Soil and Water Bacteria in the Alaskan Subarctic Tundra

Fournelle, H. J.

doi:10.14430/arctic3286

Cited by 5 publications

(3 citation statements)

References 13 publications

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“…The recovery of aerobic spore formers from the three water samples is similar to the work of Fournnelle 1967 who recovered them from Alaska water at the same low level. The level of anaerobic spore formers observed in our water samples was however lower than has been reported by Molongoski and Klug (1976).…”

Section: Discussionsupporting

confidence: 80%

“…Analysis of variance, P Յ 0.05, was used to determine whether there were significant differences between the levels of turbidity, COD, aerobic plate count, aerobic spore former counts and anaerobic spore former counts in water samples from the Olifants river, Wilge river and Loskop canal (n = 12) as well as between the bacterial counts determined on the cauliflower and broccoli from three farms and the Loskop canal (n = 3). Statistica Version 9 (Statsoft, Tulsa, OK, 1984-2009 was used for the statistical analysis.…”

Section: Discussionmentioning

confidence: 99%

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Irrigation Water as a Potential Preharvest Source of Bacterial Contamination of Vegetables

Ijabadeniyi¹,

Debusho

Vanderlinde

et al. 2011

Journal of Food Safety

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The aim of this research is to determine the bacteriological quality of the irrigation canal from Loskopdam, the two rivers that feed it and vegetables (broccoli and cauliflower) in Mpumalanga, South Africa and also to predict the presence of selected bacterial pathogens in irrigation water and on vegetables with logistic regression analysis. Water and vegetable samples were examined for the presence of total coliforms, faecal coliforms, Escherichia coli, Listeria monocytogenes, Salmonella sp., Enterococcus, Staphylococcus aureus, aerobic sporeformers, anaerobic sporeformers and aerobic colony counts were done. Apart from bacterial analysis, the following physico-chemical tests: temperature, pH, turbidity and COD were determined in water samples. The average COD and turbidity in the two rivers and the canal were higher than WHO and SA water guidelines. Sampling and analyses were done for a period of 12 months. Levels of faecal coliforms and E. coli were higher than the WHO standard. S. aureus, Intestinal Enterococci, Salmonella, L. monocytogenes were recovered from the two rivers and the canal. Apart from L. monocytogenes which was not recovered from cauliflower, all bacterial pathogens recovered from the surface water were recovered from the vegetables. 2Practical application: These results show that the rivers in Mpumalanga may contribute to the contamination in the irrigation canal which may be a possible preharvest source of contamination of broccoli and cauliflower, which may in turn constitute a health risk to consumers. Logistic regression analysis of the sampled data showed that COD was statistically reliable to predict L. monocytogenes, turbidity reliable to predict Intestinal Enterococci and faecal coliform and coliform reliable to predict Salmonella in irrigation water. Aerobic colony count (ACC) was statistically significant for the prediction of the three pathogens in vegetables.

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Section: Discussionsupporting

confidence: 80%

Section: Discussionmentioning

confidence: 99%

Irrigation Water as a Potential Preharvest Source of Bacterial Contamination of Vegetables

Ijabadeniyi¹,

Debusho

Vanderlinde

et al. 2011

Journal of Food Safety

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“…Numbers of gram positive bacteria, including spore-forming bacteria that are largely gram positive, were generally less than 10' gdw"' soil at the Biome research area. The low numbers are in agreement with findings from most other high latitude sites (Boyd et al 1966, Fournelle 1967, Dunican and Rosswall 1974). Some genera, such as Arthrobacter and Bacillus, were isolated primarily from drier areas with polygonal terrain.…”

