Eurotium cristatum, a potential probiotic fungus from Fuzhuan brick tea, alleviated obesity in mice by modulating gut microbiota.

Obesity is one of the major public health problems worldwide, mainly resulting from unhealthy lifestyles and diet. Gut microbiota dysbiosis may lead to obese humans and animals. Modulating gut bacteria through probiotics or certain dietary supplements could normalize gut microbiota and subsequently alleviate obesity. The daily consumption of Fuzhuan brick tea (FBT) or its extracts has been observed to alleviate obesity in humans and experimental animals. In this study, high-fat diet (HFD)-induced obesity in mice, such as body weight gain and fat accumulation, was prevented by the consumption of Eurotium cristatum, the dominant fungus during the manufacturing and storage of FBT. The dysbiosis of gut microbiota in C57BL/6J mice was also partially normalized. E. cristatum was able to modulate both gut fungal and bacterial compositions, based on the analysis of the microbiota composition of mice fecal samples (n = 5). E. cristatum increased acetate and butyrate-producing bacteria in mouse gut. There was five times more butyrate in the fecal samples from mice fed with E. cristatum than that from untreated HFD mice. Our results suggest that E. cristatum may be used as a probiotic fungus to alleviate obesity and to modulate gut microbiota in humans beneficially.

Selection of sourdough lactobacilli with antifungal activity for use as biopreservatives in bakery products.

Two hundred and sixteen LAB cultures from sourdoughs and dough for bread and panettone production were screened for in vitro antifungal properties against three indicator cultures ascribed to Aspergillus japonicus , Eurotium repens , and Penicillium roseopurpureum , isolated from bakery environment and moldy panettone. Nineteen preselected isolates were subjected to minimum inhibitory concentration determination against the indicator cultures. Sourdoughs prepared with the two most promising strains, identified as Lactobacillus rossiae LD108 and Lactobacillus paralimentarius PB127, were characterized. The sourdough extracts were subjected to HPLC analysis coupled with a microtiter plate bioassay against A. japonicus to identify the active fractions. MALDI-TOF MS analysis revealed the occurrence of a series of peptides corresponding to wheat α-gliadin proteolysis fragments in the active fraction from L. rossiae LD108 sourdough. The ability to prevent mold growth on bread was demonstrated for both strains, whereas L. rossiae LD108 also inhibited mold growth on panettone.

Variable beta-glucans production by different states of Eurotium amstelodami explains differences in inflammatory responses in airway cells.

Eurotium amstelodami, a mold frequently identified in housing and farm air samples, is a suspected cause of respiratory diseases such as allergic alveolitis, atopic asthma, and organic dust toxic syndrome. This fungus is present in the air in three different states (ascospores, conidia, and hyphae). The aim of this study was to test in vitro the differential inflammatory response of airway cells exposed to 1,3 betaglucanase-treated protein extract (BGPE), from E. amstelodami ascospores, conidia, and hyphae. Confluent cells from the A549 cell line were inoculated with calibrated BGPE issued from the three fungal forms. The levels of eight cytokines and chemokines involved in inflammatory responses were measured after 8 h of exposure. Beta-d-glucan (BDG) was quantified in total fungal extract as well as in the BGPE from the three fungal states. Hyphal BGPE were the only ones to induce a marked inflammatory response and they contain higher quantities of BDG. The present study adds to the growing body of evidence that beta-glucan from fungal hyphae play a crucial role in respiratory diseases.

Concentration of the genera Aspergillus, Eurotium and Penicillium in 63-microm house dust fraction as a method to predict hidden moisture damage in homes.

BACKGROUND: Quantitative measurements of mould enrichment of indoor air or house dust might be suitable surrogates to evaluate present but hidden moisture damage. Our intent was to develop a house-dust monitoring method to detect hidden moisture damage excluding the influence of outdoor air, accumulated old dust, and dust swirled up from room surfaces. METHODS: Based on standardized measurement of mould spores in the 63-microm fraction of house dust yielded by carpets, the background concentrations were determined and compared to simultaneously obtained colony numbers and total spore numbers of the indoor air in 80 non-mouldy living areas during summer and winter periods. Additionally, sampling with a vacuum-cleaner or manual sieve was compared to sampling with a filter holder or sieving machine, and the evaluative power of an established two-step assessment model (lower and upper limits) was compared to that of a one-step model (one limit) in order to derive concentration limits for mould load in house dust. RESULTS: Comparison with existing evaluation procedures proved the developed method to be the most reliable means of evaluating hidden moisture damage, yielding the lowest false-positive results (specificity 98.7%). Background measurements and measurements in 14 mouldy rooms show that even by evaluating just the indicator genera in summer and winter, a relatively certain assessment of mould infestation is possible. CONCLUSION: A one-step evaluation is finally possible for house dust. The house-dust evaluation method is based on analysis of the indicator genera Aspergillus, Eurotium and Penicillium spp., which depend on the total fungal count. Inclusion of further moisture indicators currently appears questionable, because of outdoor air influence and the paucity of measurements.

Inactivation of food spoilage fungi by ultra violet (UVC) irradiation.

The effect of ultraviolet irradiation (254 nm, UVC) on Aspergillus flavus, Aspergillus niger, Penicillium corylophilum and Eurotium rubrum was investigated using three different exposure techniques. Survival was determined for spores suspended in liquid medium after 1, 2 and 3 min UVC exposure at 4644 J/m(2)/min. The same UVC dose was applied to spores on the surface of agar plates for 5, 10, 15, 30, 60 and 120 s. Spores of A. niger were dried onto a membrane filter, then exposed to UVC treatment. In the liquid medium, treatments from 1-3 min significantly (P<0.001) reduce the number of viable spores. On the surface of agar plates, after a 15 s exposure, a 80-99% reduction of viable spores was observed for all species except A. niger, for which the reduction was only 62%. For spores dried onto filter membranes, a 3.5 log(10) reduction was achieved for A. niger after 180 s exposure. These observations suggest that UVC irradiation can effectively inactivate spores of A. flavus, P. corylophilum, E. rubrum and A. niger but the efficacy of UVC radiation against fungal spores varies significantly according to methods of exposure to the irradiation, and among genera.