Expression and characterization of a lipase EstA from Bacillus subtilis KM-BS for application in bio-hydrolysis of waste cooking oil.

A lipase EstA from Bacillus subtilis KM-BS was expressed in Escherichia coli BL21 (DE3) cells. The recombinant enzyme achieved high activity (49.67 U/mL) with protein concentration of 1.29 mg/mL under optimal conditions at the large-scale expression of 6 h and post-induction time at 30 °C using 0.1 mM isopropyl-ß-d-thiogalactopyranoside (IPTG). The optimal temperature and pH of the purified enzyme were at 45-55 °C and pH 8.0 - 9.0, respectively. Activity of the purified enzyme was stable in the presence of 1 mM Ca2+; stimulated by 1 mM Mg2+ and Mn2+, and inhibited by Fe3+. A significant amount of fatty acids was released during the hydrolysis of waste cooking oil under the catalysis of purified lipase, indicating that this recombinant lipase showed promise as a suitable candidate in industrial fields, particularly in biodiesel and detergent sector.

Anaerobic digestion of crude glycerol from biodiesel production for biogas generation: Process optimization and pilot scale operation.

Anaerobic digestion of wastes and wastewater is a complex process that can be affected by many operational parameters. In this context, the purpose of the present study was to optimize biogas production using crude glycerol (GLY) generated in biodiesel production from waste cooking oil without pretreatment or nutrient supplementation. The study was divided into two parts: the first phase consisted of an experimental design based on central composite design (CCD) with two variables (food to microorganism (F/M) ratio and cycle time) at five levels (F/M of 0.20; 0.51; 1.02; 1.53 and 2.04 gCOD/gVS; tc of 3, 4, 5, 6, 7 days) focusing on optimizing the biogas production from crude GLY in lab-scale batch reactors (500 mL). The second phase was conducted on a pilot-scale biodigester (1.2 m3) based on the optimized variables obtained from the CCD. The optimized results showed that the F/M ratio of 2.04 gCOD/gVS and a cycle time (tc) of 6 days reached the highest specific methane production (SMP) of 46 LCH4/kgVS. However, the highest SMP of 14.7 LCH4/kgVSd was obtained during the operation of the pilot-scale biodigester for the optimized conditions of F/M ratio of 0.23 gCOD/gSV and a tc of 7 days. Therefore, pilot-scale biogas production from crude GLY was demonstrated to be feasible without the use of nutrients or GLY pretreatment at 0.15 LGLY/m3 d.

Waste cooking oil and molasses for the sustainable production of extracellular lipase by Saitozyma flava.

Organic waste valorization is one of the principal goals of the circular economy. Bioprocesses offer a promising approach to achieve this goal by employing microorganisms to convert organic feedstocks into high value products through their metabolic activities. In this study, a fermentation process for yeast cultivation and extracellular lipase production was developed by utilizing food waste. Lipases are versatile enzymes that can be applied in a wide range of industrial fields, from detergent, leather, and biodiesel production to food and beverage manufacturing. Among several oleaginous yeast species screened, Saitozyma flava was found to exhibit the highest secreted lipase activity on pNP-butyrate, pNP-caproate, and pNP-caprylate. The production medium was composed of molasses, a by-product of the sugar industry, which provided nutrients for yeast biomass formation. At the same time, waste cooking oil was employed to induce and enhance extracellular lipase production. After 48 h of process, 20 g/L of yeast biomass and 150 mU/mgdw of lipase activity were achieved, with a productivity of 3 mU/mgdw/h. The purified lipase from S. flava showed optimal performances at temperature 28°C and pH 8.0, exhibiting a specific activity of 62 U/mg when using p-NPC as substrate.

An Efficient Edge Computing-Enabled Network for Used Cooking Oil Collection.

In Portugal, more than 98% of domestic cooking oil is disposed of improperly every day. This avoids recycling/reconverting into another energy. Is also may become a potential harmful contaminant of soil and water. Driven by the utility of recycled cooking oil, and leveraging the exponential growth of ubiquitous computing approaches, we propose an IoT smart solution for domestic used cooking oil (UCO) collection bins. We call this approach SWAN, which stands for Smart Waste Accumulation Network. It is deployed and evaluated in Portugal. It consists of a countrywide network of collection bin units, available in public areas. Two metrics are considered to evaluate the system's success: (i) user engagement, and (ii) used cooking oil collection efficiency. The presented system should (i) perform under scenarios of temporary communication network failures, and (ii) be scalable to accommodate an ever-growing number of installed collection units. Thus, we choose a disruptive approach from the traditional cloud computing paradigm. It relies on edge node infrastructure to process, store, and act upon the locally collected data. The communication appears as a delay-tolerant task, i.e., an edge computing solution. We conduct a comparative analysis revealing the benefits of the edge computing enabled collection bin vs. a cloud computing solution. The studied period considers four years of collected data. An exponential increase in the amount of used cooking oil collected is identified, with the developed solution being responsible for surpassing the national collection totals of previous years. During the same period, we also improved the collection process as we were able to more accurately estimate the optimal collection and system's maintenance intervals.

