scholarly journals Sensitive Whole-Cell Biosensor Suitable for Detecting a Variety of N-Acyl Homoserine Lactones in Intact Rhizosphere Microbial Communities

2007 ◽  
Vol 73 (11) ◽  
pp. 3724-3727 ◽  
Author(s):  
Kristen M. DeAngelis ◽  
Mary K. Firestone ◽  
Steven E. Lindow

ABSTRACT To investigate quorum sensing in rhizosphere soil, a whole-cell biosensor, Agrobacterium tumefaciens(pAHL-Ice), was constructed. The biosensor responded to all N-acyl homoserine lactones (AHLs) tested, except C4 homoserine lactone, with a minimum detection limit of 10−12 M, as well as to both exogenously added AHLs and AHL-producing bacterial strains in soil. This highly sensitive biosensor reveals for the first time the increased AHL availability in intact rhizosphere microbial communities compared to that in bulk soil.

2014 ◽  
Vol 26 (2) ◽  
pp. 415-422 ◽  
Author(s):  
Xuemei Deng ◽  
Guoqiang Zhuang ◽  
Anzhou Ma ◽  
Qing Yu ◽  
Xuliang Zhuang

Biosensors ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 166
Author(s):  
Sergey Bazhenov ◽  
Uliana Novoyatlova ◽  
Ekaterina Scheglova ◽  
Vadim Fomin ◽  
Svetlana Khrulnova ◽  
...  

Aliivibrio fischeri LuxR and Aliivibrio logei LuxR1 and LuxR2 regulatory proteins are quorum sensing transcriptional (QS) activators, inducing promoters of luxICDABEG genes in the presence of an autoinducer (3-oxo-hexanoyl-l-homoserine lactone). In the Aliivibrio cells, luxR genes are regulated by HNS, CRP, LitR, etc. Here we investigated the role of the luxR expression level in LuxI/R QS system functionality and improved the whole-cell biosensor for autoinducer detection. Escherichia coli-based bacterial lux-biosensors were used, in which Photorhabdus luminescensluxCDABE genes were controlled by LuxR-dependent promoters and luxR, luxR1, or luxR2 regulatory genes. We varied either the dosage of the regulatory gene in the cells using additional plasmids, or the level of the regulatory gene expression using the lactose operon promoter. It was shown that an increase in expression level, as well as dosage of the regulatory gene in biosensor cells, leads to an increase in sensitivity (the threshold concentration of AI is reduced by one order of magnitude) and to a two to threefold reduction in response time. The best parameters were obtained for a biosensor with an increased dosage of luxRA. fischeri (sensitivity to 3-oxo-hexanoyl-l-homoserine lactone reached 30–100 pM).


2004 ◽  
Vol 70 (7) ◽  
pp. 4387-4389 ◽  
Author(s):  
Michael W. Taylor ◽  
Peter J. Schupp ◽  
Harriet J. Baillie ◽  
Timothy S. Charlton ◽  
Rocky de Nys ◽  
...  

ABSTRACT We report for the first time the production of acyl homoserine lactones (AHLs) by bacteria associated with marine sponges. Given the involvement of AHLs in bacterial colonization of many higher organisms, we speculate that such quorum sensing signals could play a part in interactions between sponges and the dense bacterial communities living within them.


2019 ◽  
Vol 8 (10) ◽  
pp. 2295-2302 ◽  
Author(s):  
Sheng-Yan Chen ◽  
Wenping Wei ◽  
Bin-Cheng Yin ◽  
Yanbin Tong ◽  
Jianjiang Lu ◽  
...  

2021 ◽  
Vol 12 ◽  
Author(s):  
Chang-ye Hui ◽  
Yan Guo ◽  
Jian Wu ◽  
Lisa Liu ◽  
Xue-qin Yang ◽  
...  

Cadmium (Cd) is carcinogenic to humans and can accumulate in the liver, kidneys, and bones. There is widespread presence of cadmium in the environment as a consequence of anthropogenic activities. It is important to detect cadmium in the environment to prevent further exposure to humans. Previous whole-cell biosensor designs were focused on single-sensing constructs but have had difficulty in distinguishing cadmium from other metal ions such as lead (Pb) and mercury (Hg). We developed a dual-sensing bacterial bioreporter system to detect bioavailable cadmium by employing CadC and CadR as separate metal sensory elements and eGFP and mCherry as fluorescent reporters in one genetic construct. The capability of this dual-sensing biosensor was proved to simultaneously detect bioavailable cadmium and its toxic effects using two sets of sensing systems while still maintaining similar specificity and sensitivity of respective signal-sensing biosensors. The productions of double-color fluorescence were directly proportional to the exposure concentration of cadmium, thereby serving as an effective quantitative biosensor to detect bioavailable cadmium. This novel dual-sensing biosensor was then validated to respond to Cd(II) spiked in environmental water samples. This is the first report of the development of a novel dual-sensing, whole-cell biosensor for simultaneous detection of bioavailable cadmium. The application of two biosensing modules provides versatile biosensing signals and improved performance that can make a significant impact on monitoring high concentration of bioavailable Cd(II) in environmental water to reduce human exposure to the harmful effects of cadmium.


RSC Advances ◽  
2017 ◽  
Vol 7 (47) ◽  
pp. 29302-29305 ◽  
Author(s):  
Pei-Hsuan Chen ◽  
Chieh Lin ◽  
Kai-Hong Guo ◽  
Yi-Chun Yeh

A engineered whole-cell biosensor is developed to generate output signals for the environmental copper analysis.


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