Talk:CH391L/S12/Quorum Sensing - Revision history

Brian Renda at 18:01, 2 April 2012

Brian Renda — Mon, 02 Apr 2012 18:01:35 GMT

←Older revision		Revision as of 18:01, 2 April 2012
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	*'''[[User:Jeffrey E. Barrick\|Jeffrey E. Barrick]] 18:02, 1 April 2012 (EDT)''':In some cases, at least, it seems that quorum sensing is used for other purposes than for bacteria to "determine their densities". It may be used to determine how much flow is happening around a little clump of cells ("diffusion sensing" - kind of like testing the wind) <cite>Redfield2002</cite>. The idea is that throwing out metabolically "cheap" compounds can let you determine whether making more costly things like extracellular siderophores or proteases is worth doing, or whether they would float away too quickly to give you a benefit.		*'''[[User:Jeffrey E. Barrick\|Jeffrey E. Barrick]] 18:02, 1 April 2012 (EDT)''':In some cases, at least, it seems that quorum sensing is used for other purposes than for bacteria to "determine their densities". It may be used to determine how much flow is happening around a little clump of cells ("diffusion sensing" - kind of like testing the wind) <cite>Redfield2002</cite>. The idea is that throwing out metabolically "cheap" compounds can let you determine whether making more costly things like extracellular siderophores or proteases is worth doing, or whether they would float away too quickly to give you a benefit.
		+	***'''[[User:Brian Renda\|Brian Renda]] 14:01, 2 April 2012 (EDT)''':This is a very interesting hypothesis and I think the diffusion and density hypotheses could both be correct. In the paper, Redfield comments on how in a mixed population, the presence of non-cooperative cheaters haven't been reported and that the lack of individual benefit suggests the need for an alternative hypothesis. In a more recent publication however, found that pathogenic QS bacteria do indeed have non-cooperators and their presence decreases the virulence of the infection <cite>Rumbaugh2009</cite>. Thus individuals that do not cooperate could lead to a lower fitness of a mixed population (of cooperators and non-cooperators), selecting against non-cooperators).

	*'''[[User:Jeffrey E. Barrick\|Jeffrey E. Barrick]] 18:09, 1 April 2012 (EDT)''':Not sure what's up with this sentence..."thus allowing only bacteria on the edge of light and dark to to do."		*'''[[User:Jeffrey E. Barrick\|Jeffrey E. Barrick]] 18:09, 1 April 2012 (EDT)''':Not sure what's up with this sentence..."thus allowing only bacteria on the edge of light and dark to to do."
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	#Redfield2002 pmid=12160634		#Redfield2002 pmid=12160634
	#Pearson1999 pmid=9973347		#Pearson1999 pmid=9973347
		+	#Rumbaugh2009 pmid=19230668
	</biblio>		</biblio>

Brian Renda at 17:04, 2 April 2012

Brian Renda — Mon, 02 Apr 2012 17:04:41 GMT

←Older revision		Revision as of 17:04, 2 April 2012
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	*'''[[User:Jeffrey E. Barrick\|Jeffrey E. Barrick]] 18:09, 1 April 2012 (EDT)''':Not sure what's up with this sentence..."thus allowing only bacteria on the edge of light and dark to to do."		*'''[[User:Jeffrey E. Barrick\|Jeffrey E. Barrick]] 18:09, 1 April 2012 (EDT)''':Not sure what's up with this sentence..."thus allowing only bacteria on the edge of light and dark to to do."
		+	***'''[[User:Brian Renda\|Brian Renda]] 13:04, 2 April 2012 (EDT)''':Stutter-typing fixed.

	=References=		=References=

Brian Renda at 16:54, 2 April 2012

Brian Renda — Mon, 02 Apr 2012 16:54:18 GMT

←Older revision		Revision as of 16:54, 2 April 2012
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	*'''[[User:Yi Kou\|Yi Kou]] 12:24, 1 April 2012 (EDT)''':I am kind of interested in whether cell membrane permeability of the inducer interferes with the result; the system seems to be easily interrupted by different kinetics of inducer in and out the cell membrane.		*'''[[User:Yi Kou\|Yi Kou]] 12:24, 1 April 2012 (EDT)''':I am kind of interested in whether cell membrane permeability of the inducer interferes with the result; the system seems to be easily interrupted by different kinetics of inducer in and out the cell membrane.
		+	***'''[[User:Brian Renda\|Brian Renda]] 12:54, 2 April 2012 (EDT)''': The permeability of the inducer definitely is an important characteristic of a QS system. For AHLs, it looks like the length of the acyl-chain has a significant effect on the diffusibility of the signal across the cell membrane. One study in ''P. aeruginosa'' <cite>Pearson1999</cite> found that an efflux pump is needed to effectively export acyl-chains longer than 12 carbons. As for whether they interfere with the systems they are a part of, generally these systems are for communicating within their species and I am not sure how much variability there is in terms of membrane permeability within a population. I would expect the tuning of each system to take into account the membrane kinetics of their autoinducers. In terms of interspecies QS cross talk (engineered or otherwise), it does seem like it would be important to take into account the relative rates of membrane transport of the autoinducers. Perhaps one would need to use a stronger promoter for the larger AHLs if one wanted equivalency to shorter AHLs in terms of signal production, but I haven't found literature to support that yet.