Microwave-assisted catalytic pyrolysis of waste cooking oil to monocyclic aromatics under a bifunctional SiC ball catalyst.

Catalytic pyrolysis technology proves to be a highly effective approach for waste cooking oil management. However, high-pressure drops and easy deactivation of powder catalysts hinder the industrialization of this technology. In this study, a bifunctional SiC ball (ZSM-5/SiC ball structured) catalyst was prepared to produce monocyclic aromatics. Bifunctional SiC ball catalyst demonstrates notable microwave-responsive properties and remarkable catalytic efficacy. Results showed that the content of monocyclic aromatics under BFSB catalysis with microwave heating was the highest. Weight hourly space velocity is no longer one of the main factors affecting microwave-assisted catalytic pyrolysis under bifunctional SiC ball catalyst. Monocyclic aromatics content did not decrease significantly and was still higher than 86% when space velocity increased from 30 h-1 to 360 h-1. The highest space velocity could only be 180 h-1 under Powder ZSM-5, and the content of the monocyclic aromatics dropped rapidly to 67.68%. Furthermore, even after five operating cycles, the content of monocyclic aromatics with bifunctional SiC ball catalyst continues to surpass the initial content observed with Powder ZSM-5 at 500 °C and 180 h-1. Related characterizations revealed that coking is the primary cause of catalyst deactivation for both catalyst types; however, the bifunctional SiC ball catalyst exhibits a 29.1% lower occurrence of polyaromatic coke formation compared to Powder ZSM-5.

Biodiesel Production from Waste Cooking Oil Using Recombinant Escherichia coli Cells Immobilized into Fe3O4-Chitosan Magnetic Microspheres.

Developing reusable and easy-to-operate biocatalysts is of significant interest in biodiesel production. Here, magnetic whole-cell catalysts constructed through immobilizing recombinant Escherichia coli cells (containing MAS1 lipase) into Fe3O4-chitosan magnetic microspheres (termed MWCC@MAS1) were used for fatty acid methyl ester (FAME) production from waste cooking oil (WCO). During the preparation process of immobilized cells, the effects of chitosan concentration and cell concentration on their activity and activity recovery were investigated. Optimal immobilization was achieved with 3% (w/v) chitosan solution and 10 mg wet cell/mL cell suspension. Magnetic immobilization endowed the whole-cell catalysts with superparamagnetism and improved their methanol tolerance, enhancing the recyclability of the biocatalysts. Additionally, we studied the effects of catalyst loading, water content, methanol content, and reaction temperature on FAME yield, optimizing these parameters using response surface methodology and Box-Behnken design. An experimental FAME yield of 89.19% was gained under the optimized conditions (3.9 wt% catalyst loading, 22.3% (v/w) water content, 23.0% (v/w) methanol content, and 32 °C) for 48 h. MWCC@MAS1 demonstrated superior recyclability compared to its whole-cell form, maintaining about 86% of its initial productivity after 10 cycles, whereas the whole-cell form lost nearly half after just five cycles. These results suggest that MWCC@MAS1 has great potential for the industrial production of biodiesel.

A 4D-Printable Photocurable Resin Derived from Waste Cooking Oil with Enhanced Tensile Strength.

