Anti-Candida activity and industrial properties of Pediococcus pentosaceus NOA-2142 isolate from traditional pickled gherkin

Abstract

Antifungal activities of LAB have increased in many environments, especially in foods, due to the harms of chemical preservatives, as they are natural and capable of preventing both spoilage and infections. This antifungal activity is associated with metabolic compounds of LAB such as cyclic dipeptides, fatty acids, hydrogen peroxide, organic acids, and phenyl lactic acid (PLA) which are produced directly or indirectly. On the other hand, many Candida sp. such as Candida albicans is an opportunistic pathogen and can cause diseases ranging from superficial mucosal to life-threatening systemic infections, and spoilage in food. Therefore, the anti-candida activity of LAB is an important issue. In this study, it was aimed to reveal the anti-candida activity of Pediococcus pentosaceus NOA-2142 which isolated from a traditional pickled gherkin, and to investigate the industrial properties of this strain for widespread use. In the study, the NOA-2142 isolate was selected for its high anti-candida activity, and was determined to belong to P. pentosaceus species. Subsequently, the minimum inhibitory concentration (MIC) of the cell-free supernatant (CFS) of this isolate against pathogen strains of Candida albicans and Candida tropicalis was determined as 1/128 and 1/64, respectively. In addition, the D-3-phenyllactic acid content, which is the most likely cause of the anti-candida activity of the CFS, was determined as 163.21 mg/L. Moreover, the isolate were revealed to have the ability to grow at temperatures of 15oC and above, and in the range of 3–12% NaCl concentration and 3.0–9 pH value. The NOA-2142 isolate showed the highest susceptibility with 40.53 mm zone diameter to the clindamycin antibiotic disc. As a result, the P. pentosaceus NOA-2142 with antifungal potential could be a proper candidate as bio-preservative starter or adjunct culture, or the CFS of P. pentosaceus NOA-2142 could be used as a natural additive.