	*'''[[User:Jeffrey E. Barrick\|Jeffrey E. Barrick]] 18:02, 1 April 2012 (EDT)''':In some cases, at least, it seems that quorum sensing is used for other purposes than for bacteria to "determine their densities". It may be used to determine how much flow is happening around a little clump of cells ("diffusion sensing" - kind of like testing the wind) <cite>Redfield2002</cite>. The idea is that throwing out metabolically "cheap" compounds can let you determine whether making more costly things like extracellular siderophores or proteases is worth doing, or whether they would float away too quickly to give you a benefit.		*'''[[User:Jeffrey E. Barrick\|Jeffrey E. Barrick]] 18:02, 1 April 2012 (EDT)''':In some cases, at least, it seems that quorum sensing is used for other purposes than for bacteria to "determine their densities". It may be used to determine how much flow is happening around a little clump of cells ("diffusion sensing" - kind of like testing the wind) <cite>Redfield2002</cite>. The idea is that throwing out metabolically "cheap" compounds can let you determine whether making more costly things like extracellular siderophores or proteases is worth doing, or whether they would float away too quickly to give you a benefit.
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	#Saeidi2011 pmid=21847113		#Saeidi2011 pmid=21847113
	#Redfield2002 pmid=12160634		#Redfield2002 pmid=12160634
		+	#Pearson1999 pmid=9973347
	</biblio>		</biblio>

Brian Renda at 16:12, 2 April 2012

Brian Renda — Mon, 02 Apr 2012 16:12:51 GMT

←Older revision		Revision as of 16:12, 2 April 2012
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	*"[[User:Razan Alnahhas\|Razan Alnahhas]] 17:22, 30 March 2012 (EDT)":You wrote that QS has been used in synthetic biology as a biosensor for harmful bacteria, so could the QS system that monitors AHL levels be engineered to also respond to high concentrations of AHL by producing an antibiotic to kill the bacteria?		*"[[User:Razan Alnahhas\|Razan Alnahhas]] 17:22, 30 March 2012 (EDT)":You wrote that QS has been used in synthetic biology as a biosensor for harmful bacteria, so could the QS system that monitors AHL levels be engineered to also respond to high concentrations of AHL by producing an antibiotic to kill the bacteria?
	**'''[[User:Adam Meyer\|Adam Meyer]] 21:07, 31 March 2012 (EDT)''':Do you mean to put this QS-antibiotic system into the harmful bacteria or some other detector/killer strain? In the first case, the harmful bacteria would almost certainly just eliminate the system. In the second case, there is [http://www.ncbi.nlm.nih.gov/pubmed/21847113 this] <cite>Saeidi2011</cite>.		**'''[[User:Adam Meyer\|Adam Meyer]] 21:07, 31 March 2012 (EDT)''':Do you mean to put this QS-antibiotic system into the harmful bacteria or some other detector/killer strain? In the first case, the harmful bacteria would almost certainly just eliminate the system. In the second case, there is [http://www.ncbi.nlm.nih.gov/pubmed/21847113 this] <cite>Saeidi2011</cite>.
		+	**'''[[User:Brian Renda\|Brian Renda]] 12:12, 2 April 2012 (EDT)''': Great find Adam! In my opinion the better approach to a response is to form some type of visibile indicator than a pathogenic shift in microbial populations is occurring, since having an automatic antibiotic response may just foster competition between the two species (not to the benefit of the host, I would imagine) and lead to resistance against that antibiotic. Also, different antibiotics tend to focus on different types of bacteria (with some more broad spectrum than others). What ''would'' be really cool is if you tied different AHLs or concentrations to different antibiotics, such that the response strain could initiate a logic driven tiered response to whatever threat it detected.

	*'''[[User:Yi Kou\|Yi Kou]] 12:24, 1 April 2012 (EDT)''':I am kind of interested in whether cell membrane permeability of the inducer interferes with the result; the system seems to be easily interrupted by different kinetics of inducer in and out the cell membrane.		*'''[[User:Yi Kou\|Yi Kou]] 12:24, 1 April 2012 (EDT)''':I am kind of interested in whether cell membrane permeability of the inducer interferes with the result; the system seems to be easily interrupted by different kinetics of inducer in and out the cell membrane.

