Dichloran Rose Bengal Chloramphenicol Research Articles

Scale‐up model of forced air‐integrated gaseous chlorine dioxide for the decontamination of lowbush blueberries

AbstractGaseous chlorine dioxide (ClO2) is a promising sanitizer for frozen products because of its efficacy under nonthermal and waterless conditions. A major knowledge gap exists between laboratory trials and effectiveness at the industrial scale. To address this, a pilot study implementing a pallet‐sized fumigation container (60 harvest totes) was designed for gaseous ClO2. Fifty kilograms of blueberries were exposed to initial dose of 57.46 mg/L, representing a treatment of 2.35 mg/g of blueberries. Blueberries remained enclosed for 10 hr. Reduction of all viable cells, coliforms, yeasts, and molds were measured by plating treated samples on Tryptic Soy Agar, Violet Red Bile Agar, and Dichloran Rose Bengal Chloramphenicol Agar and compared to untreated controls. The results demonstrate that a significant reduction of 1.5 log CFU/g can be achieved against coliforms after ClO2 exposure. Our findings demonstrate a cost‐effective procedure that could be adapted to commercial processing.

Does manufacturers' size affect the prevalence of mycobiota and occurrence of mycotoxins in spices and spice-based products?

The present work aimed to establish the prevalence of mycobiota and occurrence of mycotoxins (aflatoxins and ochratoxin A) in spices and spice-based products, and correlate these to their manufacturers’ sizes. A total of 90 spice, sauce and paste samples were purchased; 3 manufacturer sizes (small, medium, large) × 3 types of samples (spices, sauces, pastes) × 5 brands × 2 replicates. The prevalence of mycobiota was assessed with dichloran rose bengal chloramphenicol (DRBC) andAspergillus flavus andAspergillus parasiticus (AFPA) medium, while the occurrence of mycotoxins was quantified with HPLC-FLD. Large-scale manufacturers were found to adopt a greater number of safety and quality certifications. Small-scale manufacturers significantly yielded the highest total fungal loads on DRBC (log 5.084±0.417 cfu/g paste, log 6.253±0.407 cfu/g sauce, log 6.662±0.222 cfu/g spice) and AFPA (log 4.461±0.451 cfu/g paste, log 5.661±0.395 cfu/g sauce, and log 6.269±0.432 cfu/g spice). Correlation analysis (Pearson’sr) revealed that manufacturers’ sizes positively influenced (DRBCr=0.781; AFPAr=0.702) the prevalence of mycobiota. Aflatoxin B1 was present in 6/30 (20%) paste samples, 1/30 sauce samples (3.33%) and 12/30 spice samples (40%). Aflatoxin B2 was only present in 2/30 sauce samples (6.67%). Aflatoxin G1 and G2 were absent from all samples. Ochratoxin A was present in 11/30 (36.67%) paste samples, 5/30 sauce samples (16.67%) and 21/30 spice samples (70%). It was found that, to a certain extent, the size of and certification adopted by manufacturers affected the prevalence of mycobiota and the occurrence of mycotoxins in spices and spice-based products analysed in the present work. Nevertheless, it is henceforth recommended that a surveillance study of this nature be extended and widened in terms of number of samples as well as type of spices, sauces and pastes to obtain a more thorough and significant profile of the products’ food safety and quality level.

Characterization of Saccharomyces cerevisiae Strains from Palm Wine for Baking Leaven Production in Republic of Congo

This study was carried out to select the autochthon yeast strains from the palm wine. The work aims to wildly isolate, characterize and identify Saccharomyces cerevisiae in order to locally and safely produce a bio-leaven and to assess their ability to ferment wheat flour dough used for the bread making and other products. Palm wine samples have been bought in the village around Brazzaville. Samples have been collected in sterile glass bottles then stored under refrigeration condition at 4°C until they were processed. Yeasts were enumerated and isolated on Dichloran Rose Bengal Chloramphenicol agar medium at 37°C. Molecular identification was carried out by a PCR-based method using species-specific primer pairs to Saccharomyces genus without sequencing stage. The results showed that palm wine contains about 3.3106 CFUmL-1. Fifty-one isolates were obtained with a percentage of 13% corresponding to Saccharomyces cerevisiae. This identity was confirmed by the molecular characterization. Five yeast strains showed high ability to ferment wheat flour dough analogous of the control. The better growth of isolates was between 28 and 37°C. However, the near neutral pH gives the higher growth. High concentration of NaCl and glucose in medium has a strong negative impact on the growth of isolates.

