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Due to the dissemination of airborne conidia and spores, molds can contaminate various surfaces. In the food industry sector, their presence and development can have health and economic implications. In order to control these undesirable microorganisms, various approaches can be used but the main one relies on the use of disinfectants. The objective of this review is to report the existing studies on the effect of various disinfectant molecules (i.e., sodium hypochlorite, chlorine dioxide, ethanol and other alcohols, hydrogen peroxide, peracetic acid, and quaternary ammonium compounds) on the inactivation of fungal spores. These studies were sorted depending on the targeted fungal species. Noteworthy, in the food industry, four log and three log reductions are required to claim a fungicidal activity for suspension (European Standard 1650, 2019) and surface (European Standard 13697/IN1, 2019) treatments, respectively. Most of the presented studies concerned Penicillium and Aspergillus species (44 and 31% of the literature, respectively). In general, for a given disinfection procedure, ascospores were more resistant than conidia, and Aspergillus conidia were more resistant than Penicillium ones. However, the variability of encountered molds (e.g. species, strains, physiological state) and disinfection procedures (e.g. molecules, concentrations, contact time) affected the efficacy of disinfectants.

Although lupin anthracnose caused by Colletotrichum lupini is a significant threat for spring and winter lupin crops, it has been poorly studied so far. This study aimed at characterizing the (i) phylogenetic, (ii) morphological, and (iii) physiological diversity of collected isolates from anthracnose-affected lupins. The genetic identification of representative isolates (n = 71) revealed that they were all C. lupini species, further confirming that lupin anthracnose is caused by this species. However, multilocus sequencing on these isolates and 16 additional reference strains of C. lupini revealed a separation into two distinct genetic groups, both of them characterized by a very low genetic diversity. The diversity of morphological characteristics of a selected subset of C. lupini isolates was further evaluated. To the best of our knowledge, microsclerotia production observed for some isolates has never been reported so far within the Colletotrichum acutatum species complex. Finally, the modeling of growth responses of a subset of C. lupini strains revealed the capacity of some strains to grow in vitro at 5°C. This ability was also evidenced in planta, because C. lupini DNA was detectable in plants from 14 days postinoculation at 5°C onward, whereas symptoms began to appear a week later, although at a very low level. Since lupin crops are planted during winter or early spring, growth studies in vitro and in planta demonstrated the capability of the species to grow at temperatures ranging from 5 to 30°C, with an optimum close to 25°C. In this study, C. lupini-specific primers were also designed for real-time quantitative PCR on fungal DNA and allowed the detection of C. lupini in asymptomatic field samples. These results open perspectives to detect earlier and limit the development of this pathogen in lupin crops.

This study aimed at quantifying the impact of the concentration of four commercial sanitizers and temperature on mold spores inactivation. The sanitizers were based on the following fungicide molecules, ethanol (ARVO 21 SR), active chlorine (ARVO CLM 600), hydrogen peroxide (Nocolyse Food) and triamine (P3 Topax 960). Food plant spores were produced under a moderate water stress, 0.95 a

Filamentous fungi are used in the dairy industry as adjunct cultures in fermented products, but can also lead to food spoilage, waste and economic losses. The control of filamentous fungi with abiotic factors contributes to longer food shelf life and prevention of fungal spoilage. One of the main abiotic factors for controlling fungal growth in foods is water activity (a

The aim of this study was to assess the impact of the physiological state and intraspecific variability on the efficacy of 70% ethanol to inactivate conidia of Penicillium commune, used as a representative species of dairy product contaminants. Four physiological states were obtained by modifying the water activity during the production of conidia (0.995 and 0.950) and the harvesting conditions (hydrated and non-hydrated). These conditions were applied to four different P. commune strains isolated from contaminated dairy products. Five minutes exposure to 70% ethanol at ambient temperature allowed total inactivation of conidia (>4 log10) regardless of the physiological state or the strain. For 1 min exposure, regardless of the strains, only dry-harvested conidia produced at aw 0.950 exhibited survivors. Survival after 2 min exposure was observed for this physiological state for P. commune UBOCC-A-116003 only. For this strain, the impact of the physiological state was greater than 1.54 log10 between dry-harvested conidia produced at aw 0.950 that exhibited survivors after 1 min treatment and the 3 other kinds of conidia that were all inactivated. For 1 min exposure, by comparing the more resistant strain to the three other strains, the impact of the intraspecific variability was 2.35 log10. These results demonstrated that the physiological state of the conidia, the representativeness of the tested species and strains should be taken into account to assess the efficacy of disinfectants in dairies.

