Mould Strains Research Articles

Assessment of fungi and viruses in Artichoke (Cynara scolymus L.) in Da Lat, Lam Dong province

Artichoke (Cynara scolymus L.), a high economic value crop, was brought to Vietnam by the French in the late 19th century. The artichoke was mainly planted in Lam Dong, Lao Cai, Vinh Phuc provinces, etc. At present, the disease situation of Artichoke plants and the lack of disease-free seedlings result in insufficient source of Artichoke for producers. Artichoke plants are mainly vegetative propagation and pathogens easily transferred from mother to daughter plants. Therefore, low propagation rate and fungal infection are two main factors hindering the expansion and development of Artichoke cultivation (in Lam Dong). Therefore, studying and evaluating the situation of fungi and viruses as well as establishing the in vitro propagation procedures in order to produce high number of disease-free seedlings are urgent for the current Artichoke shortage. In this study, samples of purple and white Artichoke varieties, which suspected fungal manifestations, were collected to assessment of fungi and viruses in artichoke. In addition, in vitro propagation by cultivating apical meristem was applied to produce disease-free seedlings. The recorded results showed that, 19 strains of mold were identified on purple and white Artichoke belonged to nine genera including Mucor (M. sp., M. circinelloides, M. fragilis, M. irregularis, and M. racemosus), Alternaria (Alternaria sp., A. alterinata, A. gaisen, A. tenuissima, and A. tillandsiae), Fusarium (F. acuminatum and F. solani), Cylindrobasidium (Cylindrobasidium sp1 and Cylindrobasidium sp2), Actinomucor elegans, Curvalaria clavata, Plectosphaerella oligotrophica, Phoma herbarum, Rhizomucor variabillis; meanwhile, the Tomato mosaic virus (ToMV) was isolated only purple Artichoke. Shoot explants obtained from apical meristem culture were completely disease-free and used for micropropagation at the next stage.

Proteomic analyses reveal mechanisms of action of biocontrol agents on ochratoxin A repression in Penicillium nordicum

Penicillium nordicum is among the main ochratoxin A (OTA) producers in dry-cured fermented sausages. Recent strategies to prevent its development on the surface of these products include the substitution of synthetic antifungals, such as potassium sorbate, by natural compounds. However, the mechanisms of action of the latter are still unclear. The Proteomic analysis is a useful tool to elucidate the basis of the antifungal compound effects on moulds. Therefore, the aim of this study was to evaluate the efficiency of biocontrol agents on the OTA repression in P. nordicum and its relation to proteome changes. Seven different combinations of rosemary leaves, rosemary essential oil, acorn shell extract and the yeast Debaryomyces hansenii have been tested as biocontrol agents against two ochratoxigenic P. nordicum strains on a dry-cured fermented sausage-based medium. The rosemary essential oil and the combination of rosemary leaves with D. hansenii provoked significant inhibition of OTA production in both moulds (p ≤ 0.05). The acorn shell extract and D. hansenii individually decreased OTA only in one of the mould strains. The Proteomic analyses revealed that rosemary essential oil reduced the abundance of proteins involved in the polyketide synthase enoylreductase domain in both moulds, which would explain the OTA reduction. However, the combination of rosemary leaves with D. hansenii showed inter-strain differences, reducing the abundance of proteins related to the cell wall integrity and to the purine pathway, depending on the tested mould. In conclusion, rosemary essential oil and the combination of rosemary leaves with D. hansenii can be proposed as efficient biocontrol agents against ochratoxigenic P. nordicum on dry-cured fermented sausages, although some inter-strain differences at proteome level were found regarding the mechanism of action involved in the reported OTA repression.

