Purification and characterization of lipase by Bacillus methylotrophicus PS3 under submerged fermentation and its application in detergent industry

UV mutagenesis for lipase overproduction from Bacillus cereus ATA179, nutritional optimization, characterization and its usability in the detergent industry

In this study, the wild-type Bacillus cereus ATA179 was mutagenized by random UV mutagenesis to increase lipase production. The mutant with maximum lipolytic activity was named Bacillus cereus EV4. The mutant strain (10.6 U/mL at 24 h) produced 60% more enzyme than the wild strain (6.6 U/mL at 48 h). Nutritional factors on lipase production were investigated. Sucrose was the best carbon source, (NH4)2HPO4 was the best nitrogen source and CuSO4 was the best metal ion source. Mutant EV4 showed a 32% increase in lipase production in the modified medium. The optimum temperature and pH were found to be 60 °C and 7.0, respectively. CuSO4, CaCl2, LiSO4, KCl, BaCl2, and Tween 20 had an activating effect on the enzyme. Vmax and Km values were found to be 17.36 U/mL and 0.036 mM, respectively. The molecular weight was determined as 28.2 kDa. The activity of lipase was found to be stable up to 60 days at 20 °C, 75 days at 4 °C, and 90 days at -20 °C. The potential of lipase in the detergent industry was investigated. The enzyme was not affected by detergent additives but was effective in removing stains in fabrics contaminated with oily substances.

In Silico and Experimental Studies on the Effect of α3 and α5 Deletion on the Biochemical Properties of Bacillus thermocatenulatus Lipase

To investigate the effect of α3 and α5 helices on the biochemical characterization of Bacillus thermocatenulatus lipase (BTL2), both helices were deleted from native BTL2 lipase. After structural modeling and characterization, the truncated btl2 gene (Δbtl2) was cloned into E. coli BL21 under the control of the T7 promoter. After cultivation and induction of the recombinant bacteria, the Δα3α5 lipase was purified by Ni-NTA column chromatography. Next, the biochemical properties of the Δα3α5 lipase were compared with the previously expressed and purified native lipase. In the presence of the substrate tributyrin (C4), the maximum activity of native and Δα3α5 lipase was 9360 and 5000 U/mg, respectively. The deletion changed the substrate specificity from tributyrin (C4) to tricaprylin (C8) substrate. Native and Δα3α5 lipase showed similar activity patterns at all temperatures and pH values, with the activity of Δα3α5 lipase being approximately 20% lower than native lipase. Triton X100 increased the activity of native and Δα3α5 lipases by 2.1- and 2.5-fold, respectively.

Unlocking the Gut's Treasure: Lipase-Producing Bacillus subtilis Probiotic from the Intestine of Microstomus kitt (Lemon sole)

The main objective of this research was to identify potential probiotic candidates belonging to the Bacillus species that could demonstrate tolerance to bile salt and acidic conditions. The study focused on isolating Bacillus strains from the intestine of marine fish-Microstomus kitt. The isolation process involved the use of selective MRS media through the pour plate method. After 24 h, one particular isolate was identified based on its morphological and biochemical traits as Bacillus species. To confirm the identity, molecular characterization of the 16S RNA from the isolated strain was performed, and the sequence analysis verified it as Bacillus subtilis strain ACL_BS 001. With the molecular confirmation, the next step was to assess the probiotic characteristics of this B. subtilis strain. Various tests were conducted to evaluate its acid/pH tolerance, NaCl tolerance, and bile salt tolerance. The results indicated that B. subtilis exhibited high viability percentages even under acidic pH, in the presence of 1.5% bile salt, and at high salt concentrations. Subsequently, we investigated the strain's ability to produce lipase, an important enzyme with potential industrial applications. B. subtilis was grown in MRS agar amended with olive oil as a lipase substrate. After incubation, the presence of lipase activity was confirmed, and the enzymatic assay revealed a significant lipase enzyme activity of 100.23 µmoles/ml of the sample. In conclusion, the study successfully isolated and identified B. subtilis from the intestine of Microstomus kitt, and the strain exhibited promising probiotic characteristics, including resistance to bile salt and acidic conditions. Furthermore, the strain was found to produce lipase, which opens up possibilities for future research focusing on isolating and purifying the lipase from this potential probiotic B. subtilis strain.