This study aimed at assessing the impact of the physiological state of fungal spores on inactivation by sodium hypochlorite, 0.1% and 0.2% active chlorine, and 3% hydrogen peroxide. In this context, two physiological states were compared for 4 fungal species (5 strains). The first physiological state corresponded to fungal spores produced at 0.99 aw and harvested using an aqueous solution (laboratory conditions), while the second one corresponded to fungal spores produced under a moderate water stress (0.95 aw) and dry-harvested (mechanical harvesting without use of any water, mimicking food plant conditions). Aspergillus flavus “food plant” conidia were more resistant to all tested fungicide molecules than the “laboratory” ones. The same phenomenon was observed for Penicillium commune UBOCC-A-116003 conidia treated with hydrogen peroxide. However, this isolate did not exhibit any inactivation difference between “laboratory” and “food plant” conidia treated with sodium hypochlorite. Similarly, the physiological state of Cladosporium cladosporioides conidia did not impact the efficacy of the tested biocides. P. commune UBOCC-A-112059 “food plant” and “laboratory” conidia were more resistant to hydrogen peroxide and sodium hypochlorite, respectively. As for Mucor circinelloides, “laboratory” spores were more resistant to all disinfectant than the “food plant” ones. Noteworthy, regardless of the physiological state, all M. circinelloides and C. cladosporioides conidia were inactivated for 5 min treatment at 0.2% active chlorine and for 2.5 min treatment at 0.1% active chlorine, while the conidia of all the other species remained viable for these treatments. The obtained data indicate that the efficacy of disinfectant molecules depends not only on the encountered fungal species and its intraspecific diversity but also on the spore physiological state.

Different strains of a given fungal species may display heterogeneous growth behavior in response to environmental factors. In predictive mycology, the consideration of such variability during data collection could improve the robustness of predictive models. Among food-borne fungi, Penicillium roqueforti is a major food spoiler species which is also used as a ripening culture for blue cheese manufacturing. In the present study, we investigated the intraspecific variability of cardinal temperatures and water activities (aw), namely, minimal (Tmin and awmin), optimal (Topt and awopt) and maximal (Tmax) temperatures and/or aw estimated with the cardinal model for radial growth, of 29 Penicillium roqueforti strains belonging to 3 genetically distinct populations. The mean values of cardinal temperatures and aw for radial growth varied significantly across the tested strains, except for Tmax which was constant. In addition, the relationship between the intraspecific variability of the biological response to temperature and aw and putative genetic populations (based on microsatellite markers) within the selected P. roqueforti strains was investigated. Even though no clear relationship was identified between growth parameters and ecological characteristics, PCA confirmed that certain strains had marginal growth response to temperature or aw. Overall, the present data support the idea that a better knowledge of the response to abiotic factors such as temperature and aw at an intraspecific level would be useful to model fungal growth in predictive mycology approaches.

Water activity (aw) is one of the most influential abiotic factors affecting fungal development in foods. The effects of aw reduction on conidial germination and radial growth are generally studied by supplementing culture medium with the non-ionic solute glycerol despite food aw can also depend on the concentration of ionic solutes such as sodium chloride (NaCl). The present study aimed at modelling and comparing the effects of aw, either modified using NaCl or glycerol, on radial growth and/or conidial germination parameters for five fungal species occurring in the dairy environment. The estimated cardinal values were then used for growth prediction and compared to growth kinetics observed on commercial fresh cheese. Overall, as compared to glycerol, NaCl significantly increased the fungistatic effect resulting from aw reduction by extending latency and/or reducing radial growth rates of Paecilomyces niveus, Penicillium brevicompactum, Penicillium expansum and Penicillium roqueforti but not of Mucor lanceolatus. Besides, NaCl significantly reduced aw range for conidial germination and delayed median germination time of P. expansum but not of P. roqueforti. Despite these observations, cardinal aw values obtained on glycerol-medium yielded similar predictions of radial growth and germination time in commercial fresh cheese as those obtained with NaCl. Thus, it indicates that, for the studied species and aw range used for model validation, the use of NaCl instead of glycerol as a aw depressor had only limited impact for fungal behavior prediction.