Mycological Assessment of Cooked Beef Products

Mycological Assessment of Cooked Beef Products

Mycological Assessment Of Cooked Beef Products

Mycological Assessment Of Cooked Beef Products

An aero mycological analysis of Mucormycetes in indoor and outdoor environments of northern India.

Mucormycosis is an angio-invasive infection, predominantly acquired by inhalation of sporangiospores from the environment. However, the burden of Mucormycetes sporangiospores in the air is not well studied. We aimed to estimate the burden of Mucormycetes spores in the outdoor and indoor (hospital) environment across different seasons in north India. A total of 380 air samples from outdoor (n = 180) and indoor (n = 200) environment were included in the study. Air samples were suctioned using air sampler (100 l/min) and cultured on Dichloran Rose Bengal Chloramphenicol (DRBC) with benomyl for selective isolation of Mucormycetes. The isolates were identified by phenotypic and genotypic methods. The mean spore count (±SD) of Mucormycetes (cfu/m3) in outdoor samples varied from 0.73 (±0.96) to 8.60 (±5.70) across different seasons. In hospital, the mean spore count varied from 0.68 (±1.07) to 1.12 (±1.07) and 0.88 (±1.01) to 1.72 (±2.17) for air-conditioned wards and non-air-conditioned wards, respectively. Rhizopus arrhizus was the predominant agent isolated from both indoor and outdoor environment followed by Cunninghamella species. We also report a single isolate of the rare mucormycete agent, Apophysomyces variabilis from outdoor environment. The present study highlights the presence of low spore burden of Mucormycetes in outdoor and hospital settings in north India. This study also reports the first isolation of A. variabilis from air samples in the Indian subcontinent.

Mycological and Mycotoxins Analysis of Kareish and Soft Cheese in Assiut, Egypt

During the present study 80 samples of kareish (semi-soft cheese with 20% fats) and soft cheese (40 % fats) were collected Assiut City during June to December 2015. The fungal content of these samples was evaluated using Dichloran Rose Bengal Chloramphenicol (DRBC) and Yeast Extract Malt extract (YM) agar media. The fungal count per sample ranged from 7 colonies/g in soft cheese to 44800 colonies/g in kareish cheese. the total number of fungal species in kareish cheese was slightly lower on DRBC than on YM (24 and 29 species respectively). The number of fungal species per sample fluctuated between 1-8 species with the highest being recovered from kareish cheese. Aspergillus was the most prevalent genus contaminating 45 -85 % of the samples with the highest being recovered from Kareish Cheese. Penicillium came next contaminating 20 - 47.5% of samples with white soft cheese being the most affected product. Candida, Clavispora, Klyveromyces and Pichia contaminated 2.5-65 % of samples and the highest incidence was that of Clavispora in kareish cheese. Aspergillus niger, A. fumigatus, A. flavus, Penicillium chrysogenum, P. aurantiogriseum and P. brevicompactum were the commonest species in cheese samples. Some yeast fungi were identified by sequencing of rRNA gene. Among the 19 species of yeasts Candida tropicalis, Clavispora lusitaniae, Pichia kudriavzevii, Pichia membranifaciens and kluyveromyces lactis were the most common. Testing the natural occurrence of aflatoxins revealed that AFM1 contaminated 55% and 50 % of kareish and soft cheese respectively whereas AFM2 was found only in 10 % of kareish cheese samples.

Impacts of Different Drying Methods on Mold Viability and Ochratoxin A Content of Grape Pomace

