Biomonitoring of water quality by aquatic bryophytes: optimization and methodological harmonization

Aquatic bryophytes, native or transplanted, can be used as reliable, simple and economical tools for biomonitoring the aquatic environment but one of the main impediments to the widespread use of these techniques is the lack of standardized protocols. Hence, the first task of this doctoral research was to address this problem in two critical reviews of the methodology used for passive and active biomonitoring (Chapters I and II). Because of the advantages of the use of transplanted mosses over the use of native mosses, the research efforts then focused on optimizing some of the key methodological aspects of applying the moss bag technique. In Chapter III, the optimal devitalizing treatment of moss samples was selected, while in Chapter IV the optimal number and position of moss bags for use in biomonitoring studies were determine

Levels of Antioxidant Compound Glutathione in Moss from Industrial Areas

Plants possess a wide range of cellular mechanisms that help them tolerate potentially toxic substances. Several studies that were carried out under laboratory conditions have demonstrated that the antioxidant compound glutathione plays a role in enabling mosses to tolerate high levels of heavy metals without toxic effects. However, until now, the antioxidant levels have not been studied in mosses under field conditions. In this study, we aimed to clarify the antioxidant concentrations of glutathione in the terrestrial moss Pseudoscleropodium purum growing in industrial environments characterised by high atmospheric levels of Cd, Ni, and Pb, and to evaluate the potential use of the compound as a biomarker. The results indicated the existence of a glutathione threshold response, which was significantly correlated with the metal toxicity and which may be influenced by metal bioavailability. Although future studies are needed to strengthen the findings, the present study suggests that total concentration of glutathione in P. purum could therefore be used as a biomarker in air pollution biomonitoring studies, provided that metal bioavailability is taken into accountThe authors of the Ecology Unit belong to the Galician Competitive Research Group GRC/GPC2016-002 and to the CRETUS Strategic Partnership (AGRUP2015/02). All of these programmes are co-funded by FEDER (EU)S

Developing a Biotechnological Tool for Monitoring Water Quality: In Vitro Clone Culture of the Aquatic Moss Fontinalis Antipyretica

One of the main factors limiting active biomonitoring with aquatic mosses is the lack of sufficient material. A laboratory culture of the moss would solve this problem and thus convert the technique into a valuable biotechnological tool for monitoring water quality. With this aim, we first established small and large scale axenic in vitro culture systems for the aquatic moss Fontinalis antipyretica. We then attempted to enhance the growth rate of the cultures by modifying temperature, photoperiod and medium composition (N:P ratio, P concentration, CO2 supply, NH4NO3 supply and sucrose supply). None of these modifications greatly increased the in vitro growth rate. However, the growth rates were sufficiently high (relative to the initial weight of the cultures) in both systems (45 and 6 mg·day−1·g−1 for flasks and bioreactors respectively) to enable the production of large amounts of material. The ability to culture the material will substantially improve the applicability of the moss bag techniqueThis work was funded by MINECO project CTM2015-70578-P. The authors belong to the Galician Competitive Research Group GRC/GPC2016-002 and to the CRETUS Strategic Partnership (AGRUP2015/02). All of these programmes are co-funded by FEDER (EU)S

Effect of Current Velocity on Cd Accumulation in the Aquatic Moss Fontinalis antipyretica

With the aim of further standardizing biomonitoring techniques with aquatic mosses, the relationship between the velocity of water flow and cadmium (Cd) accumulation in transplants of the moss Fontinalis antipyretica was investigated. For this purpose, moss transplants were exposed in a controlled aquatic environment to different concentrations of Cd (0, 4, 16 and 36 ng g−1) and different water velocities (10, 30, 50, 70 and 90 cm s−1). The Cd concentrations in the moss transplants mainly depended on the Cd concentration in the water, but a small fraction of the variance was explained by water velocity. The Cd concentrations in moss were standardized to remove the effect of the concentration in the water so all the data could be analyzed together. The regression model for the standardized concentrations explained 23% of the variance in Cd accumulation in F. antipyretica and water velocity proved to be a significant predictor of Cd accumulationThe study was partly financed by the Spanish Government (project CTM2016-70578-P)S

Levels of Antioxidant Compound Glutathione in Moss from Industrial Areas

Plants possess a wide range of cellular mechanisms that help them tolerate potentially toxic substances. Several studies that were carried out under laboratory conditions have demonstrated that the antioxidant compound glutathione plays a role in enabling mosses to tolerate high levels of heavy metals without toxic effects. However, until now, the antioxidant levels have not been studied in mosses under field conditions. In this study, we aimed to clarify the antioxidant concentrations of glutathione in the terrestrial moss Pseudoscleropodium purum growing in industrial environments characterised by high atmospheric levels of Cd, Ni, and Pb, and to evaluate the potential use of the compound as a biomarker. The results indicated the existence of a glutathione threshold response, which was significantly correlated with the metal toxicity and which may be influenced by metal bioavailability. Although future studies are needed to strengthen the findings, the present study suggests that total concentration of glutathione in P. purum could therefore be used as a biomarker in air pollution biomonitoring studies, provided that metal bioavailability is taken into account