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Compound
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Target Concepts:
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Query: EC:3.1.1.79 (
hormone-sensitive lipase
)
2,163
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Nitrobacter winogradskyi is a chemolithotrophic bacterium that plays a role in the nitrogen cycle by oxidizing nitrite to
nitrate
. Here, we demonstrate a functional N-acyl-homoserine lactone (acyl-HSL) synthase in this bacterium. The N. winogradskyi genome contains genes encoding a putative acyl-
HSL
autoinducer synthase (nwi0626, nwiI) and a putative acyl-
HSL
autoinducer receptor (nwi0627, nwiR) with amino acid sequences 38 to 78% identical to those in Rhodopseudomonas palustris and other Rhizobiales. Expression of nwiI and nwiR correlated with acyl-
HSL
production during culture. N. winogradskyi produces two distinct acyl-HSLs, N-decanoyl-l-homoserine lactone (C10-HSL) and a monounsaturated acyl-
HSL
(C10:1-HSL), in a cell-density- and growth phase-dependent manner, during batch and chemostat culture. The acyl-HSLs were detected by bioassay and identified by ultraperformance liquid chromatography with information-dependent acquisition mass spectrometry (UPLC-IDA-MS). The C=C bond in C10:1-
HSL
was confirmed by conversion into bromohydrin and detection by UPLC-IDA-MS.
...
PMID:Nitrite-Oxidizing Bacterium Nitrobacter winogradskyi Produces N-Acyl-Homoserine Lactone Autoinducers. 2609 66
The genomes of many bacteria that participate in nitrogen cycling through the process of nitrification contain putative genes associated with acyl-homoserine lactone (AHL) quorum sensing (QS). AHL QS or bacterial cell-cell signaling is a method of bacterial communication and gene regulation and may be involved in nitrogen oxide fluxes or other important phenotypes in nitrifying bacteria. Here, we carried out a broad survey of AHL production in nitrifying bacteria in three steps. First, we analyzed the evolutionary history of AHL synthase and AHL receptor homologs in sequenced genomes and metagenomes of nitrifying bacteria to identify AHL synthase homologs in ammonia-oxidizing bacteria (AOB) of the genus
Nitrosospira
and nitrite-oxidizing bacteria (NOB) of the genera
Nitrococcus
,
Nitrobacter
, and
Nitrospira
Next, we screened cultures of both AOB and NOB with uncharacterized AHL synthase genes and AHL synthase-negative nitrifiers by a bioassay. Our results suggest that an AHL synthase gene is required for, but does not guarantee, cell density-dependent AHL production under the conditions tested. Finally, we utilized mass spectrometry to identify the AHLs produced by the AOB
Nitrosospira multiformis
and
Nitrosospira briensis
and the NOB
Nitrobacter vulgaris
and
Nitrospira moscoviensis
as
N
-decanoyl-l-homoserine lactone (C
10
-
HSL
),
N
-3-hydroxy-tetradecanoyl-l-homoserine lactone (3-OH-C
14
-
HSL
), a monounsaturated AHL (C
10:1
-
HSL
), and
N
-octanoyl-l-homoserine lactone (C
8
-
HSL
), respectively. Our survey expands the list of AHL-producing nitrifiers to include a representative of
Nitrospira
lineage II and suggests that AHL production is widespread in nitrifying bacteria.
IMPORTANCE
Nitrification, the aerobic oxidation of ammonia to
nitrate
via nitrite by nitrifying microorganisms, plays an important role in environmental nitrogen cycling from agricultural fertilization to wastewater treatment. The genomes of many nitrifying bacteria contain genes associated with bacterial cell-cell signaling or quorum sensing (QS). QS is a method of bacterial communication and gene regulation that is well studied in bacterial pathogens, but less is known about QS in environmental systems. Our previous work suggested that QS might be involved in the regulation of nitrogen oxide gas production during nitrite metabolism. This study characterized putative QS signals produced by different genera and species of nitrifiers. Our work lays the foundation for future experiments investigating communication between nitrifying bacteria, the purpose of QS in these microorganisms, and the manipulation of QS during nitrification.
...
PMID:Acyl-Homoserine Lactone Production in Nitrifying Bacteria of the Genera Nitrosospira, Nitrobacter, and Nitrospira Identified via a Survey of Putative Quorum-Sensing Genes. 2888 24
