and cheap and efficient downstream processing using ATPS could allow a significant reduction in enzyme production costs. The results also show the potential of extreme environments in the East African Rift Valley as sources of valuable microbial genetic resources for the isolation of novel lipases and other industrially important enzymes.

Efficiency of an alkaline, thermostable, detergent compatible, and organic solvent tolerant lipase with hydrolytic potential in biotreatment of wastewater

Discharging the tannery wastewater into the environment is a serious challenge worldwide due to the release of severe recalcitrant pollutants such as oil compounds and organic materials. The biological treatment through enzymatic hydrolysis is a cheap and eco-friendly method for eliminating fatty substances from wastewater. In this context, lipases can be utilized for bio-treatment of wastewater in multifaceted industrial applications. To overcome the limitations in removing pollutants in the effluent, we aimed to identify a novel robust stable lipase (PersiLipase1) from metagenomic data of tannery wastewater for effective bio-degradation of the oily wastewater pollution. The lipase displayed remarkable thermostability and maintained over 81 % of its activity at 60 °C.After prolonged incubation for 35 days at 60°C, the PersiLipase1 still maintained 53.9 % of its activity. The enzyme also retained over 67 % of its activity in a wide range of pH (4.0 to 9.0). In addition, PersiLipase1 demonstrated considerable tolerance toward metal ions and organic solvents (e.g., retaining >70% activity after the addition of 100 mM of chemicals). Hydrolysis of olive oil and sheep fat by this enzyme showed 100 % efficiency. Furthermore, the PersiLipase1 proved to be efficient for biotreatment of oil and grease from tannery wastewater with the hydrolysis efficiency of 90.76 % ± 0.88. These results demonstrated that the metagenome-derived PersiLipase1 from tannery wastewater has a promising potential for the biodegradation and management of oily wastewater pollution.

Different Effects of Salt Bridges near the Active Site of Cold-Adapted Proteus mirabilis Lipase on Thermal and Organic Solvent Stabilities

Organic solvent-tolerant (OST) enzymes have been discovered in psychrophiles. Cold-adapted OST enzymes exhibit increased conformational flexibility in polar organic solvents resulting from their intrinsically flexible structures. Proteus mirabilis lipase (PML), a cold-adapted OST lipase, was used to assess the contribution of salt bridges near the active site involving two arginine residues (R237 and R241) on the helix η1 and an aspartate residue (D248) on the connecting loop to the thermal and organic solvent stabilities of PML. Alanine substitutions for the ion pairs (R237A, R241A, D248A, and R237A/D248A) increased the conformational flexibility of PML mutants compared to that of the wild-type PML in an aqueous buffer. The PML mutants became more susceptible to denaturation after increasing the dimethyl sulfoxide or methanol concentration than after a temperature increase. Methanol was more detrimental to the structural stability of PML compared to dimethyl sulfoxide. These results suggest that direct interactions of dimethyl sulfoxide and methanol with the residues near the active site can have a destructive effect on the structure of PML compared with the global effect of heat on the protein structure. This study provides insight into the conformational changes within an OST enzyme with different effects on its thermal and organic solvent stabilities.

Optimization of an organic solvent-tolerant lipase production by Staphylococcus capitis SH6. Immobilization for biodiesel production and biodegradation of waste greases

Using the statistical approach, this work seeks to optimize the process parameters to boost the generation of an organic solvent-tolerant lipase by Staphylococcus capitis SH6. The main parameters influencing the enzyme production were identified by using Plackett–Burman’s screening design. Among the test variables, only tryptone (25 g/L), malt extract (2.5 g/L), NaCl (10 g/L) and pH (7.0) contributed positively to enzyme production. Then, the crude lipase was immobilized by adsorption on CaCO3 at pH 10. A maximum immobilization efficiency of 82% was obtained by incubating 280 mg of enzyme with CaCO3 (1 g) during 30 min. The immobilized lipase was more stable toward organic solvents than the free enzyme. It retained about 90% of its original activity in the presence of ethanol and methanol. After that, the immobilized enzyme was used for biodiesel production by transesterification process between waste oil and methanol or ethanol during 24 h at 30 °C. Our results show that the lipase can be utilized efficiently in biodiesel industry. Likewise, we have demonstrated that the immobilized enzyme may be implicated in the biodegradability of waste grease; the maximum conversion yield into fatty acids obtained after 12 h at 30 °C, was 57%.

