Activity and population dynamics of heterotrophic and ammonia-oxidizing microorganisms in soil surrounding sludge bands spiked with linear alkylbenzene sulfonate: a field study.
Recent research has documented soil microorganisms to be rather sensitive to linear alkylbenzene sulfonates (LAS), which may enter the soil environment in considerable quantities following sewage sludge disposal. We here report field effects of LAS on selected microbial populations present in a sandy soil surrounding well-defined sludge bands spiked with high but realistic LAS levels (7.1 or 31.3 g/kg). Surprisingly, LAS had no effect on heterotrophic respiration in the sludge compartment per se but stimulated activity and metabolic quotient (microbial activity per unit of biomass) in the surrounding soil. By contrast, autotrophic ammonia oxidation was initially inhibited in the LAS-spiked sludge. This led to dramatic transient increases of NH4+ availability in the sludge and surrounding soil, subsequently stimulating soil ammonia oxidizers. As judged from a Nitrosomonas europaea bioluminescence toxicity assay, however, LAS or other sludge components never accumulated to toxic levels in the soil compartments and the LAS tolerance of the indigenous microbes further remained unchanged following LAS exposure. LAS effects on the investigated microbial populations largely occurred during the first two months and were confined to soil closer than 30 mm from LAS-spiked sludge. Our results strongly suggest that disposal of LAS-contaminated sludge does not pose a major risk to the function of the soil microbial community under field conditions.
Brandt
Kristian Koefoed
KK
Section of Genetics and Microbiology, Department of Ecology, Royal Veterinary and Agricultural University, Thorvaldsensvej 40, DK-1871 Frederiksberg, Copenhagen, Denmark. kkb@kvl.dk
Krogh
Paul Henning
PH
Sørensen
Jan
J
D017738:Alkanesulfonic Acids / Q000633:toxicity*; D000641:Ammonia / Q000378:metabolism*; D001419:Bacteria / Q000187:drug effects* / Q000378:metabolism*; D001673:Biodegradation, Environmental; D018533:Biomass; D019069:Cell Respiration; D006813:Humidity; D009584:Nitrogen / Q000378:metabolism; D043370:Nitrosomonas europaea / Q000187:drug effects / Q000378:metabolism; D010084:Oxidation-Reduction / Q000187:drug effects; D011157:Population Dynamics; D012722:Sewage / Q000737:chemistry*; D012987:Soil / Q000032:analysis; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis; D013696:Temperature; D013997:Time Factors
D017738:Alkanesulfonic Acids; D012722:Sewage; D012987:Soil; D012989:Soil Pollutants; C030641:alkylbenzyl sulfonic acid; D000641:Ammonia; D009584:Nitrogen