Kinetics of solid-state fermentation of lupin with Rhizophus oligosporus based on nitrogen compounds balance

Solid-state fermentation could be a potentially effective method for improving the nutritional value of legumes. The objective of this study was to explore this technology in Lupinus mutabilis, a species of lupin, using a strain of Rhizopus oligosporus mold for solid-state fermentation. Three L. mutabilis varieties (INIAP-450, INIAP-451, and Criollo) were evaluated, including the effect of the grain status (whole or ground) and integument or husk (presence or absence). Kinetic parameters of the fermentation process were studied to define the specific speed of nitrogen formation and the digestibility and nutritional quality of the resulting protein. After incubation at 28 °C for 96 h, the titratable acidity increased, the pH decreased, and the total nitrogen of the whole grain with integument reached 110 g kg−1 for the Criollo variety. The ground INIAP-450 grain without integument had the highest soluble nitrogen content, and nitrogen formation occurred at a specific rate of 0.006 h−1. The apparent digestibility of the protein in this variety increased from 82 to 96% in debittered grain, the concentration of the first limiting amino acids (methionine + cysteine) increased from 20.8 to 27.9 mg g−1 crude protein, and the protein digestibility-corrected amino acid score increased from 68.3 to 89.3%. Overall, the results confirmed the benefits of fermentation in improving the content and quality of protein in the three lupin varieties.

Evaluation of lactose oxidase as enzymatic antifungal control for Penicillium spoilage in yogurt

In this study, we investigated the antifungal activity of lactose oxidase (LO) as a potential biopreservative in dairy products. Our study objectives were to screen antifungal activity of LO against common mold strains, to detect the minimum inhibitory level of LO against the same strains, and to understand how LO affects the pH and lactic acid bacteria (LAB) counts in set yogurt. Five mold strains (Penicillium chrysogenum, Penicillium citrinum,Penicillium commune,Penicillium decumbens,and Penicillium roqueforti) were used throughout study. These strains were previously isolated from dairy manufacturing plants. Throughout the study, yogurts were stored at 21 ± 2°C for 14 d. Antifungal activity of LO was screened using 2 enzyme levels (1.2 and 12 g/L LO) against selected strains on the surface of a miniature laboratory set-yogurt model. For all tested strains, no visible mold growth was detected on the surface of yogurts covered with LO compared with control yogurt without LO. The minimum inhibitory level of LO against each strain was further investigated using 4 enzyme levels (0.12, 0.48, 0.84, and 1.2 g/L LO) on the miniature laboratory set-yogurt model. We detected 0.84 g/L LO as the minimum level inhibiting visible hyphal growth across strains. The minimum inhibitory level of LO varied for each individual strain. To study the effect of LO on the pH of yogurt, miniature laboratory set-yogurt models were covered with different enzyme levels (0.12, 0.48, 0.84, 1.2, and 12 g/L LO). At d 14, a difference was detected comparing pH values of treatments to control with no LO. Commercial low-fat set yogurt was used to study the effect of LO on LAB survival when yogurt surface was covered with 0.84 g/L LO under the same experimental conditions. Control with no LO was included. At d 14, 3 levels of catalase were added (0, 0.01, and 0.1%) to each treatment. To enumerate LAB, homogenized samples were plated on de Man, Rogosa, and Sharpe agar and incubated. Yogurts with 0.84 g/L LO had lower LAB counts compared with control yogurts, and catalase level did not have a significant effect on LAB counts. Our results demonstrated potential antifungal efficacy of LO against common spoilage organisms in dairy products with residual lactose and relatively low pH. Manufacturers should establish efficacy of LO against mold strains of interest and determine the effects of LO on organoleptic properties and LAB survival in set yogurt.

Isolation and detailed characterisation of the first sterigmatocystin hyperproducer mould strain in Hungary

AbstractAspergillus strains were isolated from Hungarian mills in order to get information on the appearance of sterigmatocystin (ST) producing moulds, whose presence has never been demonstrated in Hungary. Fungal isolates were classified into nine morphotypes, sections Nigri, Nidulantes, Versicolores (two morphotypes), Circumdati, Flavi (two morphotypes), Clavati and Terrei by classical mycological assays. ST producing strains could be classified into section Versicolores. ST production of the isolates was assessed by liquid and solid phase growth experiments and compared to ST producing reference strains: Aspergillus pepii SzMC 22332, Aspergillus versicolor SzMC 22333, Aspergillus griseoaurantiacus SzMC 22334 and Aspergillus nidulans RDIT9.32. Four of our isolates marked as Km11, Km14, Km26 and Km31 showed ST production in liquid medium. ST production on solid phase corn grit substrate was measured after three weeks of incubation, and Km26 isolate proved to be the most prominent with a toxin concentration of 277.1 μg g−1, surpassing all reference strains. The toxin-producing ability of Km26 isolate was also tested in a field experiment, where corn was infected. By the end of the experiment, ST level of 19.56 μg kg−1 was measured in infected corn.Molecular taxonomic identification of the Km26 strain was performed using internal transcribed spacer (ITS), calmodulin and tubulin sequence analyses. Based on these studies, strain Km26 was identified as Aspergillus creber.Here we report that an ST-producing A. creber strain has appeared in Hungary, and the Km26 strain is the first known extreme ST-producing mould in this country. As a result of climate change, aflatoxin B1 producing Aspergillus flavus strains have appeared in Hungary in the last decade. As strain Km26 is the only A. creber isolate in Hungary so far, there is no sign of mass prevalence, and due to the lower temperature optimum of the species compared to A. flavus, its appearance is probably not related to climate change.

