Maximum Lipase Activity Research Articles

Hierarchically ordered truncated single crystal mesoporous ZIF-8 as a solid platform for lipase immobilization

Most pristine metal organic frameworks (MOFs) are inherently microporous. To introduce desired porosity for easy enzyme infiltration and immobilization, polystyrene spheres was used as sacrificial template to design hierarchical ordered micro-mesoporous truncated single-crystalline ZIF-8 (SOM-ZIF-8). The surface area and pore diameter of the SOM-ZIF-8 were 821 m2/g and 7.09 nm which changed to 669 m2/g and 4.98 nm respectively, after lipase immobilization, suggesting the pores and surface of the SOM-ZIF-8 served as binding sites for the enzyme, and could reach a loading capacity of 134 mg/g after 24 h. The optimal conditions for achieving maximum lipase activity for free LipaseELP, ZIF-8@LipaseELP and SOM-ZIF-8@LipaseELP were pH 7.8 at 45 °C, and maintained 33.67 %, 45.6 % and 57.78 % residual activity after incubation at 80 °C for 2 h. The specific activity towards tributyrin and p-nitrophenyl acetate were observed to be SOM-ZIF-8@LipaseELP (0.25 and 45.85 U/mg) compared to ZIF-8@LipaseELP (0.211 and 43.62 U/mg) and LipaseELP (0.179 and 41.09 U/mg) respectively. The SOM-ZIF-8@LipaseELP could further be recovered and reused for 9 rounds while maintaining 73.8 % of its original activity. This study demonstrates that introducing mesoporous structures into ZIF-8 could improve its binding enzyme property for enhanced hydrolytic function.

Surfactant-facilitated metabolic induction enhances lipase production from an optimally formulated waste-derived substrate mix using Aspergillus niger: A case of machine learning modeling and metaheuristic optimization

This study introduces a novel method to enhance lipase production by integrating machine learning (ML) models and optimization algorithms. Six ML models, including support vector regression (SVR), kernel ridge regression (KRR), extreme gradient boosting (XGB), extreme learning machine (ELM), random forest (RF), and artificial neural networks (ANN), were employed to predict lipase activity in a multi-substrate system using avocado seed, coconut pulp, and palm oil mill effluent (POME) with Aspergillus niger. SVR proved the most effective (R2 = 0.9738; RMSE = 7.0089). Further optimization using manta ray foraging optimization (MFRO), particle swarm optimization (PSO), and genetic algorithm (GA) identified optimal substrate loadings, achieving a maximum lipase activity of 194.38 U/gds. The addition of a mixture of surfactants (Tween 80, Tween 20, Triton X-100) further increased lipase production to 520.95 U/gds (168.3 % increase). Global sensitivity analysis (GSA) confirmed the important roles of avocado seed, POME, and surfactants in enhancing lipase production. This approach represents a significant advancement in bioprocess scalability.

MES surfactant-based liquid soaps added with eco-enzyme and pandan wangi leaf extract (Pandanus amaryllifolius Roxb) on physical-chemistry properties, and antibacterial activity,"

The growing demand for liquid soap has spurred innovations in soap formulations, particularly using methyl ester sulfonate (MES) as a surfactant base combined with natural ingredients like eco-enzyme and fragrant pandan leaf extract. This study aimed to determine the optimal liquid soap formulation by evaluating physicochemical properties and antibacterial activity against Staphylococcus aureus. The research was conducted in two stages. First, liquid soap was produced at different temperatures (20°C, 50°C, and 100°C) to identify the optimal temperature based on maximum lipase activity. In the second stage, various formulations were prepared, incorporating eco-enzyme and fragrant pandan leaf extract at the identified optimal temperature. The six formulations tested were: F1 (MES-based soap), F2 (20% eco-enzyme), F3 (15% eco-enzyme and 5% fragrant pandan leaf extract), F4 (10% eco-enzyme and 10% fragrant pandan leaf extract), F5 (5% eco-enzyme and 15% fragrant pandan leaf extract), and F6 (20% fragrant pandan leaf extract). The formulations were assessed for lipase activity, pH, density, and viscosity. The most effective formulation was further tested for antibacterial activity using the disc diffusion method with six treatments, including MES-based soap and controls. Statistical analysis using One-Way ANOVA revealed that adding eco-enzyme and fragrant pandan leaf extract significantly affected the soap's properties. The optimal formulation, containing 5% eco-enzyme and 15% fragrant pandan leaf extract, exhibited a lipase activity of 15,778 U/mL, a pH of 5.02, a density of 1.06 g/mL, a viscosity of 3.59 cP, and an antibacterial zone of 37.22 mm, making it the best candidate for further development

