Living at the border: A community and single-cell assessment of lake bacterioneuston activity.
We assessed the physicochemical properties of the surface microlayer (SML: first 900 μm) and its underlying water (ULW: 0.2-0.5-m depth) and compared the composition and activity of their bacterial communities in six lakes located across an altitude gradient. Activity was assessed at both the community level, by measuring leucine bulk incorporation, and at the single-cell level, by using microautoradiography. Catalyzed reporter deposition fluorescence in situ hybridization was used to quantitatively assess the structure of the bacterial assemblage. Dissolved organic matter at the SML was significantly enriched in small-size molecules as compared to the ULW. Bacterial abundance in the SML ranged from 3.2 × 10(5) cells mL(-1) to 3.2 × 10(6) cells mL(-1) and was enriched in four out of six lakes when compared to the ULW. The SML and ULW showed lake-specific differences in bacterial community composition, although in most cases, both layers were dominated by Betaproteobacteria. This group also contributed the most to total activity in both layers in all lakes, followed by Actinobacteria. Despite large differences in environmental conditions among lakes, the fraction of active neustonic bacteria was very similar in most of them. Both bulk and single-cell activities are not necessarily lower in the SML than in the ULW, and well-adapted bacteria exist in the extreme conditions found in this habitat.
Hörtnagl
Paul
P
Laboratory of Aquatic Photobiology and Plankton Ecology, Institute of Ecology, University of Innsbruck, Innsbruck, Austria.
Pérez
María Teresa
MT
Sommaruga
Ruben
R
Freshw Biol. 2009 May;55(5):994-1005
20543908
Appl Environ Microbiol. 1982 Oct;44(4):945-53
16346120
Appl Environ Microbiol. 1998 Nov;64(11):4299-306
9797280
Can J Microbiol. 1976 Dec;22(12):1699-709
1009500
Appl Environ Microbiol. 2005 Sep;71(9):5551-9
16151148
FEMS Microbiol Ecol. 2007 Feb;59(2):242-54
17328765
Environ Sci Technol. 2003 Oct 15;37(20):4702-8
14594381
Microb Ecol. 1983 Dec;9(4):317-28
24221820
FEMS Microbiol Ecol. 2009 Feb;67(2):219-28
19049500
ISME J. 2008 Jul;2(7):776-89
18356822
Environ Microbiol. 2007 Sep;9(9):2200-10
17686018
FEMS Microbiol Ecol. 2005 Oct 1;54(2):269-80
16332325
Appl Environ Microbiol. 2002 Jun;68(6):3094-101
12039771
Appl Environ Microbiol. 1997 Nov;63(11):4178-84
16535724
Appl Environ Microbiol. 2002 Feb;68(2):661-7
11823205
ISME J. 2009 Jan;3(1):13-30
18784755
Environ Microbiol. 2005 May;7(5):723-36
15819854
J Colloid Interface Sci. 1998 Dec 1;208(1):191-202
9820764
Environ Microbiol. 2008 Apr;10(4):1080-6
18215160