The Mucor genus includes a large number of ubiquitous fungal species. In the dairy environment, some of them play a technological role providing typical organoleptic qualities to some cheeses while others can cause spoilage. In this study, we compared the effect of relevant abiotic factors for cheese production on the growth of six strains representative of dairy technological and contaminant species as well as of a non cheese related strain (plant endophyte). Growth kinetics were determined for each strain in function of temperature, water activity and pH on synthetic Potato Dextrose Agar (PDA), and secondary models were fitted to calculate the corresponding specific cardinal values. Using these values and growth kinetics acquired at 15 °C on cheese agar medium (CA) along with three different cheese types, optimal growth rates (μopt) were estimated and consequently used to establish a predictive model. Contrarily to contaminant strains, technological strains showed higher μopt on cheese matrices than on PDA. Interestingly, lag times of the endophyte strain were strongly extended on cheese related matrices. This study offers a relevant predictive model of growth that may be used for better cheese production control but also raises the question of adaptation of some Mucor strains to the cheese.

Conidial germination and mycelial growth are generally studied with conidia produced under optimal conditions to increase conidial yield. Nonetheless, the physiological state of such conidia most likely differs from those involved in spoilage of naturally contaminated food. The present study aimed at investigating the impact of temperature, pH and water activity (aw) during production of conidia on the germination parameters and compatible solutes of conidia of Penicillium roqueforti and Penicillium expansum. Low temperature (5°C) and reduced aw (0.900 aw) during sporulation significantly reduced conidial germination times whereas the pH of the sporulation medium only had a slight effect at the tested values (2.5, 8.0). Conidia of P. roqueforti produced at 5°C germinated up to 45h earlier than those produced at 20°C. Conidia of P. roqueforti and P. expansum produced at 0.900 aw germinated respectively up to 8h and 3h earlier than conidia produced at 0.980 aw. Furthermore, trehalose and mannitol assessments suggested that earlier germination might be related to delayed conidial maturation even though no ultra-structural modifications were observed by transmission electron microscopy. Taken together, these results highlight the importance of considering environmental conditions during sporulation in mycological studies. The physiological state of fungal conidia should be taken into account to design challenge tests or predictive mycology studies. This knowledge may also be of interest to improve the germination capacity of fungal cultures commonly used in fermented foods.

The medium-term effects of permanent or random exposure to stray voltage applied to the water trough were evaluated on milk production and stress physiology in lactating dairy cows. Seventy-four Holstein cows were assigned during two 8-wk experimental periods to 1 of 3 treatments. The treatments were permanent exposure to voltage (PERM, 1.8 V, n = 23) applied to the water trough, random exposure to voltage (RAND, 1.8 V, 36 h/wk, n = 25), and no exposure to voltage (control, n = 26). On the first day of voltage exposure, PERM cows had higher activity levels than control cows (9.8 ± 2.70 vs. −2.3 ± 2.74 14-s periods of movement/h). During the eighth week of exposure, RAND cows had higher activity levels than control cows (4.2 ± 3.64 vs. −7.7 ± 3.54 14-s periods of movement/h) and higher milk cortisol concentration than PERM cows (0.21 ± 0.024 vs. 0.14 ± 0.020 ng/mL). No differences were observed between treatments for cortisol response after an ACTH challenge during the seventh week of exposure. No effects of voltage exposure were observed on production traits and daily water intake. There was a transient decrease in milk yield on the second day of exposure in PERM cows (−1.4 ± 0.74 kg) and on the third day of exposure in RAND cows (−3.5 ± 1.03 kg) compared with control cows. In dairy cows, permanent or random exposure to stray voltage (1.8 V; 3.6 mA) could induce a transient stress response. Moreover, unpredictable voltage exposure could be considered a mild stressor, with slight modifications in stress physiology and activity but no impairment in production in the medium term.

