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Carbon monoxide conversion by anaerobic bioreactor sludges 总被引:2,自引:0,他引:2
Jan Sipma Piet N.L. Lens Alfons J.M. Stams Gatze Lettinga 《FEMS microbiology ecology》2003,44(2):271-277
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Miguel A. Moreno Cristina Pascual Alicia Gibello Sergi Ferrer Cees J. Bos Alfons J.M. Debets Guillermo Suárez 《FEMS microbiology letters》1994,124(1):35-41
Abstract A genetic transformation system for the aflatoxin-producing fungus Aspergillus parasiticus using two autonomously replicating plasmids from A. nidulans (ARp1 and pDHG25) is reported. Transformation frequencies using the plasmid pDHG25 were from 5 × 102 to 2.5 × 104 transformants per 106 viable protoplasts and μg DNA. The stability of the plasmids in the transformants was also studied. This transformation system offers a new opportunity to clone genes related to aflatoxin production using appropriate aflatoxin-defective mutants. 相似文献
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Molecular analysis of the waxy locus of Zea mays 总被引:1,自引:0,他引:1
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The importance of autotrophic versus heterotrophic oxidation of atmospheric ammonium in forest ecosystems with acid soil 总被引:3,自引:0,他引:3
Alfons J.M. Stams E. Marinka Flameling Emile C.L. Marnette 《FEMS microbiology letters》1990,74(4):337-344
Abstract The role of autotrophic and heterotrophic nitrifying microorganisms in the oxidation of atmospheric ammonium in two acid and one calcareous location of a Dutch woodland area was investigated. In soil slurries nitrate formation was completely inhibited by acetylene, a specific inhibitor of autotrophic ammonium-oxidizing bacteria. A survey of nitrifiers in the forest soils showed that both autotrophic ammonium- and nitrite-oxidizing bacteria were present in high numbers and evidence was obtained that autotrophic bacteria are able to nitrify below pH 4. These results show that autotrophic nitrifying bacteria may account for most of the nitrification in the examined soils. To assess the contribution of heterotrophic nitrifiers, about 200 strains of heterotrophic bacteria and 21 morphologically distinct fungal strains were isolated from the acid soil locations and tested for their ability to nitrify. Only one Penicillium strain produced nitrate in test media, but its nitrate formation when added to acid soils was poor. These findings indicate that in the investigated soil heterotrophs are of minor importance in the oxidation of atmospheric ammonium. 相似文献