Alkaliphilic and thermostable lipase production by leaf litter fungus Leptosphaerulina trifolii A SMR-2011.

Fungi that inhabit fire-prone forests have to be adapted to harsh conditions and fungi affiliated to Ascomycota recovered from foliar litter samples were used for bioprospecting of molecules such as enzymes. Agni's fungi isolated from leaf litter, whose spores are capable of tolerating 110 oC were screened for thermostable lipases. One of the isolates, Leptosphaerulina trifolii A SMR-2011exhibited high positive lipase activity than other isolates while screening through agar plate assay using Tween 20 in the medium. Maximum lipase activity (173.2 U/mg) of L. trifolii was observed at six days of inoculation and decreased thereafter. Among different oils used, the maximum lipase activity was attained by soybean oil (940.1 U/mg) followed by sunflower oil (917.1 U/mg), and then by mustard oil (884.8 U/mg), showing its specificity towards unsaturated fatty acids. Among the various organic nitrogen sources tested, soybean meal showed maximum lipase activity (985.4 U/mg). The partially purified enzyme was active over a wide range of pH from 8 to 12 with a pH optimum of 11.0 (728.1 U/mg) and a temperature range of 60-80 oC with an optimal temperature of 70 oC (779.1 U/mg). The results showed that lipase produced by L. trifolii is alkali stable and retained 85% of its activity at pH 11.0. This enzyme also showed high thermal stability retaining more than 50% of activity when incubated at 60 oC to 90°C for 2h. The ions Ca2+ and Mn2+ induced the lipase activity, while Cu2+ and Zn2+ ions lowered the activity compared to control. These results suggests that the leaf litter fungus L. trifolii serves as a potential source for the production of alkali-tolerant and thermostable lipase.

Thermostable CaCO3-Immobilized Bacillus subtilis Lipase for Sustainable Biodiesel Production from Waste Cooking Oil

Due to the increasing demand for green processes in renewable energy production, the extracellular Bacillus subtilis B-1-4 lipase was used as a biocatalyst for producing biodiesel from waste cooking oil. Response surface methodology was employed for the optimization of enzyme production. Lipase activity was modeled with a quadratic function of four factors that primarily influence the culture medium. Thanks to this model, an optimal lipase activity of 1.7 ± 0.082 U/mL was achieved with the best culture medium composition: 16 g/L of tryptone, 15 g/L of yeast extract, 15 g/L of NaCl, and a 0.15 initial optical density at 600 nm (OD600 nm). The maximal lipase activity was measured at 45 °C and pH 8, using para-nitrophenyl palmitate as a substrate. The enzyme maintained above 94% and 99% of its initial activity at temperatures ranging from 40 to 50 °C and at pH 8, respectively. Moreover, it exhibited a higher residual activity than other Bacillus lipases in the presence of organic solvents. Residual activities of 86.7% and 90.2% were measured in the presence of isopropanol and ethanol, respectively. The lipase was immobilized by adsorption onto CaCO3 powder. FT-IR and SEM were used to characterize the surface-modified support. After immobilization, a lipase activity of 7.1 U/mg of CaCO3 was obtained. Under the optimized conditions, the highest biodiesel yield of 71% was obtained through the transesterification of waste cooking oil using the CaCO3-immobilized Bacillus subtilis lipase. This research reveals a method for the utilization of waste cooking oil for biodiesel production using an efficient immobilized thermostable lipase, providing environmental and economic security.