Effective Treatment of Cutaneous Mold Infections by Antimicrobial Blue Light That Is Potentiated by Quinine.

Cutaneous mold infections commonly result from an array of traumatic injuries that involve direct inoculation of contaminated soil into wounds. Here, we explored the use of antimicrobial blue light (aBL; 405 nm wavelength) and the combination of aBL with quinine hydrochloride (aBL + Q-HCL) for the treatment of cutaneous mold infections. Efficacy of aBL and aBL + Q-HCL in killing clinically important pathogenic molds (Aspergillus fumigatus, Aspergillus flavus, and Fusarium oxyprorum) was investigated. Ultraperformance liquid chromatography identified and quantified endogenous porphyrins in the mold conidia. Finally, a mouse model of dermabrasion wound infected with a bioluminescent variant of A. fumigatus was developed to investigate the efficacy of aBL in treating cutaneous mold infections. We demonstrated that mold conidia are tolerant to aBL, but Q-HCL enhances efficacy. Transmission electron microscopy revealed intracellular damage by aBL. aBL + Q-HCL resulted in intracellular and cell wall damage. Porphyrins were observed in all mold strains, with A. fumigatus having the highest concentration. aBL and aBL + Q-HCL effectively reduced the burden of A. fumigatus within an established dermabrasion infection and limited recurrence posttreatment. aBL and aBL + Q-HCL may offer a novel approach for the treatment of mold infections.

Evaluation of the efficacy of commercial protective cultures to inhibit mold and yeast in cottage cheese

Biopreservation is defined as using microbes, their constituents, or both to control spoilage while satisfying consumer demand for clean-label products. The study objective was to investigate the efficacy of bacterial cultures in biopreserving cottage cheese against postprocessing fungal contamination. Cottage cheese curd and dressing were sourced from a manufacturer in New York State. Dressing was inoculated with 3 different commercial protective cultures-PC1(mix of Lacticaseibacillus spp. and Lactiplantibacillus spp.), PC2 (Lacticaseibacillus rhamnosus), and PC3 (Lactic. rhamnosus)-following the manufacturer recommended dosage and then mixed with curd. A control with no protective culture was included. Nine species of yeast (Candida zeylanoides, Clavispora lusitaniae, Debaryomyces hansenii, Debaryomyces prosopidis, Kluyveromyces marxianus, Meyerozyma guilliermondii, Pichia fermentans, Rhodotorula mucilaginosa,and Torulaspora delbrueckii) and 11 species of mold (Aspergillus cibarius, Aureobasidium pullulans, Penicillium chrysogenum, Penicillium citrinum,Penicillium commune,Penicillium decumbens,Penicillium roqueforti,Mucor genevensis,Mucor racemosus,Phoma dimorpha, andTrichoderma amazonicum) were included in the study. Fungi strains were previously isolated from dairy processing environments and were inoculated onto the cheese surface at a rate of 20 cfu/g. Cheese was stored at 6 ± 2°C. Yeast levels were enumerated at 0, 7, 14, and 21 d postinoculation. Mold growth was visually observed on a weekly basis through d 42 of storage and imaged. Overall, the protective cultures were limited in their ability to delay the outgrowth in cottage cheese, with only 8 of the 20 fungal strains showing an effect of the cultures compared with the control. The protective cultures were not very effective against yeast, with only PC1 able to delay the outgrowth of 3 strains: D. hansenii, Tor. delbrueckii, and Mey. guilliermondii. The efficacy of these protective cultures against molds in cottage cheese was more promising, with all protective cultures showing the ability to delay spoilage of at least 1 mold strain. Both PC1 and PC2 were able to delay Pen. chrysogenum and Pho. dimorpha outgrowth, and PC1 also delayed Pen. commune,Pen. decumbens,and Pen. roqueforti to different extents compared with the controls. This study demonstrates that commercial lactic acid bacteria cultures vary in their performance to delay mold and yeast outgrowth, and thus each protective culture should be evaluated against the specific strains of fungi of concern within each specific dairy facility.

