Fate and movement of microorganisms in the environment

Alexander, Martin; Andow, David A.; Gillett, James W.

doi:10.1007/bf01867456

Cited by 7 publications

(5 citation statements)

References 134 publications

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“…Despite its importance, there is as yet little information concerning the fate of introduced rhizobia in alley cropping fields. In order to become established in the field, introduced rhizobia must coexist with competitors and predators and maintain themselves during periods of low nutrient availability (Alexander, 1986). Fluctuating environmental conditions and management practices can also influence the survival of inoculants in the field.…”

Section: Inoculation With An Effective and Persistentmentioning

confidence: 99%

Persistence and recovery of introduced Rhizobium ten years after inoculation on Leucaena leucocephala grown on an Alfisol in southwestern Nigeria

Sanginga

Danso

Mulongoy³

et al. 1994

Plant Soil

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Establishment of Leucaena leucocephala was poor at Ibadan (Transition forest-savanna zone) andFashola (savanna zone, 70 km north of Ibadan) in southwestern Nigeria as a result of low soil fertility and the presence of only a few native rhizobia capable of nodulating it. Inoculation with L. leucocephala at these two locations in 1982 resulted in striking responses with Rhizobiurn strains IRc 1045 and IRc 1050 isolated from L. leucocephala grown in Nigeria. The persistence of inoculated effective Rhizobiurn strains after inoculation is desirable since it removes the need for reinoculation. Because of the perennial nature of L. leucocephala and its use in long-term alley farming experiments, we examined the persistence of inoculated rhizobial strains after inoculation, and their ability to sustain N2-fixation and biomass production at Ibadan. In 1992, ten years after Rhizobium introduction, uninoculated, L. leucocephala fixed about 150 kg N ha -1 yr -~ or about 41% of total plant N compared to 180kg N ha -I yr -~ or 43% measured in 1982. Serological typing of the nodules using the Enzyme-Linked-Immunosorbent Assay (ELISA) and intrinsic resistance to the streptomycin test revealed that most of the nodules (96%) formed on L. leucocephala in 1992 were by Rhizobiurn strains IRc 1045 and IRc 1050, which were inoculated in 1982. Nodules were absent on uninoculated L. Ieucocephala grown on the adjacent field with no history of L. leucocephala cultivation. We conclude that the N 2 fixed by Rhizobium strains IRc 1045 and IRc 1050 persisted for many years in the absence of L. leucocephala and sustained effectively fixed N 2 which growth and yield of L. leucocephala after several years, thus encouraging a possible low-input alley farming system by smallholder farmers in Nigeria.

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Section: Inoculation With An Effective and Persistentmentioning

confidence: 99%

Persistence and recovery of introduced Rhizobium ten years after inoculation on Leucaena leucocephala grown on an Alfisol in southwestern Nigeria

Sanginga

Danso

Mulongoy³

et al. 1994

Plant Soil

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“…The risk of infection from pathogenic micro‐organisms depends on die‐off rates, attenuation and dilution factors (Alexander et al . ; Ferguson et al . ; Pedley et al .…”

Section: Introductionmentioning

confidence: 99%

Quantification of microbial risks to human health caused by waterborne viruses and bacteria in an urban slum

et al. 2013

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Aims: To determine the magnitude of microbial risks from waterborne viruses and bacteria in Bwaise III in Kampala (Uganda), a typical slum in Sub-Saharan Africa. Methods and Results: A quantitative microbial risk assessment (QMRA) was carried out to determine the magnitude of microbial risks from waterborne pathogens through various exposure pathways in Bwaise III in Kampala (Uganda). This was based on the concentration of Escherichia coli O157:H7, Salmonella spp., rotavirus (RV) and human adenoviruses F and G (HAdV) in spring water, tap water, surface water, grey water and contaminated soil samples. The total disease burden was 680 disability-adjusted life years (DALYs) per 1000 persons per year. The highest disease burden contribution was caused by exposure to surface water open drainage channels (39%) followed by exposure to grey water in tertiary drains (24%), storage containers (22%), unprotected springs (8%), contaminated soil (7%) and tap water (0Á02%). The highest percentage of the mean estimated infections was caused by E. coli O157:H7 (41%) followed by HAdV (32%), RV (20%) and Salmonella spp. (7%). In addition, the highest infection risk was 1 caused by HAdV in surface water at the slum outlet, while the lowest infection risk was 2Á71 9 10 À6 caused by E. coli O157:H7 in tap water. Conclusions:The results show that the slum environment is polluted, and the disease burden from each of the exposure routes in Bwaise III slum, with the exception of tap water, was much higher than the WHO reference level of tolerable risk of 1 9 10 À6 DALYs per person per year.