Optimization of organic solvent-tolerant lipase production by Acinetobacter sp. UBT1 using deoiled castor seed cake.

Organic solvent-tolerant lipase-producing microorganisms were isolated from petrol spilled soil. From ten morphologically distinct lipase-producing bacterial isolates, highest amount of lipase-producing isolate UBT1 was identified as Acinetobacter sp. using 16S rRNA gene sequencing (NCBI Accession No: MH879815). An increase in lipase production from 42 U/mL to 243 U/mL was obtained when different deoiled seed cakes were supplemented instead of olive oil in the medium. Further optimization of media components by the statistical approach assisted in discerning the main influencing media components and their optimum concentrations. Nine components glucose, castor seedcake, potassium nitrate, gum arabic, calcium chloride, magnesium sulphate, potassium di-hydrogen phosphate, dipotassium hydrogen phosphate, and ferric chloride were selected for Plackett-Burman design. The optimum concentrations of three significant selected components for the lipase production were found to be 0.025 gm% glucose, 0.002 gm% calcium chloride, and 0.2 gm% potassium di-hydrogen phosphate as determined by Response Surface Methodology. Increase in lipase production with 292.29 U/mL was achieved in the media containing optimized components and 2 gm% deoiled castor seed cake. Purification studies with ammonium sulphate precipitation, dialysis, and gel permeation chromatography resulted in 77.54% recovery with 5.77-fold partially purified lipase. The residual activity of lipase in 50 and 75% concentration of n-hexane among other solvents after 24h was 105.05 and 90.42%, respectively, indicating its solvent tolerance. The present study reports the isolation of organic solvent-tolerant lipase-producing Acinetobacter sp. UBT1, optimization of the culture media for lipase production using the deoiled castor seed cake, and its partial purification.

An organic solvent-tolerant lipase of Streptomyces pratensis MV1 with the potential application for enzymatic improvement of n6/n3 ratio in polyunsaturated fatty acids from fenugreek seed oil.

Lipase-catalyzed esterification is an efficient technique in the production of polyunsaturated fatty acid (PUFA) concentrates which are applied for nutrition and health purposes. In this project, a solvent-tolerant lipase from Streptomyces pratensis MV1 was immobilized and purified by a hydrophobic support. The purified lipase revealed enhanced activity and stability towards chemicals, organic solvents, and a broad range of pH values. The production of lipase was enhanced to 7.0 U/mL after optimization by a central composite design. Acylglycerols (AGs) rich in α-linolenic acid (45%, w/w) were produced and a favorable n-6/n-3 free fatty acid (FFA) ratio of 1.1 was achieved in fenugreek seed oil using the immobilized lipase. The ability of S. pratensis lipase in ester synthesis and the improvement of n6/n3 FFA ratio make it a suitable candidate in food production industries.Electronic supplementary materialThe online version of this article (10.1007/s13197-020-04784-w) contains supplementary material, which is available to authorized users.

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.

Purification and characterization of a mesophilic organic solvent tolerant lipase produced by Acinetobacter sp. K5b4

