Antifungal and antibacterial effects of newly created lactic acid bacteria associations depending on cultivation media and duration of cultivation

Abstract

Background The newly created associations of lactic acid bacteria (LAB) isolated from Armenian dairy products (yoghurt, sour cream and different varieties of cheese), as well as from the gastrointestinal tract of honeybees were screened according to their antifungal and antibacterial activity. Results LAB strains were mixed at equal proportions (1:1) according to mathematical planning of experiments. Antifungal and antibacterial effects of different combinations (associations) were determined in different media, employing well-diffusion and total diffusion into agar methods. A number of fungal and bacterial test-organisms, including pathogenic ones, were used. Pure LAB strain cultures were used as a control. The antifungal effect of the most active strain Lactobacillus rhamnosus MDC 9661 in the associations with other LAB strains was partly decreased. At the same time, some mixed LAB cultures in DeMan, Rogosa and Sharpe (MRS) medium demonstrated significant antibacterial activity against wide spectra of test-organisms only in the case of simultaneous cultivation of LAB strains. On the other hand, in the case of different LAB strains cultivated in MRS with 24-h time break between mix formations by different strains, no inhibitory activity was revealed. But the inhibitory effect of many LAB associations against test-organisms was significantly increased in the case of separated cultivation in milk. Conclusion The inhibitory effect of mixed LAB associations showed stronger dependence on the cultivation media and on the duration of cultivation with respect to each other. The co-cultivation of some strains, like L. rhamnosus MDC 9661, could lead to changed antagonistic activity. Consequently, the results are significant for creation and further investigation of LAB associations, as effective probiotics, and for their probable application in the production of antimicrobial preparations.

Value-Added Utilization of Citrus Peels in Improving Functional Properties and Probiotic Viability of Acidophilus-bifidus-thermophilus (ABT)-Type Synbiotic Yoghurt during Cold Storage

“…The antibacterial activities of different probiotic strains play an important role as bio-preservatives in a wide range of dairy foods [ 43 , 44 ]. In the present work, the antibacterial activity of the ABT synbiotic yoghurt was evaluated by a disc diffusion assay, which was expressed as the inhibition zone against pathogenic strains.…”

Antimicrobial properties of Pediococcus acidilactici and Pediococcus pentosaceus isolated from silage

“…Representatives of the genera Penicillium, Aspergillus, Monilia, Mucor, Endomyces, Cladosporium, Fusarium and Rhizopus are the most common spoilage fungi of bakery products (Legan, 1993;Salas et al, 2018). Production of mycotoxins is considered as one of the major problems associated with mold growth and is regarded as a potential public health hazard (Legan, 1993;Matevosyan et al, 2019;Sadiq et al, 2019). Application of different food associated LAB presents one potential option for bio-preservatives: most LAB have GRAS status and their safety has been proven over time.…”

“…Application of different food associated LAB presents one potential option for bio-preservatives: most LAB have GRAS status and their safety has been proven over time. It has previously been reported that some LAB can be producers of a variety of antifungal metabolites, including organic acids (Sadiq et al, 2019;Stiles, 1996); wide range of different low molecular weight compounds (Niku-Paavola et al, 1999;Salas et al, 2018); different peptides and proteins (Magnusson & Schnürer, 2001;Okkers et al, 1999) with potential for controlling spoilage moulds.…”

Combination therapy in Mucormycosis: Current evidence from the world literature, a mini review

“…A retrospective case study described the adjunctive role of HBOT in mucormycosis with diabetes (94% survival) [49] . Calcineurin inhibitors and probiotics are the other adjunctive therapy used in various studies that showed a synergistic role along with L-AMB [ 50 , 51 ].…”