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The microbiological activity of hydrogenic (developed from peats) soils from the Wizna and Kuwasy bogs was determinated. Different origin and various degree of organic matter transformation of these soils differently affected their microbial activity (microorganisms populations, enzyme activity and the degree of mineralization of nitrogen compounds).
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Oporność drobnoustrojów na negatywny wpływ wysokiej temperatury uwarunkowana jest oddziaływaniem szeregu czynników, do których zaliczyć można między innymi warunki środowiskowe, panujące podczas hodowli, takie jak: np. skład chemiczny podłoża czy jego odczyn. Wyniki badań przeprowadzonych przez wielu niezależnych autorów wskazują, że zdolność do wzrostu i rozwoju w warunkach wysokich temperatur drobnoustroje termofilne zawdzięczają przede wszystkim specyficznym właściwościom biochemiczno-fizjologicznym komórek, a w mniejszym stopniu ich budowie morfologicznej.
The year 2010 marks the 100th anniversary of Robert Koch’s death. His name is well known as one of the founders of modern microbiology, the discoverer of the etiologic agents of anthrax, tuberculosis, cholera and wound infection. What is equally important, he developed the methodologies and concepts that made microbiology a scientific discipline. He is best known for having developed the rules, or postulates, that determine the specific agent of an infectious disease. Koch’s postulates were a landmark in medical microbiology because they could be used to prove beyond any doubt that specific bacteria were the cause of an infectious disease. However, significant limitations to the postulates were soon recognized and restricted their wider scientific application. Now, over a century later, a more rigorous method to test causability still has to be developed. Technological advances led to the discovery of viruses, prions and new classes of bacteria that cannot fulfill Koch’s postulates. Advances in molecular microbiology have demonstrated that virtually all microorganisms can be considered opportunistic. They constantly turn their virulence genes on and off in a context-dependent manner to acquire unique phenotypes. They have evolved sophisticated mechanisms to sense changes in the environment and respond accordingly when their survival is threatened. Local environmental cues are gathered by bacteria at the membrane level and transmitted do deeper circuits within their cytoplasm, where they are processed by another sensing system, known as the quorum sensing signaling system. As a result of the processing of environmental information, the bacteria shift their phenotype to adjust better to the local conditions, resulting in either pathogenic or non-pathogenic behavior. Infectious pathogenesis is dictated by the chemical crosstalk between the complex network of bacteria- -bacteria, host-bacteria, and host-host. The ability of bacteria to intercommunicate and process information about resource availability and the health status of the host has led to the concept of bacteria behaving like a social group. The study of social networks developed among bacteria in their natural habitats is called sociomicrobiology.
Aura
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1994
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nr 02
7-9
Microorganisms, represented by viruses, bacteria, fungi and algae (cyanophytes) are of critical importance to life and life processes on Earth. Microorganisms participate directly and indirectly in life processes of all higher organisms, and they occur everywhere: in soil, water and air. They are involved in biochemical processes of decomposition and mineralization of soil organic compounds, in mobilizing mineral nutrients, in cycling chemical elements, in fixing atmospheric nitrogen, in syntheses of biologically active substances, in plant nutrition etc. By their role in functions of all terrestrial systems the microorganisms participate in development, conservation and maintenance of the natural environment. The author discusses principles of the function of microorganisms in soil, gives account of their significance in affecting and protecting human health, in food processing and in conservation of the natural environment.
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