The extracellular lipase produced by Acinetobacter sp. K5b4 was purified to homogeneity using ultrafiltration (cutoff 30 KDa) followed by gel filtration chromatography on Sephadex G-50. The enzyme was purified to homogeneity with an apparent molecular mass of 133 KDa by SDS-PAGE. This purification resulted on 10.24 fold with 18.3% recovery. The Km and Vmax of purified enzyme when using pNPL hydrolysis were 4.0 mM and 73.53 nmol/ml/min, respectively. The pure enzyme was greatly stimulated in the presence of 20, 40 and 60% (v/v) methanol, DMSO and acetone whereas, ethanol, acetonitrile and propanol decreased the enzyme activity. Maximum enzyme activity was achieved at pH 7.0 and incubation temperature of 27 °C. The enzyme was stable within a pH range of 6.5 to 7 at 27 °C for 1 h. The enzyme activity was enhanced up to 36% by KCl, BaCl2, MgCl2 and CaCl2 while obviously inhibited (10–20%) by CoCl2, ZnCl2, MnCl2 and CuCl2. No inhibitory effects were observed with 1.0 and 5.0 mM of 2-mercaptoethanol and EDTA. Similarly, SDS at 1.0 mM does not affect the enzyme activity while high reduction (80%) was observed at 5.0 mM SDS concentration. The enzyme was active against p-nitrophenyl esters of C8, C12 and C16 with highest preference to the medium carbon chain p-nitrophenyl caprylate (C8). The fact that the enzyme displays distinct stability in the presence of methanol, DMSO and acetone suggests that this lipase is suitable as biocatalyst in organic synthesis where such hydrophilic organic solvents are used as a reaction media.

Screening and Isolation of an Organic Solvent Tolerant Lipase Producing Bacteria from Various Oil Contaminated Sites

Screening and Isolation of an Organic Solvent Tolerant Lipase Producing Bacteria from Various Oil Contaminated Sites

Cloning, overexpression, and characterization of a novel organic solvent-tolerant lipase from Paenibacillus pasadenensis CS0611

We found a novel lipase gene in the Paenibacillus pasadenensis CS0611 strain. The lipase gene sequence was cloned into the pET-28a expression vector to construct a recombinant lipase protein containing 6 × His tags at the C- and N-termini, respectively. High-level expression of the lipase in E.coli BL21 (DE3) was obtained upon induction with IPTG at 20 °C. The recombinant lipase activity was approximately 1631-fold higher than the wild type. His-tagged recombinant lipase was purified rapidly and efficiently by using Ni-charged affinity chromatography with 63.5% recovery and a purification factor of 10.78. The purified lipase was stable in a broad range of temperatures and pH values, with the optimal temperature and pH being 50 °C and 7.0, respectively. Its activity was stimulated to different degrees in the presence of metal ions such as Ca2+, Mg2+, and some non-ionic surfactants. In addition, the purified lipase was activated by a series of water-miscible organic solvents such as some short carbon chain alcohols and was highly tolerant to some water-immiscible organic solvents.

An Organic Solvent-Tolerant Lipase with Both Hydrolytic and Synthetic Activities from the Oleaginous Fungus Mortierella echinosphaera.

Lipase enzymes of the oleaginous fungal group Mortierella are rarely studied. However, considering that most commercial lipases are derived from filamentous fungal sources, their investigation can contribute to the cost-effective development of new biotechnological processes. Here, an extracellular lipase with a molecular mass of 30 kDa was isolated from Mortierella echinosphaera CBS 575.75 and characterized. The purified lipase exhibited an optimal p-nitrophenyl palmitate (pNPP)-hydrolyzing activity at 25 °C and pH 6.6–7.0 and proved to be highly stable at temperatures up to 40 °C and under broad pH conditions. The enzyme was active under low temperatures, retaining 32.5% of its activity at 10 °C, and was significantly stable in polar and non-polar organic solvents. The Km, Vmax, and kcat for pNPP were 0.336 mM, 30.4 μM/min, and 45.7 1/min for pNPP and 0.333 mM, 36.9 μM/min, and 55.6 1/min for pNP-decanoate, respectively. The pNPP hydrolysis was inhibited by Hg2+, N-bromosuccinimide, and sodium dodecyl sulfate, while ethylenediaminetetraacetic acid and metal ions, such as Ca2+, Mg2+, Na+, and K+ enhanced the activity. The purified lipase had non-regioselective activity and wide substrate specificity, showing a clear preference for medium-chained p-nitrophenyl esters. Besides its good transesterification activity, the enzyme appeared as a suitable biocatalyst to operate selective esterification reactions to long-chained alkyl esters. Adsorption to Accurel MP1000 improved the storage stability of the enzyme at 5 °C. The immobilized lipase displayed tolerance to a non-aqueous environment and was reusable for up to five cycles without significant loss in its synthetic and hydrolytic activities. These findings confirm the applicability of both the free and the immobilized enzyme preparations in future research.