In pursuit of enhancing the mechanical properties, especially the tensile strength, of 4D-printable consumables derived from waste cooking oil (WCO), we initiated the production of acrylate-modified WCO, which encompasses epoxy waste oil methacrylate (EWOMA) and epoxy waste oil acrylate (EWOA). Subsequently, a series of WCO-based 4D-printable photocurable resins were obtained by introducing a suitable diacrylate molecule as the second monomer, coupled with a composite photoinitiator system comprising Irgacure 819 and p-dimethylaminobenzaldehyde (DMAB). These materials were amenable to molding using an LCD light-curing 3D printer. Our findings underscored the pivotal role of triethylene glycol dimethacrylate (TEGDMA) among the array of diacrylate molecules in enhancing the mechanical properties of WCO-based 4D-printable resins. Notably, the 4D-printable material, composed of EWOA and TEGDMA in an equal mass ratio, exhibited nice mechanical strength comparable to that of mainstream petroleum-based 4D-printable materials, boasting a tensile strength of 9.17 MPa and an elongation at break of 15.39%. These figures significantly outperformed the mechanical characteristics of pure EWOA or TEGDMA resins. Furthermore, the EWOA-TEGDMA resin demonstrated impressive thermally induced shape memory performance, enabling deformation and recovery at room temperature and retaining its shape at -60 °C. This resin also demonstrated favorable biodegradability, with an 8.34% weight loss after 45 days of soil degradation. As a result, this 4D-printable photocurable resin derived from WCO holds immense potential for the creation of a wide spectrum of high-performance intelligent devices, brackets, mold, folding structures, and personalized products.

The perception of food vendors on the associated effects of used cooking oil in Lagos State, Nigeria.

Used cooking oils (UCOs) represent the residual oil and fat used for deep-frying foods. This study determined the perception and practices of food vendors on the reuse and disposal of UCOs. The study aims to provide information on UCO management and its potential environmental impacts. The descriptive cross-sectional study utilized a mixed-method approach. A three-stage sampling technique was applied to select 291 commercial food vendors selling deep-fried foods. The data were collected using interviewer-administered questionnaire, and three focus group discussions. The results showed that 61.0% of the respondents positively perceived the environmental effects of reusing and disposing UCO, and 99.0% repeatedly use the same cooking oil for deep-frying till depletion. The respondents' perception on cooking oil reuse and disposal were influenced by wealth, ethnicity, education, and years of experience. Most respondents demonstrated a positive awareness on the environmental impact of UCO, though a significant gap remained between their knowledge and practice.

In vitro evaluation of the toxicological effects of cooking oil fumes using a self-designed microfluidic chip.

Cooking oil fumes (COFs) are widely acknowledged as substantial contributors to indoor air pollution, having detrimental effects on human health. Despite the existence of commercialized in vitro aerosol exposure platforms, assessment risks of aerosol pollutants are primarily evaluated based on multiwell plate experiments by trapping and redissolving aerosols to conduct comprehensive in vitro immersion exposure manner. Therefore, an innovative real-time exposure system for COF aerosol was constructed, featuring a self-designed microfluidic chip as its focal component. The chip was used to assess toxicological effects of in vitro exposure to COF aerosol on cells cultured at the gas-liquid interface. Meanwhile, we used transcriptomics to analyze genes that exhibited differential expression in cells induced by COF aerosol. The findings indicated that the MAPK signaling pathway, known for its involvement in inflammatory response and oxidative stress, played a crucial role in the biological effects induced by COF aerosol. Biomarkers associated with inflammatory response and oxidative stress exhibited corresponding alterations. Furthermore, the concentration of COF aerosol exposure and post-exposure duration exert decisive effects on these biomarkers. Thus, the study suggests that COF can induce oxidative stress and inflammatory response in BEAS-2B cells, potentially exerting a discernible impact on human health.

Multiple-heated cooking oil promotes early hepatic and renal senescence in adult male rats: the potential regenerative capacity of oleuropein.

For economic purposes, cooking oil is repeatedly heated in food preparation, which imposes serious health threats. This study investigated the detrimental effects of multiple-heated cooking oil (MHO) on hepatic and renal tissues with particular focusing on cellular senescence (CS), and the potential regenerative capacity of oleuropein (OLE). Adult male rats were fed MHO-enriched diet for 8 weeks and OLE (50 mg/kg, PO) was administered daily for the last four weeks. Liver and kidney functions and oxidative stress markers were measured. Cell cycle markers p53, p21, cyclin D, and proliferating cell nuclear antigen (PCNA) were evaluated in hepatic and renal tissues. Tumor necrosis factor-α (TNF-α) and Bax were assessed by immunohistochemistry. General histology and collagen deposition were also examined. MHO disturbed hepatic and renal structures and functions. MHO-fed rats showed increased oxidative stress, TNF-α, Bax, and fibrosis in liver and kidney tissues. MHO also enhanced the renal and hepatic expression of p53, p21, cyclin D and PCNA. On the contrary, OLE mitigated MHO-induced oxidative stress, inflammatory burden, apoptotic and fibrotic changes. OLE also suppressed CS and preserved kidney and liver functions. Collectively, OLE displays marked regenerative capacity against MHO-induced hepatic and renal CS, via its potent antioxidant and anti-inflammatory effects.