International audience; Penicillium roqueforti has the ability to produce secondary metabolites, including roquefortine C (ROQC) and mycophenolic acid (MPA). In a previous study, the presence of these mycotoxins, alone or in co-occurrence, has been reported in blue-veined cheese. A high variability of mycotoxin content has also been observed, although the majority of samples exhibited relatively low concentrations. The observed variability raises the question of the factors impacting ROQC and MPA production. In this context, the mycotoxigenic potential of 96 P. roqueforti strains (biotic factor) and the effect of some abiotic factors (pH, temperature, NaCl and O2 contents, and C/N ratio) on mycotoxin production were evaluated. A high intraspecific diversity, established via genotypic (RAPD) and phenotypic (FTIR) approaches, was observed. It was associated with mycotoxigenic potential variability and may thus explain part of the observed variability in mycotoxin content of blue-veined cheese. Moreover, a significant decrease of ROQC and MPA production was observed for conditions (temperature, C/N ratio, O2 and NaCl concentrations) encountered during cheese-making compared with optimal growth conditions. The results also highlighted that there was no significant effect of addition of ROQC amino-acid precursor on the production of both mycotoxins whereas a pH increase from 4.5 to 6.5 slightly reduced MPA but not ROQC production.

This work aimed first to compare 2 diets differing in their percentage of concentrate [low (LO): 30% concentrate vs. High (HI): 60% concentrate] by measuring simultaneously feeding behavior, rumen parameters, blood and plasma parameters, and milk yield and composition in 8 mid-lactation goats. The second aim was to study the interrelationships between these variables and to analyze the between-animal variability to better understand the between-animal differences in acidosis susceptibility. All of the animals received the 2 diets ad libitum as total mixed ration according to a crossover design of two 4-wk periods. Mean daily DMI was similar between the 2 diets but the variability was higher for the HI than for the LO diet. Goats produced more milk when fed the HI diet compared with the LO diet but with a lower fat:protein ratio (0.81 vs. 0.99). They ate more rapidly the HI than the LO diet but stopped eating sooner after the afternoon feed allowance, and spent less time chewing. The increase in concentrate percentage modified rumen parameters: the pH and acetate:propionate ratio decreased and total VFA, ammonia, and soluble carbohydrate concentrations increased. Hematocrit, plasma NEFA, and blood K and Ca concentrations decreased but glycemia and uremia increased. Other parameters were not modified: milk fat content, blood pH, and bicarbonate and Na concentrations. A large between-animal variability was detected for all the measured parameters, especially for feeding behavior, with important consequences on rumen and blood parameters. This work confirmed the effects of a high percentage of concentrate on feeding behavior, rumen and blood parameters, and milk production, and some known relationships such as the positive link between rumen pH and chewing index. It also pointed out, other relationships between parameters seldom measured at the same time; such as rumen redox potential or blood pH and chewing index, or the negative link between blood and rumen pH. When the animals spent a lot of time chewing, they probably produced a lot of saliva that buffered the rumen pH and prevented them from suffering from subacute ruminal acidosis. However, they used part of their blood bicarbonates reserve, which might have induced metabolic acidosis, as rumen and blood pH were inversely related. This could explain why some animals suffer from acidosis and others do not in a herd receiving the same diet, and why some animals seem to suffer more from subacute ruminal acidosis and others from metabolic acidosis.

