ISSN:
1365-2427
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
SUMMARY. 1. We assessed substratum effects on lotic biofilm development by placing glass and white pine sampling units in a fourth-order boreal river, and analysing, at 6-week intervals, upper-surface biofilms for ATP, chlorophyll, ergosterol, and the activities of nine exoenzymes.2. All parameters, except chlorophyll standing stock (range 80–320 μg dm−2) and β-xylosidase activity (range 0.4–4.8 μmol h−1 dm−2), were significantly greater for epixylic biofilms than for epilithic ones, but the magnitude of the increases varied from 2 to 5 fold, showing that, even under similar hydrodynamic conditions, epilithic and epixylic biofilms are structurally and functionally distinct. For example, ergosterol concentrations ranged from undetectable to 0.93 μg dm−2 for epilithon and from 11–49 μg dm−2 for epixylon; corresponding ranges for ATP were 1.6–3.7 (epilithon) and 4.2–7.7 μg dm−2 (epixylon), for acid phosphatase activity: 2.3–4.9 and 20–41 μmolh−1dm−2, and for alkaline phosphatase activity: 1.9–8.1 and 29–150 μmol h−1dm−2, respectively.3. The more extensive epixylic development was attributed to utilization of the wood substratum as a supplemental carbon source and to a higher density of microbial attachment sites.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2427.1991.tb00483.x