A lipase from Lacticaseibacillus rhamnosus IDCC 3201 with thermostability and pH resistance for use as a detergent additive

Lipases are important biocatalysts and ubiquitous in plants, animals, and microorganisms. The high growth rates of microorganisms with low production costs have enabled the wide application of microbial lipases in detergent, food, and cosmetic industries. Herein, a novel lipase from Lacticaseibacillus rhamnosus IDCC 3201 (Lac-Rh) was isolated and its activity analyzed under a range of reaction conditions to evaluate its potential industrial application. The isolated Lac-Rh showed a molecular weight of 24 kDa and a maximum activity of 3438.5 ± 1.8 U/mg protein at 60 °C and pH 8. Additionally, Lac-Rh retained activity in alkaline conditions and in 10% v/v concentrations of organic solvents, including glycerol and acetone. Interestingly, after pre-incubation in the presence of multiple commercial detergents, Lac-Rh maintained over 80% of its activity and the stains from cotton were successfully removed under a simulated laundry  setting. Overall, the purified lipase from L. rhamnosus IDCC 3201 has potential for use as a detergent in industrial applications. KEY POINTS: • A novel lipase (Lac-Rh) was isolated from Lacticaseibacillus rhamnosus IDCC 3201 • Purified Lac-Rh exhibited its highest activity at a temperature of 60 °C and a pH of 8, respectively • Lac-Rh remains stable in commercial laundry detergent and enhances washing performance.

A polylactic acid degrading lipase from Bacillus safensis: Characterization and structural analysis

A polylactic acid degrading triacylglycerol lipase (TGL) was identified from Bacillus safensis based on genome annotation and validated by real-time quantitative PCR. TGL displayed optimal activity at pH 9.0 and 55 °C. It maintained stability at pH 9.0 and temperatures 45 °C. The activity of TGL was found to benefit from the presence of potassium sodium ions, and low concentrations of Triton X-100. The TGL could erode the surface of polylactic acid films and increase its hydrophilicity. The hydrolysis products of polylactic acid by TGL were lactate monomer and dimer. TGL contains a classical catalytic triad structure of lipase (Ser77, Asp133, and His156) and an Ala-X-Ser-X-Gly sequence. Compared with some lipases produced by the same genus Bacillus, TGL is highly conserved in its amino acid sequence, mainly reflected in the amino acid residues that exercise the enzyme activity, including the catalytic activity center and the substrate binding sites.

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.

Purification and characterization of extracellular lipase from a thermotolerant strain: Bacillus subtilis TTP-06

In current study, lipase from a thermotolerant Bacillus subtilis TTP-06 was purified in a stepwise manner by using ammonium sulfate precipitation and column chromatography. Thenceforth, it was subjected to sodium dodecyl sulfate- and native-polyacrylamide gel electrophoresis to check the homogeneity of the purified enzyme. The ideal substrate concentration, pH, temperature, reaction duration and lipase specificity were identified. With a yield of 11.02%, purified lipase displayed activity of 8.51 U/mg. Thenceforward, the homogeneously purified enzyme was considered to be a homo-dimer of 30 kDa subunits. Enzyme had Km and Vmax value of 9.498 mM and 19.92 mol mg-1 min-1, respectively. Additionally, the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) method was used to investigate the purified lipase and estimate its 3-D structure, which revealed a catalytic triad of serine, aspartate and histidine.

