Propionic Acid Fermentation—Study of Substrates, Strains, and Antimicrobial Properties

Abstract

Since milk whey is an abundant dairy by-product and a significant threat to the environment, its utilization is of great interest. The study compares valorization of lactose and lactates—the main carbon sources of whey—by fermentation—an environmentally friendly process. Antimicrobials released during fermentation by food-grade bacteria can help increase the microbiological safety of food. Propionic acid—a strong antimicrobial—is obtained mainly by the petrochemical route, yet there is increasing interest in its synthesis in biotechnological pathway. Five strains of propionic acid bacteria (Acidipropionibacterium acidipropionici, Propionibacterium cyclohexanicum, Propionibacterium freudenreichii, Acidipropionibacterium jensenii and Acidipropionibacterium thoenii) were investigated for their ability to produce organic acids and biomass using Na lactate or lactose as carbon sources. Selected fermentates were investigated for their antimicrobial efficacy during in vitro studies with foodborne pathogens: Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus. Results confirm that the production of acids and biomass is considerably influenced by the added carbon source. The tested fermentates have strong and specific antimicrobial activity against Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus. In addition, inhibition of Staphylococcus aureus and Klebsiella pneumonia depends on the activity of produced bacteriocins. The article also discusses the possibility of increasing the antimicrobial activity of fermentates by acidification.

Propionibacteria as promising tools for the production of pro-bioactive scotta: a proof-of-concept study

“…Thus, STAC 4 and STAC 42.1 were the best and the least propionic acid producers, and the same trend was observed also for acetic acid ( Table 8 ). P/A molar ratio was generally higher than that found on lactose containing medium by Unigunde et al (2023) and comparable on the two scotta for all isolates except for STAC 42.1. This showed the highest P/A ratio, reaching 4.61 in scotta 1 ( Table 8 ).…”

“…Propionic acid is a known inhibitor of fungal growth, widely utilized as preservative by the agrifood industry. While it is mainly obtained through the petrochemical route ( Unigunde et al, 2023 ), its production from agrifood by-products represents a more sustainable and environmentally friendly processes. Accordingly, P. freudenreichii fermentates containing, among the others, propionic and acetic acids and bacteriocins, find application as natural shelf-life extenders with the commercial names MicrogardTM (Du pont Danisco) and Inhibit 3600 DairyTM (Mezzoni Foods).…”

An overview of fermentation in the food industry - looking back from a new perspective

“…Propionic acid bacteria are microorganisms that produce propionic acid and are involved in producing fermented propionic cheeses, such as Swiss cheese, with exceptional adaptability to technological and physiological stress conditions. The propionic acid fermentation in cheese causes characteristic pores, cracks, and a slightly sweet flavor (Antone et al 2022 ; Bücher et al 2021 ). Propionic acid bacteria are also responsible for the formation of carbon dioxide during the fermentation process, which gives cheese its airy, spongy texture.…”

“…It is characterized by the production of carbohydrates during fermentation, except for lactic acid, propionic acid, and acetic acid (Vakhrusheva et al 2022 ). As a result of PAB's metabolic activities, the product is enriched with organic acids, vitamins (B2, B12, K, and folate), and other nutrients, increasing the stability and nutritional value of food products (Antone et al 2022 ). Fermented dairy products provide an ideal environment for probiotic bacteria to grow in the human gut.…”

Shelf-Stability of Kiln- and Liquid-Smoked Inulin-Fortified Emulsion-Type Pangasius Mince Sausage at Refrigerated Temperature

“…9 Temperature (pasteurization, sterilization, refrigeration, chilling, or freezing) is a key factor in increasing the length of storage of the processed products. 10 Therefore, the current study was aimed to develop inulinfortified kiln-and liquid-smoked sausage and further investigate its stability at refrigerated temperatures (5 ± 1 °C).…”