Purification and characterization of lipase from a new strain Staphylococcus argenteus MG2 (MTCC 12820)

The lipase enzyme was isolated and purified from Staphylococcus argenteus MG2 (MTCC 12820) to homogeneity using ammonium sulphate precipitation followed by chromatographic techniques. This process resulted in a purification factor of 40.96-fold and a 26.25% recovery with a specific activity of 744.68 U mg-1. The molecular weight of the purified lipase was determined by SDS-PAGE to be 45 kDa. The Km and Vmax values of the purified lipase were calculated to be 4.95 mM and 79.36 µmol/min/mg-1, respectively. The maximum lipase activity was observed at pH 7.0 and 30 ºC with 100% stability, and it was also found to be stable in a broad range of pH (5-12) and temperature (30-90 ºC). The enzymatic activity of this Staphylococcal lipase was increased by Ca2+ to 105.71% at a concentration of 1 mM CaCl2. Additionally, it exhibited marked stability and activity in organic solvents. In the presence of 1% SDS surfactant, it retained 85.16% residual activity, while the metal chelator EDTA (inhibitor) reduced the lipase activity to 83.87% residual activity at a concentration of 1% w/v. This alkali-stable and thermo-stable lipase can be exploited by extending its use in the preparation of detergents and in various industrial and biotechnological applications.

Molecular Cloning of the Extracellular Lipases of Bacillus Amyloliquefaciens Isolated from Agrifood Wastes.

The lipase enzyme (EC: 3.1.1.3) is one of the most important catalysts in food, dairy, detergent, and textile industries. This study was performed to identify, isolate and characterize of lipase producing bacterial strain from agrifood wastes and to identify and characterize of their lipase genes. In the present study, two lipase-producing isolates were identified from the effluent of Golbahar meat products and Soveyda vegetable oil factories using in silico and in vitro approaches. The results of morphological, biochemical, and molecular characterizations showed that both lipase-producing isolates belong to the Bacillus amyloliquefaciens species. Phylogenetic analysis confirmed the results of phenotypic, biochemical, and molecular characterizations. The results showed differences between LipA and LipB in the Golbahar and Soveyda isolates. Three different amino acids (residues 14, 100, and 165) were observed in LipA and one different amino acid (residue 102) was detected in LipB extracellular lipases. The proteinmolecular weightof the two extracted lipases ranged from 20 to 25 kDa. The identified extracellular lipases also had different physicochemical features. The maximum lipase activity of the Golbahar and Soveyda isolates was observed at 45 °C and at the pH of 8, but the Golbahar isolates exhibited higher lipase activity compared to the Soveyda isolates. The Golbahar and Soveyda isolates exhibited different activities in the presence of some ions, inhibitors, denaturing agents, and organic solvents and the Golbahar isolates showed better lipase activity than the Soveyda isolates. In this study, two extracellular lipase-producing isolates of B. amyloliquefaciens were identified from different food industries, and their characteristics were investigated. The results of various investigations showed that the lipases produced by the Golbahar isolate have better characteristics than the lipases of the Soveyda isolate. The Golbahar lipases have a suitable temperature and pH activity range and maintain their activity in the presence of some ions, inhibitors, denaturing agents, and organic solvents. After further investigation, the Golbahar isolate lipase can be used in various industries. In addition, this lipase can be used enzyme engineering processes and its activity can be arbitrarily changed by targeted mutations. The results of this study can increase our knowledge of extracellular lipases and may turn out to have industrial applications.