Characterization of Detergent-Compatible Lipases from Candida albicans and Acremonium sclerotigenum under Solid-State Fermentation

The purpose of this study was to compare and explore the potential of two distinct lipases at industrial levels after their production using wheat bran substrate in solid-state fermentation. Lipases from Candida albicans (C. albicans) and Acremonium sclerotigenum (A. sclerotigenum) were characterized to assess their compatibility and suitability for use in laundry detergents. The effects of pH, temperature, metal ions, inhibitors, organic solvents, and various commercially available detergents on these lipases were studied in order to compare their activity and stability profiles and check their stain removal ability. Both lipases remained stable across the wide pH (7-10) and temperature (30-50 °C) ranges. C. albicans lipase exhibited optimum activity (51.66 U/mL) at pH 7.0 and 37 °C, while A. sclerotigenum lipase showed optimum activity (52.12 U/mL) at pH 8.0 and 40 °C. The addition of Ca2+ and Mg2+ ions enhanced their activities, while sodium dodecyl sulfate (SDS) and ethylenediamine tetraacetic acid (EDTA) reduced their activities. Lipase from both strains showed tolerance to various organic solvents and considerable stability and compatibility with commercially available laundry detergents (>50%); however, A. sclerotigenum lipase performed slightly better. Characterization of these crude lipases showed nearly 60% relative activity after incubation for 2 h in various detergents, thus suggesting their potential to be employed in the formulation of laundry detergents with easy and efficient enzyme production. The production of thermostable and alkaline lipases from both strains makes them an attractive option for economic gain by lowering the amount of detergent to be used, thus reducing the chemical burden on the environment.

A Thermostable Lipase Isolated from Brevibacillus thermoruber Strain 7 Degrades Ɛ-Polycaprolactone

The tremendous problem with plastic waste accumulation has determined an interest in biodegradation by effective degraders and their enzymes, such as thermophilic enzymes, which are characterized by high catalytic rates, thermostability, and optimum temperatures close to the melting points of some plastics. In the present work, we report on the ability of a thermophilic lipase, by Brevibacillus thermoruber strain 7, to degrade Ɛ-polycaprolactone (PCL), as well as the enzyme purification, the characterization of its physicochemical properties, the product degradation, and its disruptive effect on the PCL surface. The pure enzyme showed the highest reported optimum temperature at 55 °C and a pH of 7.5, while its half-life at 60 °C was more than five hours. Its substrate specificity referred the enzyme to the subgroup of lipases in the esterase group. A strong inhibitory effect was observed by detergents, inhibitors, and Fe3+ while Ca2+ enhanced its activity. The monomer Ɛ-caprolactone was a main product of the enzyme degradation. Similar elution profiles of the products received after treatment with ultra-concentrate and pure enzyme were observed. The significant changes in PCL appearance comprising the formation of shallower or deeper in-folds were observed after a week of incubation. The valuable enzyme properties of the lipase from Brevibacillus thermoruber strain 7, which caused a comparatively quick degradation of PCL, suggests further possible exploration of the enzyme for effective and environment-friendly degradation of PCL wastes in the area of thermal basins, or in thermophilic remediation processes.

Optimization and characterization of alkaliphilic lipase from a novel Bacillus cereus NC7401 strain isolated from diesel fuel polluted soil