Jeffrey E. Barrick at 22:09, 1 April 2012

Jeffrey E. Barrick — Sun, 01 Apr 2012 22:09:28 GMT

←Older revision		Revision as of 22:09, 1 April 2012
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	*'''[[User:Jeffrey E. Barrick\|Jeffrey E. Barrick]] 18:02, 1 April 2012 (EDT)''':In some cases, at least, it seems that quorum sensing is used for other purposes than for bacteria to "determine their densities". It may be used to determine how much flow is happening around a little clump of cells ("diffusion sensing" - kind of like testing the wind) <cite>Redfield2002</cite>. The idea is that throwing out metabolically "cheap" compounds can let you determine whether making more costly things like extracellular siderophores or proteases is worth doing, or whether they would float away too quickly to give you a benefit.		*'''[[User:Jeffrey E. Barrick\|Jeffrey E. Barrick]] 18:02, 1 April 2012 (EDT)''':In some cases, at least, it seems that quorum sensing is used for other purposes than for bacteria to "determine their densities". It may be used to determine how much flow is happening around a little clump of cells ("diffusion sensing" - kind of like testing the wind) <cite>Redfield2002</cite>. The idea is that throwing out metabolically "cheap" compounds can let you determine whether making more costly things like extracellular siderophores or proteases is worth doing, or whether they would float away too quickly to give you a benefit.
		+
		+	*'''[[User:Jeffrey E. Barrick\|Jeffrey E. Barrick]] 18:09, 1 April 2012 (EDT)''':Not sure what's up with this sentence..."thus allowing only bacteria on the edge of light and dark to to do."

	=References=		=References=

Jeffrey E. Barrick at 22:02, 1 April 2012

Jeffrey E. Barrick — Sun, 01 Apr 2012 22:02:25 GMT

←Older revision		Revision as of 22:02, 1 April 2012
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	*"[[User:Razan Alnahhas\|Razan Alnahhas]] 17:22, 30 March 2012 (EDT)":You wrote that QS has been used in synthetic biology as a biosensor for harmful bacteria, so could the QS system that monitors AHL levels be engineered to also respond to high concentrations of AHL by producing an antibiotic to kill the bacteria?		*"[[User:Razan Alnahhas\|Razan Alnahhas]] 17:22, 30 March 2012 (EDT)":You wrote that QS has been used in synthetic biology as a biosensor for harmful bacteria, so could the QS system that monitors AHL levels be engineered to also respond to high concentrations of AHL by producing an antibiotic to kill the bacteria?
-	**'''[[User:Adam Meyer\|Adam Meyer]] 21:07, 31 March 2012 (EDT)''':Do you mean to put this QS-antibiotic system into the harmful bacteria or some other detector/killer strain? In the first case, the harmful bacteria would almost certainly just eliminate the system. In the second case, there is [http://www.ncbi.nlm.nih.gov/pubmed/21847113 this]	+	**'''[[User:Adam Meyer\|Adam Meyer]] 21:07, 31 March 2012 (EDT)''':Do you mean to put this QS-antibiotic system into the harmful bacteria or some other detector/killer strain? In the first case, the harmful bacteria would almost certainly just eliminate the system. In the second case, there is [http://www.ncbi.nlm.nih.gov/pubmed/21847113 this] <cite>Saeidi2011</cite>.

	*'''[[User:Yi Kou\|Yi Kou]] 12:24, 1 April 2012 (EDT)''':I am kind of interested in whether cell membrane permeability of the inducer interferes with the result; the system seems to be easily interrupted by different kinetics of inducer in and out the cell membrane.		*'''[[User:Yi Kou\|Yi Kou]] 12:24, 1 April 2012 (EDT)''':I am kind of interested in whether cell membrane permeability of the inducer interferes with the result; the system seems to be easily interrupted by different kinetics of inducer in and out the cell membrane.

		+	*'''[[User:Jeffrey E. Barrick\|Jeffrey E. Barrick]] 18:02, 1 April 2012 (EDT)''':In some cases, at least, it seems that quorum sensing is used for other purposes than for bacteria to "determine their densities". It may be used to determine how much flow is happening around a little clump of cells ("diffusion sensing" - kind of like testing the wind) <cite>Redfield2002</cite>. The idea is that throwing out metabolically "cheap" compounds can let you determine whether making more costly things like extracellular siderophores or proteases is worth doing, or whether they would float away too quickly to give you a benefit.