Value added utilization of grape pomace (GP) has been the interest of many food researchers due to its high contents in fiber and polyphenols. However, the contamination of GP by molds and ochratoxin A (OTA) present a serious safety issue to food or feed use of GP. To ensure the safety of direct usage of GP as food ingredient, this study investigated the effects of drying method on mold viability and ochratoxin A (OTA) content of GP. Pomaces of seven grape cultivars were dehydrated by freeze, room temperature and vacuum drying methods. The total population of yeast and mold colonies was enumerated using Dichloran Rose Bengal Chloramphenicol Agar (DRBC) and Dichloran Glycerol 18% (DG18) media. The OTA was extracted by 70% methanol aqueous solution, and then quantified by an ELISA method. Regardless the grape cultivars, vacuum drying most effectively reduced the viability of mold in GP samples, while freeze-drying was the least effective method. OTA was present in all pomace samples tested but the contents of OTA in GP varied with grape variety. Vacuum drying and freeze drying significantly reduced the OTA contents of most of the pomace samples tested whereas room temperature drying increased OTA contents of all GP samples tested compared with OTA contents measured before drying. Overall, vacuum dry and freeze dry methods resulted in safer GP for food and feed use due to the greater reduction of viable molds and OTA content.

Estimation of growth parameters of six different fungal species for selection of strains to be used in challenge tests of bakery products

Abstract The objective of this study was to estimate the growth rate, lag time and the times for the appearance of visible mycelium ( t v ) of six fungal species ( Paecilomyces variotii , Penicillium paneum , Penicillium polonicum , Penicillium spinulosum , Penicillium citrinum and Aspergillus sydowii ). The growth parameters were determined at 20 °C, 25 °C and 30 °C and in two culture media (18% Dichloran Glycerol Agar - DG-18 and Dichloran Rose Bengal Chloramphenicol Agar – DRBC) aiming the selection of most appropriate strains for use in challenge tests and for the development of predictive models. Seventy-two growth curves were obtained after measuring the diameter of the colonies for 14 days at 20 °C, 25 °C and 30 °C. Values of growth rate between 1.4 and 11.1 (day −1 ) were obtained in this study. Faster growth rates (> 7 day −1 ) were observed for Pa. variotii (LMQA-001) and P. paneum (LMQA-002) at 25 °C. The lag times varied between 0.7 and 4.2 days, with 50% of the values being as short as 0.7−1.4 day. The variability between the species was analyzed and coefficients of variation (CV) of 44.2% and 41% for the growth rate were observed at 30 °C. At 20 °C and 25 °C, CV varied from 28.3% to 32.9%, respectively. Given these results, Pa. variotii and P. paneum could be considered for further use in microbiological challenge tests aiming to assess the robustness of bakery products formulations.

Short communication: Pseudomonas azotoformans causes gray discoloration in HTST fluid milk

Pseudomonas species are well recognized as dairy product spoilage organisms, particularly due to their ability to grow at refrigeration temperatures. Although Pseudomonas-related spoilage usually manifests itself in flavor, odor, and texture defects, which are typically due to production of bacterial enzymes, Pseudomonas is also reported to cause color defects. Because of consumer complaints, a commercial dairy company shipped 4 samples of high temperature, short time (HTST)-pasteurized milk with distinctly gray colors to our laboratory. Bacterial isolates from all 4 samples were identified as Pseudomonas azotoformans. All isolates shared the same partial 16S rDNA sequence and showed black pigmentation on Dichloran Rose Bengal Chloramphenicol agar. Inoculation of one pigment-producing P. azotoformans isolate into HTST-pasteurized fluid milk led to development of gray milk after 14 d of storage at 6°C, but only in containers that had half of the total volume filled with milk (∼500 mL of milk in ∼1,000-mL bottles). We conclusively demonstrate that Pseudomonas can cause a color defect in fluid milk that manifests in gray discoloration, adding to the palette of color defects known to be caused by Pseudomonas. This information is of considerable interest to the dairy industry, because dairy processors and others may not typically associate black or gray colors in fluid milk with the presence of microbial contaminants but rather with product tampering (e.g., addition of ink) or other inadvertent chemical contamination.

Mycobiota of Slovak wine grapes with emphasis on aspergillus and penicillium species in the south Slovak wine region