Five Bacillus cereus strains including B. cereus AVP12, B. cereus NC7401, B. cereus BDBCO1, B. cereus JF70 and B. specie JL47 isolated from the diesel fuel polluted soil adhered to the roots of Tagetes minuta were screened for lipase production with phenol red agar method. B. cereus NC7401 strain successfully expressing and secreting lipase with maximal lipolytic activity was subjected to a submerged fermentation process with five different carbon (starch, glucose, maltose, fructose, and lactose) and five different nitrogen (tryptone, ammonium nitrate, peptone, urea, yeast extract) sources to produce lipase enzyme. Maximum enzyme activity was found with starch (30.6 UmL-1), maltose (40 UmL-1), and tryptone (38.6 UmL-1), and the lipases produced using these sources were named lipase A, B, and C respectively. The total protein content of 8.56, 8.86, and 2.75 μg mL-1 were obtained from B. cereus NC7401 cultured using starch, maltose, and tryptone respectively. Lipase was stable between temperature range 30–80°C and pH 5–10 whereas optimally active at 55°C and pH 8.0. The enzyme was relatively stable for 10 days at 4°C and its optimum reaction time with the substrate was 30 minutes. It was tolerant to 1.5% (v/v) methanol as an organic solvent, 1.5% (v/v) Triton X-100 as a media additive and 1.5% (w/v) Ni2+ as a metal ion. SDS, n-hexane, and Ag+ inhibited lipolytic activity. Oil stains were removed from cotton fabric which showed oil removal efficiency enhancement in the presence of a lipase. Fat hydrolysis of 20, 24, and 30% was achieved following 6 hours of incubation of the fat particles with lipase A, B, and C respectively at a concentration of 20 mg mL-1. To as best of our knowledge, this study on lipases extracted from bacteria of Azad Kashmir, Pakistan origin has never been reported before.

Investigation of Lipolytic-Secreting Bacteria from an Artificially Polluted Soil Using a Modified Culture Method and Optimization of Their Lipase Production

Compared to lipases from plants or animals, microbial lipases play a vital role in different industrial applications and biotechnological perspectives due to their high stability and cost-effectiveness. Therefore, numerous lipase producers have been investigated in a variety of environments in the presence of lipidic carbon and organic nitrogen sources. As a step in the development of cultivating the unculturable functional bacteria in this study, the forest soil collected from the surrounding plant roots was used to create an artificially contaminated environment for lipase-producing bacterial isolation. The ten strongest active bacterial strains were tested in an enzyme assay supplemented with metal ions such as Ca2+, Zn2+, Cu2+, Fe2+, Mg2+, K+, Co2+, Mn2+, and Sn2+ to determine bacterial tolerance and the effect of these metal ions on enzyme activity. Lipolytic bacteria in this study tended to grow and achieved a high lipase activity at temperatures of 35-40 °C and at pH 6-7, reaching a peak of 480 U/mL and 420 U/mL produced by Lysinibacillus PL33 and Lysinibacillus PL35, respectively. These potential lipase-producing bacteria are excellent candidates for large-scale applications in the future.

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.

An uncharacterized protein from the metagenome with no obvious homology to known lipases shows excellent alkaline lipase properties and potential applications in the detergent industry

A novel lipase, Lip486, which has no obvious homology with known lipases, was discovered using functional metagenomics technology. Phylogenetic tree analysis suggested that the enzyme belongs to a new subfamily called lipolytic enzyme family II. To explore the enzymatic properties, lip486 was expressed heterologously and efficiently in Escherichia coli. The recombinant enzyme displayed the highest activity on the substrate p-nitrophenyl caprate with a carbon chain length of 10, and its optimum temperature and pH were 53 °C and 8.0, respectively. The recombinant Lip486 showed good activity and stability in strong alkaline and medium-low-temperature environments. The results of compatibility and soaking tests showed that the enzyme had good compatibility with 4 kinds of commercial detergents, and an appropriate soaking time could further improve the enzyme activity. Oil stain removal test results for a cotton cloth indicated that the washing performance of commercial laundry detergent supplemented with Lip486 was further improved. In addition, as one of the smallest lipases found to date, Lip486 also has the advantages of high yield, good stability and easy molecular modification. These characteristics reflect the good application prospects for Lip486 in the detergent and other industries in the future.

