scholarly journals Roseomonas fluminis sp. nov. isolated from sediment of a shallow stream

2018 ◽  
Vol 68 (3) ◽  
pp. 782-787 ◽  
Author(s):  
Yongseok Ko ◽  
Jeeyeo Yim ◽  
Woon Mo Hwang ◽  
Keunsoo Kang ◽  
Tae-Young Ahn
Keyword(s):  
Shallow Stream

Distribution of nitrifying bacteria in a shallow stream

1997 ◽  
Vol 36 (8-9) ◽  
pp. 161-166 ◽  
Author(s):  
Ivana Jancarkova ◽  
Tove A. Larsen ◽  
Willi Gujer
Keyword(s):  
Field Experiments ◽  
Heterotrophic Bacteria ◽  
Pollution Source ◽  
Nitrifying Bacteria ◽  
Channel Water ◽  
River Bed ◽  
Hydraulic Conditions ◽  
Major Floods ◽  
Shallow Stream ◽  
Stream Bed

A project investigating the dynamics of self-purification processes in a shallow stream is carried out. Effects of the concentration gradient due to the distance to the pollution source, of hydraulic conditions in the river bed and of storm floods on the distribution of nitrifying bacteria were studied with the help of laboratory and field experiments. Nitrifiers density on the surface of the stream bed increased rapidly up to a distance of 300 m from the WWTP indicating possible competition of the nitrifiers with the heterotrophic bacteria close to the WWTP. Afterwards a slight decrease in the downstream direction was observed. In vertical profiles, higher bacterial densities were found at sites with rapid infiltration of channel water to the stream bed than at sites with no exchange between channel water and stream bed water or where stream bed water exfiltrated. A major flood event scoured the nitrifiers nearly totally from the surface of the river bed. Major floods belong so to the most dominant processes controlling self-purification in shallow streams. Minor floods, however, don't scour bacteria in the depth of the stream bed that could then be important for the self-purification processes.

Dankookia rubra gen. nov., sp. nov., an alphaproteobacterium isolated from sediment of a shallow stream

2016 ◽  
Vol 54 (6) ◽  
pp. 420-425 ◽  
Author(s):  
Wan-Hoe Kim ◽  
Do-hak Kim ◽  
Keunsoo Kang ◽  
Tae-Young Ahn
Keyword(s):  
Shallow Stream

Landscape Influences on Stream Habitats and Biological Assemblages

2006 ◽  
Keyword(s):  
Landscape Scale ◽  
Riparian Zones ◽  
Total Abundance ◽  
Stream Channels ◽  
Urban Centers ◽  
Explanatory Variables ◽  
Agricultural Areas ◽  
Abundance And Distribution ◽  
Shallow Stream ◽  
Agricultural Regions

<em>Abstract.</em>—Wood is an important component of small to medium-sized streams in forested regions, but has been poorly studied in agricultural areas. Our goals were to (1) characterize the abundance, size, and distribution of wood in low-gradient streams in two agricultural regions, (2) quantify the influence of reach- and landscape-scale factors on the abundance and distribution of wood in these streams, and (3) compare trends across two study areas. Wood abundance was quantified in stream reaches in two diverse agricultural regions of the Midwestern United States: central Michigan and southeastern Minnesota. Wood abundance was quantified in 71 stream reaches, and an array of channel, riparian zone, and landscape features were characterized. Multiple regressions were conducted to predict abundance from those explanatory variables. We found that large wood was relatively scarce in these low-gradient streams compared to low-gradient streams in forested regions. Mean log size was greater, but total abundance was lower in Minnesota than Michigan. In Minnesota, greatest wood abundance and greatest extent of accumulations were predicted in wide, shallow stream channels with high substrate heterogeneity and woody riparian vegetation overhanging the channel. Models were dominated by reach-scale variables. In Michigan, largest densities of wood and accumulations were associated with catchments in hilly regions containing urban centers, with low soil water capacity, wide, shallow stream channels, low coarse particular organic matter standing stocks, and woody riparian zones. Models contained both reach- and landscape-scale variables. Difference in the extent of agricultural and forest land use/cover between Michigan and Minnesota may explain the differences in the models predicting wood variables. Patterns in wood abundance and distribution in these Midwestern streams differ from those observed in high gradient regions, and in low-gradient streams within forested regions. This has important implications for ecosystem processes and management of headwater streams in agricultural regions.