Production and Optimization of a Lipase-Producing Bacteria Enterobacter hormachei Isolated from an Oil-Contaminated Soil

Lipase enzymes possess a wide range of industrial applications. Thus, the capacity of lipase-producing bacteria to proliferate on tributyrin agar medium was used to screen for them among various sources. The lipase producing bacteria with highest zone of clearance on the screening media were preserved on the agar slants. The preserved slants were characterized by16SrRNA gene sequencing. The nucleotide sequence so obtained by the 16SrRNA gene sequence was then put through phylogenetic analysis and homology search using the NCBI’s BLAST program. The sequence of lipase producing bacteria showed maximum resemblance with Enterobacter hormaechei bacterial strain. These bacterial strains were produced by inoculating the culture in the inoculum media and allowing it to enrich over night. Subsequently, 3% of the inoculum from the inoculum media was added to the production media, which was then incubated for 48 hours in a rotary shaker. After production the media was centrifuged and supernatant was extracted and used further for optimization, Optimization of the physiochemical parameters of the bacterial strain like inoculum pH, incubation period, inoculum size was found using one factor at a time (OFAT) approach and medium parameters like different carbon source, nitrogen source, substrate, minerals, salts (11 factors) were screened using Plackett-Burman (PB) design which is a full factorial design. The Lipase activity was found by using a titrimetric method using olive oil and Arabic gum mixture as substrate mixture. The maximum lipase activity was found for inoculum pH of 5, 48 hours of incubation time, and 5% inoculum size. The results of the PB design showed the significant parameters to be glucose (carbon source), peptone (nitrogen source), KH2PO4 (salt), and NaCl (mineral). The organism of the soil sample containing bacterial strain showed maximum lipase activity of 70 U/ml and protein concentration of 4.3 μg/mL at the optimized conditions. After centrifuging the culture media that had been improved, the supernatant was collected and partially purified using dialysis and the ammonium sulfate precipitation procedure. Following precipitation, the supernatant’s activity was measured to be 74 U/mL. After being gathered, the pallet was dialyzed in a dialysis bag and added to a buffer. Both the protein content and the lipase activity were estimated. The protein concentration determined by Lowry’s technique was found to be 6.2 μg/mL, and the lipase activity was reported to be 85.22 U/mL.

Crude oil biodegradation potential of lipase produced by Bacillus subtilis and Pseudomonas aeruginosa isolated from hydrocarbon contaminated soil

Microbial biodegradation of oil pollutants and their derivatives has become the most environmental-friendly method in the developing world. The aim of this study was to evaluate crude oil biodegradation potential of lipase produced by indigenous bacteria from oil contaminated soil. Indigenous bacteria isolates were identified as species of Bacillus subtilis and Pseudomonas aeruginosa, the isolates were able to produce lipase as revealed in their zone of clearance on tween 80 agar plates and the presence of lipase produced by the two bacteria were further confirmed using spectrophotometric analyses. Lipase produced by B. subtilis showed maximal lipase activity at pH 8 and 40°C while the enzyme produced by P. aeruginosa showed maximal lipase activity (U/mL) at pH 8 and 50°C when subjected to various pH and temperature respectively. Lipase produced by B. subtilis recorded 8.11 ± 0.70% of crude oil degradation in mineral salt medium within 28 days, while that of P. aeruginosa recorded 15.6 ± 0.03% of crude oil biodegradation. The GC–MS analysis of the crude oil treatment showed complete mineralization of several compounds, and also showed peak reduction which indicates lipase efficiency in the degradation of hydrocarbons. As revealed by GC–MS analysis, out of the 8 hydrocarbons identified in an undegraded oil, 5 were completely degraded by the enzyme activities while 2 (toluene and methyl, cyclopentane) were identified with hydrocarbons treated with lipase. The enzymes produced by B. subtilis and P. aeruginosa can serve as useful product for bioremediation of crude oil contaminated soil.

