scholarly journals Bacterial community composition in the water column of the deepest freshwater Lake Baikal as determined by next-generation sequencing

2016 ◽  
Vol 92 (7) ◽  
pp. fiw094 ◽  
Author(s):  
Maria I. Kurilkina ◽  
Yulia R. Zakharova ◽  
Yuri P. Galachyants ◽  
Darya P. Petrova ◽  
Yuri S. Bukin ◽  
...  
2021 ◽  
Vol 22 (9) ◽  
Author(s):  
Karunia Adetera Nungki Wijayanti ◽  
Indah Istiqomah ◽  
Murwantoko Murwantoko

Abstract. Wijayanti KAN, Istiqomah I, Murwantoko. 2021. Bacterial abundance and community composition in green, brown and red water from intensive Catfish (Clarias sp.) culture ponds in Yogyakarta, Indonesia. Biodiversitas 22: 3677-3684. Catfish (Clarias sp.) is an important aquaculture commodity in Indonesia and cultured in an intensive system. Microorganisms play an important role in maintaining water quality of aquaculture system. The objective of this study was to determine the bacterial abundance and community composition of green, brown and red water collected from intensive catfish culture ponds in Yogyakarta using next-generation sequencing method. The water samples were collected from intensive catfish culture ponds with different colors, namely green, brown and red ponds located in Yogyakarta. The DNA from water samples was extracted using DNA extraction kit and used as template for 16S rRNA amplification. The V3-V4 hypervariable regions of the 16S rRNA gene were amplified apply for next-generation sequencing technology. This study could explore effectively the bacterial community in water samples. The bacterial communities in this catfish culture water showed higher bacterial richness compared to the other aquaculture system. The diversity of the green, brown and red catfish culture water ponds was similar with the number OTUs of the green, brown and red water samples, which were 1269; 1387 and 1323 OTUs respectively. The 694 OTUs (34.42%) were common core microbiomes in all catfish culture ponds, the 212 OTUs (10.51%) are present on green and brown water ponds, the 182 OTUs (9.02%) were on green and red water ponds, and the 183 OTUs (9.07%) were present on green and brown water ponds. However, the composition of the bacterial community was different. The most dominant phylum in green and brown water ponds was Proteobacteria with relative abundance in green water and brown water 71.6% and 47.0% respectively, whereas, the most dominant phylum in red water was Firmicutes (29.5%). The dominance of Firmicutes phylum in red water ponds may be caused by application of probiotic bacteria, the high organic content, and low oxygen concentration.


2020 ◽  
Vol 17 (7) ◽  
pp. 2085-2106
Author(s):  
Dario Fussmann ◽  
Avril Jean Elisabeth von Hoyningen-Huene ◽  
Andreas Reimer ◽  
Dominik Schneider ◽  
Hana Babková ◽  
...  

Abstract. Despite advances regarding the microbial and organic-molecular impact on nucleation, the formation of dolomite in sedimentary environments is still incompletely understood. Since 1960, apparent dolomite formation has been reported from mud sediments of the shallow, oligohaline and alkaline Lake Neusiedl, Austria. To trace potential dolomite formation or diagenetic alteration processes in its deposits, lake water samples and sediment cores were analyzed with respect to sediment composition, hydrochemistry and bacterial community composition. Sediments comprise 20 cm of homogenous mud with 60 wt % carbonate, which overlies dark-laminated consolidated mud containing 50 wt % carbonate and plant debris. Hydrochemical measurements reveal a shift from oxic lake water with pH 9.0 to anoxic sediment pore water with pH 7.5. A decrease in SO42- with a concomitant increase in ΣH2S and NH4+ from 0 to 15 cm core depth indicates anaerobic heterotrophic decomposition, including sulfate reduction. The bacterial community composition reflects the zonation indicated by the pore water chemistry, with a distinct increase in fermentative taxa below 15 cm core depth. The water column is highly supersaturated with respect to (disordered) dolomite and calcite, whereas saturation indices of both minerals rapidly approach zero in the sediment. Notably, the relative proportions of different authigenic carbonate phases and their stoichiometric compositions remain constant with increasing core depth. Hence, evidence for Ca–Mg carbonate formation or ripening to dolomite is lacking within the sediment of Lake Neusiedl. As a consequence, precipitation of high-magnesium calcite (HMC) and protodolomite does not occur in association with anoxic sediment and sulfate-reducing conditions. Instead, analytical data for Lake Neusiedl suggest that authigenic HMC and protodolomite precipitate from the supersaturated, well-mixed aerobic water column. This observation supports an alternative concept to dolomite formation in anoxic sediments, comprising Ca–Mg carbonate precipitation in the water column under aerobic and alkaline conditions.


2017 ◽  
Vol 82 (4) ◽  
pp. 960-968 ◽  
Author(s):  
Mi-Hwa Lee ◽  
Fan-Zhu Li ◽  
Jiyeon Lee ◽  
Jisu Kang ◽  
Seong-Il Lim ◽  
...  

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