Planktonic and Benthic Bacteriovorous Protozoa at Eleven Stations in Puget Sound and Adjacent Pacific Ocean

1969 ◽  
Vol 26 (2) ◽  
pp. 299-304 ◽  
Author(s):  
Bruce Lighthart
Keyword(s):  
Pacific Ocean ◽  
Water Column ◽  
Deep Sea ◽  
Heterotrophic Bacteria ◽  
Puget Sound ◽  
Ecological Role ◽  
Population Densities ◽  
Sediment Samples

Bacteriovorous Protozoa and heterotrophic bacteria quantitatively cultured from 31 samples collected at eight stations in Puget Sound and three in the adjacent Pacific Ocean (one station being 1520 m deep) ranges from undetectable to approximately 1000 Protozoa per ml and 5–80,000 bacteria/ml. Flagellates in the genera Bodo, Oikomonas, Monas, Rynchomonas, and Actinomonas were the most prevalent forms cultured. One ciliate and several sarcodinoids were also grown. The regression of predatory Protozoa on prey bacteria in sediment samples was calculated to be 580 bacteria for every bacteriovorous protozoan. Population densities of both bacteriovorous Protozoa and heterotrophic bacteria in the samples decreased from sediment to the water column, and from shore seaward. The ecological role of bacteriovorous Protozoa in the shallow and deep sea is discussed.

scholarly journals The Ecological Role of Water-Column Microbes in the Sea

1983 ◽  
Vol 10 ◽  
pp. 257-263 ◽  
Author(s):  
F Azam ◽  
T Fenchel ◽  
JG Field ◽  
JS Gray ◽  
LA Meyer-Reil ◽  
...  
Keyword(s):  
Water Column ◽  
Ecological Role

The incidence of bdellovibrios in an artificial environment: the national aquarium in Baltimore

1987 ◽  
Vol 33 (6) ◽  
pp. 483-488 ◽  
Author(s):  
H. N. Williams ◽  
S. Toon ◽  
E. Faulk ◽  
W. A. Falkler Jr.
Keyword(s):  
Heterotrophic Bacteria ◽  
Surface Film ◽  
Chemical Properties ◽  
Physical Factors ◽  
Sediment Samples ◽  
Artificial Environment ◽  
Controlled Environments ◽  
Physical And Chemical ◽  
Number Of Bacteria

The presence of bdellovibrios was established in three aquatic tanks in the National Aquarium in Baltimore and the incidence of the predators was studied. Each of three tanks differed in physical and chemical properties and in the kinds of animal inhabitants. Samples of water, sediment, and bioring surface film were collected from various tanks and were cultured for bdellovibrios and heterotrophic bacteria. The total number of bacteria in the samples was estimated by the direct count method. At the time of sampling, measurements were taken of the water temperature and salinity. Of 12 samples collected periodically from each of two tanks over a 12-month period, bdellovibrios were recovered from 8 samples. In a third tank the predators were recovered from 7 of the 12 samples. Of samples collected daily over a 10-day period from two tanks, bdellovibrios were recovered from one tank each day, but the organisms were not recovered from the second tank during the 10-day period. The predators were recovered more often from water and sediment samples than from samples of the surface film of biorings. With few exceptions, a greater number of the predators were recovered from sediment samples than from samples of water and bioring surface film. From each tank the number of bdellovibrios recovered was observed to fluctuate greatly. The basis for the observed fluctuations was not determined. The incidence of recovery of bdellovibrios from aquarium tanks in this study suggests that the organisms are capable of becoming established as resident flora in an artificial environment such as an aquarium. An aquarium with suitable environmental conditions presents great opportunities to conduct carefully selected studies on the ecology of bdellovibrios in an environment in which certain chemical and physical factors are controlled. Studies of bdellovibrios in controlled environments may lead to a greater understanding of the activities and role of these predators.

Endangered Butterflies and their Non-Native Host Plants: Examining Shifting Values of Belonging in Restoration

2019 ◽  
Vol 3 (1) ◽  
pp. 1-9
Author(s):  
Robert M. Anderson ◽  
Amy M. Lambert
Keyword(s):  
Ecological Restoration ◽  
Native Species ◽  
Puget Sound ◽  
A Value ◽  
The Social ◽  
Remote Island ◽  
Scientific Truth ◽  
Native Host

The island marble butterfly (Euchloe ausonides insulanus), thought to be extinct throughout the 20th century until re-discovered on a single remote island in Puget Sound in 1998, has become the focus of a concerted protection effort to prevent its extinction. However, efforts to “restore” island marble habitat conflict with efforts to “restore” the prairie ecosystem where it lives, because of the butterfly’s use of a non-native “weedy” host plant. Through a case study of the island marble project, we examine the practice of ecological restoration as the enactment of particular norms that define which species are understood to belong in the place being restored. We contextualize this case study within ongoing debates over the value of “native” species, indicative of deep-seated uncertainties and anxieties about the role of human intervention to alter or manage landscapes and ecosystems, in the time commonly described as the “Anthropocene.” We interpret the question of “what plants and animals belong in a particular place?” as not a question of scientific truth, but a value-laden construct of environmental management in practice, and we argue for deeper reflexivity on the part of environmental scientists and managers about the social values that inform ecological restoration.

Ecological Role of Exopolysaccharides of Bacillariophyta: A Review

2017 ◽  
Vol 19 (1) ◽  
pp. 5-24 ◽  
Author(s):  
E. I. Shnyukova ◽  
E. K. Zolotareva
Keyword(s):  
Ecological Role

scholarly journals The role of bacterial urease activity on the uniformity of carbonate precipitation profiles of bio-treated coarse sand specimens

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Charalampos Konstantinou ◽  
Yuze Wang ◽  
Giovanna Biscontin ◽  
Kenichi Soga
Keyword(s):  
Calcium Carbonate ◽  
Calcium Chloride ◽  
Urease Activity ◽  
Coarse Sand ◽  
Carbonate Precipitation ◽  
Population Densities ◽  
Carbonate Cements ◽  
Microbially Induced Carbonate Precipitation

AbstractProtocols for microbially induced carbonate precipitation (MICP) have been extensively studied in the literature to optimise the process with regard to the amount of injected chemicals, the ratio of urea to calcium chloride, the method of injection and injection intervals, and the population of the bacteria, usually using fine- to medium-grained poorly graded sands. This study assesses the effect of varying urease activities, which have not been studied systematically, and population densities of the bacteria on the uniformity of cementation in very coarse sands (considered poor candidates for treatment). A procedure for producing bacteria with the desired urease activities was developed and qPCR tests were conducted to measure the counts of the RNA of the Ure-C genes. Sand biocementaton experiments followed, showing that slower rates of MICP reactions promote more effective and uniform cementation. Lowering urease activity, in particular, results in progressively more uniformly cemented samples and it is proven to be effective enough when its value is less than 10 mmol/L/h. The work presented highlights the importance of urease activity in controlling the quality and quantity of calcium carbonate cements.

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