Photoreactivity and bacterioplankton availability of aliphatic versus aromatic amino acids and a protein
- Author(s)
- Bettina Reitner, Alois Herzig, Gerhard J. Herndl
- Abstract
In batch culture experiments with natural bacerial assemblages collected from a humic-rich lake (Lake Neusiedl, Austria), labile organic nitrogen containing model substrates (alanine [Ala], an aliphatic amino acid, tryptophan [Trp], an aromatic amino acid, and bovine serum albumin [BSA], as protein) were added to 0.2 μm filtered lake water prior to exposure (for 9 h) to surface levels of the full range of solar radiation or being held in the dark. These organic nitrogen species were chosen to investigate compound-specific differences in the photochemical transformation of labile dissolved organic matter (DOM) and its subsequent availability to bacteria. 'Photocoloring' or humification in the Trp-amended water exposed to natural solar radiation and significant dissolved organic carbon (DOC) loss (120 μM C over 9 h exposure) resulted, after inoculation of the natural bacterial assemblage, in a lower maximum bacterial abundance in the previously solar radiation-exposed treatments as compared to the dark control. In contrast, the absorbance characteristics of solar-irradiated Ala- and BSA-amended water were almost identical to the unamended control and to the Ala- and BSA-amended treatments kept in the dark. Also, no significant difference in the maximum bacterial abundance of the solar radiation-exposed Ala- and BSA-amended treatments was detectable as compared to the corresponding dark controls. Our data indicate that Trp is a potential source of solar radiation-mediated humification in Lake Neusiedl.
- Organisation(s)
- Department of Botany and Biodiversity Research, Functional and Evolutionary Ecology
- External organisation(s)
- Royal Netherlands Institute for Sea Research
- Journal
- Aquatic Microbial Ecology
- Volume
- 26
- Pages
- 305-311
- No. of pages
- 7
- ISSN
- 0948-3055
- Publication date
- 01-2002
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 106021 Marine biology
- Keywords
- ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics, Aquatic Science
- Sustainable Development Goals
- SDG 14 - Life Below Water
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/b4944520-877b-40ef-b64f-39a6367d81ed