Lipase and protease activities in Koji cheeses surface-ripened with <i>Aspergillus</i> strains

Koji molds are safe microorganisms belonging to the genus Aspergillus and are used in the production of traditional Japanese fermented foods, such as miso, soy sauce, and sake. Koji molds produce many types of enzymes, including amylase, lipase, and protease, that are used in food processing treatments. To examine the potential of Koji molds for cheese ripening, we measured the lipase and protease activities on cheese curds ripened using five strains of Koji molds (Aspergillus oryzae or A. sojae) and compared them with curds ripened using Penicillium candidum or P. roqueforti. Compared with Penicillium, Koji molds showed similar or higher protease activity on the cheese surface. Lipase activity varied markedly among Koji mold strains; some showed comparable activity to Penicillium, and others showed lower activity. Considering the lipase and protease activities, some Koji molds can be applied to the production of surface mold-ripened cheeses.

Aflatoxin B1 and Sterigmatocystin Binding Potential of Lactobacilli.

Due to global climate change, mould strains causing problems with their mycotoxin production in the tropical–subtropical climate zone have also appeared in countries belonging to the temperate zone. Biodetoxification of crops and raw materials for food and feed industries including the aflatoxin B1 (AFB1) binding abilities of lactobacilli is of growing interest. Despite the massive quantities of papers dealing with AFB1-binding of lactobacilli, there are no data for microbial binding of the structurally similar mycotoxin sterigmatocystin (ST). In addition, previous works focused on the detection of AFB1 in extracts, while in this case, analytical determination was necessary for the microbial biomass as well. To test binding capacities, a rapid instrumental analytical method using high-performance liquid chromatography was developed and applied for measurement of AFB1 and ST in the biomass of the cultured bacteria and its supernatant, containing the mycotoxin fraction bound by the bacteria and the fraction that remained unbound, respectively. For our AFB1 and ST adsorption studies, 80 strains of the genus Lactobacillus were selected. Broths containing 0.2 µg/mL AFB1and ST were inoculated with the Lactobacillus test strains. Before screening the strains for binding capacities, optimisation of the experiment parameters was carried out. Mycotoxin binding was detectable from a germ count of 107 cells/mL. By studying the incubation time of the cells with the mycotoxins needed for mycotoxin-binding, co-incubation for 10 min was found sufficient. The presence of mycotoxins did not affect the growth of bacterial strains. Three strains of L. plantarum had the best AFB1 adsorption capacities, binding nearly 10% of the mycotoxin present, and in the case of ST, the degree of binding was over 20%.

Microbiological Quality of "Soumbala", an African Locust Bean (Parkia biglobosa) Condiment Sold in the Markets of Abidjan, Côte d’Ivoire

Aims: Produced in an artisanal way from the fermentation of the seeds of Parkia biglobosa, “Soumbala”, is a condiment very appreciated in several African countries including Côte d'Ivoire. This study was conducted to assess the microbiological quality and fungal profile of this condiment sold in the markets of nine communes in Abidjan.
 Study Design: Food safety.
 Place and Duration of Study: Soumbala's samples were collected in the markets during the month of October 2019 and analyzed at the Laboratory of Microbiology and Food Biotechnology of the Nangui Abrogoua University, Côte d'Ivoire.
 Methodology: For this purpose, 27 samples of "Soumbala" were taken from the different markets and analysed. The loads of the different microorganisms (mesophilic aerobic germs, total coliforms, moulds) were determined by counting after culture in agar medium. The microbiological quality has been assessed according to Directive 2005/2073/EC. The physico-chemical composition (pH, titratable acidity, moisture content) of "Soumbala" has been determined according to standard methods. The identification of the mould strains isolated from the different samples was carried out using the identification keys.
 Results: The results of the various physico-chemical parameters obtained ranged from 13.81 to 20.31%, 5.58 to 6.50 and 3.73 to 9.06 % for moisture content, pH and titratable acidity, respectively. The mesophilic aerobic germ loads of 7.21 to 7.70 log10 cfu/g determined in the analyzed samples are above the acceptability limit (6 log10 cfu/g) applied in this study. The maximum loading of total coliforms was 3.92 log10 cfu/g. All mould loads are below the acceptability limit. The mould strains isolated and identified from the identification keys belong to the genus Aspergillus.
 Conclusion : A public health risk related to the consumption of "Soumbala" could exist if these moulds produced mycotoxin.