The Southern Slovak wine growing region is warmest part of Slovakia and is suitable for cultivating the grapes for production of wines at high quality. From the eight vineyards were collected 8 samples of wine grapes (white 7, blue 1) during harvesting 2011, 2012 and 2013. The aim of this work was to gain more knowledge about mycobiota on grapes originating from Slovakia, to identify Aspergillus and Penicillium species according to their morphopogy and evaluate the presence of secondary metabolites (also including intracellular and extracellular mycotoxins) produced in in vitro conditions by thin layer chromatography method from fresh grape berries. Fifty wine grapes per bunch (approximately 7 - 8 berries per plate) that showed no symptoms were randomly selected on Dichloran Rose Bengal Chloramphenicol agar medium. The plates were then incubated aerobically at 25 ±1 °C for 5 to 7 days in the dark. Of these samples were identified 17 genera. One hundred percent of samples were colonies by the genus Penicillium and 75% by the genus Aspergillus. During the survey, 135 isolates belonging to 9 Penicillium species (P. aurantiogriseum, P. canescens, P. citrinum, P. crustosum, P. decumbens, P. expansum, P. funiculosum, P. chrysogenum and P. purpurogenum) and 26 isolates belonging to 3 Aspergillus species (A. clavatus, A. flavus and A. section Nigri) were isolated and identified from exogenous contamination. The main occurring penicillium species of the samples were P. expansum (37.5% Fr), followed P. citrinum, P. chrysogenum and P. crustosum (25% Fr). The main occurring aspergillus species of the samples were A. section Nigri (62.5%). Eight potentially toxigenic species were tested for their toxigenic ability. It was confirmed the production of various mycotoxins such as aflatoxin B1, citrinin, patulin, cyclopiazonic acid, penitrem A and roquefortin C. Out of 34 strains, 56% produced at least one mycotoxin.

Species of genera Botrytis, Fusarium and Rhizopus on grapes of the Slovak origin

Our research was focused to identify the Botrytis, Fusarium and Rhizopus species from grapes of the Slovak origin. A further goal of the project was to characterized toxinogenic potential of chosen strains of species Fusarium. 50 samples of grapes, harvested in years 2011, 2012 and 2013 from various wine-growing regions were analyzed in this study. For the isolation of species the of direct plating method was used: a) surface-sterilized berries (using 1% freshly pre-pared chlorine) b) berries and c) damaged berries on DRBC (Dichloran Rose Bengal Chloramphenicol agar). For each analysis were used 50 berries (or all damaged berries from sample). The cultivation was carried at 25 ±1°C, for 5 to 7 days in dark. After incubation, the colonies of Botrytis, Fusarium and Rhizopus were transferred to identification media and after incubation strains were identified to species level. Thirteen species of fusaria (F. acuminatum, F. avenaceum, F. culmorum, F. equiseti, F. graminearum, F. oxysporum, F. proliferatum, F. semitectum, F. solani, F. sporotrichioides, F. subglutinans F. tricinctum and F. verticilioides) were identified. Frequency of fusaria isolation was 92 %. Botrytis cinerea was determined from 86% samples and Rhizopus from 94%. Chosen strains of species of genus Fusarium were able to produce following mycotoxins: deoxynivalenol, T-2 toxin, HT-2 toxin and diacetoxyscirpenol in in vitro conditions as determinated by thin-layer chromatography. Thirty-two (68%) of tested isolates of Fusarium species were able to produce at least one mycotoxin.

Role of Fungal Biomass in N-Hexane Biofiltration

The biofiltration of n-hexane is studied to optimize determinants factors of hydrophobic VOC filtration efficiency. Four trickle-bed air biofilters (TBABs) were employed; two of which were supplied with nutrients buffered at a neutral pH, while another two at an acidic pH of 4 to induce and enhance fungal growth. The loading rate of n-hexane was kept constant in all TBABs at 13 g/m3/h. At each pH levels studied, the biomass of the TBABs was pre-acclimated using different ratios of n-hexane and methanol. The fungal biomass responsible for the degradation of n-hexane was then examined and quantified. Dichloran Rose Bengal Chloramphenicol agar was used for fungi quantification, and optical microscopy for classification. Effluent biomass was validated by measuring volatile suspended solids. Fungal counts resulting from n-hexane biodegradation were related to nitrate and carbon consumption. It was found that n-hexane elimination capacity closely followed biomass growth, and reached a steady-state at an optimum biomass density of roughly 3000 cfu/ml. Major shifts in fungal species were observed in all TBABs. Dominant fungal species grew slowly to become the most numerous, and were found to provide maximum elimination capacity, although TBABs pre-acclimated to higher methanol concentrations took less time to reach this steady-state. It was concluded, therefore, that steady and monitored growth of TBAB biomass is an essential factor in maximizing fungi’s ability to metabolize VOCs and that a new ecological biofiltration model may be the most effective at VOC purification. Keywords