Antimicrobial Peptides from Plants: A cDNA-Library Based Isolation, Purification, Characterization Approach and Elucidating Their Modes of Action

Even in a natural ecosystem, plants are continuously threatened by various microbial diseases. To save themselves from these diverse infections, plants build a robust, multilayered immune system through their natural chemical compounds. Among the several crucial bioactive compounds possessed by plants' immune systems, antimicrobial peptides (AMPs) rank in the first tier. These AMPs are environmentally friendly, anti-pathogenic, and do not bring harm to humans. Antimicrobial peptides can be isolated in several ways, but recombinant protein production has become increasingly popular in recent years, with the Escherichia coli expression system being the most widely used. However, the efficacy of this expression system is compromised due to the difficulty of removing endotoxin from its system. Therefore, this review suggests a high-throughput cDNA library-based plant-derived AMP isolation technique using the Bacillus subtilis expression system. This method can be performed for large-scale screening of plant sources to classify unique or homologous AMPs for the agronomic and applied field of plant studies. Furthermore, this review also focuses on the efficacy of plant AMPs, which are dependent on their numerous modes of action and exceptional structural stability to function against a wide range of invaders. To conclude, the findings from this study will be useful in investigating how novel AMPs are distributed among plants and provide detailed guidelines for an effective screening strategy of AMPs.

Effects of Steaming, Microwaving, and Hot-Air Drying on the Physicochemical Properties and Storage Stability of Oat Bran

Oat bran is a nutrient-dense, resource-rich byproduct that is produced from oat milling. Oxidative deterioration is the main reason that limits the utilisation of oat bran. Thus, improving the storage stability of oat bran has become an urgent requirement. This study aimed to investigate the inhibition of oat bran deterioration via steaming, microwaving, and hot-air drying treatments and the effects of these methods on oat bran physicochemical properties and storage stability. Results indicated that, after the three heating treatments, the solubility of oat bran increased and the powder fluidity showed no significant change ( $P<0.05$ ). Steam-treated oat bran demonstrated increased initial gelatinisation temperature, peak temperature, and enthalpy, significantly reduced peak viscosity, trough viscosity, breakdown value, final viscosity, and setback value, and significantly improved thermal stability ( $P<0.05$ ). During accelerated storage, oat bran samples subjected to the three heat treatments showed increased sensory scores and L ${}^{\ast }$ , a ${}^{\ast }$ , and b ${}^{\ast }$ values, whereas due to the decrease of lipase activity in oat bran, their fatty acid values and malondialdehyde content increased slowly and were always lower than those of unprocessed oat bran. All three heat treatments could improve the storage stability and the quality deterioration of oat bran during storage due to oil oxidation. Steaming had the most significant effect.

Lipase from new isolate Bacillus cereus ATA179: optimization of production conditions, partial purification, characterization and its potential in the detergent industry

In this study, 341 Bacillus sp. strains were isolated from agricultural soils of Turkey. The potent extracellular lipase producer was selected. It was identified by 16S rRNA, named as Bacillus cereus ATA179. Optimal nutritional and physical parameters for lipase production were determined. Sucrose as the carbon source, (NH₄)₂HPO₄ as the nitrogen source, CaCl₂ as the metal ion were obtained. The best results of physical parameters were stated at 45°C, pH 7.0, shaking rate 50 rpm, inoculation amount 7% and inoculum age 24 h. ATA179 strain showed a 51% increase in enzyme production in the modified medium created by optimizing nutritional and physical conditions. Optimum pH value and temperature were found as 6.0 and 55 °C, respectively. CaCl₂, Tween 20, Triton X-100 had an activating effect on enzyme activity. V_max and K_m kinetic values were found as 18.28 U/mL and 0.11 mM, respectively. The molecular weight was determined as 47 kDa. Lipase was found to be stable up to 75 days at -20 ºC. The potential of the enzyme in detergent industry was also investigated. It was not affected by detergent additives, but was found to be effective in removing oils from contaminated fabrics. This new lipase may have potential to be used in detergent industry.