Selection of Lactic Acid Bacteria Isolated from Fresh Fruits and Vegetables Based on Their Antimicrobial and Enzymatic Activities.

Lactic acid bacteria (LAB) are an important source of bioactive metabolites and enzymes. LAB isolates from fresh vegetable sources were evaluated to determine their antimicrobial, enzymatic, and adhesion activities. A saline solution from the rinse of each sample was inoculated in De Man, Rogosa and Sharpe Agar (MRS Agar) for isolates recovery. Antimicrobial activity of cell-free supernatants from presumptive LAB isolates was evaluated by microtitration against Gram-positive, Gram-negative, LAB, mold, and yeast strains. Protease, lipase, amylase, citrate metabolism and adhesion activities were also evaluated. Data were grouped using cluster analysis, with 85% of similarity. A total of 76 LAB isolates were recovered, and 13 clusters were formed based on growth inhibition of the tested microorganisms. One cluster had antimicrobial activity against Gram-positive bacteria, molds and yeasts. Several LAB strains, PIM4, ELO8, PIM5 and CAL14 strongly inhibited the growth of L. monocytogenes and JAV15 and TOV9 strongly inhibited the growth of F. oxysporum. Based on enzymatic activities, 5 clusters were formed. Seven isolates hydrolyzed starch, 46 proteins, 14 lipids, and 36 metabolized citrate. LAB isolates with the best activities were molecularly identified as Leuconostoc mesenteroides, Enterococcus mundtii and Enterococcus faecium. Overall, LAB isolated from vegetables showed potential technological applications and should be further evaluated.

Bovine Hemoglobin Enzymatic Hydrolysis by a New Eco-Efficient Process-Part II: Production of Bioactive Peptides.

Bovine cruor, a slaughterhouse waste, was mainly composed of hemoglobin, a protein rich in antibacterial and antioxidant peptides after its hydrolysis. In the current context of food safety, such bioactive peptides derived from enzymatic hydrolysis of hemoglobin represent potential promising preservatives for the food sector. In this work, the hemoglobin hydrolysis to produce bioactive peptides was performed in a regulated pH medium without the use of chemical solvents and by an eco-efficient process: electrodialysis with bipolar membrane (EDBM). Bipolar/monopolar (anionic or cationic) configuration using the H+ and OH− generated by the bipolar membranes to regulate the pH was investigated. The aim of this study was to present and identify the bioactive peptides produced by EDBM in comparison with conventional hydrolysis and to identify their biological activity. The use of the EDBM for the enzymatic hydrolysis of hemoglobin has allowed for the production and identification of 17 bioactive peptides. Hydrolysates obtained by EDBM showed an excellent antimicrobial activity against six strains, antioxidant activity measured by four different tests and for the first time anti-fungal activities against five yeasts and mold strains. Consequently, this enzymatic hydrolysis carried out in regulated pH medium with bipolar membranes could provide bioactive peptides presenting antibacterial, antifungal and antioxidant interest.

