Abstract
Nutrients and light are the most determinant factors for microbial benthic assemblages in oligotrophic forested streams. We investigated the importance of nutrients and light availability on the structure and the function of epilithic biofilms in a Mediterranean forested stream (Fuirosos, Spain). Biofilms grew on artificial substrata in both enriched and unenriched reaches where shade conditions were simulated. Four different treatments were generated: higher light unenriched, lower light unenriched, higher light enriched (HL-E) and lower light enriched. Chlorophyll a, bacterial density, extracellular polymeric substances (EPS), extracellular leucine aminopeptidase (LAmP) and alkaline phosphatase (APase) activities were analysed during the colonisation at days 4, 9, 16, 22 and 52. At day 52, confocal laser scanning microscopy (CLSM) was used to determine differences in biofilm architecture. CLSM evidenced differences in thickness and structural complexity of biofilms grown in different conditions. Biofilms in HL-E were the thickest and had the most complex structure. The CLSM highlighted that the EPS was agglomerated in the upper layer of enriched-grown biofilms, but evenly distributed through the biofilm in unenriched biofilms. CLSM 3D images suggested that cyanobacteria increased under higher nutrient conditions. Nutrient enrichment caused the decrease of APase activity. Interaction between the two factors affected LAmP activity. HL-E had the highest LAmP and the lowest APase activities, an indication that biofilm responses to nutrients mostly occurred with high-light availability. Our results revealed that the conjoint availability of light and nutrients caused the highest changes in biofilm spatial organisation, microbial structure and functioning in oligotrophic forested streams.
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References
Acuña, V., I. Muñoz, A. Giorgi, M. Omella, F. Sabater & S. Sabater, 2005. Drought and postdrought recovery cycles in an intermittent Mediterranean stream: structural and functional aspects. Journal of the North American Benthological Society 24: 919–933.
Ainsworth, A. M. & R. Goulder, 2000. Downstream change in leucine aminopeptidase activity and leucine assimilation by epilithic microbiota along the River Swale, northern England. The Science of the Total Environment 251/252: 191–204.
American Public Health Association, 1989. Standard Methods for the Examination of Water and Wastewater, 17th ed. APHA, Washington, DC.
Barranguet, C., S. A. M. van Beusekom, B. Veuger, T. R. Neu, E. M. M. Manders, J. J. Sinke & W. Admiraal, 2004. Studying undisturbed autotrophic biofilms: still a technical challenge. Aquatic Microbial Ecology 34: 1–9.
Battin, T. J., L. A. Kaplan, J. D. Newbold, X. Cheng & C. Hansen, 2003. Effects of current velocity on the nascent architecture of stream microbial biofilms. Applied and Environmental Microbiology 69: 5443–5452.
Berman, T., 1970. Alkaline phosphatases and phosphorus availability in Lake Kinneret. Limnology and Oceanography 15: 663–674.
Chróst, R. J., 1990. Microbial ectoenzymes in aquatic environments. In Overbeck, J. & R. J. Chróst (eds), Aquatic Microbial Ecology: Biochemical and Molecular Approaches. Springer, New York: 47–78.
Chróst, R. J., 1991. Environmental control of the synthesis and activity of aquatic microbial ectoenzymes. In Chróst, R. J. (ed.), Microbial Enzymes in Aquatic Environments. Springer, New York: 29–59.
Chróst, R. J. & J. Overbeck, 1987. Kinetics of alkaline phosphatase activity and phosphorus availability for phytoplankton and bacterioplankton in Lake Pluβsee (North German eutrophic lake). Microbial Ecology 13: 229–248.
Dodds, W. K., B. J. F. Biggs & R. L. Lowe, 1999. Photosynthesis-irradiance patterns in benthic microalgae: variations as a function of assemblage thickness and community structure. Journal of Phycology 35: 42–53.
