scholarly journals Littoral and sub-littoral sediments in Lake Biwa. Division based on a thermal structure of the lake and their possible roles in the lake ecosystem.

2002 ◽  
Vol 63 (3) ◽  
pp. 249-254
Author(s):  
Jun MURASE
Keyword(s):  
Lake Biwa ◽  
Thermal Structure ◽  
Lake Ecosystem ◽  
Littoral Sediments

scholarly journals Construction and Validation of Lake Biwa Basin Simulation Model with Integration of Three Components of Land, Lake Flow, and Lake Ecosystem

2011 ◽  
Vol 34 (9) ◽  
pp. 125-141 ◽  
Author(s):  
Yuichi SATO ◽  
Eiji KOMATSU ◽  
Hideaki NAGARE ◽  
Hiroshi UEHARA ◽  
Takashi YUASA ◽  
...  
Keyword(s):  
Simulation Model ◽  
Lake Biwa ◽  
Lake Ecosystem ◽  
Three Components

scholarly journals Communities of T4-like bacteriophages associated with bacteria in Lake Baikal: diversity and biogeography

PeerJ ◽  
2022 ◽  
Vol 10 ◽  
pp. e12748
Author(s):  
Sergey Anatoljevich Potapov ◽  
Irina Vasilievna Tikhonova ◽  
Andrey Yurjevich Krasnopeev ◽  
Maria Yurjevna Suslova ◽  
Natalia Albertovna Zhuchenko ◽  
...  
Keyword(s):  
Lake Baikal ◽  
Water Samples ◽  
Lake Biwa ◽  
Amino Acid Level ◽  
Amplicon Sequencing ◽  
Lake Ecosystem ◽  
The Pacific ◽  
Close Relationship ◽  
T4 Bacteriophage ◽  
Marine Viruses

Lake Baikal phage communities are important for lake ecosystem functioning. Here we describe the diversity of T4-bacteriophage associated with the bacterial fraction of filtered water samples collected from the pelagic zone, coastal zone and shallow bays. Although the study of the diversity of phages for the g23 gene has been carried out at Lake Baikal for more than ten years, shallow bays that comprise a significant part of the lake’s area have been neglected, and this gene has not previously been studied in the bacterial fraction. Phage communities were probed using amplicon sequencing methods targeting the gene of major capsid protein (g23) and compared phylogenetically across sample locations and with sequences previously retrieved from non-bacterial fractions (<0.2 um) and biofilms (non-fractionated). In this study, we examined six water samples, in which 24 to 74 viral OTUs were obtained. The sequences from shallow bays largely differed from those in the pelagic and coastal samples and formed individual subcluster in the UPGMA tree that was obtained from the comparison of phylogenetic distances of g23 sequence sets from various ecosystems, reflecting differences in viral communities depending on the productivity of various sites of Lake Baikal. According to the RefSeq database, from 58.3 to 73% of sequences of each sample had cultivated closest relatives belonging to cyanophages. In this study, for phylogenetic analysis, we chose the closest relatives not only from the RefSeq and GenBank NR databases but also from two marine and one freshwater viromes: eutrophic Osaka Bay (Japan), oligotrophic area of the Pacific Ocean (Station ALOHA) and mesotrophic and ancient Lake Biwa (Japan), which allowed us to more fully compare the diversity of marine and freshwater phages. The identity with marine sequences at the amino acid level ranged from 35 to 80%, and with the sequences from the viral fraction and bacterial one from Lake Biwa—from 35.3 to 98% and from 33.9 to 89.1%, respectively. Therefore, the sequences from marine viromes had a greater difference than those from freshwater viromes, which may indicate a close relationship between freshwater viruses and differences from marine viruses.

Thermal structure of the southern Apennines along the Val d'Agri-Bari transect

2014 ◽  
Vol 32 ◽  
pp. 3-6
Author(s):  
Stefania Candela ◽  
Stefano Mazzoli ◽  
Antonella Megna ◽  
Stefano Santini
Keyword(s):  
Thermal Structure ◽  
Southern Apennines

Contribution of large bacteria to bacterial biomass in a deep freshwater lake (Lake Biwa, Japan)

2020 ◽  
Vol 85 ◽  
pp. 131-139
Author(s):  
S Shen ◽  
Y Shimizu
Keyword(s):  
Cell Volume ◽  
Bacterial Cell ◽  
Lake Biwa ◽  
Bacterial Biomass ◽  
Spatial Variations ◽  
Freshwater Lake ◽  
Heterotrophic Nanoflagellates ◽  
Bacterial Productivity ◽  
Transmission Electron ◽  
Seasonal And Spatial Variations

Despite the importance of bacterial cell volume in microbial ecology in aquatic environments, literature regarding the effects of seasonal and spatial variations on bacterial cell volume remains scarce. We used transmission electron microscopy to examine seasonal and spatial variations in bacterial cell size for 18 mo in 2 layers (epilimnion 0.5 m and hypolimnion 60 m) of Lake Biwa, Japan, a large and deep freshwater lake. During the stratified period, we found that the bacterial cell volume in the hypolimnion ranged from 0.017 to 0.12 µm3 (median), whereas that in the epilimnion was less variable (0.016 to 0.033 µm3, median) and much lower than that in the hypolimnion. Additionally, in the hypolimnion, cell volume during the stratified period was greater than that during the mixing period (up to 5.7-fold). These differences in cell volume resulted in comparable bacterial biomass in the hypolimnion and epilimnion, despite the fact that there was lower bacterial abundance in the hypolimnion than in the epilimnion. We also found that the biomass of larger bacteria, which are not likely to be grazed by heterotrophic nanoflagellates, increased in the hypolimnion during the stratified period. Our data suggest that estimation of carbon flux (e.g. bacterial productivity) needs to be interpreted cautiously when cell volume is used as a constant parametric value. In deep freshwater lakes, a difference in cell volume with seasonal and spatial variation may largely affect estimations.

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