Upcycling of the industrial waste as a sustainable source of axenic fungal strain (Aspergillus oryzae) for scale up enzymatic production with kinetic analysis and Box–Behnken design application

Abstract The utilization of industrial waste for valuable product synthesis is essential for mitigating the environmental impact of climate change and managing waste disposal challenges. Industrial waste is always a big challenge for global warming. In this study, a novel fungus strain was isolated, and identified as Aspergillus oryzae (AKMS), from the oily surface of industrial effluent from an oil industry. Submerged fermentation was exploited to achieve maximum lipases production. A sequence of batch experiments was performed, altering five primary components: sucrose (for carbon), molasses (constituting nutrient mix), yeast extract (as nitrogen supply), sunflower oil (used as an activating agent), and Tween-80 (functioning as an emulsifying agent). These elements are recognized for their substantial impact on the proliferation of microorganisms and, consequently, the synthesis of lipases. The maximum lipase activity for each ingredient was determined, with sucrose showing 2.4 ± 0.539 U/mL at 0.15 g/L, molasses at 1.499 ± 0.291 U/mL at 0.25 g/L, Tween 80 % at 3.33 ± 0.484 U/mL at 0.25 g/L, sunflower oil at 7.49 ± 0.282 U/mL at 1 % v/v, and yeast extract at 4.165 ± 0.841 U/mL at 0.075 % v/v. The optimization of the lipase production and activity was done by using RSM (Box–Behnken design) with the 41st run yielding the maximum activity of 9 U/mL, while the 25th run showed the minimum activity of 4 U/mL, enzyme estimation (U/mL and U/g), glucose (g/L), and dry cell mass estimation (g/L) were monitored up to 120 h of fermentation in a custom-made fermenter with a working volume of 7 L. The highest production of extracellular and intracellular lipases (27.4 ± 0.378 U/mL and 25.4 ± 0.208 U/g, respectively) was observed at the 40 h interval, with the highest value of dry cell mass at 20 g/L. Glucose concentration initially peaked and subsequently decreased over time. A. oryzae exhibited the capability to produce triacyl glycerol acyl hydrolases, demonstrating its potential significance in biotechnological applications. These novel findings shed light on the efficient utilization of oil industry waste soil for isolation of microorganism for sustainable lipase production and highlight the biotechnological promise of the novel isolated fungal strain, which was reported first time in this study.

Molecular cloning, overexpression, characterization, and In silico modelling analysis of a novel GDSL autotransporter-dependent outer membrane lipase (OML) of Pseudomonas guariconensis

The outer membrane lipase (oml) gene, encoding a novel autotransporter-dependent lipase from Pseudomonas guariconensis, was cloned and sequenced. The oml gene has an open reading frame of 1866 bp. It encodes the 621 amino acid autotransporter-dependent GDSL lipase (OML), which has the highest sequence similarity (64.08 %) with the EstA of Pseudomonas aeruginosa (PDB:3kvn.1. A). OML was expressed and purified, which showed a purified band of approximately 70 kDa. The purified enzyme showed maximum activity at pH 9 and 40 °C. Substrate specificity studies and kinetic study by Lineweaver-Burk plot of purified OML showed Km of 1.27 mM and Vmax of 333.33 U/mL with p-nitrophenyl palmitate. The purified enzyme showed good stability in the presence of hexane, methanol, and ethanol, while the presence of the metal ion Mg2+ showed maximum lipase activity. Bioinformatics analysis supported the in vitro findings by predicting enzyme substrate specificity towards long-chain fatty acids and fatty acids with shorter chain lengths. The stability of the interaction of the protein-ligand complex (OML-ricinoleic acid) was confirmed using MDS and castor oil bioconversion using purified OML was confirmed using High-Performance Liquid Chromatography (HPLC).

Modelling and optimization of biodiesel production from waste fish oil using nano immobilized rPichiapastoris whole cell biocatalyst with response surface methodology and hybrid artificial neural network based approach

In this study, zinc oxide (ZnO) nano particle immobilized recombinant whole cell biocatalyst (rWCB) was used for bioconversion of waste fish oil in to biodiesel in a lab scale packed bed reactor (PBR). Central composite design and hybrid artificial neural network (ANN) models were explored to optimize the production of biodiesel. Developed rWCB exhibited maximum lipase activity at 15 % (v/v) of glutaraldehyde concentration and 6 % (w/v) of ZnO nanoparticles at pH of 7. Maximum biodiesel yield reached about 91.54 ± 1.86 % after 43 h in PBR using hybrid ANN model predicted process conditions of 13.2 % (w/v) of nano immobilized rWCB concentration and 4.7:1 of methanol to oil ratio at 33 °C. Importantly, developed nano immobilized rWCB was adequately stable for commercialization. Thus, production of biodiesel from waste fish oil using ZnO nano immobilized rWCB could become potential candidate for commercialization.

