The application of microparticle‐enhanced cultivation (MPEC) is an attractive method to control mycelial morphology, and thus enhance the production of metabolites and enzymes in the submerged cultivations of filamentous fungi. Unfortunately, most literature data deals with the spore‐agglomerating species like aspergilli. Therefore, the detailed quantitative study of the morphological evolution of four different fungal species (Aspergillus terreus, Penicillium rubens, Chaetomium globosum, and Mucor racemosus) based on the digital analysis of microscopic images was presented in this paper. In accordance with the current knowledge, these species exhibit different mechanisms of agglomerates formation. The standard submerged shake flask cultivations (as a reference) and MPEC involving 10 μm aluminum oxide microparticles (6 g·L−1) were performed. The morphological parameters, including mean projected area, elongation, roughness, and morphology number were determined for the mycelial objects within the first 24 hr of growth. It occurred that heretofore observed and widely discussed effect of microparticles on fungi, namely the decrease in pellet size, was not observed for the species whose pellet formation mechanism is different from spore agglomeration. In the MPEC, C. globosum developed core‐shell pellets, and M. racemosus, a nonagglomerative species, formed the relatively larger, compared to standard cultures, pellets with distinct cores.

Some molds commonly occurring in the natural environment produce mycotoxins in the process of secondary metabolism. Aspergillus flavus and A. parasiticus are species of molds, which are responsible for the production of aflatoxins and are crucial in the pathogenesis of human diseases. Aspergillus species present in decaying plants, the soil and their spores are transferred via air currents and insects to crops and food storages. Aflatoxins B1, B2, G1, G2, M1 and M2 are the most common derivatives of aflatoxins. Ingestion of contaminated food is the main source of exposure to aflatoxins, which adversely affect the health of both humans and animals. The compounds can cause acute or chronic toxic effects of a teratogenic, mutagenic, carcinogenic, immunotoxic or hepatotoxic character. Molecular aflatoxins affect DNA mutations, postranslation peptids chains modification, proteins and nucleic acids methylation and the formation of free radicals.Due to aflatoxins carcinogenic features and frequent occurrence in food and forages they are routinely examinated in some groceries and agricultural products.

No abstract

No abstract

No abstract

Biosynthesis of metabolites and enzymes by filamentous fungi depends on their morphological form in submerged cultures. However, their early stages of growth lasting approximately 24 h, from the introduction of spores to the medium until the formation of stable morphological forms, such as clumps or pellets, have rarely been the objects of experimental and modeling studies. Microparticle‐enhanced cultivation (MPEC) has been applied only to a few fungal species, mainly Aspergilli. Therefore, the objective of this work was to formulate the kinetic model to describe the early stages of the fungal evolution in the standard cultivation and MPEC for Aspergillus terreus, Chaetomium globosum, Penicillium rubens, and Mucor racemosus. These fungi exhibit various mechanisms of agglomerates formation in submerged cultures. The experiments were performed in batch shake flasks (parameters identification) and a stirred tank bioreactor (model verification). In the balance equation for fungal cells, the mean projected area of hyphal objects measured by the digital analysis of microscopic images was used as the dependent variable. The analysis of the experimental data and model solution revealed that the effect of the microparticles (aluminum oxide at 6 g L−1) in MPEC toward the studied filamentous fungi was to the high extent species dependent. This effect was most evident in the case of spore coagulative A. terreus and noncoagulative M. racemosus.

It is the first detailed study of an inulinolytic fungus Aspergillus niger ATCC 204447 since its discovery, covering submerged cultivations both in shake flasks and a stirred tank bioreactor. Various carbon sources were applied to induce the inulinolytic activity in shake flask cultures. The highest volumetric and specific (per gram of biomass) activities (respectively 0.68 U/mL and 184 U g/X) were observed for the initial inulin and sucrose concentrations equal to 20 g/L. The fungus grew as large (>3 mm) spherical pellets. The influence of inoculum density and application of microparticle‐enhanced cultivation (MPEC) were studied in the batch bioreactor cultivations. Inoculum density moderately affected the inulinolytic activities, whose highest values were 0.7 U/mL and 165 U g/X at the lowest studied spore density of 3.33·108 L−1. Dispersed hyphae evolved in the bioreactor made the broth difficult to aerate due to high apparent viscosity (exceeding 200 Pa sn at shear rate about 0.05 s−1) and shear thinned properties (flow behavior index below 0.2). In MPEC (10 μm talc microparticles) the pellets of diameter between 1 and 2 mm were formed, which facilitated the aeration of the broth and increased the specific inulinolytic activity 3.5‐fold.

The article is focused on the international competitive position of V4 countries in the foreign trade of agri-food industry products. The V4 countries' accession to the EU significantly changed exporters and importers' situation in these countries, providing them with better access to numerous markets. Integrating them into the single internal market area promoted trade and resulted in an increase of intra-EU exports and imports. The agri-food products market strongly benefited from such an opportunity, which was significantly limited before 2004 by duties and quotas. The article presents changes in international trade in agri-food products in the V4 countries and their competitiveness. We employ share of the analyzed country in global exports (EMS), import-export coverage (TC), revealed comparative advantages (RCA), and the intensity of intra-industry trade Grubel-Lloyd Index (GL) to assess the competitiveness. Our results show that Poland performed the best in international trade in agri-food products among the V4 countries. The result was confirmed by partial indicators and the total competitiveness index.