engleski

Adenylate energy charge (AEC) as a useful indicator of environmental stress in Synurella ambulans (Müller, 1846) from the hyporheic zone of the Sava River

Groundwater organisms are exposed to progressive pollution and multi-xenobiotic stressors that influence the organism’s physiology, metabolism and finally ecosystem functioning and biodiversity. A useful index of stress response at the cellular level is the adenylate energy charge (AEC). AEC is determined as the ratio of adenosine triphosphate (ATP), adenosine diphosphate (ADP) and adenosine monophosphate (AMP) as follows AEC= ([ATP]+1/2[ADP])/([ATP]+[ADP]+[AMP]). The aim of the study was to quantify for the first time adenine nucleotides in stygophilous crustacean Synurella ambulans and compare the AEC at two sampling sites with various levels of pollution in four seasons. Separation and quantification of nucleotides was performed using ion-pair reversed phase HPLC, with UV detection at 260 nm. Amphipods were collected from the hyporheic zone (HZ) of the Sava River at Jarun-Zagreb and Medsave-Zaprešić (upstream of pharmaceutical wastewater outlet) sampling sites in December 2018 and April, July, October 2019. The Medsave population had significantly higher AEC values (0.41 ; 0.45) than the Jarun population (0.35 ; 0.31) in winter and spring sampling campaigns, indicating higher energy supply and thus lower metabolic stress. The possible impact of concentrations of metals/metalloids in interstitial water and in amphipods on seasonal and spatial variation of the AEC are discussed. AEC was shown as a useful index of environmental stress in S. ambulans since it can directly measure the change in available energy and thus the metabolic stress experienced by a given organism. In conclusion, it appears that the seasonal and spatial variations of the AEC values reflect the ecological state in the HZ. The financial support of the European Regional Development Fund for the Qua/Qua Protein project (KK.01.1.1.07.0023) and of Croatian Science Foundation for the AQUAMAPMET (IP-2014-09-4255) are highly acknowledged.

adenine nucleotides ; amphipod ; groundwater ecosystems ; multi-xenobiotic stressors ; pollution

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