Enhanced bacterial growth in response to photochemical transformation of dissolved organic matter
Year: 1995
Type: article
Abstract: We tested the hypothesis that light, especially UV‐B radiation, increases the availability of dissolved organic matter (DOM) to pelagic bacteria in lake water. Filtered (0.2 µm) and autoclaved humic lake water (water color 70 mg Pt liter−1, 12 mg dissolved organic C liter−1) was exposed to simulated sunlight (UV‐B, 1.14 W m−2; UV‐A, 3.87 W m−2; and PAR, 20 W m−2) for various periods of time (0–100 h). Irradiated water was then inoculated with a natural bacterial assemblage (0.6‐µm filtered water) and bacterial yield was measured in the stationary phase of the resulting batch cultures. Both bacterial numbers and cell volumes increased (numbers by 65% and volumes as much as 360%) with increasing UV radiation, resulting in an almost sixfold increase in bacterial biomass. Our experiment shows that light exposure can enhance availability of natural lake DOM to bacteria, possibly through cleavage of macromolecules into smaller units, and may influence both carbon cycling and food webs in lake water.
Source: Limnology and Oceanography
Institution: Lund University
Language: English
Subfield: Oceanography
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2164728726