Fate and activity of microorganisms introduced into soil.

Veen, Johannes A. van; Overbeek, L.S. van; Elsas, Jan Dirk van

doi:10.1128/.61.2.121-135.1997

Cited by 514 publications

(191 citation statements)

References 128 publications

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“…In contrast, the present study included 36 different soils and showed a faster initial decline of E. coli O157:H7 in sandy soils but no differences in the final survival time between both soil types. In general, it is stated that finer-textured (clayey) soils result in prolonged survival of introduced bacteria compared with coarser-textured (sandy) soils because of higher availability of protective pore spaces against feeding by soil fauna like protozoa (van Veen et al, 1997). This could explain the faster initial decrease in E. coli O157:H7 numbers in the sandy soils compared with the loamy soils.…”

Section: Difference Between Soil Types and Management Regimesmentioning

confidence: 99%

Manure‐amended soil characteristics affecting the survival of E. coli O157:H7 in 36 Dutch soils

Franz

Semenov

Termorshuizen

et al. 2008

Environmental Microbiology

178

151

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The recent increase in foodborne disease associated with the consumption of fresh vegetables stresses the importance of the development of intervention strategies that minimize the risk of preharvest contamination. To identify risk factors for Escherichia coli O157:H7 persistence in soil, we studied the survival of a Shiga-toxin-deficient mutant in a set of 36 Dutch arable manure-amended soils (organic/conventional, sand/loam) and measured an array of biotic and abiotic manure-amended soil characteristics. The Weibull model, which is the cumulative form of the underlying distribution of individual inactivation kinetics, proved to be a suitable model for describing the decline of E. coli O157:H7. The survival curves generally showed a concave curvature, indicating changes in biological stress over time. The calculated time to reach the detection limit ttd ranged from 54 to 105 days, and the variability followed a logistic distribution. Due to large variation among soils of each management type, no differences were observed between organic and conventional soils. Although the initial decline was faster in sandy soils, no significant differences were observed in ttd between both sandy and loamy soils. With sandy, loamy and conventional soils, the variation in ttd was best explained by the level of dissolved organic carbon per unit biomass carbon DOC/biomC, with prolonged survival at increasing DOC/biomC. With organic soils, the variation in ttd was best explained by the level of dissolved organic nitrogen (positive relation) and the microbial species diversity as determined by denaturing gradient gel electrophoresis (negative relation). Survival increased with a field history of low-quality manure (artificial fertilizer and slurry) compared with high-quality manure application (farmyard manure and compost). We conclude that E. coli O157:H7 populations decline faster under more oligotrophic soil conditions, which can be achieved by the use of organic fertilizer with a relatively high C/N ratio and consequently a relatively low rate of nutrient release.

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Section: Difference Between Soil Types and Management Regimesmentioning

confidence: 99%

Manure‐amended soil characteristics affecting the survival of E. coli O157:H7 in 36 Dutch soils

Franz

Semenov

Termorshuizen

et al. 2008

Environmental Microbiology

178

151

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“…protozoa and are exposed to unfavorable conditions. Both good and poor survival and activity of inoculants has been observed in soils [20,21], activated sludge, and anaerobic reactors [222 5].…”

Section: Applications Of Catabolic Mges: An Overview Of Bioaugmentatimentioning

confidence: 99%

Catabolic mobile genetic elements and their potential use in bioaugmentation of polluted soils and waters

Top

Springael

Boon

2002

FEMS Microbiology Ecology

171

130

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Genes that encode the degradation of both naturally occurring and xenobiotic organic compounds are often located on plasmids, transposons or other mobile and/or integrative elements. The list of published reports of such mobile genetic elements (MGEs) keeps growing as researchers continue to isolate and characterize new degrading bacteria and their corresponding degradative genes. There is also growing evidence that horizontal exchange of catabolic (degradative) genes among bacteria in microbial communities plays an important role in the evolution of catabolic pathways. Around 10 years ago the hypothesis was raised that we might be able to accelerate this natural gene exchange and pathway construction by introducing and subsequently spreading degradative genes, located on MGEs, into well established, competitive indigenous microbial populations as a means of bioaugmentation of polluted soils and waters. During the last decade, only a few reports on successful MGE- mediated bioaugmentation have been published. After summarizing the diversity of degradative MGEs, this review presents an overview of studies that have monitored the transfer of degradative genes in soil microcosms and in activated sludge and other wastewater treatment reactors, with emphasis on those that have clearly shown a direct effect of gene transfer on accelerated biodegradation. A few successful cases suggest that the strategy could indeed work under specific conditions, such as when the in situ degradation potential is absent and the pollutant degrading transconjugants can grow and become numerically dominant populations in the bacterial community. Further studies in this area are obviously needed to improve our current knowledge on the efficiency of gene dissemination as a tool in bioremediation.

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“…The microorganisms thus constructed, called genetically engineered microorganisms (GEMs), have widely been applied to biotechnology in a pure-culture system, for instance production of recombinant proteins. In contrast, their application to environmental biotechnology has been limited (Van Veen et al ., 1997;Sayler and Ripp, 2000), even though several laboratory studies have shown that GEMs introduced into bioremediation processes could improve the efficiency of pollutant removal. To cite an instance, a GEM that had been designed to simultaneously degrade mixtures of chloro-and methylaromatics has been shown to protect activated sludge communities from toxic phenol mixtures (Erb et al ., 1997).…”

Section: Introductionmentioning

confidence: 99%

Stable augmentation of activated sludge with foreign catabolic genes harboured by an indigenous dominant bacterium

Watanabe¹,

Teramoto

Harayama

2002

Environmental Microbiology

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Comamonas sp. rN7 is a phenol-degrading bacterium that represents the dominant catabolic population in activated sludge. The present study examined the utility of this bacterium for establishing foreign catabolic genes in phenol-digesting activated sludge. The phc genes coding for phenol hydroxylase and its transcriptional regulators of C. testosteroni R5 were integrated into the chromosome of strain rN7. The specific phenol-oxygenating activity of a resultant transformant designated rN7(R503) was three times higher than the activity of strain rN7, and the phc genes were stably inherited by rN7(R503) grown in a non-selective laboratory medium. Inoculation of phenol-acclimatized activated sludge with rN7(R503) resulted in a high phenol-oxygenating activity and improved resistance to phenol-shock loading compared to sludge inoculated with either no cells, rN7 or R5. Quantitative competitive polymerase chain reaction (PCR) showed that the phc genes were retained in the rN7(R503)-inoculated sludge at a density of more than 108 copies per ml of mixed liquor for more than 35 days, whereas those in the R5-inoculated sludge disappeared rapidly. No transfer of the phc genes to other indigenous populations was apparent in the rN7(R503)-harbouring sludge. From these results, we concluded that the phenol treatment of the activated sludge was enhanced by the phc genes harboured by the rN7(R503) population. This study suggests a possible bioaugmentation strategy for stably utilizing foreign catabolic genes in natural ecosystems.

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Fate and activity of microorganisms introduced into soil.

Cited by 514 publications

References 128 publications

Manure‐amended soil characteristics affecting the survival of E. coli O157:H7 in 36 Dutch soils

Manure‐amended soil characteristics affecting the survival of E. coli O157:H7 in 36 Dutch soils

Catabolic mobile genetic elements and their potential use in bioaugmentation of polluted soils and waters

Stable augmentation of activated sludge with foreign catabolic genes harboured by an indigenous dominant bacterium

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