Effects of microwave treatment on the stability and antioxidant capacity of a functional wheat bran

A functional wheat bran (FWB) was obtained from wheat grains that were rich in wheat aleurone. The effects of the microwave (MW) power (2.5, 5.0, 7.5, and 10.0 kW) and treatment time (15, 30, 60, 90, and 120 s) on the moisture and free fatty acid (FFA) content, lipase activity, and antioxidant activity of the FWB were investigated. The purpose of this study is to stabilize the FWB against lipid oxidation and rancidity and as much as possible to retain its antioxidant activities. MW treatment significantly decreased the FFA content, moisture content, and lipase activity of the FWB. Moreover, MW treatment significantly increased the total phenolic content (TPC) and antioxidant activity of the FWB without drastically altering its color. MW treatment at 7.5 kW and 120 s was found to be optimal for stabilizing the FWB and increasing its antioxidant activity. The stabilized FWB was proven to be far more stable than the control FWB during storage. Thus, MW treatment is an effective stabilization method for the storage and utilization of FWB. Additional research is needed for the exact mechanism of the decrease of FFA content and increase of antioxidant activity of FWB induced by MW treatment.

Purification and characterization of a novel extracellular, alkaline, thermoactive, and detergent-compatible lipase from Aeromonas caviae LipT51 for application in detergent industry

Lipase producer bacterium isolated from Erzurum was identified as Aeromonas caviae LipT51 (GenBank ID: MN818567.1) by 16S rDNA sequencing and conventional methods. Extracellular lipase was purified by ammonium sulphate precipitation, centrifugal filtration, and anion-exchange chromatography resulting in 6.1-fold purification with 28% final yield. Molecular weight was 31.6 kDa on SDS-PAGE. Lipase was stable over a broad range of pH (6-11) and temperature (25-70 °C), and showed optimum activity at pH 9 and 60 °C. Km and Vmax for pNPP hydrolysis were 0.88 mM and 34.2 U/mg protein, respectively. Ba²⁺, Ca²⁺, Co²⁺, Cu²⁺, Fe³⁺, and Mg²⁺ increased activity, while Mn²⁺, Mo²⁺, Ni²⁺, Zn²⁺, and other additives partially decreased. Activity and stability increased with laundry detergent and slightly decreased with handwash and dishwashing detergents. Alkaline and thermostable lipase from newly isolated A. caviae has been shown for the first time to be remarkably compatible with laundry detergent and improve washing performance by enhanced oil-stain removal.

Retracted: Partial purification and characterization of lipase from locally produced edible oil-seeds and its relevance in industries

Lipase was extracted from germinating seeds of Helianthus annus (Sunflower), Zea mays (Maize), and Brassica compastris (Mustard). The lipolytic activity was assessed using olive oil as substrate at different germination-time and the maximum-activity was obtained after 120 hr. Partial-purification was executed by precipitating the seed-homogenate with varying concentration of ammonium sulfate solution. 80% ammonium sulfate solution showed maximum lipase activity of 5320IUml-1 , 3500IUml-1 , 3080IUml-1 with 9.6, 6.9, and 4.8-fold purification and total protein content of 162, 84, and 60 mg for partially purified enzyme extracts namely SN5, BN5, and MN5, respectively. The optimum temperature and pH observed for hydrolysis of olive oil were 37°C, and 8.0 respectively. Enzyme was found to be stable upto 6 days at 4°C and its activity was stimulated by Ca+2 ions. Oil-stains removal from cotton fabric was observed to be superior in the presence of lipase and detergent. Moreover, the SN5, BN5, and MN5 lipase increased free fatty acid release upto 4.2, 4.3, and 3.8 mg, respectively than wastewater without treatment of lipase (0.21 mg) and promoted fat hydrolysis to approximately 40, 42, and 48% mass reduction after 6 hr incubation of fat particle at a concentration of 20 mg/ml. Biodiesel produced by catalyzing transesterification of vegetable oil with SN5, BN5, and MN5 lipase provided an acid value of 0.8, 1.08, and 0.5 mg/g, viscosity 5.50, 5.7, and 5.53 mm2 /s and density 0.87, 0.88, and 0.79 g/ml, respectively. To the best of our knowledge, no such study has been conducted prior on lipase from the seeds mentioned above in Azad Kashmir region.

