A stromatolitic cyanobacterial crust in a Mediterranean stream optimizes organic matter use
1998; Inter-Research Science Center; Volume: 16; Linguagem: Inglês
10.3354/ame016131
ISSN1616-1564
AutoresAnna M. Romaní, Sergi Sabater,
Tópico(s)Marine and coastal ecosystems
ResumoAME Aquatic Microbial Ecology Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials AME 16:131-141 (1998) - doi:10.3354/ame016131 A stromatolitic cyanobacterial crust in a Mediterranean stream optimizes organic matter use Anna M. Romaní, Sergi Sabater* Departament d'Ecologia, Facultat de Biologia, Universitat de Barcelona, Avgda Diagonal 645, E-08028 Barcelona, Spain *Addressee for correspondence. E-mail: ssabater@porthos.bio.ub.es ABSTRACT: The bedrock of La Solana (NE Spain) stream is a thick calcareous cyanobacterial crust with a layered structure similar to a stromatolite. Different algal patches, which appear along with seasonal changes (especially discharge, temperature and light), characterize the stromatolite. This structure has a great capacity for organic matter utilization, as indicated by the high extracellular enzymatic activities (b-glucosidase, b-xylosidase and phosphatase) measured in the stromatolitic algal patches over an annual cycle. However, each patch showed a particular ability in the use of organic matter since a different hydrolytic potential capacity was measured. The highest β-glucosidase and b-xylosidase activities were measured in the mixed community (cyanobacterial crust with a sparsely developed overstorey), indicating that the understorey of this stromatolitic crust is highly active. In the Zygnema-Spirogyra community, autotrophic activity might enhance b-glucosidase activity in spring, whilst in the diatom bloom (which appeared in May-June), polysaccharides released by algae and mucilagenous material from the diatom stalks might regulate the ectoenzymatic activities. The adaptation of the Rivularia community to oligotrophic conditions occurring in summer, autumn and winter is shown by the extremely high phosphatase activity, related to the low phosphorus concentration in stream water. The appearance and progressive substitution of the different patches can be interpreted as the adaptive response to the most available organic matter source, as well as a way of surviving the drastic environmental changes characteristic of Mediterranean streams. KEY WORDS: Organic matter · Stromatolite · Ectoenzymatic activities · Bacteria · Algae · Mediterranean streams Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in AME Vol. 16, No. 2. Publication date: November 27, 1998 Print ISSN: 0948-3055; Online ISSN: 1616-1564 Copyright © 1998 Inter-Research.
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