Microscopic fungi recovered from honey and their toxinogenity.

The objective of this investigation was to contribute towards the knowledge of microbiology of honey, more than 50 samples of honey from Slovakia and other countries were mycologically investigated in terms of the overall fungal diversity and toxicological potential of isolated fungi from Penicillium genera. The study revealed that out of 13 genera recovered, Penicillium was the most frequent and diverse genus, followed by Aspergillus and Cladosporium being found in 65.91 % (29 samples), 34.1 % (15 samples) and 29.55 % (13 samples), respectively. The most frequently encountered taxa from Penicillium genera were Penicillium chrysogenum (found in 22.73 %), Penicillium brevicompactum (13.64 %), Penicillium crustosum (11.36 %) and Penicillium griseofulvum (11.36 %). In addition, the following genera were recorded (in descending order) Mycelia (18.18 %), Fusarium (11.36 %), Mucor (9.09 %), Acremonium (6.82 %), Alternaria (4.55 %), Epicoccum (4.55 %), and finally Botrytis, Eurotium Trichoderma and Phoma all were encountered in 2.27 % of the samples being represented. The mean value counts of total fungi ranged from 0.00 to 2 × 10(2) cfu.g(-1). Outcomes from mycotoxin screening within the appropriate potentially toxinogenic species from Penicillium genera showed a number of mycotoxin producers, namely those forming citrinin (n = 1), cyclopiazonic acid (n = 5), griseofulvin (n = 5), patulin (n = 5), penitrem A (n = 2) and roquefortin C (n = 13).

Growth of infant fecal bacteria on commercial prebiotics.

Fecal bacteria from 33 infants (aged 1 to 6 months) were tested for growth on commercial prebiotics. The children were born vaginally (20) or by caesarean section (13). Bifidobacteria, lactobacilli, gram-negative bacteria, Escherichia coli, and total anaerobes in fecal samples were enumerated by selective agars and fluorescence in situ hybridization. The total fecal bacteria were inoculated into cultivation media containing 2 % Vivinal® (galactooligosaccharides-GOS) or Raftilose® P95 (fructooligosaccharides-FOS) as a single carbon source and bacteria were enumerated again after 24 h of anaerobic cultivation. Bifidobacteria dominated, reaching counts of 9-10 log colony-forming units (CFU)/g in 17 children born vaginally and in seven children delivered by caesarean section. In these infants, lactobacilli were more frequently detected and a lower number of E. coli and gram-negative bacteria were determined compared to bifidobacteria-negative infants. Clostridia dominated in children without bifidobacteria, reaching counts from 7 to 9 log CFU/g. Both prebiotics supported all groups of bacteria tested. In children with naturally high counts of bifidobacteria, bifidobacteria dominated also after cultivation on prebiotics, reaching counts from 8.23 to 8.77 log CFU/mL. In bifidobacteria-negative samples, clostridia were supported by prebiotics, reaching counts from 7.17 to 7.69 log CFU/mL. There were no significant differences between bacterial growth on Vivinal® and Raftilose® P95 and counts determined by cultivation and FISH. Prebiotics should selectively stimulate the growth of desirable bacteria such as bifidobacteria and lactobacilli. However, our results showed that commercially available FOS and GOS may stimulate also other fecal bacteria.

Mycobiota and mycotoxins in bee pollen collected from different areas of Slovakia.

Contamination by microscopic fungi and mycotoxins in different bee pollen samples, which were stored under three different ways of storing as freezing, drying and UV radiation, was investigated. During spring 2009, 45 samples of bee-collected pollen were gathered from beekeepers who placed their bee colonies on monocultures of sunflower, rape and poppy fields within their flying distance. Bee pollen was collected from bees' legs by special devices placed at the entrance to hives. Samples were examined for the concentration and identification of microscopic fungi able to grow on Malt and Czapek-Dox agar and mycotoxins content [deoxynivalenol (DON), T-2 toxin (T-2), zearalenone (ZON) and total aflatoxins (AFL), fumonisins (FUM), ochratoxins (OTA)] by direct competitive enzyme-linked immunosorbent assays (ELISA). The total number of microscopic fungi in this study ranged from 2.98 ± 0.02 in frozen sunflower bee pollen to 4.06 ± 0.10 log cfu.g(-1) in sunflower bee pollen after UV radiation. In this study, 449 isolates belonging to 21 fungal species representing 9 genera were found in 45 samples of bee pollen. The total isolates were detected in frozen poppy pollen 29, rape pollen 40, sunflower pollen 80, in dried poppy pollen 12, rape pollen 36, sunflower 78, in poppy pollen after UV radiation treatment 54, rape 59 and sunflower 58. The most frequent isolates of microscopic fungi found in bee pollen samples of all prevalent species were Mucor mucedo (49 isolates), Alternaria alternata (40 isolates), Mucor hiemalis (40 isolates), Aspergillus fumigatus (33 isolates) and Cladosporium cladosporioides (31 isolates). The most frequently found isolates were detected in sunflower bee pollen frozen (80 isolates) and the lowest number of isolates was observed in poppy bee pollen dried (12 isolates). The most prevalent mycotoxin of poppy bee pollen was ZON (361.55 ± 0.26 µg.kg(-1)), in rape bee pollen T-2 toxin (265.40 ± 0.18 µg.kg(-1)) and in sunflower bee pollen T-2 toxin (364.72 ± 0.13 µg.kg(-1)) in all cases in frozen samples.

