Polyvinylpolypyrrolidone spin columns were used to rapidly purify crude soil DNA extracts from humic materials for polymerase chain reaction (PCR) analysis. The PCR detection limit for the tfdC gene, encoding chlorocatechol dioxygenase from the 2,4-dichlorophenoxyacetic acid degradation pathway, was 10(1)-10(2) cells/g soil in inoculated soils. The procedure could be applied to the amplification of biodegradative genes from indigenous microbial populations from a wide variety of soil types, and the entire analysis could be performed within 8 h.
Polyvinylpolypyrrolidone spin columns were used to rapidly purify crude soil DNA extracts from humic materials for polymerase chain reaction (PCR) analysis. The PCR detection limit for the tfdC gene, encoding chlorocatechol dioxygenase from the 2,4-dichlorophenoxyacetic acid degradation pathway, was 10(1)-10(2) cells/g soil in inoculated soils. The procedure could be applied to the amplification of biodegradative genes from indigenous microbial populations from a wide variety of soil types, and the entire analysis could be performed within 8 h.
Deleya aesta required Na+ for the uptake of 8 of 11 metabolites tested; the other three were transported at low rates in the absence of Na+ but at much higher rates in its presence. The optimal concentration of Na+ for maximum rate of transport of all the metabolites was 200 to 300 mM. Higher concentrations added as NaCl inhibited transport to the same extent as equiosomolar concentrations of other salts and sucrose. Li+ but not K+ could replace Na+ for the uptake of some metabolites but was only one-half as effective. Competition studies indicated that a number of different transport systems were involved in uptake. Inhibitor studies of succinate, L-alanine, and D-glucose accumulation (the last in both the presence and absence of Na+) suggested that for each a membrane potential was required. The relationship between rates of transport and oxidation of succinate by intact cells at various Na+ concentrations indicated that the Na+ requirement for oxidation reflected the Na+ requirement for transport. For D-glucose, the relationship was more complex, sinced over a narrow, low concentration range, Na+ inhibited respiration but not transport. Evidence for the presence in D. aesta 134 of a Na+-activated NADH–quinone acceptor oxidoreductase was obtained. Key words: Deleya aesta, marine bacteria, sodium, membrane transport, respiration.
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