Application of oil-degrading agents consisted of thermophilic Bacillus subtilis and Bacillus glycinifermentans in food waste

ABSTRACT This work aims to investigate the effective removal of oil in food waste (FW). Two bacteria, Bacillus subtilis and Bacillus glycinifermentans, were obtained under high temperature conditions and named YZQ-2 and YZQ-5, respectively. The oil degradation rate of two bacteria was explored under different pH value, temperature, and NaCl concentration. In addition, the lipase and emulsifying activity were evaluated. The maximum oil degradation rate was 83.41 ± 0.86% and the maximum lipase activity reached 89.73 ± 20.89 U L-1 with YZQ-2. The fermentation broth of YZQ-2 displayed exceptional emulsification activity. Subsequently, YZQ-2 and YZQ-5 were added to aerobic FW composting. The moisture content of the compost treated with inoculated strains decreased at a faster rate during the first three days of composting. The microbial quantity increased rapidly in the first three days, and the oil degradation rate reached 39.96% after five days. Due to the excellent adaptability to high temperature and ability to degrade oil, strains YZQ-2 and YZQ-5 exhibit superior potential for various applications.

Production, purification, and characterization of cold-active lipase from the psychrotroph Pseudomonas sp. A6

Cold-active lipases are presently employed extensively in the detergent, chemical intermediate, fine chemical, food, and pharmaceutical industries. Seven cold-adaptive bacteria were isolated from the Mediterranean Sea near Alexandria, Egypt, and tested for their ability to produce cold-active lipase, with the highest activity at 10 °C. The most potent isolate was Pseudomonas sp. A6. To determine the most important variables, the bacterium was exposed to a necessary medium component and environmental factor screening using a single factor-at-a-time approach, followed by a multifactorial Plackett-Burman design strategy. After purification and characterization, the optimal activity levels for the cold-active lipase were figured out. Inoculation of Pseudomonas A6 under near optimum conditions using medium consisting of (g/L) peptone 7.14; soybean oil 7.5% (v/v); K2HPO4, 0.4; MgSO4, 0.1; glucose 2; pH 8; and temperature 10 °C led to a maximum lipase activity anticipated to be 23.36 U/mL. Purified lipase showed the best activity and thermal stability at a pH of 8 and a temperature of 10 °C. The Pseudomonas A6 lipase tolerated the monovalent ions, while greater valence ions did not.

Soil biochemical inticators of initial presence of fat in different archaeological contexts

The article proposes a new biochemical approach for the reconstruction of the initial presence of fat-containing products in different archaeological contexts (ceramic vessels from burials, soil samples in different parts of the skeleton and cultural layers of archaeological sites) based on the study of qualitative and quantitative changes in the parameters of the soil microbial community, namely, specific groups of microorganisms (lipolytics), a number of lipolytic enzymes, as well as the utilization spectrum of readily available low molecular weight sub-strates. Ground samples of the studied objects were collected in the following regions: ceramic vessels — the Republic of North Ossetia-Alania and the Chechen Republic; burials — Krasnodar Krai; the cultural layer of the settlement — Lipetsk region. The number of lipolytic microorganisms and the level of enzymatic activity in the soil directly depend on the amount of the incoming substrate, in the decomposition of which they participate. After the decomposition of organic residues in the soil, a microbial and enzyme pools are formed, which can persist for a long period. The obtained preliminary data on the study of the decomposition dynamics of fatty substrates give us possibility for the reconstruction of the initial presence of fat in different archaeological contexts using the methods of soil microbiology and biochemistry. But, for a more accurate extrapolation of the results of a model experiment to archaeological objects, more points of observation in time are needed, since the introduction of substrates with different properties and composition can provoke microbial community succession in different ways. Hence, the equilibrium state of the microbial community in each variant of the experiment will be reached at different times. However, the results of the study of soils and cultural layers of archaeological sites of Bronze Age and early me-dieval time have convincingly shown the possibility of applying our approach. As we assumed, the maximum li-pase activity was found in the soil samples under the skull, chest and pelvis, i.e. in areas of human body with the highest content of fat tissues. This showed the possibility for reconstruction the original contents of the vessels from burials using the methods of soil microbiology and biochemistry. A high number of lipolytic microorganisms and lipase activity were detected only in 15–20 % of the vessels. We suggest that fat food may not have been as widely used in the funeral rite as ritual food. The study of lipase activity made it possible to clarify the features of the economic usage of the territory of archaeological site, to identify possible places for cooking.