Comparison of dichloran rose bengal chloramphenicol and Sabouraud dextrose agar with cycloheximide and chloramphenicol for airborne mold sampling

The more the mold species isolated on a culture medium, the more the sampling environment is represented accurately. According to the sampling purpose, it is crucial to use the best culture medium for mold. However, no study is available regarding the comparison of dichloran rose bengal chloramphenicol (DRBC) and Sabouraud dextrose agar with cycloheximide and chloramphenicol (SDA-CHX-CHL) culture media in terms of their application for airborne sampling, isolation, and identification of fungi. Airborne mold samples were impacted onto both DRBC and SDA-CHX-CHL, simultaneously using single-stage Andersen sampler. The limit of detection (LOD) value for airborne mold count was 7 CFU m−3 (1 colony growth on the Petri dish). The total mold counts (TMC) ranged between <7 and 504 CFU m−3 (med 56 CFU m−3) and <7 and 1218 CFU m−3 (med 259 CFU m−3), collected on SDA-CHX-CHL and DRBC, respectively. Significantly higher TMC were observed on DRBC than on SDA regardless of the sampling environment (i.e, indoor or outdoor) (p < 0.05). Among the most predominant mold genera, observation frequencies of Penicillium spp. and Aspergillus spp. on both culture media were found to be more than 70%. Observation frequencies of Cladosporium spp., Alternaria spp., and yeast were found to be higher in samples collected on DRBC than those on SDA-CHX-CHL. Finally, DRBC was found to be superior to SDA in terms of both number of colonies and number of genera isolated from the air.

Prelimanary Observation On Microbial Population in The Soaking Water During Bedak Sejuk Production

Background/Objectives: During the production of Bedak sejuk (local face powder cosmetic made from rice), the soaking water were changed intermittently because of its pungent smell, believe to be caused by microbial reactions. In this initial investigation, we monitored the microbial population in the series of batch fermentation of Bedak sejuk. Methods: Local polished rice grains (Indica) were soaked in tap water (w/v) at ambient temperature mimicking the usual preparation of Bedak sejuk. The overall soaking period was 28 days (two times of soaking, 14 days for each interval). The soaking water was serially diluted and then spread over several types of agar. To count the Lactic Acid Bacteria (LAB), the diluted samples were spread on the MRS media, yeast and mould were spread on Dichloran Rose Bengal Chloramphenicol agar (DRBC) while coliforms were spread on Petri-Film. The results were indicated as Colony-Forming Units per milligram (CFU/mL) of soaking water. Findings: For the first batch fermentation, the microbial count in soaking water was 11.44 log CFU/mL. LAB counts increased from 3.02 to 6.14 log CFU/mL at the end of fermentation time. Yeasts count increased from 1.68 to 2.78 log CFU/mL, mould count also increased from 0.73 to 1.31 log CFU/mL while coliform count decreased from 3.88 to 1.21 log CFU/mL. While for the second batch fermentation, microbial count in soaking water was 13.15 log CFU/mL. LAB counts increased from 5.65 to 6.81 log CFU/mL at the end of fermentation time. Yeasts count increased from 2.34 to 3.37 log CFU/mL, mould count also increased from 1.33 to 2.08 log CFU/mL while coliform count decreased from 2.38 to 0.89 log CFU/ml. Application: The results of the study have given the initial background information on the varieties of microbial populations that presence during the natural fermentation of Bedak sejuk.

Colonization of grapes berries by Alternaria sp. and their ability to produce mycotoxins