Antiradical activity of natural honeys and antifungal effect against Penicillium genera.

The purpose of the study was to examine the antiradical activity of 11 natural honeys and to evaluate the antifungal properties of honey. Honey samples (10) were collected from different locations of Slovak Republic. Honeys were native to different plant species of Robinia pseudoacaccia, Brassica napus subs. napus, Castanea sativa Mill. Thymus serpyllum vulgaris and the other samples had multifloral origin. The low antiradical activitity in honey samples was determined. The best results were found in thyme honey from Rhodos (11.84 %) and Castanea honey from Nitra (10.61 %). The lowest antiradical activity was found in Acacia honey and determined to be 7.62 %. Statistically significant differences (P< 0.001) were found among thyme/Rhodos and Castanea/Nitra. The antifungal activities of honey samples were tested by 10 %, 25 % and 50 % (by mass per volume) concentration against fungi Penicillium crustosum, P. expansum, P. griseofulvum, P. raistrickii and P. verrucosum and by the agar well diffusion method. The solutions containing 10 % (by mass per volume) of honey did not have any effect on the growth of fungi. The strongest antifungal effect was shown by 50 % honey concentration against P. raistrickii.

Microbial communities in bees, pollen and honey from Slovakia.

As the honey-bee gastrointestinal tract microflora and pollen are the primary sources for the honey microbial community, the aim of this work was to study and characterize the microbial transit among them. Therefore, an exhaustive microbial analysis of honey, adult honey-bee gastrointestinal tract, and pollen from different Slovakian regions and different seasons, was conducted. Microbial screening revealed that the primary sources of microbial community present in Slovakian honey are pollen and the honey-bees' digestive tract microflora, containing microorganisms normally present in dust, air and flowers. We found that the digestive tract of Slovakian adult honey-bees is highly populated by anaerobic, rather than aerobic bacteria, where coliforms, enterococci, staphylococci, Bacillus sp., Pseudomonas sp., microscopic fungi and yeast were found. Interestingly, statistical differences were found between the microflora of the gastrointestinal tract of summer and winter bees. Pollen revealed the presence of mesophil anaerobic and aerobic microorganisms, coliforms and microscopic fungi. Among these, the most representative genera were Alternaria, Cladosporium and Penicillium . In honey the counts of total anaerobic and total aerobic bacteria, that of coliforms, enterococci, bacilli, microscopic fungi and yeasts were monitored. Most frequently microscopic fungi belonging to genera Penicillium, Cladosporium and Alternaria were found.

Environmental concentration of selected elements and relation to physicochemical parameters in honey.

The purpose of this study was to evaluate the content of selected elements and physicochemical indicators of the honey of Apis mellifera. Samples of blossom, blend and honeydew honeys were randomly obtained from the Eastern, Western and Central of Slovakia. Contents of elements were measured with the use of flame atomic absorption spectrophotometry (FAAS) method and anodic stripping voltammetry (ASV) method with CGMDE as working electrode. The content of heavy metals (mg/kg dry weight) ranged as follows: Zn 0.25-3.82; Cu 0.12-1.37; Ni 0.06-0.60; Mg 0.10-50.43; Ca 10.32-87.21; Pb and Cd were under detectable limit (0.001 mg/kg). The physical and chemical indicators ranged as follows: moisture (%) 16.00-19.80; HMF (mg/kg) 10.00-40.00; pH 3.58-5.12; conductivity (mS/m) 13.45-99.12 and a(w) 0.456-0.659. Significant difference (P < 0.05) for elements and physicochemical indicators was analyzed. Significant correlations between Cu - Zn, Cu - Ni, Cu - Mg, Ca - Zn and Ca - Mg were detected. With reference to Codex Alimentarius of Slovakia, maximal levels of heavy metals content and selected physicochemical properties were not exceeded. On average, the content of trace elements decreased in the order: Ca > Mg > Zn > Cu > Ni and physicochemical indicators decreased: conductivity > HMF > moisture > pH > a(w).