Dubois, M., K. A. Gilles, J. K. Hamilton, P. A. Rebers & F. Smith, 1956. Colorimetric method for determination of sugars and related substances. Analytical Chemistry 28: 350–356.
Francoeur, S. N. & R. G. Wetzel, 2003. Regulation of periphytic leucine-aminopeptidase activity. Aquatic Microbial Ecology 31: 249–258.
Freeman, C. & M. A. Lock, 1995. The biofilm polysaccharide matrix: A buffer against changing organic substrate supply? Limnology and Oceanography 40: 273–278.
Guasch, H. & S. Sabater, 1995. Seasonal variations in photosynthesis-irradiance responses by biofilms in Mediterranean streams. Journal of Phycology 31: 727–735.
Hill, W. R. & A. W. Knight, 1988. Nutrient and light limitation of algae in two northern California streams. Journal of Phycology 24: 125–132.
House, W. A., 2003. Geochemical cycling of phosphorus in rivers. Applied Geochemistry 18: 739–748.
Jeffrey, S. W. & G. F. Humphrey, 1975. New spectrophotometric equations for determining chlorophylls a, b, c1 and c2 in higher plants, algae and natural phytoplankton. Biochemie und Physiologie der Pflanzen 167: 191–194.
Lamberti, G. A., 1996. The role of periphyton in benthic food webs. In Stevenson, R. J., M. L. Bothwell & R. L. Lowe (eds), Algal Ecology: Freshwater Benthic Ecosystems. Academic Press, San Diego, CA: 533–572.
Lawrence, J. R., M. R. Chenier, R. Roy, D. Beaumier, N. Fortin, G. D. W. Swerhone, T. R. Neu & C. W. Greer, 2004. Microscale and molecular assessment of impacts of nickel, nutrients, and oxygen level on structure and function of river biofilm communities. Applied and Environmental Microbiology 70: 4326–4339.
Lazazzera, B. A., 2000. Quorum sensing and starvation: signals for entry into stationary phase. Current Opinion in Microbiology 3: 177–182.
Mosisch, T. D., S. E. Bunn & P. M. Davies, 2001. The relative importance of shading and nutrients on algal production in subtropical streams. Freshwater Biology 46: 1269–1278.
Neu, T. R., G. D. W. Swerhone & J. R. Lawrence, 2001. Assessment of lectin-binding analysis for in situ detection of glycoconjugates in biofilm systems. Microbiology 147: 299–313.
Neu, T. R., G. D. W. Swerhone, U. Böckelmann & J. R. Lawrence, 2005. Effect of CNP on composition and structure of lotic biofilms as detected with lectin-specific glycoconjugates. Aquatic Microbial Ecology 38: 283–294.
Paul, B. J. & H. C. Duthie, 1989. Nutrient cycling in the epilithon of running waters. Canadian Journal of Botany 67: 2302–2309.
Rier, S. T. & R. J. Stevenson, 2002. Effects of light, dissolved organic carbon, and inorganic nutrients on the relationship between algae and heterotrophic bacteria in stream periphyton. Hydrobiologia 489: 179–184.
Rier, S. T., K. A. Kuehn & S. N. Francoeur, 2007. Algal regulation of extracellular enzyme activity in stream microbial communities associated with inert substrata and detritus. Journal of the North American Benthological Society 26: 439–449.
Roberts, S., S. Sabater & J. Beardall, 2004. Benthic microalgal colonization in streams of differing riparian cover and light availability. Journal of Phycology 40: 1004–1012.
Romaní, A. M. & S. Sabater, 1999. Effect of primary producers on the heterotrophic metabolism of a stream biofilm. Freshwater Biology 41: 729–736.
Romaní, A. M. & S. Sabater, 2000. Influence of algal biomass on extracellular enzyme activity in river biofilms. Microbial Ecology 40: 16–24.
