This study assessed the application of whole lipolytic cells in the pretreatment of slaughterhouse wastewater to reduce its lipid content. The fungal biomass of Rhizopus oryzae was evaluated in the hydrolysis of slaughterhouse wastewater containing high lipid concentrations, focusing on the biomass’s concentration and the effect of using an emulsifier and surfactant. The use of the whole-cells lipase of Rhizopus oryzae grown in a residual vegetable oil medium proved effective in the hydrolysis of slaughterhouse wastewater, generating concentrations of free fatty acids (FFA) ranging from 40.36 to 90.14 mM. The action of lipase in the hydrolysis of slaughterhouse residues indicated its effectiveness in pretreating lipid-rich liquid residues, potentially boosting the microbiota of this anaerobic treatment. The results showed that lipase activity without surfactant exhibited a similar performance to that of Triton X-100 in the hydrolysis of liquid residues. However, the combination of lipase and surfactant could represent a promising strategy to optimize free fatty acid production from slaughterhouse residues, strengthening anaerobic treatment processes and potentially enhancing the overall efficiency of waste management systems.

Large quantities of residual cooking oil are being increasingly generated in various sectors, as it is often improperly disposed of and causes serious environmental problems. A commonly used alternative is the use of lipases in enzymatic hydrolysis, since it is rather attractive to several sectors, in addition to allowing the use of products generated thereof, such as: free fatty acids, diacylglycerols, monoacylglycerols and free glycerol, moreover, it is capable of operating in mild temperature and pressure conditions. Therefore, the present study aimed to evaluate alternatives for the hydrolysis of residual frying oil by evaluating the efficiency of different types of supports and heating systems using free and immobilized forms of lipase from Burkholderia cepacia (BCL) and Porcine pancreas (PPL) as biocatalyst. Polyhydroxybutyrate (PHB), niobium oxide (Nb₂O₅) and chitosan (CHIT) were evaluated as support for immobilizing BCL and PPL lipases, and superior results were found regarding the hydrolytic activity of immobilization derivatives using PHB and Nb₂O₅. Among the heating systems under evaluation, the highest percentage of residual oil hydrolysis was found using the ultrasound system for both free and immobilized lipases, reaching 57.91% hydrolysis for lipases immobilized on Nb₂O₅ and 61.11% hydrolysis for the derivative immobilized on PHB. The operational stability of both biocatalysts was evaluated using similar half-life time values for both. Thus, it was observed that the ultrasound system was efficient in improving lipase performance in the hydrolysis of free fatty acids, once this unconventional heating system is quite promising for accelerating such enzymatic reactions.

The objective this stud was to evaluate the antimicrobial activity of essential oils (organic vs. conventional) of Origanum vulgare L. in the action against Candida albicans, Escherichia coli and Staphylococcus aureus. The inoculation of rhizobacteria (environmental (ME) and Bacillus subtilis) potentiated the antimicrobial action. The essential oils of Traditional (organic) cultivation presented antibacterial action and antifungal, while the essential oil of conventional cultivation (NPK) showed no any antibacterial or antifungal activity. It was concluded that the formulation of vermicomposting and the use of rhizobacteria are potential technologies and tools for family farmers and traditional community in the cultivation of orégano.

The use of agro-industrial by-products and processing residues, which are rich in carbohydrates, proteins, and lipids, in the production of lipases allows the sustainable use of these residues, reducing environmental impacts. In this study, the immersion water of lentils, soybeans, and textured soy protein was evaluated as carbon and nitrogen sources in the production of whole-cell lipases, and the resulting biomass was used in the hydrolysis of residual soybean oil with conventional heating and ultrasound. The results showed that the best culture medium was the one with 50% textured soybean protein, reaching values of 149.04 U/g of hydrolytic activity, 12.92 g/L of biomass concentration, 144.17 U of total biomass activity, and specific and volumetric productivities of 2.07 U/g·h and 20.02 U/L·h, respectively. The positive effect of adding soybean frying oil to the crop was observed, which increased cell production and hydrolytic activity. The biomass obtained showed potential for the ultrasound-assisted hydrolysis of vegetable oils, reaching approximately 43.36% hydrolysis in 7 h of reaction, with an initial rate of 31.03 mmol/h. It is concluded that soybean protein processing water is a viable candidate to replace traditional nitrogen sources, being an economically attractive alternative due to its wide generation in restaurants.

Production of esters, organic compounds with emollient, emulsifying, and aromatic properties is growing due to high demand and their applications in the cosmetics industry. The synthesis of these compounds involves the reaction between a carboxylic acid and an alcohol, which can be catalyzed by lipases. In this context, the objective of this study was to produce mycelium-bound lipases of the fungus Rhizopus oryzae through submerged cultivation, with the aim of applying them in the synthesis of ethylene glycol oleate, ethylene glycol stearate, and isoamyl palmitate esters, which are relevant to the cosmetic industry. The influence of solvent usage (heptane), biocatalyst mass, and acid/alcohol molar ratio was evaluated in the esterification reactions. In the synthesis of the three tested esters, and in the presence of heptane solvent, an equimolar ratio (1:1) of each acid and alcohol with a concentration of 0.01 mol L-1 was utilized. The reactions were performed in agitated Erlenmeyer flasks at 40 °C with an agitation speed of 200 rpm. The lipolytic biomass of Rhizopus oryzae showed better performance in the synthesis of isoamyl palmitate, achieving a maximum conversion of 83% in 24 h of reaction using 0.30 g of lipolytic biomass and the solvent heptane. In addition, it was observed that higher concentrations of catalyst biomass (0.45 g) and lower molar ratios (1:1.5) of acid to alcohol resulted in a higher conversion of isoamyl palmitate ester, reaching conversions of 48.59 and 83.11%, respectively.