Carbon and nitrogen stable isotope fractionation in the sediment of Lake Bled (Slovenia)

1997 ◽  
Vol 99 (1-4) ◽  
pp. 315-323 ◽  
Author(s):  
S. Lojen ◽  
N. Ogrinc ◽  
T. Dolenec
Keyword(s):  
Stable Isotope ◽  
Isotope Fractionation ◽  
Nitrogen Stable Isotope ◽  
Carbon And Nitrogen ◽  
Stable Isotope Fractionation

scholarly journals Carbon and nitrogen stable isotope fractionation during abiotic hydrolysis of pesticides

Chemosphere ◽  
2018 ◽  
Vol 213 ◽  
pp. 368-376 ◽  
Author(s):  
Jérémy Masbou ◽  
Guillaume Drouin ◽  
Sylvain Payraudeau ◽  
Gwenaël Imfeld
Keyword(s):  
Stable Isotope ◽  
Isotope Fractionation ◽  
Nitrogen Stable Isotope ◽  
Carbon And Nitrogen ◽  
Stable Isotope Fractionation ◽  
Hydrolysis Of

scholarly journals Determination of the in situ growth rate of Microcystis based on carbon and nitrogen stable isotope fractionation

2017 ◽  
Vol 18 (3) ◽  
pp. 984-993 ◽  
Author(s):  
Shucong Zhen ◽  
Wei Zhu
Keyword(s):  
Growth Rate ◽  
Stable Isotope ◽  
Growth Rates ◽  
Isotope Fractionation ◽  
Taihu Lake ◽  
Nitrogen Stable Isotope ◽  
Average Growth ◽  
Carbon And Nitrogen ◽  
Stable Isotope Fractionation

Abstract Stable isotope fractionation of carbon and nitrogen in algal cells can be affected by photosynthesis, temperature, nutrient and CO2 concentrations, and cell size. As a consequence, carbon and nitrogen stable isotope techniques are not popular for determining algal growth rates. To counter these issues, this study used BG11 medium to cultivate Microcystis in the laboratory. First, the carbon and nitrogen stable isotope values of the culture medium and the algae are determined. Then, based on changes in isotope fractionation before and after cell division, a function μ = 1.32(1 + x)−0.52 relating growth rate and stable isotope fractionation is established. By substituting stable isotope values from Taihu Lake water and Microcystis into this function, the growth rate of the Microcystis in Taihu Lake is calculated to be 0.64 d−1 in May and 0.12 d−1 in September, with an average growth rate of 0.42 d−1. By incorporating most of the above-mentioned factors influencing isotope fractionation, this method can determine the growth rate of algae based directly on the stable isotope fractionation relationship, enabling simple and practical determination of algae growth rates.

Challenges for interpreting stable isotope fractionation of carbon and nitrogen in tropical aquatic ecosystems

2009 ◽  
Vol 30 (5) ◽  
pp. 749-753 ◽  
Author(s):  
Susan S. Kilham ◽  
Meshagae Hunte-Brown ◽  
Piet Verburg ◽  
Catherine M. Pringle ◽  
Matt R. Whiles ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Aquatic Ecosystems ◽  
Isotope Fractionation ◽  
Carbon And Nitrogen ◽  
Stable Isotope Fractionation ◽  
Tropical Aquatic Ecosystems

TRANSFER EFFICIENCY FROM PRIMARY PRODUCERS TO RUDITAPES PHILIPPINARUM ON AN INTERTIDAL FLAT IN HIROSHIMA BAY, JAPAN

2017 ◽  
Author(s):  
Sosuke Otani ◽  
Sosuke Otani ◽  
Akira Umehara ◽  
Akira Umehara ◽  
Haruka Miyagawa ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Secondary Production ◽  
Isotope Ratios ◽  
Ruditapes Philippinarum ◽  
Transfer Efficiency ◽  
Food Sources ◽  
Stable Isotope Ratios ◽  
Primary Producers ◽  
Nitrogen Stable Isotope ◽  
Carbon And Nitrogen

Fish yields of Ruditapes philippinarum have been decreased and the resources have not yet recovered. It needs to clarify food sources of R. philippinarum, and relationship between primary and secondary production of it. The purpose on this study is to reveal transfer efficiency from primary producers to R. philippinarum and food sources of R. philippinarum. The field investigation was carried out to quantify biomass of R. philippinarum and primary producers on intertidal sand flat at Zigozen beach in Hiroshima Bay, Japan. In particular, photosynthetic rates of primary producers such as Zostera marina, Ulva sp. and microphytobenthos were determined in laboratory experiments. The carbon and nitrogen stable isotope ratios for R. philippinarum and 8 potential food sources (microphytobenthos, MPOM etc) growing in the tidal flat were also measured. In summer 2015, the primary productions of Z. marina, Ulva sp. and microphytobenthos were estimated to be 70.4 kgC/day, 43.4 kgC/day and 2.2 kgC/day, respectively. Secondary production of R. philippinarum was 0.4 kgC/day. Contribution of microphytobenthos to R. philippinarum as food source was 56-76% on the basis of those carbon and nitrogen stable isotope ratios. Transfer efficiency from microphytobenthos to R. philippinarum was estimated to be 10-14%. It was suggested that microphytobenthos might sustain the high secondary production of R. philippinarum, though the primary production of microphytobenthos was about 1/10 compared to other algae.

scholarly journals Unravelling the process of petroleum hydrocarbon biodegradation in different filter materials of constructed wetlands by stable isotope fractionation and labelling studies

2021 ◽  
Author(s):  
Andrea Watzinger ◽  
Melanie Hager ◽  
Thomas Reichenauer ◽  
Gerhard Soja ◽  
Paul Kinner
Keyword(s):  
Stable Isotope ◽  
Constructed Wetlands ◽  
Hydrogen Isotope ◽  
Petroleum Hydrocarbon ◽  
Isotope Fractionation ◽  
Isotope Effects ◽  
Filter Material ◽  
Hydrocarbon Biodegradation ◽  
Stable Isotope Fractionation ◽  
Filter Materials

AbstractMaintaining and supporting complete biodegradation during remediation of petroleum hydrocarbon contaminated groundwater in constructed wetlands is vital for the final destruction and removal of contaminants. We aimed to compare and gain insight into biodegradation and explore possible limitations in different filter materials (sand, sand amended with biochar, expanded clay). These filters were collected from constructed wetlands after two years of operation and batch experiments were conducted using two stable isotope techniques; (i) carbon isotope labelling of hexadecane and (ii) hydrogen isotope fractionation of decane. Both hydrocarbon compounds hexadecane and decane were biodegraded. The mineralization rate of hexadecane was higher in the sandy filter material (3.6 µg CO2 g−1 day−1) than in the expanded clay (1.0 µg CO2 g−1 day−1). The microbial community of the constructed wetland microcosms was dominated by Gram negative bacteria and fungi and was specific for the different filter materials while hexadecane was primarily anabolized by bacteria. Adsorption / desorption of petroleum hydrocarbons in expanded clay was observed, which might not hinder but delay biodegradation. Very few cases of hydrogen isotope fractionation were recorded in expanded clay and sand & biochar filters during decane biodegradation. In sand filters, decane was biodegraded more slowly and hydrogen isotope fractionation was visible. Still, the range of observed apparent kinetic hydrogen isotope effects (AKIEH = 1.072–1.500) and apparent decane biodegradation rates (k = − 0.017 to − 0.067 day−1) of the sand filter were low. To conclude, low biodegradation rates, small hydrogen isotope fractionation, zero order mineralization kinetics and lack of microbial biomass growth indicated that mass transfer controlled biodegradation.

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