Our research focused on identify the Alternaria species from grapes (surface sterilized berries and non-surface sterilized berries) of Slovak origin and characterize their toxinogenic potential in in vitro conditions. We analyzed 47 samples of grapes, harvested in years 2011, 2012 and 2013 from various wine-growing regions. For the isolation of species, the method of direct plating berries and surface-sterilized berries (using 1 % freshly pre-pared chlorine) on DRBC (Dichloran Rose Bengal Chloramphenicol agar) was used. For each analysis was used 50 berries. Only undamaged berries have been used for analysis. The cultivation was carried at 25 ±1°C, for 5 to 7 days in dark. After incubation, the colonies of Alternaria were transferred on PCA - potato-carrot agar and CYA - Czapek-yeast extract agar and cultured for 7 days at room temperature and natural light. A total 4 species-groups of the genus Alternaria were isolated from grapes berries: Alternaria alternata (1369 isolates), Alternaria arborescens (734 isolates), Alternaria infectoria (143 isolates), and Alternaria tenuissima (3579 isolates). According to European Union legislation mycotoxins produced by species genus Alternaria are not monitored in foods and food commodities. Mycotoxins such as alternariol and alternariol monomethylether are mutagenic and genotoxic in various in vitro systems. Selected strains were tested for production of altenuene, alternariol monomethylether and alternariol. In neither case of A. infectoria species-group isolates was confirmed the production of tested mycotoxins in in vitro conditions by TLC method. The ability to produce altenuene, alternariol monomethylether and alternariol in in vitro conditions was detected in isolates of Alternaria alternata, Alternaria arborescens and Alternaria tenuissima species-groups. Isolates of Alternaria alternata species-group (44 tested isolates) were able to produce altenuene (24 isolates), alternariol monomethyleter (42 isolates) and alternariol (43 isolates). Only one isolate did not produce any mycotoxins. Isolates of Alternaria arborescens species-group (38 tested isolates) were able to produce altenuene (24 isolates), alternariol monomethyleter (33 isolates) and alternariol (36 isolates). Only two isolates did not produce any mycotoxins. Isolates of Alternaria tenuissima species-group (87 tested isolates) were able to produce altenuene (42 isolates), alternariol monomethyleter (41 isolates) and alternariol (73 isolates). Thirteen isolates did not produce any mycotoxins.

Comparison of New and Traditional Culture-Dependent Media for Enumerating Foodborne Yeasts and Molds

Fifty-six foods and food ingredients were analyzed for populations of naturally occurring yeasts and molds using Petrifilm rapid yeast and mold (RYM) count plates, Petrifilm yeast and mold (YM) count plates, dichloran rose bengal chloramphenicol (DRBC) agar plates, acidified potato dextrose agar (APDA) plates, and dichloran 18% glycerol (DG18) agar plates. Colonies were counted after incubating plates for 48, 72, and 120 h at 25°C. Of 56 foods in which either yeasts or molds were detected on at least one medium incubated for 120 h, neither yeasts nor molds were detected in 55.4, 73.2, 21.4, 19.6, and 71.4% of foods plated on the five respective media and incubated for 48 h; 10.7, 14.3, 3.6, 1.8, and 19.6% of foods were negative after 72 h, and 3.6, 1.8, 0, 0, and 0% of foods were negative after 120 h. Considering all enumeration media, correlation coefficients were 0.03 to 0.97 at 48 h of incubation; these values increased to 0.75 to 0.99 at 120 h. Coefficients of variation for total yeasts and molds were as high as 30.0, 30.8, and 27.2% at 48, 72, and 120 h, respectively. The general order of performance was DRBC = APDA > RYM Petrifilm > YM Petrifilm ≥ DG18 when plates were incubated for 48 h, DRBC > APDA > RYM Petrifilm > YM Petrifilm ≥ DG18 when plates were incubated for 72 h, and DRBC > APDA > RYM Petrifilm > YM Petrifilm > DG18 when plates were incubated for 120 h. Differences in performance among media are attributed to the diversity of yeasts and molds likely to be present in test foods and differences in nutrient, pH, and water activity requirements for resuscitation of stressed cells and colony development.

Mycobiota of Slovak wine grapes with emphasis on Aspergillus and Penicillium species in the small carpathian area

