It was found in long-term incubation experiments (100 weeks) that in soil non amended with organic compounds, mineralization proceeded in a steady state after an initial reactive respiration and corresponded approximately to the rate of mineralization of soil organic matter under natural conditions. The addition of nitrogen influenced this mineralization process only very slightly. The addition of starch decreased the stability of organic compounds in the soil at first but the newly formed organic substances were gradually stabilized again. The addition of nitrogen to starch increased the extent and the rate of these alterations. The overall extent of mineralization of the substrate after the addition of starch alone exceeds the amount of the added substrate; a small accumulation of the substrate could be observed after the addition of starch together with nitrogen.

• MeSH
• Biotransformation MeSH
• Depression, Chemical MeSH
• Stimulation, Chemical MeSH
• Nitrogen metabolism   pharmacology   MeSH
• Fertilizers MeSH
• Soil Microbiology * MeSH
• Starch pharmacology   MeSH
• Carbon metabolism   MeSH
• Publication type
• Journal Article MeSH
• Comparative Study MeSH
• Names of Substances
• Nitrogen MeSH
• Fertilizers MeSH
• Starch MeSH
• Carbon MeSH

Mineralization of native organic matter and U-14C-glucose was followed by measuring the formation of CO2 and its radioactivity in chernozem soil presterilized by gamma-radiation and inoculated with a washed suspension of Cellulomonas sp. cells. The introduced bacteria mineralized the soil organic component to a higher extent in variants enriched with glucose. This so-called priming effect of glucose was observed also in the presence of chloramphenicol, inhibiting the growth of the bacteria. The increased mineralization of the native soil organic fraction was also detected in samples that were not enriched with glucose when the bacterial suspension was first disintegrated ultrasonically and the material then used for the inoculation. Possible participation of phenomena of the type of cometabolism and activation of cell membrane transport mechanisms on the occurrence of the priming effect of glucose in the soil is discussed.

• MeSH
• Actinomycetales drug effects   growth & development   metabolism   MeSH
• Depression, Chemical MeSH
• Chloramphenicol pharmacology   MeSH
• Glucose pharmacology   MeSH
• Culture Techniques MeSH
• Carbon Dioxide biosynthesis   MeSH
• Fertilizers MeSH
• Soil Microbiology * MeSH
• Sterilization MeSH
• Gamma Rays MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Chloramphenicol MeSH
• Glucose MeSH
• Carbon Dioxide MeSH
• Fertilizers MeSH

Decomposition of preparations of various fractions of fulvic acids in pure cultures of bacteria and in the soil was investigated. In the soils enriched with fulvic acids the amount of bacteria increased, oxygen consumption and formation of carbon dioxide followed a typical sigmoid curve. The above measurements indicated that mineralization occurred after a very short or negligible lag phase. During the decomposition of fulvic acids the ability of microorganisms to oxidize aromatic compounds, e.g. vanillic and p-hydroxybenzoic acid, increased. The presence of aromatic structures in the used preparations of fulvic acids was demonstrated on the basis of their IR spectra and according to the results of chromatographic analyses of their hydrolysates. The results indicated a relationship between metabolism of fulvic acids and aromatic compounds. In samples of the soil preincubated with glucose with fulvic acids decomposed more rapidly than in untreated samples.

• MeSH
• Bacteria metabolism   MeSH
• Benzopyrans metabolism   MeSH
• Biodegradation, Environmental MeSH
• Hydroxybenzoates metabolism   MeSH
• Vanillic Acid metabolism   MeSH
• Carbon Dioxide biosynthesis   MeSH
• Soil Microbiology * MeSH
• Oxygen Consumption MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Benzopyrans MeSH
• Hydroxybenzoates MeSH
• Vanillic Acid MeSH
• Carbon Dioxide MeSH