Role of ROS-mediated PERK/ATF4 signaling activation in extracorporeal tube formation injury of human umbilical vein endothelial cells induced by cooking oil fume PM2.5 exposure.

Cooking oil fume-derived PM2.5 (COF-PM2.5) is a major source of indoor air contamination in China, which has been demonstrated to be a hazard factor of cardiovascular and cerebrovascular diseases. This study aimed to investigate the role of ROS-mediated PERK/ATF4 signaling activation in COF-PM2.5-inhibited extracorporeal tube formation in human umbilical vein endothelial cells (HUVECs). HUVECs were treated with 100 µg/mL COF-PM2.5 at different times, with or without 100 nM PERK activity inhibitor GSK2606414 (GSK) or 200 µM antioxidant N-acetylcysteine (NAC) pretreatment. Our results showed that COF-PM2.5 exposure can inhibit extracorporeal tube formation and down-regulate VEGFR2 expression in HUVECs. Furthermore, our data indicated that COF-PM2.5 exposure can activate the PERK/ATF4 signaling in HUVECs. Mechanistically, pretreatment with GSK interdicted PERK/ATF4 signaling, thereby reversing COF-PM2.5-downregulated VEGFR2 protein expression in HUVECs. Furthermore, NAC reversed VEGFR2 expression downregulated induced by COF-PM2.5 by inhibiting the upregulation of intracellular ROS levels and PERK/ATF4 signaling in HUVECs. As above, COF-PM2.5 exposure could induce ROS release from HUVECs, which in turn activate the endoplasmic reticulum PERK/ATF4 signaling and inhibit tube formation of HUVECs.

Production efficiency and cost reduction potential of biodiesel fuel plants using waste cooking oil in Japan.

Biodiesel fuel (BDF) is a potentially carbon-neutral fuel that could play a potentially important role in preventing global warming. However, its high production cost poses a challenge for many BDF producers. To establish an efficient method for BDF production and increase its cost competitiveness, the production efficiencies of 35 BDF plants in Japan, which produce BDF from waste cooking oil, were evaluated. Moreover, the cost reduction potential associated with improved efficiency was estimated. The empirical analysis revealed that (1) approximately 92% of the BDF plants have inefficient production; (2) they exhibit two predominant types of inefficiencies, technical and scale inefficiencies, and (3) improvement of production inefficiency can lead to an average production cost reduction of 3.52 yen per liter of BDF. To increase the production efficiency, it is important to improve the quality of the waste cooking oil used and increase the production scale. It is recommended that operators of inefficient BDF plants learn the production activities of the most efficient plants identified in this study. Furthermore, government policies focused on efficient BDF plants are essential to increase BDF production with limited resources.

Conversion of Waste Cooking Oil into Bio-Fuel via Pyrolysis Using Activated Carbon as a Catalyst.

The utilization of activated carbon (AC) as a catalyst for a lab-scale pyrolysis process to convert waste cooking oil (WCO) into more valuable hydrocarbon fuels is described. The pyrolysis process was performed with WCO and AC in an oxygen-free batch reactor at room pressure. The effects of process temperature and activated carbon dosage (the AC to WCO ratio) on the yield and composition are discussed systematically. The direct pyrolysis experimental results showed that WCO pyrolyzed at 425 °C yielded 81.7 wt.% bio-oil. When AC was used as a catalyst, a temperature of 400 °C and 1:40 AC:WCO ratio were the optimum conditions for the maximum hydrocarbon bio-oil yield of 83.5 and diesel-like fuel of 45 wt.%, investigated by boiling point distribution. Compared to bio-diesel and diesel properties, bio-oil has a high calorific value (40.20 kJ/g) and a density of 899 kg/m3, which are within the bio-diesel standard range, thus demonstrating its potential use as a liquid bio-fuel after certain upgradation processes. The study revealed that the optimum AC dosage promoted the thermal cracking of WCO at a reduced process temperature with a higher yield and improved quality compared to noncatalytic bio-oil.

Long-term consumption of recycled cooking oil induces cell death and tissue damage.