The effects of permanent or random exposure to stray voltage on a water trough were evaluated in growing–finishing Romane male lambs between the age of 13 and 19 weeks. Ninety lambs were assigned during two 6-week experimental periods to one of three treatments, with 30 animals in each treatment (15 per experimental period). The treatments were permanent exposure to voltage (PERM, 3.5 V) on the water trough, random exposure to voltage (RAND, 3.5 V, 34 h/week) and no voltage exposure for the control group (CONT). No effects of voltage exposure were observed on production parameters: growth, average daily gain and water intake. The stress physiology seemed to be slightly modified with a lower plasma cortisol concentration at slaughter in PERM lambs compared to CONT lambs (P < 0.05) and a higher adrenal medulla weight in PERM lambs compared to CONT lambs (P < 0.05). However, no differences were observed between treatments in heart-rate, basal plasma cortisol concentration and tyrosine hydroxylase and phenylethanolamine-Nmethyl transferase activities. Carcass yield, temperature and the pH of the M. longissimus dorsi were not modified by voltage exposure during rearing. In the good carcass conformation class (R class in EUROP grading scheme), there were fewer fat carcasses (grade 4 of 5) in the PERM and RAND compared to the CONT group (P < 0.05). In conclusion, no major effects of voltage exposure were observed in male lambs on production, carcass parameters and stress physiology. Stray voltage could be considered as a mild stressor in growing–finishing lambs.

Consequences of low electrical currents on the welfare of dairy cattle. Emphasis on individual variability When heifers were exposed to an electrical current which voltage was increased daily, a short-term persistent reaction threshold of 2.3 V (3.5 mA) was observed, despite a large individual variability. In the medium-term, a multi-criteria experimental approach in dairy cows exposed to a permanent (predictable) or random (unpredictable) voltage of 1.8 V (3.6 mA) on the water trough showed no modification of the amount and composition of milk, although a transient acute stress response was observed. Cows exposed permanently to the voltage became habituated to it, whereas those exposed unpredictably may have shown signs of a mild chronic stress. The individual variability of the cow resistance could explain the differences in behavioural responses. In farms, it is important to reduce the presence of stray voltage, even of low level, as they may affect animal welfare., Lors de l’application d’une tension électrique augmentée progressivement chaque jour, un seuil de réaction persistante de 2,3 V (3,5 mA) a été mis en évidence à court terme chez des génisses, malgré une forte variabilité individuelle. À moyen terme, une analyse multicritère a montré que l’exposition de vaches laitières, de manière permanente (prévisible) ou aléatoire (imprévisible), à une tension de 1,8 V (3,6 mA) au niveau de l’abreuvoir n’a pas modifié la quantité de lait produite ni sa composition, bien qu’une réponse de stress aigu transitoire ait été observée. Les vaches exposées de manière permanente se sont habituées, contrairement aux vaches exposées de manière imprévisible chez lesquelles la présence d’un stress chronique modéré est envisagée. La variabilité individuelle de résistance des vaches pourrait expliquer la variabilité des réponses comportementales. En élevage, il est important de limiter la présence de tensions parasites, même de faible niveau, qui pourraient perturber le bien-être des animaux., Rigalma Karim, Roussel Sabine, Deschamps François, Duvaux-Ponter Christine. Conséquences de faibles courants électriques sur le bien-être de bovins laitiers. Prise en compte de la variabilité individuelle. In: Bulletin de l'Académie Vétérinaire de France tome 163 n°3, 2010. pp. 251-255.

L’élevage des animaux de rente implique une utilisation croissante d’équipements électriques et électroniques ainsi que le recours à du matériel et à des structures métalliques qui sont autant de facteurs favorisant l’apparition des courants électriques parasites. Les tensions à l’origine de ces courants, généralement inférieures à 10 volts, sont dues principalement à un défaut de mise à la terre et à une mauvaise équipotentialité des masses métalliques. Les animaux, en raison d’une faible résistance électrique, sont sensibles à ces faibles tensions électriques. Le contact direct du nez (mufle, groin) et des pattes avec le milieu humide diminue leur résistance au courant électrique alors que, chez l’homme, le port d’équipements de protection comme les bottes en caoutchouc augmente cette résistance. En élevage, les tensions électriques parasites sont parfois mises en cause lorsque des modifications comportementales, une dégradation de l’état sanitaire ou des baisses de production sont observées chez les animaux. Cependant, les expérimentations menées en milieu contrôlé montrent rarement un effet direct des tensions électriques parasites sur les paramètres zootechniques bien que des modifications comportementales et physiologiques, probablement liées à la présence d’un stress, soient parfois mises en évidence. La grande variabilité de réponse des animaux et le caractère imprévisible des tensions électriques parasites expliquent les difficultés à les diagnostiquer et à caractériser leurs effets sur les animaux en élevage., Modern farming techniques involve an increasing use of electrical and electronic equipment together with metallic features which can be responsible for stray-voltage. Stray-voltage, less than 10 volts, is often due to a faulty connection between the electrical circuit and the earth. Animals, due to a lower electrical resistance than humans, are more sensitive to these low voltages. Moreover, direct contact of the muzzle and hooves with often wet surroundings reduces their resistance to electric current, whereas in man, the fact of wearing protective gloves and rubber boots increases this resistance. In farms, when animal behaviour modifications, deterioration of health status or reductions in production are observed, stray-voltage is sometimes implicated. However, experiments conducted under controlled conditions rarely show the effects of stray-voltage on production parameters. Nevertheless, some behavioural and physiological changes, probably related to the presence of stress, are often observed. The unpredictability of stray-voltage and the great variability in the response to stray-voltage exposure make diagnosis and characterisation of its effects in farm animals difficult.