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“…Sunlight is reported to be one of the most detrimental factors to the survival of E. coli in water (Chamberlin and Mitchell 1978;Fujioka et al 1981), and available water has been suggested as being most critical for E. coli's survival in soils (Unc and Goss 2003). Other factors that have been shown or suggested to influence the survival of bacteria as mentioned above include temperature, pH, nutrients, predators, soil type, season, and competition with other organisms (Chamberlin and Mitchell 1978;Fujioka et al 1981;Alexander 1986;Sherr et al 1987;Ferguson et al 2003;Unc and Goss 2003). There is very little information available on whether the factors influencing microbial survival are the same for aquatic systems, manure, and soil matrices (Ferguson et al 2003).…”

Section: Introductionmentioning

confidence: 99%

Survival of Escherichia coli in Beef Cattle Fecal Pats Under Different Levels of Solar Exposure

Meays

Broersma

Nordin

2005

Rangeland Ecology & Management

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Understanding the survival and transport of Escherichia coli in feces on land and in water is important when trying to assess contamination of water by grazing animals. A fecal-pat experiment was conducted in July and August of 2003 to investigate the survival of E. coli under 4 levels of solar exposure controlled by using shade cloth. Fresh beef cattle manure was uniformly blended to produce 2.5-and 1.6-kg fecal pats, which were placed in plastic trays or in contact with the soil and covered with 0%, 40%, 80%, or 100% shade cloth treatments and replicated 5 times. Samples from each fecal pat were collected at Time 0 to establish E. coli levels; sampling was repeated at Day 1, Day 3, and approximately weekly thereafter for 45 days to determine die-off. E. coli concentration and percent moisture were measured for each fecal sample. At the end of the experiment, fecal pats under the 0% shade cloth had the lowest E. coli concentrations, followed by the 40%, 80%, and 100% treatments, with 0.018, 0.040, 0.11, and 0.44 3 10 6 colony-forming units (CFU) g À1 , respectively. Fecal-pat size was significant only on Day 17, when large fecal pats had higher concentrations of E. coli (P , .0001). There was no significant difference (P ¼ 0.43) in E. coli concentration between the fecal pats in contact with the soil vs. those in plastic trays. Percent moisture of fecal pats was not a good covariate. Age of fecal pats, as well as exposure to solar radiation negatively influences the survival of E. coli. From a management perspective, E. coli in fecal pats under forested situations would survive longer than in open grasslands due to shading, and any possible contamination by E. coli would be greatest within 7 days of removing cattle from a riparian area or pasture. Resumen Entender la supervivencia y transporte de E. coli en las heces sobre el tierra y en el agua es importante cuando intentamos evaluar la contaminació n del agua por los animales en apacentamiento. En Julio y Agosto del 2003 se condujo un experimento con tortas de heces fecales para investigar la supervivencia del E. coli bajo cuatro niveles de exposició n solar controlada usando una tela para sombreado. Estiércol fresco de ganado bovino para carne fue mezclado uniformemente para producir tortas de 2.5 y 1.6 kg, que se colocaron en charolas o en contacto con el suelo bajo tratamientos de 0%, 40%, 80%, y 100% de sombreado repetidos cinco veces. Muestras de cada torta fecal se colectaron en el tiempo cero para establecer los niveles de E. coli y en el día uno, día tres y aproximadamente cada semana durante 45 días para determinar la diná mica de mortalidad de la bacteria. La concentració n de E. coli y humedad se midieron en cada muestreo fecal. Al final del experimento, las tortas fecales bajo 0% de sombreado tuvieron las menores concentraciones de E. coli, seguida por los tratamientos de 40%, 80%, y 100% (0.018, 0.040, 0.11, y 0.44 3 10 6 unidades formadoras de colonias (CFU) g À1 respectivamente). El tamañ o de la torta fecal fue significativo solo en el día 17, ...

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Fate and movement of microorganisms in the environment

Cited by 7 publications

References 134 publications

Persistence and recovery of introduced Rhizobium ten years after inoculation on Leucaena leucocephala grown on an Alfisol in southwestern Nigeria

Persistence and recovery of introduced Rhizobium ten years after inoculation on Leucaena leucocephala grown on an Alfisol in southwestern Nigeria

Quantification of microbial risks to human health caused by waterborne viruses and bacteria in an urban slum

Survival of Escherichia coli in Beef Cattle Fecal Pats Under Different Levels of Solar Exposure

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