Recycled cooking oil (RCO) is widely used in many small restaurants. However, the health risk posed by long-term consumption of RCO is unclear. In this study, C57 mice were treated with RCO for 34 weeks. Organ coefficients of the liver, stomach, and kidney were found to be decreased. H&E staining revealed overt lesions in the pancreas, liver, kidney, esophagus, duodenum, and ileum of RCO-treated mice. Immunohistochemistry showed significant DNA damage in the duodenum and ileum and apoptosis in the lungs of the RCO-treated mice. Immunoblotting showed elevated levels of γ-H2AX, Bcl-2/Bax, TNFα, cleaved Caspase-3 and poly ADP-ribose polymerase (PARP). Increased levels of lactate dehydrogenase (LDH) and decreased levels of succinate dehydrogenase (SDH) were also detected. These findings suggest that long-term consumption of RCO produces various toxicities in mice with important implications for humans. DNA damage followed by mitochondria-associated apoptosis, and necrosis is likely to contribute to the toxicities.

High-yield α-humulene production in Yarrowia lipolytica from waste cooking oil based on transcriptome analysis and metabolic engineering.

BACKGROUND: α-Humulene is an important biologically active sesquiterpene, whose heterologous production in microorganisms is a promising alternative biotechnological process to plant extraction and chemical synthesis. In addition, the reduction of production expenses is also an extremely critical factor in the sustainable and industrial production of α-humulene. In order to meet the requirements of industrialization, finding renewable substitute feedstocks such as low cost or waste substrates for terpenoids production remains an area of active research. RESULTS: In this study, we investigated the feasibility of peroxisome-engineering strain to utilize waste cooking oil (WCO) for high production of α-humulene while reducing the cost. Subsequently, transcriptome analysis revealed differences in gene expression levels with different carbon sources. The results showed that single or combination regulations of target genes identified by transcriptome were effective to enhance the α-humulene titer. Finally, the engineered strain could produce 5.9 g/L α-humulene in a 5-L bioreactor. CONCLUSION: To the best of our knowledge, this is the first report that converted WCO to α-humulene in peroxisome-engineering strain. These findings provide valuable insights into the high-level production of α-humulene in Y. lipolytica and its utilization in WCO bioconversion.

Synergistic Effect of Reactive Oxygen Species in Photothermocatalytic Removal of VOCs from Cooking Oil Fumes over Pt/CeO2/TiO2.

The volatile organic compounds (VOCs) from cooking oil fumes are very complex and do harm to humans and the environment. Herein, we develop the high-efficiency and energy-saving synergistic photothermocatalytic oxidation approach to eliminate the mixture of heptane and hexanal, the representative VOCs with high concentrations in cooking oil fumes. The Pt/CeO2/TiO2 catalyst with nanosized Pt particles was prepared by the simple hydrothermal and impregnation methods, and the physicochemical properties of the catalyst were measured using numerous techniques. The Pt/CeO2/TiO2 catalyst eliminated the VOC mixture at low light intensity (100 mW cm-2) and low temperature (200 °C). In addition, it showed 25 h of catalytic stability and water resistance (water concentration up to 20 vol %) at 140 or 190 °C. It is concluded that O2 picked up the electrons from Pt to generate the •O2- species, which were transformed to the O22- and O- species after the rise in temperature. In the presence of water, the •OH species induced by light irradiation on the catalyst surface and the •OOH species formed via the thermal reaction were both supplementary oxygen species for VOC oxidation. The synergistic interaction of photo- and thermocatalysis was generated by the reactive oxygen species.

A simple and rapid homogeneous fluorescence polarization immunoassay for rapid identification of gutter cooking oil by detecting capsaicinoids.

In order to address the widespread concerns with food safety such as adulteration and forgery in the edible oil field, this study developed a fluorescence polarization immunoassay (FPIA) based on a monoclonal antibody in a homogeneous solution system for determination of capsaicinoids in gutter cooking oil by using chemically stable capsaicinoids as an adulteration marker. The prepared fluoresceinthiocarbamyl ethylenediamine (EDF) was coupled with capsaicinoid hapten C, and the synthesized tracer was purified by thin-layer chromatography (TLC) and showed good binding to the monoclonal antibody CPC Ab-D8. The effects of concentration of tracer and recognition components, type and pH of buffer and incubation time on the performance of FPIA were studied. The linear range (IC20 to IC80) was 3.97-97.99 ng/mL, and the half maximal inhibitory concentration (IC50) was 19.73 ng/mL, and the limit of detection (LOD) was 1.56 ng/mL. The recovery rates of corn germ oil, soybean oil and peanut blend oil were in the range of 94.7-132.3%. The experimental results showed that the fluorescence polarization detection system could realize the rapid detection of capsaicinoids, and had the potential to realize on-site identification of gutter cooking oil. As a universal monoclonal antibody, CPC Ab-D8 can also specifically identify capsaicin and dihydrocapsaicin, so the proposed method can be used to quickly monitor for the presence of gutter cooking oil in normal cooking oil.