The Slovak wine-growing region is divided into six viticulture areas. The largest in size and the most important over the centuries has been the Small Carpathian area (around 5800 ha of vineyards) spreads in the western of Slovakia. The objectives of this study were: to gain more knowledge about mycobiota on grapes originating from Slovakia, with a focus on genera Aspergillus and Penicillium and their ability to produce mycotoxins in in vitro conditions by thin layer chromatography method. From the twelve vineyards were collected 14 samples of wine grapes (white 6, blue 8) during harvesting 2011, 2012 and 2013. Fifty wine grapes per bunch (approximately 7-8 berries per plate) that showed no symptoms were randomly selected on Dichloran Rose Bengal Chloramphenicol agar medium. The plates were then incubated aerobically at 25 ±1 °C for 5 to 7 days in the dark. Of these samples were identified 22 genera. Ninety-three percent of samples were colonies by the genus Penicillium and 79% by the genus Aspergillus. During the survey, 251 isolates belonging to 14 Penicillium species (P. aurantiogriseum, P. citrinum, P. coprophylum, P. crustosum, P. expansum, P. funiculosum, P. glabrum, P. griseofulvum, P. chrysogenum, P. oxalicum, P. polonicum, P. purpurogenum, P. roqueforti and P. thomii) and 37 isolates belonging to 7 Aspergillus species (A. clavatus, A. flavus, A. section Nigri, A. ostianus, A. parasiticus, A. versicolor and A. westerdijkiae) were isolated and identified from exogenous contamination. The main occurring penicillium species of the samples were P. chrysogenum (36% Fr), followed P. crustosum (29% Fr), P. griseofulvum (21% Fr) and P. expansum (21% Fr). The main occurring aspergillus species of the samples were A. section Nigri (64%). Thirteen potentially toxigenic species were tested for their toxigenic ability. It was confirmed the production of various mycotoxins such as aflatoxin B1, G1, citrinin, griseofulvin, patulin, cyclopiazonic acid, penitrem A, roquefortin C and sterigmatocystin. Out of 124 strains, 84% produced at least one mycotoxin.

Inhibitory Activity of Artemisiaspicigera Essential Oil Against Fungal Species Isolated From Minced Meat

Background: Meat is an important source of several nutrients. The capability top of fresh meat to rot, causing the group of studies food science, biological and chemical stability meat consideration. Objectives: This study was conducted to examine the inhibitory effect of Artemisias spicigera essential oil against fungal species isolated from minced meat. Materials and Methods: Two types of media dichloran 18% glycerol (DG18) agar and dichloran rosebengal chloramphenicol (DRBC) agar were selected for the mycological analysis of the minced meat samples. To evaluate the antifungal activity of essential oils, the microdilution broth method based on the CLSI (M27A) guideline was used. Results: Artemisias spicigera essential oil has an inhibitory effect on the growth of fungi found in samples of minced meat. Aspergillus, Penicillium and Cladosporium were the most common genera on both medium types. Average Minimum Inhibitory Concentration 50 = 1.88 µL/mL and MIC 90 = 2 µL/mL were reported. The genus of Mucor with MIC = 1.0 µL/mL was the most sensitive and Aspergilus versicolor was the most resistant species to the essential oil with MIC = 4 µL/mL. Conclusions: The results of the present study show a favorable inhibitory effect of Artemisias spicigera essential oil on fungal growth, especially Aspergillus species. According to the results, antifungal components of Artemisias spicigera in different forms are used to prevent fungal pollution.

Mycotoxigenic fungi and natural co-occurrence of mycotoxins in rainbow trout (Oncorhynchus mykiss) feeds.

Samples of rainbow trout feed were analyzed with the aim to determine the mycobiota composition and the co-occurrence of mycotoxins. A total of 28 samples of finished rainbow trout feed from hatcheries in the provinces of Río Negro and Neuquén, Argentina, were studied. Fungal counts were obtained on three culture media in the ranges of <10 to 4.2 × 104 CFU/g on Dichloran Rose Bengal Chloramphenicol Agar (DRBC), <10 to 5.1 × 104 CFU/g on Dichloran Chloramphenicol Peptone Agar (DCPA) and <10 to 3.6 × 104 CFU/g on Dichloran 18% Glycerol Agar (DG18). The most frequent mycotoxigenic fungi were Eurotium (frequency (Fr) 25.0%), followed by Penicillium (Fr 21.4%) and Aspergillus (Fr 3.6%). The most prevalent mycotoxigenic species were E. repens (Fr 21.4%) and E. rubrum (Fr 14.3%). All samples were contaminated with mycotoxins: 64% samples were contaminated with T-2 toxin (median 70.08 ppb), 50% samples with zearalenone (median 87.97 ppb) and aflatoxins (median 2.82 ppb), 25% with ochratoxin A (median 5.26 ppb) and 3.57% samples with deoxynivalenol (median 230 ppb). Eight samples had a fumonisins contamination level below the limit of detection. Co-occurrence of six mycotoxins was determined in 7% of the samples.