Directed Evolution of Pseudomonas fluorescens Lipase Variants With Improved Thermostability Using Error-Prone PCR

Lipases catalyze the hydrolysis of fats and oils, and have been widely used in various industrial fields. However, bacterial lipases have a lower thermostability in industrial processes, which was a limiting factor in their industrial application. In this study, we obtained an improve variant of Pseudomonas fluorescens lipase (PFL) with enhanced thermostability using classical error-prone PCR. Wild-type PFL showed an optimal temperature and pH of 50°C and pH 7.5, respectively. Due to the low thermostability of PFL, a library containing over 3000 individual mutants as constructed using error-prone PCR. Screening for thermotolerance yielded the mutants L218P and P184C/M243C with T_m values of 62.5 and 66.0°C, which was 2.5 and 6°C higher than that of the WT, respectively. The combination of the two mutants (P184C/M243C/L218P) resulted in an approximately additive effect with a T_m value of 68.0°C. Although the increase of T_m was not substantial, the mutant also had dramatically increased methanol tolerance. Structural analysis revealed that the introduction of a disulfide bond between P184C and M243C and the substitution of Pro to reduce the flexibility of a loop increased the thermostability of PFL, which provides a theoretical foundation for improving the thermostability and methanol tolerance of lipase family I.1 to resist the harsh conditions of industrial processes.

Identification and characterization of a polyurethanase with lipase activity from Serratia liquefaciens isolated from cold raw cow's milk

Lipases are associated with food spoilage and are also used in various biotechnological applications. In this study, we sought to purify, identify, and characterize a lipase from S. liquefaciens isolated from cold raw cow's milk. The lipase partially purified by ultrafiltration and gel filtration showed a specific activity of 2793 U/mg. By zymography, the enzyme presented approximately 65 kDa, and LC-MS/MS allowed the identification of a polyurethanase with a conserved domain of family I.3 lipase. The modeled and validated structure of polyurethanase was able to bind to different fatty acids and urethane by molecular docking. The polyurethanase showed optimum activity at pH 8.0 and 30 °C. In the presence of ions, activity was decreased, except for Ca²⁺, Mg²⁺, and Ba²⁺. Reducing agents did not alter the activity, while amino acid modifiers reduced enzyme activity. It is concluded that polyurethanase with lipase activity represents a potential enzyme for the deterioration of milk and dairy products, as well as a candidate for industrial applications.

Ion-Pair Interaction and Hydrogen Bonds as Main Features of Protein Thermostability in Mutated T1 Recombinant Lipase Originating from Geobacillus zalihae

A comparative structure analysis between space- and an Earth-grown T1 recombinant lipase from Geobacillus zalihae had shown changes in the formation of hydrogen bonds and ion-pair interactions. Using the space-grown T1 lipase validated structure having incorporated said interactions, the recombinant T1 lipase was re-engineered to determine the changes brought by these interactions to the structure and stability of lipase. To understand the effects of mutation on T1 recombinant lipase, five mutants were developed from the structure of space-grown T1 lipase and biochemically characterized. The results demonstrate an increase in melting temperature up to 77.4 °C and 76.0 °C in E226D and D43E, respectively. Moreover, the mutated lipases D43E and E226D had additional hydrogen bonds and ion-pair interactions in their structures due to the improvement of stability, as observed in a longer half-life and an increased melting temperature. The biophysical study revealed differences in β-Sheet percentage between less stable (T118N) and other mutants. As a conclusion, the comparative analysis of the tertiary structure and specific residues associated with ion-pair interactions and hydrogen bonds could be significant in revealing the thermostability of an enzyme with industrial importance.