Ecotoxicity Evaluation of Spent Biomixtures Used for Pesticides Degradation

Biobed in which the biomixture is the most important element has been developed and used as a simple, cheap and high effective method to degrade residues of pesticides. However, the ecotoxicity evaluation of spent biomixtures used for pesticides degradation to manage and reuse have not been paid enough attention. In present study, the biomixture composed by the top soil: straw: spent mushroom substrate (Pleurotus pulmonarius) in the volumetric proportions of 1:2:1 and the culture of lignin-degrading mold strain (Penicillium chrysogenum N2) (5% v/w) was used to degrade Cartap (100 mg/kg), Cypermethrin (100 mg/kg), Chlopyrifos (100 mg/kg) and 2,4-D (10 mg/kg) denoted by SB-Car, SB-Cyp, SB-Chlor and SB-2,4-D, respectively. The ecotoxicity evaluation of spent biomixtures was carried out using the tests with soil plants, fauna and microorganisms. The results showed that, they almost inhibited neither the growth of soil plants (GI > 0.8, germination > 90%, fresh weight > 98% of the controls) nor the nitrogen mineralization in soil (for SB-Cyp, SB-Chlor và SB-2,4-D). Also, they caused no the acute toxicity to earthworms (no significant mortality and wet biomass reduction between the controls and treatments at concentrations < 100 g/kg dry soil).

Evaluation of the efficacy of commercial protective cultures against mold and yeast in queso fresco

In this study, we evaluated the efficacy of 3 commercial protective cultures designated PC1 (Lactobacillusspp.), PC2 (Lactobacillusrhamnosus), and PC3 (Lactobacillusrhamnosus) as biopreservatives in queso fresco (QF) against 9 yeast strains (Candida zeylanoides, Clavispora lusitaniae, Debaryomyces hansenii, Debaryomyces prosopidis, Kluyveromyces marxianus, Meyerozyma guilliermondii, Pichia fermentans, Rhodotorula mucilaginosa, and Torulaspora delbrueckii) and 11 mold strains (Aspergillus cibarius, Aureobasidium pullulans, Penicillium chrysogenum, Penicillium citrinum,Penicillium commune,Penicillium decumbens,Penicillium roqueforti,Mucor genevensis,Mucor racemosus,Phoma dimorpha, andTrichoderma amazonicum). All fungal spoilage strains were previously isolated from dairy processing environments. A positive control (C) with no protective culture was included. Fungal spoilage organisms were inoculated on cheese surfaces at an inoculum level of 20 cfu/g, and cheeses were stored at 6 ± 2°C throughout the study. For yeast enumeration, cheeses were sampled on d 0, 7, 14, and 21 postinoculation. Significant inhibition was detected for each yeast strain by comparing yeast counts for each cheese treated with protective culture against the control cheese using one-way ANOVA with Bonferroni correction performed individually at d 7, 14, and 21 postinoculation. Mold growth was visually observed and imaged weekly through 70 d postinoculation. Whereas PC3 inhibited Cl. lusitaniae, Mey. guilliermondii, and Ph. dimorpha, PC2 inhibited the outgrowth of Cl. lusitaniae, D. hansenii, and Ph. dimorpha. Protective culture 1 had the broadest spectrum of efficacy across yeast and molds, delaying spoilage caused by 4 distinct yeast strains (Cl. lusitaniae, D. hansenii, D. prosopidis, and Mey. guilliermondii), and inhibiting visible growth of 2 mold strains (P. chrysogenum and Ph. dimorpha). Results demonstrated that commercial protective cultures vary in performance, as indicated by the breadth of mold and yeast inhibition at both the genus and species level. This study suggests that manufacturers looking into using protective cultures should investigate their efficacy against specific fungal strains of concern.

The mechanism on decreasing the microbiological contamination of superfine green tea powder by ball milling

The present study compared the microbial population in the samples of steamed green tea and its superfine green tea powder by determining and analyzing microbial changes during ball milling, which is the key step of producing superfine green tea powder. The results showed that after ball milling the microbial counts of superfine green tea powder were dramatically decreased than steam green teas in which the total aerobic count were more than 104 CFU/g in 14/19 samples. With the duration of ball milling, the microbial population of superfine green tea powder was correspondingly decreased till below 103 CFU/g. To study the mechanism of ball milling on microbial counts’ decreasing, a mold strain was isolated, purified and identified from the samples. Subsequently, the mold strain was cultured and individually ball-milled. The results indicated that fungal cell wall was disrupted and then microbial DNA was released during the process. Moreover, microbial populations in the tea samples were negatively correlated with cell wall breakage ratio. It was suggested that the ball milling was effective strategy for controlling the microbial contamination during the processing of superfine green tea powder.