A cold and organic solvent tolerant lipase produced by Antarctic strain Rhodotorula sp. Y-23.

Psychrotolerant yeast Rhodotorula sp. Y-23 was isolated from the sediment core sub-samples of Nella Lake, East Antarctica. Isolate was screened for lipase production using plate assay method followed by submerged fermentation. Production optimization revealed the maximum lipase production by using palmolein oil (5% v/v), pH 8.0 and inoculum size of 2.5% v/v at 15 °C. The potential inducers for lipase were 1% w/v of galactose and KNO3 , and MnCl2 (0.1% w/v). Final productions with optimized conditions gave 5.47-fold increase in lipase production. Dialyzed product gave a purification fold of 5.63 with specific activity of 26.83 U mg-1 and 15.67% yields. This lipase was more stable at pH 5.0 and -20 °C whereas more activity was found at pH 8.0 and 35 °C. Stability was more in 50 mM Fe3+ , EDTA-Na (20 mM), sodium deoxycholate (20 mM), H2 O2 (1% v/v), and almost all organic solvents (50% v/v). Tolerance capacity at wider range of pH and temperature with having lower Km value i.e., 0.08 mg ml-1 and higher Vmax 385.68 U mg-1 at 15 °C make the studied lipase useful for industrial applications. Besides this, the lipase was compatible with commercially available detergents, and its addition to them increases lipid degradation performances making it a potential candidate in detergent formulation.

Purification and Characterization of Active Aggregates of an Organic Solvent Tolerant Lipase from Marinobacter sp. EMB5

Background: Marinobacter is a halophilic bacterial genus and a bio-geochemically important group in sea water, is generally associated with the bioremediation of hydrocarbon-rich effluents released into the salt-rich environment by various anthropogenic activities. It is a well-known lipase producer-the NCBI Protein database shows nearly 520 Marinobacter lipases. In this context, its lipase and esterase are considered important. However, their enzymatic properties in purified form have been scantily studied. Since hydrocarbons are acted upon on solvent water interface, the stability and catalytic behavior of Marinobacter lipase in non-aqueous media needs to be more specifically investigated. Aim: Marinobacter sp. EMB5 was isolated from Kozhikode, Kerala, India. It was found to be potent lipase producer. The aim of the present work was to obtain a purified preparation and undertake its detailed characterization with respect to above aspects. Work: The crude Marinobacter sp. lipase was purified by Sephacryl S200 gel filtration chromatography. The lipase eluted as a single activity peak in void volume and had a very high molecular mass. Aggregation has not been reported in case of Marinobacter lipase, so far, although it is known in other lipases. The aggregated lipase was mixed with 2-propanol (70%, v/v) and disaggregated lipase was obtained as a single activity peak in Sephacryl S200 gel filtration chromatography corresponding to 82 kDa molecular mass. This monomeric species was less active than aggregated purified preparation. Hence, further characterization and studies were carried out on purified active aggregate lipase. It was stable in a wide range of organic solvents at high concentration up to 24 h. The organic solvent stability was further investigated by Far UV CD spectroscopy and fluorescence spectroscopy. Conclusion: Due to the fact that Marinobacter sp. EMB5 lipase remained stable in organic solvents for prolonged incubation periods, it has potential to be used in industrial organic synthesis.

