Soil is one of the natural habitats of microorganisms that are significantly involved in the continuous transformation of organic and inorganic substances. The issues currently faced by this area of research are based on the occurrence of extraneous synthetic substances (xenobiotics) in the environment. These xenobiotics do not have a natural origin but have been artificially synthesized by humans. The contamination of the xenobiotic environment occurs with the development of human economic activity (industry and agriculture); xenobiotics are resistant to degradation processes, accumulate in soil and act on microorganisms. Biogenic substances are, by way of exception, easily decomposable. Few studies have been conducted to analyze the relationship between the occurrence of biogenic and xenobiotic substances in soil and their effects on microorganisms. The aim of this dissertation was to gain knowledge about the influence of biogenic and xenobiotic substances on the metabolism of soil microorganisms and to improve the procedures used to evaluate the influence of chemicals applied to the soil. This dissertation is also devoted to the study of soil enzymes. The dissertation is divided into two parts. The first theoretical part is further divided into: a) a review article on adsorption of enzymes to the solid soil component and factors limiting their activity. This review article summarizes some of the important findings published in the scientific literature and provides information on adsorption of enzymes to the solid soil component and factors limiting their activity. The first part of this review article discusses in particular the problems of enzyme interactions with the solid soil component and enzyme adsorption kinetics. In the second part of this paper I deal with the issue of factors that can affect the activity of adsorbed enzymes (b) An overview on lignin. This review article summarizes the knowledge about the chemical composition of lignin and its content in forest soils, lignin biodegradation and microorganisms producing ligninolytic enzymes; lignin peroxidase, manganese-dependent peroxidase and other versatile peroxidases are amongst the most conspicuous ligninolytic enzymes. (c) An article on the influence of agrochemicals on soil and soil micro-organisms. The aim of this review article was to summarize the knowledge of the influence of agrochemicals on sustainability and soil health. The second experimental part contains knowledge about the effects of xenobiotic (chlortetracycline and sulfapyridine) and biogenic substances (ascorbic acid and amino acids) on soil microorganisms. The results obtained showed the effect of chlortetracycline and sulfapyridine on the activity of soil enzymes depending on the enzyme studied and the antibiotic used. Within this experimental part, the influence of oxytetracycline and sulfamethoxazole on the structure and function of the microbial community in the soil was also studied. The results obtained showed the different effects of both tested antibiotics on cumulative respiration and carbon microbial biomass in soil. In the framework of this dissertation, a study of respiration of forest soils after application of ascorbic acid and amino acids was also carried out. The results obtained from these experiments showed an increase in respiratory activity after administration of ascorbic acid or ascorbic acid in combination with amino acids, depending on the properties of the soil samples tested; maximum respiratory activity in acidic soils was induced after the addition of L-glutamic acid and alkaline soils after the addition of beta-alanine. The size of the mesh holes has a significant effect on soil disturbance that affects pore structure, fungal hyphae, fungal fraction and bacterial fraction. The effects are dependent on the soil type and the vegetation cover. Sifting through 2 mm sieve increases the mineralization of exogenously supplied carbohydrates and phenolic substances compared to 5 mm and the sieve of significant importance (p <0.05), especially in organic horizons, due to increased microbial metabolism and changes in other soil properties.
| Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:425087 |
| Date | January 2018 |
| Creators | Datta, Rahul |
| Source Sets | Czech ETDs |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/doctoralThesis |
| Rights | info:eu-repo/semantics/restrictedAccess |
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