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Previously chemically characterized Juniperus communis essential oil (EO) and post-distillation waste (PDW) were tested for cytotoxicity and antimicrobial activity against food contaminants. Microdilution assay showed that PDW induced moderate antifungal (minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values, ranging between 0.118-0.900 mg mL-1), and an antibacterial effect against Listeria monocytogenes (MIC and minimum bactericidal concentration (MBC) were 0.39 and 0.74 mg mL-1 , respectively). Combinations of EO/PDW with selected antibiotics induced synergistic antilisterial activity in the checkerboard assay. The MTT assay determined that cytotoxicity against colon cancer cells was high for the EO but negligible for PDW (IC 50 values were 0.087-0.106 and 1.450-6.840 mg mL-1 , respectively). The selectivity indices indicated high selectivity of PDW against tested fungi and L. monocytogenes. In the adhesion-inhibition assay, PDW reduced in vitro adhesion of L. monocytogenes to colon cells (29-62% of inhibition). In conclusion, PDW exhibited an antimicrobial effect against important food spoilage and poisoning fungi and L. monocytogenes, and also reduced in vitro adhesion of L. monocytogenes to colon cells. The results indicate that J. communis PDW could be considered as natural preservative against food spoilage and poisonous fungi, and as an adjuvant to conventional therapy of listeriosis.

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For the purpose of removing viruses from infected plant material, cryotherapy is a novel application of the plant cryopreservation technique. The use of various cryotherapy procedures and treatments necessitates the examination of cryo-treated material for the presence of the targeted pathogen in order to gauge the effectiveness of the therapy. In our study, we evaluated the efficiency of reverse transcription-polymerase chain reaction (RT-PCR) and qPCR (quantitative PCR) methods for the detection of plum pox virus (PPV) in cryo-treated material of plums ‘Belošljiva’ and ‘Crvena Ranka’. A qRCR assay showed higher sensitivity in comparison to conventional RT-PCR.

Juniperus communis essential oil and post-distillation waste were tested for their antibacterial potential against common food contaminants. Results of microdilution assay directed further study of Listeria monocytogenes. Checkerboard assay showed synergistic antilisterial effect of both substances with conventional antibiotics. By evaluating of their cytotoxicity on human colon cells, post-distillation waste was denoted as selective against L. monocytogenes, being able to interfere with its in vitro adhesion on colon cells. On the other hand, the food preservative potential of J. communis essential oil was studied and compared with the activity of Satureja montana essential oil. In a microdilution assay, both substances induced antilisterial effect against reference ATCC 19111 strain and three wild isolates. A checkerboard assay showed synergism against isolates. An in vitro time-kill assay was used to confirm the types of interaction, and to estimate curve MIC values. Finally, in situ antilisterial efficacies of the individual essential oils and their mixture on red wine-marinated beef, previously inoculated with ATCC 19111 strain or primoisolate from beef carcass, were determined. All treatments enhanced the antilisterial potential of wine marinade. In conclusion, derivatives of J. communis possess significant antilisterial potential both in in vitro and in situ conditions, so further research is advised.

Apples are the third most produced fruit in the world, behind bananas and oranges, in terms of volume. Over the past ten years, Serbia's apple production has nearly doubled. Apples are less subjected to viral and viroid attacks than other fruit species. Most viruses cause no visible symptoms on the plant's organs, and the trees either seem to be in good condition or, in the case of sensitive cultivars, their yield is reduced. Apple stem pitting virus (ASPV), apple stem grooving virus (ASGV), apple chlorotic leaf spot virus (ACLSV), and apple mosaic virus (ApMV) are four apple economically important and widely distributed viruses. Among the viroids, the apple scar skin viroid (ASSVd) is particularly destructive for apple production.