Biochemical characterization of a novel cold-active, halophilic and organic solvent-tolerant lipase from B. licheniformis KM12 with potential application for biodiesel production

Nowadays, finding a talented lipase with high potency in biodiesel production has been attracted to researchers. In this study, an extracellular salt tolerant, cold-active and organic solvent-stable lipase producing bacterium was isolated from oil-contaminated environments located in Kerman province (Iran) and identified as Bacillus licheniformis KM12. Lipase was purified by 36.0% recovery and molecular weight was estimated about 33 kDa by SDS–PAGE. The optimal pH and temperature for lipase activity were found to be 8.0 and 35 °C, respectively. Lipase activity was remarkably increased about 37% after 20 min incubation at 20 °C. Km value of KM12 lipase was 0.53 mM for p-nitrophenyl palmitate (p-NPP) and maximum activity was detected for pNP-decanoate and glyceryl-decanoate substrates. KM12 lipase displayed significant stability in different organic solvents after 7 and 21 days of incubation, especially in polar organic solvents. Biodiesel production with 78% yields was achieved with the one-step addition of methanol at around 18 h by using Myrtus oil (as a non-edible oils feedstocks). These unique properties of KM12 lipase make it talented as a potential biocatalyst for biodiesel production.

Optimization of thermostable organic solvent-tolerant lipase production by thermotolerant Rhizopus sp. using solid-state fermentation of palm kernel cake.

This study enhanced the production of thermostable organic solvent-tolerant (TS-OST) lipase by locally isolated thermotolerant Rhizopus sp. strain using solid-state fermentation (SSF) of palm kernel cake (PKC). The optimum conditions were achieved using a series of statistical approaches. The cultivation parameters, which include fermentation time, moisture content, temperature, pH, inoculum size, various carbon and nitrogen sources, as well as other supplements, were initially screened by the definitive screening design, and one-factor-at-a-time using PKC as the basal medium. Three significant factors (olive oil concentration, pH, and inoculum size) were further optimized using face-centred central composite design. The results indicated a successful and significant improvement of lipase activity by almost two-fold compared to the initial screening production. The findings showed that the optimal conditions were 2% (v/w) inoculum size, 2% (v/w) olive oil, 0.6% (w/w) peptone, 2% (v/w) ethanol, 70% moisture content at initial pH 10.0 and 45°C within 72h of fermentation. Process optimization resulted in maximum lipase activity of 58.63 U/gram dry solids (gds). The analysis of variance showed that the statistical model was significant (p value <0.0001) and reliable with a high value of R2 (0.98) and adjusted R2 (0.96). This indicates a better correlation between the actual and predicted responses of lipase production. By considering this study, the low-cost PKC through SSF appears to be promising in the utilization of agro-industrial waste for TS-OST lipase production. This is because satisfactory enzyme activity could be attained that promises industrial applications.

Process optimization for production and purification of a thermostable, organic solvent tolerant lipase from Acinetobacter sp. AU07.

The purpose of this study was to isolate, purify and optimize the production conditions of an organic solvent tolerant and thermostable lipase from Acinetobacter sp. AU07 isolated from distillery waste. The lipase production was optimized by response surface methodology, and a maximum production of 14.5 U/mL was observed at 30 °C and pH 7, using a 0.5% (v/v) inoculum, 2% (v/v) castor oil (inducer), and agitation 150 rpm. The optimized conditions from the shake flask experiments were validated in a 3 L lab scale bioreactor, and the lipase production increased to 48 U/mL. The enzyme was purified by ammonium sulfate precipitation and ion exchange chromatography and the overall yield was 36%. SDS-PAGE indicated a molecular weight of 45 kDa for the purified protein, and Matrix assisted laser desorption/ionization time of flight analysis of the purified lipase showed sequence similarity with GDSL family of lipases. The optimum temperature and pH for activity of the enzyme was found to be 50 °C and 8.0, respectively. The lipase was completely inhibited by phenylmethylsulfonyl fluoride but minimal inhibition was observed when incubated with ethylenediaminetetraacetic acid and dithiothreitol. The enzyme was stable in the presence of non-polar hydrophobic solvents. Detergents like SDS inhibited enzyme activity; however, there was minimal loss of enzyme activity when incubated with hydrogen peroxide, Tween 80 and Triton X-100. The kinetic constants (Km and Vmax) revealed that the hydrolytic activity of the lipase was specific to moderate chain fatty acid esters. The Vmax, Km and Vmax/Km ratio of the enzyme were 16.98 U/mg, 0.51 mM, and 33.29, respectively when 4-nitrophenyl palmitate was used as a substrate.

