Antimicrobial Activities of Olive Oil Mill Wastewater Extracts against Selected Microorganisms

Abstract

Discovering eco-friendly alternatives to synthetic chemicals has become an increasingly popular area of research. Natural products are now in the spotlight for their potential use as replacements for synthetic chemicals. To maximize the benefits of these natural products, it is important to use efficient extraction methods, especially from agroindustrial waste. Olive oil mill wastewater (OOMW) is a byproduct of the olive oil production process and is considered a pollutant; however, OOMW contains a wide range of phenolic compounds that have proven antimicrobial properties. This study investigates the extraction of these compounds from OOMW, with the aim of determining their potential antimicrobial activities against several bacterial strains and fungi, including Bacillus spizizenii, Bacillus cereus, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella aerogenes, Streptococcus uberis, Enterococcus faecalis, and Candida albicans. The OOMW extracts (OEs) were prepared by using three different solvents: ethyl acetate, ethanol, and methanol. The highest total phenolic contents (4.03 g, GAE/L) and the strongest antibacterial activity were obtained with methanol extraction. All OEs showed no antifungal activity against C. albicans. OEs, particularly methanol extracts of OOMW, can be used as bioactive substances in various industries as nutraceuticals and food ingredients, respectively.

Polyphenol-Rich Extracts from Agroindustrial Waste and Byproducts: Results and Perspectives According to the Green Chemistry and Circular Economy

“…Beyond food safety and preservation concerns, the antioxidant and antimicrobial properties of olive phenolic compounds can be applied to prevent infections caused by harmful microorganisms in humans and animals. Extracts from olive oil mill wastewater using ethanol, methanol, or ethyl acetate as solvents exhibited antimicrobial activity against a wide range of pathogens as Enterococcus faecalis , Klebsiella aerogenes , Pseudomonas aeruginosa , Streptococcus uberis , and Staphylococcus aureus . In contrast to other in vitro studies focused on Ole and leaves extracts, no inhibition was found against Candida albicans . , In this case, as in many instances, including HTyr, discrepancies in findings between studies may arise.…”

From antiquity to contemporary times: how olive oil by-products and waste water can contribute to health

“…savastanoi and Agrobacterium tumefaciens ) ( 49 ). Against therapeutically relevant Gram-positive and Gram-negative infections, resistant and multi-resistant to current antibiotic drugs, various OMWW samples demonstrated considerable antibacterial activity ( 50 , 51 ).…”

Novel Perspectives on Food-Based Natural Antimicrobials: A Review of Recent Findings Published since 2020

“…For this purpose, interest in natural antimicrobials, which are alternatives to the use of synthetic chemicals generally preferred, is increasing day by day [ 36 ]. Considering the use of food processing by-products (e.g., olive oil mill wastewater), fruit and vegetable products (peels, seed, and pomace), various herbs, spices, and flowers (essential oils) are considered as natural antimicrobials with their bioactive compounds [ 37 , 38 , 39 , 40 ]. Extracts and powders of these plant-based products, which show naturally antimicrobial properties, have been evaluated both to increase the quality of bakery, meat, and dairy products and to extend their shelf life ( Table 1 ).…”