Section: Introductionsupporting

confidence: 91%

An Arctic ecosystem : the coastal tundra at Barrow, Alaska

Brown¹

1980

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Carex-Poa meadow (Type III) is the most extensive vegetation type, covering 41% of the research area. Bryophytes, primarily mosses, and lichens cover relatively larger areas than do the graminoids. The mosses Pogonatum alpinum and Dicranum elongatum and the lichens Cetraria richardsonii and Dactylina arctica are characteristic species. The Carex-Oncophorus meadow, Dupontia meadow, and Carex-Eriophorum meadow all have the same superficial meadow physiognomy. The Carex-Poa meadow is separated from the other meadow vegetation types by the abundance of Poa arctica, which is prominent when in flower, and by the presence of a high lichen diversity. Carex-Poa meadow is best developed in the drier parts of the polygonized sedge meadow complex where large, flat, and sometimes slightly raised low-centered polygons with barely discernible troughs occur. The Carex-Poa meadow is also common on hummocky rims of low-centered polygons in wetter areas and in areas with pronounced polygon development.Carex-Oncophorus meadow (Type IV), the second most extensive vegetation type, occupying 2\% of the map area, develops on moister sites than the Carex-Poa meadow. It occurs on flat polygon centers and in drained, shallow polygon troughs. It is distinguished from Carex-Poa meadow on the basis of reduced lichen cover and the presence of mosses such as Calliergon sarmentosum, Oncophorus wahlenbergii, and Aulacomnium turgidum, and of Dupontia fisheri and Peltigera aphthosa. The Carex-Oncophorus meadow has the greatest number of graminoid species and was the vegetation type most intensively studied during the Tundra Biome program.Dupontia meadow (Type V) occupies l^o of the mapped area. It is characteristic of flat, slowly draining sites and wet polygon troughs. Eriophorum russeolum is also common in this type, but the low cover of Carex and the greater abundance of Dupontia and Eriophorum angustifolium distinguish it from the other meadow types. Woody dicotyledons are essentially absent but several forbs occur. Cerastium Jenisejense, Stellaria edwardsii and S. laeta may form distinctive mats, and Saxifraga cernua is a common erect forb. The vegetation that composes the Carex-Eriophorum meadowThe Coastal Tundra at Barrow 29 (Type VI) is variable. This type includes the sparse vegetation of the basins of low-centered polygons as well as the more abundant vegetation of some pond margins. It has no woody species, and only a few lichens.Saxifraga foliolosa is characteristic of the basins and CalUergon sarmentosum is characteristic of the pond margins. Drepanocladus brevifolius is common throughout this type. Low species diversity, thick organic mat, and highly organic soils distinguish Type VI from the other meadow types. Spring snow cover on this type is moderately deep and late to recede.The vegetation type termed Arctophila pond margin (Type VII) is also found in slow-flowing streams and is the most distinct of the principal types, although it occupies only Z^/o of the area. Woody plants and hchens are totally absent. Single-shooted graminoi...

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Characterization of Viable Bacteria from Siberian Permafrost by 16S rDNA Sequencing

et al. 1997

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Viable bacteria were found in permafrost core samples from the Kolyma-Indigirka lowland of northeast Siberia. The samples were obtained at different depths; the deepest was about 3 million years old. The average temperature of the permafrost is -10 degrees C. Twenty-nine bacterial isolates were characterized by 16S rDNA sequencing and phylogenetic analysis, cell morphology, Gram staining, endospore formation, and growth at 30 degrees C. The majority of the bacterial isolates were rod shaped and grew well at 30 degrees C; but two of them did not grow at or above 28 degrees C, and had optimum growth temperatures around 20 degrees C. Thirty percent of the isolates could form endospores. Phylogenetic analysis revealed that the isolates fell into four categories: high-GC Gram-positive bacteria, beta-proteobacteria, gamma-proteobacteria, and low-GC Gram-positive bacteria. Most high-GC Gram-positive bacteria and beta-proteobacteria, and all gamma-proteobacteria, came from samples with an estimated age of 1.8-3.0 million years (Olyor suite). Most low-GC Gram-positive bacteria came from samples with an estimated age of 5,000-8,000 years (Alas suite).

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Soil and Water Bacteria in the Alaskan Subarctic Tundra

Cited by 5 publications

References 13 publications

Irrigation Water as a Potential Preharvest Source of Bacterial Contamination of Vegetables

Irrigation Water as a Potential Preharvest Source of Bacterial Contamination of Vegetables

An Arctic ecosystem : the coastal tundra at Barrow, Alaska

Characterization of Viable Bacteria from Siberian Permafrost by 16S rDNA Sequencing

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