THE ECOLOGICAL CONDITION OF THE LAKE IN THE ORIKHOVITSA VILLAGE

The study deals with the ecological state of the lake in the Orikhovitsa village of Uzhhorod district of Transcarpathian region, which is used for unorganized recreation and fishing by the residents of the nearby villages. To analyze the water quality according to standard methods, a number of hydrochemical parameters were set, in particular pH, chloride-, sulfate-, nitrate-, nitrite anions, polyphosphates, ammonium ions; suspended solids, Ferum total, dissolved Oxygen, BSC5, HCC and permanganate oxidation. The obtained results were compared with the normalized values determined for the reservoirs, used of recreation, everyday life and fishery purposes.The analysis of the results indicates that, that according to the defined hydrochemical and sanitary-hygienic indicators of water quality (except total iron, suspended solids and microbial contamination) no exceedance of the normalized values for both water use purposes was observed.The content of the Ferum total exceeded the normalized values for reservoirs of recreation purpose by 1.7 times. In the same time the exceedance in 2.4-10.0 times in case of water reservoirs for industrial fishing during all seasons represents a significant risk for human health and for aquatic organisms as well.The content of suspended matter in all selected water samples from the lake exceeded the normalized values for reservoirs of recreational purposes, which is ≤ 0.75 mg/dm3, and ranged from 5.0 mg/dm3 to 6.8 mg/dm3, which is 6.7-9.1 times more, than the set value. Due to the ability of suspended solids to absorb contaminants and microflora on their surface as well as for aesthetic reasons, this reservoir cannot be considered suitable for swimming. However, according to the requirements for fish farms, all water samples taken from the lake met the quality standards according to the relevant indicator.The results of microbiological analysis of the state of the reservoir in the summer time show that the reservoir does not meet the sanitary and hygienic standards for the bacterial content of Escherichia coli, Staphylococcus aureus and Streptococcus. The content of pathogenic strains of staphylococci and molds exceeded the normalized values. Warning signs notifing of this fact should be installed.

In vitro antifungal effects of spices on ochratoxin A production and related gene expression in Penicillium nordicum on a dry-cured fermented sausage medium

Penicillium nordicum, an ochratoxin A (OTA) producer, widely contaminates the surface of dry-cured fermented sausages. Although the meat industry uses antifungal synthetic compounds during ripening, consumers' preferences currently stand up for natural preservatives. The aim of this study was to evaluate the antifungal effect of spices commonly added to dry-cured fermented sausages during their processing on P. nordicum for establishing their value as an alternative strategy to synthetic compounds. The mould strain was grown on a dry-cured fermented sausage-based medium containing oregano, rosemary or thyme. Moreover, an antifungal commercial preparation containing potassium sorbate and natamycin was tested alone and in combination with the spices. The growth rate, OTA accumulation and relative expression of genes involved in OTA biosynthesis (otapks and otanps) and some stress pathways (Hog1 and Rho1) were evaluated. In the growth assessment, the oregano alone or in combination with the antifungal preparation significantly reduced the growth rate. Different patterns were observed at both sampling times for the OTA production and gene expression analyses, and even differences between treatments at the same incubation period were observed. Regarding OTA accumulation, significant reductions were found when adding oregano or rosemary in the presence and absence of the antifungal compounds. While a stimulation of the expression of most of the tested genes was obtained at the initial stages, a repression was generally found at the end of the incubation. This makes sense since the mycotoxin accumulation was usually higher at the initial stages than at the end of the incubation. Accordingly, such spices would allow satisfying the current consumers’ demand for natural preservatives minimising the hazard associated with the OTA presence in cured meats at the same time.

