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Fuel ethanol production, using a simultaneous saccharification and fermentation process (SSF) of native starch from corn flour, has been performed using Saccharomyces cerevisiae and a granular starch hydrolyzing enzyme. The quantitative effects of mash concentration, enzyme dose and pH were investigated with the use of a Box-Wilson central composite design protocol. Proceeding from results obtained in optimal fermentation conditions, a kinetics model relating the utilization rates of starch and glucose as well as the production rates of ethanol and biomass was tested. Moreover, scanning electron microscopy (SEM) was applied to investigate corn starch granule surface after the SFF process. A maximum ethanol concentration of 110.36 g/l was obtained for native corn starch using a mash concentration of 25%, which resulted in ethanol yield of 85.71%. The optimal conditions for the above yield were found with an enzyme dose of 2.05 ml/kg and pH of 5.0. These results indicate that by using a central composite design, it is possible to determine optimal values of the fermentation parameters for maximum ethanol production. The investigated kinetics model can be used to describe SSF process conducted with granular starch hydrolyzing enzymes. The SEM micrographs reveal randomly distributed holes on the surface of granules.

A public motor road net crossing forest complexes influences the natural environment to a very high degree. Soils in roadside forest ecotone zones constitute a certain filter buffering chemical contamination generated by motor traffic. The aim of the paper is to present the methods of identification of transport contaminants influencing the roadside stand condition. The results of monitoring roadside ecotone zones indicate the necessity of applying such technical appliances as oil‐derivative separators, filtering screens or geomembranes close to motor roads to limit the migration of chemical compounds and preserve the homeostasis of precious natural forest complexes.

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The forest cover in Poland reaches almost 30% of the country’s area. Polish forests are characterized by high biodiversity. Unfortunately, in recent years, the forests of Central Europe have been affected by climate change problems, in particular meteorological drought. In Poland, even those stands which consist of species that were widely recognized as drought tolerant and easily adaptable to environmental changes are beginning to die. The article presents engineering methods applicable to forest environment protection, largely developed at the University of Life Sciences in Poznań and implemented by the State Forests—National Forest Holding in Poland, to minimize the effects of drought. Among the issues raised are ways to protect forests against fires, modern technologies for fire road surface construction and small-scale water retention in forests. A comprehensive solution to problems related to progressive drought is a must. Scientists and foresters are observing the dying of large areas of stands and, at the same time, intensification of wildlife migration due to the search for new habitats as a consequence of the drought. Therefore, the issue of building animal crossings during the current dynamic expansion of the road network in Poland has also been presented in the paper. Another subject pointed to in the text is forest tourism. Forests provide opportunities for recreation and rest to society. However, the increasing tourist pressure in some regions may cause adverse environmental effects. Finally, the paper shows some examples of supporting forest environment protection using remote sensing techniques. Generally, the aim of the paper is to present experiences and comprehensive solutions implemented in Poland.