Molecular insights on PS-PLA1 lipase activity of human ABHD16B

The human alpha beta hydrolase domain (ABHD) proteins are ubiquitous and regulate the cellular lipids' anabolic and catabolic processes. The structural aspects for specific biochemical function of many ABHD proteins related to physiological disorders and its link to pathological conditions remain unknown. Here putative human ABHD16B protein was overexpressed in Saccharomyces cerevisiae for its biological activity. In-vitro enzymatic assay of the recombinant ABHD16B protein with fluorescently tagged glycerophospholipids revealed that the PLA1 activity is observed with phosphatidylserine (PS). In addition, it efficiently hydrolyzed monoacylglycerol over triacylglycerols. Further, molecular dynamic simulations and per residue binding free energy decomposition analysis revealed that the origin of PS-specific PLA1 activity of ABHD16B is due to the electrostatic interaction of the PS head group with K8, R319, and E178, which led to having the hydrogen bond interaction of sn-1 acyl chain ester to the catalytic site residues. Site-directed mutagenesis of the 245GXSXG249 motif of ABHD16B reduced the maximal lipase activity of PS and MAG. In summary, these results revealed that ABHD16B plays a vital role in PS selectivity that in turn, controls the specific subcellular pools of 2-LPS metabolism in the tissues at low pH.

Aspergillus niger based lipase-tween 80 aggregates as interfacial activated biocatalyst for biodiesel production: Optimization using response surface methodology

Biodiesel is a renewable energy source, which is produced through transesterification reactions. Despite great attention to develop enzymatic biodiesel production, there are serious obstacles to the industrial development of it such as its cost and slow reaction rate. Along with disadvantages, there are several advantages for enzymatic biodiesel production. Higher purity of fuel and glycerol is known as the most important achievement of enzymatic process. In this study, performance of four different fungi for lipase production was investigated and Aspergillus niger was selected as enzyme source. Lipase production were optimized using experimental design and the optimized factors were determined as pH 5, temperature 30 °C, Potato Dextrose Broth (PDB) 3 % w/v, olive oil 1.50 % v/v, with maximum lipase activity of 42.8±0.51 U/mg. In order to interfacial activation of the lipase, effect of surfactants was studied. Therefore, surfactant-enzyme aggregates were used as biocatalyst for transesterification reaction. Effects of factors on biodiesel yield were studied too. The yield was 96.41±1.20 % at the optimized conditions (methanol/oil molar ration 5.50:1, enzyme concentration 19 % v/ w, Tween 80 concentration 19 mg L–1, temperature 40 °C and reaction time 46 h).