Waste cooking oil used as carbon source for microbial lipid production: Promoter or inhibitor.

In this study, waste cooking oil (WCO) co-fermentation with food waste by variable pH strategy was developed for microbial lipid production. Results showed that when WCO substitution rate within the range of 1.56-4.68% (corresponding to the WCO content in food waste), lipid production from Rhodosporidium toruloides 2.1389 could be increased by 7.2 g/kg food waste because of the better synergistic effect. Mechanism analysis revealed that the fatty acid salt produced from WCO under alkaline condition, as a surface active agent, could improve lipid production, but excessive WCO (29.2 g/L) would inhibit the lipid production due to its hindrance to the oxygen. The lipid composition analysis found that the produced lipid could be used as raw material for biodiesel production. It was estimated that 15.0 million tonnes of biodiesel could be produced from global food waste yearly by adopting the proposed WCO co-fermentation with variable pH strategy, together with reduction of about 0.31 million tonnes of CO2 equivalents and 1435 tonnes of SO2. It is expected that this study may lead to the paradigm shift in future biodiesel production from food waste.

The toxicity of cooking oil fumes on human bronchial epithelial cells through ROS-mediated MAPK, NF-κB signaling pathways and NLRP3 inflammasome.

Cooking oil fumes (COFs) are the main pollutants in kitchen and indoor air, which threaten human health. Exposure to COFs may lead to respiratory diseases and impair pulmonary function. To investigate the toxicity of COFs on human bronchial epithelial cells (Beas-2B) and explore the underlying mechanisms, MTT assay was conducted to detect the viability of Beas-2B. Intracellular reactive oxygen species (ROS) levels and nitric oxide (NO) levels were determined with DCFH-DA assay and DAF-FM assay. The expression of genes involved in inflammation were measured with quantitative real-time PCR (qRT-PCR). The phosphorylation and the expression of proteins related to Mitogen-activated protein kinase (MAPK), NF-κB signaling pathways were measured with western blot. Our results revealed that COFs decreased cell viability, increased the ROS levels and NO levels and induced apoptosis in Beas-2B cells. The results of qRT-PCR and western blot showed that the expression of NLRP3, p65, iNOS, IL-1ß, and the factors related to oxidative stress and inflammation increased, NF-κB signaling pathway and MAPK signaling pathway were activated. This study provided some useful information to evaluate the toxicity of COFs and revealed the possible mechanism for the damage on respiratory system induced by COFs.

Biodegradation of waste cooking oil and simultaneous production of rhamnolipid biosurfactant by Pseudomonas aeruginosa P7815 in batch and fed-batch bioreactor.

Biosurfactants are non-toxic, surface-active biomolecules capable of reducing surface tension (ST) and emulsifying interface at a comparably lower concentration than commercial surfactants. Yet, poor yield, costlier substrates, and complex cultivation processes limit their commercial applications. This study focuses on producing biosurfactants by Pseudomonas aeruginosa P7815 in batch and fed-batch bioreactor systems using waste cooking oil (WCO) as the sole carbon source. The batch study showed a 92% of WCO biodegradation ability of P. aeruginosa producing 11 g L-1 of biosurfactant. To enhance this biosurfactant production, a fed-batch oil feeding strategy was opted to extend the stationary phase of the bacterium and minimize the effects of substrate deprivation. An enhanced biosurfactant production of 16 g L-1 (i.e. 1.5 times of batch study) was achieved at a feed rate of 5.7 g L-1d-1 with almost 94% of WCO biodegradation activity. The biosurfactant was characterized as rhamnolipid using Fourier transform infrared spectroscopy (FTIR), and its interfacial characterization showed ST reduction to 29 ± 1 mN m-1 and effective emulsification stability at pH value of 4, temperature up to 40 °C and salinity up to 40 g L-1. The biosurfactant exhibited antibacterial activity with minimum inhibitory concentration (MIC) values of 100 µg mL-1 and 150 µg mL-1 for pathogenic E. hirae and E. coli, respectively. These findings suggest that biodegradation of WCO by P. aeruginosa in a fed-batch cultivation strategy is a potential alternative for the economical production of biosurfactants, which can be further explored for biomedical, cosmetics, and oil washing/recovery applications.