The aim of this study was to compare rumen pH and time-budget in eight mid-lactation goats receiving two diets in a cross-over design (low-concentrate diet (L): 30% and high-concentrate diet (H): 60% concentrate). Feeding H increased daily intake (4.3 +/- 0.08% v. 4.7 +/- 0.08% of body weight for L and H, respectively) and daily milk production (3.01 +/- 0.130 v. 3.50 +/- 0.130 kg/day of 3.5% fat-correaed milk for L and H, respectively). It decreased milk fat and inverted the fat-to-protein ratio (1.07 +/- 0.054 v. 0.94 +/- 0.054 for L and H, respectively). As suggested by the percentage of time spent with rumen pH below 6.0 (23.4 +/- 6.60% v. 39.9 +/- 5.88% for L and H, respectively), H was more acidogenic than L. When offered H instead of L, goats spent less time eating (298 +/- 17.5 v. 265 +/- 17.5 min for L and H, respectively) and ruminating (521 +/- 21.0 v. 421 +/- 21.0 min for L and H, respectively) but more time resting (352 +/- 27.1 v. 459 +/- 21.1 min for L and H, respectively) over a 24-h period. They also tended to spend more time drinking (20 +/- 2.9 v. 25 2.9 min for L and H, respectively; P = 0.08) when offered H rather than L. These differences in activities were mainly observed during the first hours following feeding. When offered H, goats adapted their feeding behaviour around the feedings, which allowed them to limit the physiological disturbances potentially inducible by H and to increase milk production, without experiencing too much acidosis.

The requirements for polyunsaturated fatty acids during brain development are high and in certain situations supply may be inadequate. Numerous studies in rodents have shown that it diet rich in linolenic acid improves learning ability and modifies emotional reactivity of offspring. Thirty-two goats received from 1.5 months before to 2 months after parturition either a control supplement (C, rapeseed supplement, n = 16), rich in oleic acid (C 18: 1 n - 9) or a test supplement (L, linseed supplement, n = 16), rich in linolenic acid (C18:3n - 3). At birth the profile of fatty acids was measured in blood, mammary secretions and tissue samples from the goats and their kids. After birth the kids were fed a mixture of milk obtained from the same treatment group as their dam and their emotional reactivity and learning ability were studied. The profile of fatty acids was also measured in goat milk and kid plasma. Plasma proportions of linolenic acid, eicosapentaenoic acid (C20:5n - 3) and docosahexaenoic acid (C22:6n - 3) were increased (P < 0.05) and arachidonic acid (C20:4n - 6) decreased (P < 0.01) by L compared to C in goats and kids at birth. At I I days. L kids spent more time sniffing the environment (P < 0.01) and less time immobile (P < 0.05) in a novel environment and passed more frequently next to the novel object (P < 0.05). The kids also tended to spend more time watching the object (P = 0.079) and tended to delay the first vocalisation with mouth open (P = 0.070) compared to C kids. Learning ability in a T-maze test at 46 days and the reaction to a startling stimulus at 48 days were unaffected by treatment. In conclusion, a diet rich in linseed given to gestating and lactating goats seems to increase the attention/exploration of their kids at 11 days without affecting their learning ability. (C) 2008 Elsevier B.V. All rights reserved.