СКРИНІНГ ЦВІЛЕВИХ ГРИБІВ НА ЗДАТНІСТЬ ДО СИНТЕЗУ КРЕАТИНІНДЕІМІНАЗИ

Determination of creatinine concentration in biological fluids is becoming increasingly relevant as a clinical test. Various chemical and physico-chemical methods have been proposed to determine creatinine concentration in biological samples, including various modifications of the well-known Jaffe color reaction, although it has several drawbacks, namely, a low specificity and sensitivity to positive and negative interference from related substances. In addition, the available methods are time consuming, require a complicated sample preparation procedure, expensive reagents, highly qualified personnel and, most importantly, do not allow real-time analysis. Therefore, increasing attention has been paid to enzymatic methods for the determination of creatinine, particularly, using microbial creatinine deiminase. In this regard, the search for new microorganisms – effective producers of specific creatinine deiminases – is an actual task for microbial enzymology and analytical biotechnology. We have analyzed creatinine deiminase activity for 10 strains of different molds: Botrytis aclada , Botrytis allii 100(5), Monilinia fructicola , Sporobolomyces salmonicolor , Totula sp., Stachybotris chartarum , Pichiapini , Aspergillus oryzea , Trichoderma lignorum , Aspergillus glaucus , Trichothecium roseum , Aureobasidium pullulans . Among the strains tested, the enzyme activity was detected in the following species: M. fructicola, A. pullulans, B. allii, T. roseum, and C. g lobosum , although only two fungi, B. allii and C. globosum , were able to use creatinine as the sole nitrogen source. Creatinine deiminase activity in cell free extracts of B. allii and C. globosum , grown in glucose medium supplemented with creatinine (as the sole carbon and nitrogen source, respectively) was 2.5 and 1.5 times higher, related to that for the strains grown in glucose-sodium nitrate medium. Therefore, the fungi B. allii and C. globosum can be used for isolation of creatinine deiminase to be used in construction of biosensors selective to creatinine.

Galactomyces geotrichum mold isolated from a traditional fried cottage cheese produced omega-3 fatty acids

Thirty nine strains of Galactomyces geotrichum molds were isolated from a traditional fried cottage cheese and production of polyunsaturated fatty acids (PUFA) was assessed. Among them eleven strains produced an extracellular lipids enriched in n-6 and n-3 PUFA. The extracellular lipids produced by G. geotrichum strain 38 contained the highest amounts of total PUFA (24.3%), with the highest contribution of n-3 fatty acids (17.9%), where α-linolenic, eicosapentaenoic, docosapentaenoic and docosahexaenoic acids were the main contributors. To obtain maximal production of PUFA, composition of the medium consisted of 10 g/L rapeseed oil, 5 g/L yeast extract, 0.05 g/L K2HPO4, 0.17 g/L MgSO4, 0.015 g/L MnSO4, 0.015 g/L ZnSO4, 0.05 g/L FeSO4, and 10 mg/L vitamin B12. The optimal growth conditions at 30 °C involve: aeration at 1.5 vvm (volume of air per volume of broth per minute) at pH 6.5. The cheese produced under described conditions contained higher amount of n-3 PUFA (0.25 mg/g cheese) in comparison to control (0.01 mg/g). α-Linolenic acid predominated among n-3 fatty acids. Galactomyces geotrichum is a natural microflora of dairy products, and could be used to enrich food/cheese in deficient omega-3 lipids.

Identification of Dermatophyte and Nondermatophyte Molds Isolated from Animal Lesions Suspected to Dermatomycoses.

Background:Dermatomycoses contain superficial fungal infections of keratinized layers of the body such as skin, hair, and nail that affect more than 20%–25% of people and animals worldwide. Some fungi can cause superficial infections in animals after accidental penetration and colonization on injured skin and can be transmitted to humans by exposure. The infection caused mainly by dermatophyte species and may also be caused rarely by yeasts and nondermatophytic molds.Materials and Methods:Eighty-two skin scrapings and hair samples were collected from animals (sheep, cow, cat, camel, calf, goat, horse, and dog) in three specialized pet clinics and three livestock and slaughterhouses. The isolates were identified using direct microscopy, culture, and polymerase chain reaction-sequencing of ITS1-5.8SrDNA-ITS2 region.Results:Thirteen mold strains out of 82 clinical samples (15.8%) were isolated from animal lesions. Acremonium exuviarum (n = 4; 30.7%), Sarocladium implicatum (n = 2; 15.4%), Arthroderma otae (n = 2; 15.4%), Chaetomium iranianum (n = 1; 7.7%), Trichothecium roseum (n = 1; 7.7%), Lichtheimia ramosa (n = 1; 7.7%), Penicillium chrysogenum (n = 1; 7.7%), and Microsporum equinum (n = 1; 7.7%) were isolated from clinical specimens.Conclusion:Since opportunistic fungi are increasing as etiological agents of dermatomycoses, isolation of these molds from wounds can be a warning to veterinarians, and daily cleaning of wounds with a proper disinfectant is recommended for the prevention of fungal colonization.