Cloning, Expression, and Characterization of a Cold-Active and Organic Solvent-Tolerant Lipase from Aeromicrobium sp. SCSIO 25071.

The gene encoding lipase (Lip98) from Aeromicrobium sp. SCSIO 25071 was cloned and functionally expressed in Escherichia coli. Lip98 amino acid sequence shares the highest (49%) identity to Rhodococcus jostii RHA1 lipase and contains a novel motif (GHSEG), which is different from other clusters in the lipase superfamily. The recombinant lipase was purified to homogeneity with Ni-NTA affinity chromatography. Lip98 showed an apparent molecular mass of 30 kDa on SDS gel. The optimal temperature and pH value for enzymatic activity were recorded at 30°C and 7.5, respectively. Lip98 exhibited high activity at low temperatures with 35% maximum activity at 0°C and good stability at temperatures below 35°C. Its calculated activation energy was 4.12 kcal/mol at the low temperature range of 15-30°C. Its activity was slightly affected by some metal ions such as K(+), Ca(2+), and Na(+). The activity of Lip98 was increased by various organic solvents such as DMSO, ethanol, acetone, and hexane with the concentration of 30% (v/v) and retained more than 30% residual activity in neat organic solvent. The unique characteristics of Lip98 imply that it is a promising candidate for industrial application as a nonaqueous biocatalyst and food additive.

A novel thermostable and organic solvent-tolerant lipase from Xanthomonas oryzae pv. oryzae YB103: screening, purification and characterization.

Thermostable lipases offer major biotechnological advantages over mesophilic lipases. In this study, an intracellular thermostable and organic solvent-tolerant lipase-producing strain YB103 was isolated from soil samples and identified taxonomically as Xanthomonas oryzae pv. oryzae. The lipase from X. oryzae pv. oryzae YB103 (LipXO) was purified 101.1-fold to homogeneity with a specific activity of 373.9 U/mg. The purified lipase showed excellent thermostability, exhibiting 51.1% of its residual activity after incubation for 3 days at 70 °C. The enzyme showed optimal activity at 70 °C, suggesting it is a thermostable lipase. LipXO retained 75.1-154.1% of its original activity after incubation in 20% (v/v) hydrophobic organic solvents at 70 °C for 24 h. Furthermore, LipXO displayed excellent stereoselectivity (e.e.p >99%) toward (S)-1-phenethyl alcohol in n-hexane. These unique properties of LipXO make it promising as a biocatalyst for industrial processes.

Purification and characterization of organic solvent-tolerant lipase from Streptomyces sp. OC119-7 for biodiesel production

This study determined the lipolytic activity of Streptomyces isolates and then purified and characterized the lipase obtained from Streptomyces sp. OC 119-7, the isolate demonstrated to have the high lipolytic activity. Ammonium sulfate precipitation and gel filtration chromatography were used to purify the extracellular alkaline lipase obtained from Streptomyces sp. OC 119-7, and resulted in 5.52-fold purification with 68.055 U/mg specific activity. The enzyme showed optimal activity at pH 8.0 and 50 °C, with stability in a temperature range of 40–60 °C and at pHs of ≥7. Enzyme activity was enhanced by the presence of Ca2+ and Mg2+ and inhibited by the presence of Mn2+, Co2+, Cu2+, Zn2+, K+, Na+ and PMSF. OC 119-7 lipase displayed stability against surfactants and organic solvents. LipOC 119-7 catalyzed transesterification of olive oil with methanol, suggesting that this lipase may be a potential enzymatic catalyst for biodiesel production.