	=References=		=References=
	<biblio>		<biblio>
-	#Saeidi2011 pmid:21847113	+	#Saeidi2011 pmid=21847113
		+	#Redfield2002 pmid=12160634
		+	</biblio>

Yi Kou at 16:24, 1 April 2012

Yi Kou — Sun, 01 Apr 2012 16:24:08 GMT

←Older revision		Revision as of 16:24, 1 April 2012
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	**'''[[User:Adam Meyer\|Adam Meyer]] 21:07, 31 March 2012 (EDT)''':Do you mean to put this QS-antibiotic system into the harmful bacteria or some other detector/killer strain? In the first case, the harmful bacteria would almost certainly just eliminate the system. In the second case, there is [http://www.ncbi.nlm.nih.gov/pubmed/21847113 this]		**'''[[User:Adam Meyer\|Adam Meyer]] 21:07, 31 March 2012 (EDT)''':Do you mean to put this QS-antibiotic system into the harmful bacteria or some other detector/killer strain? In the first case, the harmful bacteria would almost certainly just eliminate the system. In the second case, there is [http://www.ncbi.nlm.nih.gov/pubmed/21847113 this]

		+	*'''[[User:Yi Kou\|Yi Kou]] 12:24, 1 April 2012 (EDT)''':I am kind of interested in whether cell membrane permeability of the inducer interferes with the result; the system seems to be easily interrupted by different kinetics of inducer in and out the cell membrane.

Adam Meyer at 01:08, 1 April 2012

Adam Meyer — Sun, 01 Apr 2012 01:08:17 GMT

←Older revision		Revision as of 01:08, 1 April 2012
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	*"[[User:Razan Alnahhas\|Razan Alnahhas]] 17:22, 30 March 2012 (EDT)":You wrote that QS has been used in synthetic biology as a biosensor for harmful bacteria, so could the QS system that monitors AHL levels be engineered to also respond to high concentrations of AHL by producing an antibiotic to kill the bacteria?		*"[[User:Razan Alnahhas\|Razan Alnahhas]] 17:22, 30 March 2012 (EDT)":You wrote that QS has been used in synthetic biology as a biosensor for harmful bacteria, so could the QS system that monitors AHL levels be engineered to also respond to high concentrations of AHL by producing an antibiotic to kill the bacteria?
-	**'''[[User:Adam Meyer\|Adam Meyer]] 21:07, 31 March 2012 (EDT)''':Do you mean to put this QS-antibiotic system into the harmful bacteria or some other detector/killer strain. In the first case, the harmful bacteria would almost certainly just eliminate the system. In the second case, there is ~~something like this~~ [http://www.ncbi.nlm.nih.gov/pubmed/21847113 ~~Saeidi 2011~~]	+	**'''[[User:Adam Meyer\|Adam Meyer]] 21:07, 31 March 2012 (EDT)''':Do you mean to put this QS-antibiotic system into the harmful bacteria or some other detector/killer strain? In the first case, the harmful bacteria would almost certainly just eliminate the system. In the second case, there is [http://www.ncbi.nlm.nih.gov/pubmed/21847113 this]

Adam Meyer at 01:07, 1 April 2012

Adam Meyer — Sun, 01 Apr 2012 01:07:15 GMT

←Older revision		Revision as of 01:07, 1 April 2012
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	*"[[User:Razan Alnahhas\|Razan Alnahhas]] 17:22, 30 March 2012 (EDT)":You wrote that QS has been used in synthetic biology as a biosensor for harmful bacteria, so could the QS system that monitors AHL levels be engineered to also respond to high concentrations of AHL by producing an antibiotic to kill the bacteria?		*"[[User:Razan Alnahhas\|Razan Alnahhas]] 17:22, 30 March 2012 (EDT)":You wrote that QS has been used in synthetic biology as a biosensor for harmful bacteria, so could the QS system that monitors AHL levels be engineered to also respond to high concentrations of AHL by producing an antibiotic to kill the bacteria?
		+	**'''[[User:Adam Meyer\|Adam Meyer]] 21:07, 31 March 2012 (EDT)''':Do you mean to put this QS-antibiotic system into the harmful bacteria or some other detector/killer strain. In the first case, the harmful bacteria would almost certainly just eliminate the system. In the second case, there is something like this [http://www.ncbi.nlm.nih.gov/pubmed/21847113 Saeidi 2011]
		+
		+
		+
		+	=References=
		+	<biblio>
		+	#Saeidi2011 pmid:21847113

Razan Alnahhas: New page: *"~~~~":You wrote that QS has been used in synthetic biology as a biosensor for harmful bacteria, so could the QS system that monitors AHL levels be engineered to also respond to high conc...

Razan Alnahhas — Fri, 30 Mar 2012 21:22:37 GMT

New page: *"~~~~":You wrote that QS has been used in synthetic biology as a biosensor for harmful bacteria, so could the QS system that monitors AHL levels be engineered to also respond to high conc...

New page

*"[[User:Razan Alnahhas|Razan Alnahhas]] 17:22, 30 March 2012 (EDT)":You wrote that QS has been used in synthetic biology as a biosensor for harmful bacteria, so could the QS system that monitors AHL levels be engineered to also respond to high concentrations of AHL by producing an antibiotic to kill the bacteria?