Valorization of Waste Cooking Oil into Biodiesel via Bacillus stratosphericus Lipase Amine-Functionalized Mesoporous SBA-15 Nanobiocatalyst

In this study, evaporation-induced self-assembly was applied to prepare amine-functionalized nano-silica (NH2-Pr-SBA-15). That was simply used to immobilize Bacillus stratosphericus PSP8 lipase (E–NH2–Pr-SBA-15), producing a nanobiocatalyst with good stability under vigorous shaking and a maximum lipase activity of 45 ± 2 U/mL. High-resolution X-ray diffractometer, Fourier transform infrared spectroscopy, N2 adsorption-desorption, field-emission scanning electron, and high-resolution transmission electron microscopic analyses proved the successful SBA-15 functionalization and enzyme immobilization. Response surface methodology based on a 1/2 fraction-three-levels face center composite design was applied to optimize the biodiesel transesterification process. This expressed efficient percentage conversion (97.85%) and biodiesel yield (97.01%) under relatively mild operating conditions: 3.12 : 1 methanol to oil ratio, 3.08 wt.% E–NH2–Pr-SBA-15 loading, 48.6°C, 3.19 h at a mixing rate of 495.53 rpm. E–NH2–Pr-SBA-15 proved to have a long lifetime, operational stability, and reusability.

Identification and Optimization Study of Lipase Producing Bacteria Isolated from Municipal Waste and Bio-deteriorated Waste

Bio-deteriorated waste is the leftover organic matter of unwanted raw food which if not handled properly or left for natural degradation can cause health issues. Microorganisms have the ability to biodegrade waste by secreting enzymes. The aim of the work was to isolate and identify lipase-producing bacteria from waste polluted (Bio-deteriorated waste and Municipal Solid Waste) dumping sites of Gandhinagar, Gujarat, India. Lipase-producing bacteria were isolated using tributyrin agar as a selective medium. Out of 7 bacterial isolates, 1 isolate (HAL-2) gave the highest lipolytic activity. HAL-2 was identified as Bacillus pumilus by 16S rRNA sequencing. The bacterial isolate gave maximum lipase activity (0.68 U/mL) at 37°C and pH 7.0 Culture medium parameters such as carbon source, nitrogen source, pH, and inoculum size were varied for the purpose of optimization. The maximum lipase production was observed at pH 7.0, 37°C temperature. Inoculum size had an effect of direct proportionality on lipase activity. Glycerol tributyrate was found to be the best substrate (0.68 U/mL). Sucrose and Tryptone in the medium increased enzyme production when compared with other carbon and nitrogen sources.

Cryptococcus albidus D24'ten Lipaz Üretimi Üzerindeki En Etkili Besin Maddelerinin Öneminin Belirlenmesi

In this study, the optimization of the medium components used for the production of lipase enzyme from Cryptococcus albidus D24 was performed using the Plackett-Burman statistical design method (PBD), and the most important nutrients affecting the production of lipase enzyme from D24 strain were determined as the first step. According to PBD, the highest lipase activity (19.34 U/ml/min) was obtained with medium including Tween 80 (X2) 2.5% (v/v), and (g/L) Peptone (X4) 8.0, Yeast Extract (X6) 7.5, Beef Extract (X7) 7.5, Malt Extract (X8) 7.5, NH4Cl (X9) 6.0, NaNO3 (X10) 1.5, (NH4)NO3 (X12) 6.0, (NH4)HCO3(X13) 6.0, MgSO4.7H2O (X15) 1.0, and KH2PO4 (X16) 2.0 at the end of 144 h cultivation. Regarding the concentration effect (CE) values obtained from PBD, NH4Cl (CE=7.1587), olive oil (CE=3.5544), (NH4)HCO3 (CE=3.0747), and tryptone (CE=2.1427) were evaluated as the more effective nutrients among the sixteen compounds studied. After that, the optimum concentrations of these effective compounds were experimented with Response Surface Methodology (RSM). Experimental results showed that the medium containing olive oil (X3) 1.5% (v/v), and (g/L) tryptone (X5) 3.0, NH4Cl (X9) 7.5, and (NH4)HCO3 (X13) yielded maximum lipase activity (12.03 U/ml/min) compared to other studied compounds. Although the maximum lipase activity obtained with RSM methodology was lower than that obtained by PBD, the cost of the nutrients used to produce one-unit enzyme is 0.104 Euro in the PBD, while only 0.0277 Euro is spent in RSM. In other words, the production of lipase using compounds coded X3, X5, X9, and X13 provides a cost-effective process.