I.—A Bronze Cauldron front the River Cherwell, Oxfordshire, with notes on cauldrons and other bronze vessels of allied types

Archaeologia ◽  
1930 ◽  
Vol 80 ◽  
pp. 1-36 ◽  
Author(s):  
E. Thurlow Leeds
Keyword(s):  
Bronze Vessels ◽  
Interesting Class ◽  
Shallow Stream

The bronze cauldron here illustrated (pl. 1) has recently been added to the British prehistoric collections in the Ashmolean Museum. It was acquired from the person into whose hands it passed almost immediately after discovery, but of the conditions of discovery it has been impossible to ascertain more than that it was found by some bathers in the bed of the River Cherwell at Shipton-on-Cherwell. Chance was indeed kind when it allowed a vessel of a highly interesting class to be rescued from the mud in which it had lain in a comparatively shallow stream for over two thousand years, in what must, in view of the extreme fragility in relation to its size, be regarded as a quite remarkable state of preservation.

scholarly journals Flavihumibacter cheonanensis sp. nov., isolated from sediment of a shallow stream

2014 ◽  
Vol 64 (Pt_9) ◽  
pp. 3235-3239 ◽  
Author(s):  
Wan-Hoe Kim ◽  
Siwon Lee ◽  
Tae-Young Ahn
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Phylogenetic Trees ◽  
Rrna Gene ◽  
Strictly Aerobic ◽  
Content Type ◽  
Link Type ◽  
Gene Sequence Analysis ◽  
Taxonomic Approach ◽  
Shallow Stream

A Gram-reaction-positive, rod-shaped, strictly aerobic and non-motile bacterial strain, designated WS16T, was isolated from the sediment of a shallow stream located in Cheonan, Korea. The strain grew optimally at 28 °C, at pH 7.0 and in the absence of NaCl. Phylogenetic trees based on 16S rRNA gene sequences suggested that the isolate belonged to the genus Flavihumibacter of the phylum Bacteroidetes . Comparative 16S rRNA gene sequence analysis showed that strain WS16T was related most closely to Flavihumibacter petaseus T41T (96.8 % similarity). The isolate contained MK-7 as the predominant menaquinone and iso-C15 : 0, iso-C15 : 1 and iso-C17 : 0 3-OH as the major fatty acids. The genomic DNA G+C content of the isolate was 45.9 mol%. The results of a polyphasic taxonomic approach indicated that strain WS16T represents a novel species of the genus Flavihumibacter , for which the name Flavihumibacter cheonanensis sp. nov. is proposed. The type strain is WS16T ( = KACC 17467T = JCM 19322T).

scholarly journals Population Structure and Habitat Use of the Endangered Watercress Darter

2016 ◽  
Vol 7 (2) ◽  
pp. 499-508 ◽  
Author(s):  
R. Scot Duncan ◽  
Bernard R. Kuhajda ◽  
Caitlin A. Hodges ◽  
Ashley L. Messenger
Keyword(s):  
Habitat Preferences ◽  
Fish Fauna ◽  
Ceratophyllum Demersum ◽  
Preferred Habitat ◽  
Freshwater Fish Fauna ◽  
Metal Frame ◽  
Shallow Stream ◽  
Complex Habitat ◽  
Throw Trap ◽  
Imperiled Species

Abstract Despite Alabama's exceptionally diverse freshwater fish fauna, many of its fish species face extinction. Some of the state's most imperiled species dwell within coldwater springs, but a deficit of knowledge about their ecology hampers protection efforts. The watercress darter Etheostoma nuchale is a species confined to five springs in the greater Birmingham metropolitan area. Roebuck Spring likely harbors the largest population. Its pool has been surveyed occasionally, but there had been no survey of its run, a shallow stream flowing from the pool. We investigated the darter's use of the run, its habitat preferences, and characteristics of the habitats where it is most abundant. We quantified the abundance of stream microhabitats, then estimated darter density in the stream's five most common habitats using a throw trap, a high-walled metal frame dropped in the habitat. We found darters at densities vastly exceeding typical estimates derived using seine nets. We estimated the run harbored 116,932 (79,358–155,965) darters, two-thirds of which were juveniles. The most preferred habitat was coontail Ceratophyllum demersum, a submergent plant not previously known to provide darter habitat. Coontail grew prolifically in swift currents, which was surprising given that darter habitats described previously had little to no current. Coontail provided a more structurally complex habitat than the plants of the other microhabitats studied. Our results suggest that spring runs can support substantial densities of the watercress darter if dense submergent vegetation is present.

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