BIOTECHNOLOGY AS A USEFUL TOOL FOR NUTRITIONAL IMPROVEMENT OF CEREAL-BASED MATERIALS ENRICHED WITH POLYUNSATURATED FATTY ACIDS AND PIGMENTS

Cereals represent a major food supply for humanity. Although these sources are rich in proteins and carbohydrates, many of them are deficient in several essential nutrients, such as polyunsaturated fatty acids (PUFAs) and carotenoid pigments. One possible approach how to enhance the content of PUFAs or carotenoids in cereal diet is based on biotechnological transformation of cereal materials by solid state fermentations. This technique is powerful tool for effective valorisation of these resources to various types of value-added bioproducts with demanded properties and functions. Selected filamentous Mucorales fungi were applied for conversion of numerous agroindustrial substrates to bioproducts enriched with PUFAs, such as gamma-linolenic acid (GLA), dihomo-gamma-linolenic acid (DGLA), arachidonic acid (AA) and eicosapentaenoic acid (EPA). On the other hand, a range of yeast species utilizing agroindustrial substrates were employed for formation of carotenoids, such as β-carotene, torulene, torularhodine and astaxanthin. Such naturally prepared cereal based bioproducts enriched with either PUFAs or carotenoid pigments may be used as an inexpensive food and feed supplement. The work was supported by grant VEGA No. 1/0747/08 from the Grant Agency of Ministry of Education, Slovak Republic

Analysis of the Properties of EN AC 51200 Aluminum Alloy

The article will be focused on analysis of properties of aluminum alloy for the casting of type Al-Mg. As an experimental material was used aluminum alloy EN AC 51200, supplied in a cast state without a heat treatment. It was produced by the continuous casting method. Experiments deal with microstructural material analysis, fractographic analysis, mechanical and fatigue tests. The microstructure of the testing sample was examined using an optical microscope Neophot 32. Fatigue properties of aluminum alloy was tested by three-point bending cyclic loading. The fracture surface of the testing sample was examined using scanning electron microscopy (SEM), where sample was observed on various stages of the fatigue process, its characteristics and differences of fracture surfaces

Response of spring barley cultivars to Ramularia leaf spot in conditions of the Czech Republic

The fungus Ramularia collo-cygni is increasingly important as the causal agent of Ramularia leaf spot (RLS). The work aimed to identify gene resources suitable for developing new breeding lines of spring barley with improved resistance. We tested 144 spring barley cultivars at 3 locations in the Czech Republic over 3 years (2009–2011). Only minor and statistically insignificant differences were observed between the individual cultivars in reaction to RLS. No cultivars were observed to have resistance to Ramularia collo-cygni, but significant influence of location and year on the intensity of RLS infection in barley was observed

Biotechnological production and application of the antibiotic pimaricin: biosynthesis and its regulation

Pimaricin (natamycin) is a small polyene macrolide antibiotic used worldwide. This efficient antimycotic and antiprotozoal agent, produced by several soil bacterial species of the genus Streptomyces, has found application in human therapy, in the food and beverage industries and as pesticide. It displays a broad spectrum of activity, targeting ergosterol but bearing a particular mode of action different to other polyene macrolides. The biosynthesis of this only antifungal agent with a GRAS status has been thoroughly studied, which has permitted the manipulation of producers to engineer the biosynthetic gene clusters in order to generate several analogues. Regulation of its production has been largely unveiled, constituting a model for other polyenes and setting the leads for optimizing the production of these valuable compounds. This review describes and discusses the molecular genetics, uses, mode of action, analogue generation, regulation and strategies for increasing pimaricin production yields