| 1. |
- Andrén, O., et al.
(författare)
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Barley straw decomposition with varied levels of microbial grazing by Folsomia fimetaria (L.) (Collembola, Isotomidae)
- 1985
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Ingår i: Oecologia. - : Springer-Verlag New York. - 0029-8549 .- 1432-1939. ; 68:1, s. 57-62
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Tidskriftsartikel (refereegranskat)abstract
- Folsomia fimetaria (L.) were added (0, 5, 10, 20 animals) to 0.100 g barley straw which had been inoculated 10 days (244 h) earlier with a natural soil microflora. Respiration (CO2 evolution) was monitored continuously. Mass loss, fungal standing crop (total and FDA-active), bacterial and protozoan biomass were estimated 42 days (1,000 h) after microbial inoculation. The degree of surface cover by hyphae was surveyed at regular intervals. No significant differences (P>0.05) were found in respiration, mass loss or microbial biomass, but the density of surface hyphae were reduced by addition of Collembola. Fungal production was low, less than 5% of the estimated microbial production, and could not account for all collembolan growth during incubation. F. fimetaria appeared to consume mainly bacteria and protozoa, and had little impact on carbon mineralization.
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| 2. |
- Schnürer, Johan, 1957-, et al.
(författare)
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Effects of moisture on soil microorganisms and nematodes : A field experiment
- 1986
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Ingår i: Microbial Ecology. - : Springer-Verlag New York. - 0095-3628 .- 1432-184X. ; 12:2, s. 217-230
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Tidskriftsartikel (refereegranskat)abstract
- The effects of soil moisture changes on bacteria, fungi, protozoa, and nematodes and changes in oxygen consumption were studied in a field experiment. In one plot the soil was drip-irrigated daily for 10 days, while an adjacent plot experienced one rainfall and was then allowed to dry out. Oxygen consumption was the parameter measured which responded most rapidly to changes in soil moisture content. Lengths of fluorescein diacetate-active hyphae paralleled oxygen consumption in both plots. Total hyphal length was not affected by one rainfall but increased from 700 mg-1 dry weight soil to more than 1,600 m in less than 10 days in the irrigated plot. In the rain plot, bacterial numbers doubled within 3 days and declined during the following period of drought. In the irrigated plot, numbers increased by 50% and then remained constant over the duration of the study. Only small changes in protozoan numbers were observed, with the exception of the last sampling date in the irrigated plot when large numbers of naked amoebae were recorded 2 days after a large natural rainfall. Nematode numbers, especially obligate root feeders, increased in both treatments. The increases were caused by decoiling rather than growth. The results indicate that fungal respiration was dominating, while bacteria, lacking a suitable source of energy, were less active, except for the first days.
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| 3. |
- Schnürer, Johan, 1957-, et al.
(författare)
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Fungi, bacteria and protozoa in soil from four arable cropping systems
- 1986
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Ingår i: Biology and Fertility of Soils. - New York : Springer. - 0178-2762 .- 1432-0789. ; 2:3, s. 119-126
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Tidskriftsartikel (refereegranskat)abstract
- The effects of four cropping systems on soil microorganisms were investigated during 3 years. The cropping systems were B0, barley without nitrogen fertilizers; B120, barley with 120 kg N ha-1 year-1; GL, grass ley receiving 200 kg N ha-1 year-1; and LL, lucerne ley without nitrogen fertilizer additions. At samplings in September during three consecutive years no differences were found between treatments. Total fungal lengths ranged between 0.7 and 2.0 × 103 m and bacterial numbers between 3.5 and 7.2 × 109 g-1 dry wt. soil.Twenty samplings over 3 years in B120 and in GL indicated higher numbers of bacteria and protozoa during the growing season, except for periods with moisture stress. No clear seasonal trends were found for the fungi. When comparing mean values for the 20 samplings, the grass ley contained significantly (P < 0.05) higher numbers of amoebae. Means of the bacterial numbers and biomass, total and FDA-active hyphal lengths were also higher or equal (FDA-active hyphae) but not significantly so.Seventy-nine per cent of the bacterial biomass and 73% of the total fungal lengths were found in the top soil, where also 85% of the oxygen was consumed.
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| 4. |
- Schnürer, Johan, 1957-, et al.
(författare)
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Inhibitory effects of foscarnet on herpesvirus multiplication in cell culture
- 1981
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Ingår i: Archives of Virology. - Vienna, Austria : Springer. - 0304-8608 .- 1432-8798. ; 68:3-4, s. 203-209
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Tidskriftsartikel (refereegranskat)abstract
- The effect of phosphonoformate (INN; foscarnet sodium) on Herpes Simplex Virus type 1 replication in cell-culture has been studied. At 55 μm, foscarnet reduced the yield by 50 per cent which correlated well with a 50 per cent reduction of plaque formation at 60 μm. Foscarnet had to be added before 8 hours post infection to inhibit virus production. The inhibition of herpesvirus plaque formation by the presence of foscarnet for 24 hours was not reversed by the removal of the drug. The inhibition of virus replication by foscarnet could, in contrast to the inhibition by acycloguanosine, not be reversed by addition of deoxynucleosides.
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