Biodiesel production from transesterification of Serratia sp. ISTD04 lipids using immobilised lipase on biocomposite materials of biomineralized products of carbon dioxide sequestrating bacterium

Production of biodiesel from lipids of Serratia sp. ISTD04 by lipase of Pseudomonas sp. ISTPL3 immobilised on biocomposite materials to increase the enzyme stability and reusability was studied. Lipase extracted, partially purifiedand immobilized onto activated biochar, impregnated with calcite obtained from biomineralization-based conversion of CO₂ from ISTD04, and bioactive ceramics materials, Na₂Ca₂Si₃O₉ prepared by chemical process. The composition, structure and texture of biocomposite materials determined by SEM and EDS methods. The composition of synthesized biodiesel was determined by GC-MS. The results imply that the immobilized lipase on activated biochar impregnated with calcite gave the maximum yield of fatty acid methyl esters (FAME:97.41%) followed by immobilized lipase on biochar (FAME:94.91), immobilized lipase on glass-ceramic (FAME:91.50%) and NaOH (FAME:85.63%). The reusability of lipase immobilized on activated biochar impregnated with calcite retained 75.11%and 50% catalytic activity after 5 and 10 cycles of transesterification reaction, respectively.

Indoxyl Acetate as a Substrate for Analysis of Lipase Activity

Lipases play a crucial role in metabolism of microbes, fungi, plants, and animals, and in analytical chemistry, they are often used in detection of fats and triglycerides. Determination of lipase activity is also important in toxicology, when lipase activity can be both increased and decreased by organophosphates and other pesticides and in medicine for diagnosis of heart diseases. The standard method for lipase activity determination is based on cleaving ester bonds in lipase buffer containing Tween. Our aim was to find a method with faster and more sensitive response. It is known that acetylcholinesterase belongs to the same group of hydrolases enzymes as lipases and it cleaves indoxyl acetate, so we assume indoxyl acetate could report a similar reaction with lipase. Our method is based on indoxyl acetate as a substrate for lipase, where indoxyl acetate is cleaved by lipase to indoxyl and acetate moiety and blue indigo is created. The method was optimized for different times and amount of enzyme and compared with the standard Tween assay. The calibration curve measured in reaction time 20 minutes with 10 μl of lipase exhibited the best analytical parameters, and it showed Michaelis-Menten response with the Michaelis-Menten constant equal to 8.72 mmol/l. The indoxyl acetate-based method showed faster and more sensitive response than the standard method for lipase activity determination, so it has great potential in biosensor construction and it could be used in industry, medicine, toxicology, and common practice where the activity of lipases is need to be measured.

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.

Realm of Thermoalkaline Lipases in Bioprocess Commodities

For decades, microbial lipases are notably used as biocatalysts and efficiently catalyze various processes in many important industries. Biocatalysts are less corrosive to industrial equipment and due to their substrate specificity and regioselectivity they produced less harmful waste which promotes environmental sustainability. At present, thermostable and alkaline tolerant lipases have gained enormous interest as biocatalyst due to their stability and robustness under high temperature and alkaline environment operation. Several characteristics of the thermostable and alkaline tolerant lipases are discussed. Their molecular weight and resistance towards a range of temperature, pH, metal, and surfactants are compared. Their industrial applications in biodiesel, biodetergents, biodegreasing, and other types of bioconversions are also described. This review also discusses the advance of fermentation process for thermostable and alkaline tolerant lipases production focusing on the process development in microorganism selection and strain improvement, culture medium optimization via several optimization techniques (i.e., one-factor-at-a-time, surface response methodology, and artificial neural network), and other fermentation parameters (i.e., inoculums size, temperature, pH, agitation rate, dissolved oxygen tension (DOT), and aeration rate). Two common fermentation techniques for thermostable and alkaline tolerant lipases production which are solid-state and submerged fermentation methods are compared and discussed. Recent optimization approaches using evolutionary algorithms (i.e., Genetic Algorithm, Differential Evolution, and Particle Swarm Optimization) are also highlighted in this article.