scholarly journals Ecophysiological Interaction between Nitrifying Bacteria and Heterotrophic Bacteria in Autotrophic Nitrifying Biofilms as Determined by Microautoradiography-Fluorescence In Situ Hybridization

2004 ◽  
Vol 70 (3) ◽  
pp. 1641-1650 ◽  
Author(s):  
Tomonori Kindaichi ◽  
Tsukasa Ito ◽  
Satoshi Okabe
Keyword(s):  
Acetic Acid ◽  
In Situ Hybridization ◽  
Bacterial Community ◽  
16S Rrna ◽  
Fluorescence In Situ Hybridization ◽  
Heterotrophic Bacteria ◽  
Nitrifying Bacteria ◽  
Community Members ◽  
Biofilm Community

ABSTRACT Ecophysiological interactions between the community members (i.e., nitrifiers and heterotrophic bacteria) in a carbon-limited autotrophic nitrifying biofilm fed only NH4 + as an energy source were investigated by using a full-cycle 16S rRNA approach followed by microautoradiography (MAR)-fluorescence in situ hybridization (FISH). Phylogenetic differentiation (identification) of heterotrophic bacteria was performed by 16S rRNA gene sequence analysis, and FISH probes were designed to determine the community structure and the spatial organization (i.e., niche differentiation) in the biofilm. FISH analysis showed that this autotrophic nitrifying biofilm was composed of 50% nitrifying bacteria (ammonia-oxidizing bacteria [AOB] and nitrite-oxidizing bacteria [NOB]) and 50% heterotrophic bacteria, and the distribution was as follows: members of the alpha subclass of the class Proteobacteria (α-Proteobacteria), 23%; γ-Proteobacteria, 13%; green nonsulfur bacteria (GNSB), 9%; Cytophaga-Flavobacterium-Bacteroides (CFB) division, 2%; and unidentified (organisms that could not be hybridized with any probe except EUB338), 3%. These results indicated that a pair of nitrifiers (AOB and NOB) supported a heterotrophic bacterium via production of soluble microbial products (SMP). MAR-FISH revealed that the heterotrophic bacterial community was composed of bacteria that were phylogenetically and metabolically diverse and to some extent metabolically redundant, which ensured the stability of the ecosystem as a biofilm. α- and γ-Proteobacteria dominated the utilization of [14C]acetic acid and 14C-amino acids in this biofilm. Despite their low abundance (ca. 2%) in the biofilm community, members of the CFB cluster accounted for the largest fraction (ca. 64%) of the bacterial community consuming N-acetyl-d-[1-14C]glucosamine (NAG). The GNSB accounted for 9% of the 14C-amino acid-consuming bacteria and 27% of the [14C]NAG-consuming bacteria but did not utilize [14C]acetic acid. Bacteria classified in the unidentified group accounted for 6% of the total heterotrophic bacteria and could utilize all organic substrates, including NAG. This showed that there was an efficient food web (carbon metabolism) in the autotrophic nitrifying biofilm community, which ensured maximum utilization of SMP produced by nitrifiers and prevented buildup of metabolites or waste materials of nitrifiers to significant levels.

scholarly journals Use of Microautoradiography Combined with Fluorescence In Situ Hybridization To Determine Dimethylsulfoniopropionate Incorporation by Marine Bacterioplankton Taxa

2004 ◽  
Vol 70 (8) ◽  
pp. 4648-4657 ◽  
Author(s):  
Maria Vila ◽  
Rafel Simó ◽  
Ronald P. Kiene ◽  
Jarone Pinhassi ◽  
José M. González ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Gulf Of Mexico ◽  
Fluorescence In Situ Hybridization ◽  
Marine Bacteria ◽  
Heterotrophic Bacteria ◽  
Phytoplankton Bloom ◽  
Mediterranean Coast ◽  
Marine Bacterioplankton ◽  
Significant Uptake

ABSTRACT The fraction of planktonic heterotrophic bacteria capable of incorporating dissolved dimethylsulfoniopropionate (DMSP) and leucine was determined at two coastal sites by microautoradioagraphy (AU). In Gulf of Mexico seawater microcosm experiments, the proportion of prokaryotes that incorporated sulfur from [35S]DMSP ranged between 27 and 51% of 4′,6-diamidino-2-phenylindole (DAPI)-positive cells, similar to or slightly lower than the proportion incorporating [3H]leucine. In the northwest Mediterranean coast, the proportion of cells incorporating sulfur from [35S]DMSP increased from 5 to 42% from January to March, coinciding with the development of a phytoplankton bloom. At the same time, the proportion of cells incorporating [3H]leucine increased from 21 to 40%. The combination of AU and fluorescence in situ hybridization (FISH) revealed that the Roseobacter clade (α-proteobacteria) accounted for 13 to 43% of the microorganisms incorporating [35S]DMSP at both sampling sites. Significant uptake of sulfur from DMSP was also found among members of the γ-proteobacteria and Cytophaga-Flavobacterium groups. Roseobacter and γ-proteobacteria exhibited the highest percentage of DAPI-positive cells incorporating 35S from DMSP (around 50%). Altogether, the application of AU with [35S]DMSP combined with FISH indicated that utilization of S from DMSP is a widespread feature among active marine bacteria, comparable to leucine utilization. These results point toward DMSP as an important substrate for a broad and diverse fraction of marine bacterioplankton.

Comparison of detection specificity of nitrifying bacteria in biofilm using fluorescence in situ hybridization and in situ fluorescent antibody methods

2003 ◽  
Vol 47 (5) ◽  
pp. 129-132
Author(s):  
N. Noda ◽  
Y. Ebie ◽  
M. Matsumura ◽  
S. Tsuneda ◽  
A. Hirata ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Fluorescent Antibody ◽  
Nitrifying Bacteria ◽  
Specific Fluorescence ◽  
Antibody Method ◽  
In Situ Detection ◽  
Detection Specificity ◽  
Fluorescent Antibody Method

The in situ fluorescent antibody and fluorescence in situ hybridization (FISH) methods are very useful in the in situ detection of specific bacteria like nitrifiers in a biofilm. In this study, simultaneous staining using the FISH and in situ fluorescent antibody methods was examined. As a result, no specific fluorescence was observed with either method when FISH was performed followed by the in situ fluorescent antibody method; however, when the in situ fluorescent antibody method was performed first followed by FISH, specific fluorescence was observed in both cases. Moreover, it was suggested that the detection specificities of FISH and the in situ fluorescent antibody method are almost identical.

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