Romaní, A. M., A. Giorgi, V. Acuña & S. Sabater, 2004. The influence of substratum type and nutrient supply on biofilm organic matter utilization in streams. Limnology and Oceanography 49: 1713–1721.
Romaní, A. M., K. Fund, J. Artigas, T. Schwartz, S. Sabater & U. Obst, 2008. Relevance of polymeric matrix enzymes during biofilm formation. Microbial Ecology 56: 427–436.
Rosso, A. L. & F. Azam, 1987. Proteolytic activity in coastal oceanic waters: depth distribution and relationship to bacterial populations. Marine Ecology Progress Series 41: 231–240.
Sabater, S., S. Bernal, A. Butturini, E. Nin & F. Sabater, 2001. Wood and leaf debris input in a Mediterranean stream: the influence of riparian vegetation. Archiv für Hydrobiologie 153: 91–102.
Sabater, S., V. Acuña, A. Giorgi, E. Guerra, I. Muñoz & A. M. Romaní, 2005. Effects of nutrient inputs in a forested Mediterranean stream under moderate light availability. Archiv für Hydrobiologie 163: 479–496.
Sabater, S., A. Elosegi, V. Acuña, A. Basaguren, I. Muñoz & J. Pozo, 2008. Effect of climate on the trophic structure of temperate forested streams. A comparison of Mediterranean and Atlantic streams. Science of the Total Environment 390: 475–484.
Siuda, W. & R. J. Chróst, 1987. The relationship between alkaline phosphatase (APA) activity and phosphate availability for phytoplankton and bacteria in eutrophic lakes. Acta Microbiologica Polonica 36: 247–257.
Stock, M. S. & A. K. Ward, 1989. Establishment of a bedrock epilithic community in a small stream: microbial (algal and bacterial) metabolism and physical structure. Canadian Journal of Fisheries and Aquatic Sciences 46: 1874–1883.
Stream Solute Workshop, 1990. Concepts and methods for assessing solute dynamics in stream ecosystems. Journal of the North American Benthological Society 9: 95–119.
Taulbee, W. K., S. D. Cooper & J. M. Melack, 2005. Effects of nutrient enrichment on algal biomass across a natural light gradient. Archiv für Hydrobiologie 164: 449–464.
Von Schiller, D., E. Martí, J. L. Riera & F. Sabater, 2007. Effects of nutrients and light on periphyton biomass and nitrogen uptake in Mediterranean streams with contrasting land uses. Freshwater Biology 52: 891–906.
Winterbourn, M. J., 1990. Interactions among nutrients, algae and invertebrates in a New Zealand mountain stream. Freshwater Biology 23: 463–474.
Ylla, I., A. M. Romaní & S. Sabater, 2007. Differential effects of nutrients and light on the primary production of stream algae and mosses. Fundamental and Applied Limnology - Archiv für Hydrobiologie 170: 1–10.
Acknowledgments
This study was supported by European projects MODELKEY and KEYBIOEFFECTS (MRTN-CT-2006-035695). Additional funding was provided by the projects CGL2007-65549/BOS, CGL2008-05618-C02-01/BOS and SCARCE (Consolider-Ingenio 2010, CSD2009-00065) of the Spanish Ministry of Science and Innovation, and by the project VIECO (009/RN08/011) of the Spanish Ministry of Environment and Marine and Rural Affairs. Monica Roldán and the UAB Microscope Service provided technical help with the CLSM analysis.
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Guest editors: L. Ector, D. Hlúbiková & L. Hoffmann / Proceedings of the 7th International Symposium “Use of Algae for Monitoring Rivers”, Luxembourg, November 23–25, 2009
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Proia, L., Romaní, A.M. & Sabater, S. Nutrients and light effects on stream biofilms: a combined assessment with CLSM, structural and functional parameters. Hydrobiologia 695, 281–291 (2012). https://doi.org/10.1007/s10750-012-1117-x
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DOI: https://doi.org/10.1007/s10750-012-1117-x