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44

Short answer: There is no benefit for their use in households. Long answer: These soaps (see here for the complete list) contain the so called quaternary ammonium compounds Benzalkonium chloride and Cetrimonium chloride which indeed have antimicrobial properties. While they do not promote resistance to these compounds (see reference 1), their use is still ...


14

Chris has correctly identified the antibacterial agent in the hand soap depicted in the image in the question, and therefore his answer is superior as a direct answer. Nevertheless, other members of the Softsoap series of hand soap uses triclosan, 0.15% as their antibacterial agent, as seen in an image of their ingredient list on the reverse of the bottle. ...


5

You may be interested to look into the Old friends hypothesis, since this is related to how the human immune system may respond to reduced biodiversity in the microbiota. The basic idea is that the human immune system is developed by exposture to the microbiota, and without exposture to organisms from our evolutionary past, immune system regulation might ...


4

This is more of a comment. Triclosan binds to bacterial enoyl-acyl carrier protein reductase (ENR) enzyme, which is encoded by the gene FabI. This binding increases the enzyme's affinity for nicotinamide adenine dinucleotide (NAD+). This results in the formation of a stable, ternary complex of ENR-NAD+-triclosan, which is unable to participate in ...


4

I agree with @Chris that this is mostly a matter of definitions - Greenfacts defines biocides as: According to the Biocides Directive (98/8/EC), biocidal products are those that are intended to destroy, render harmless, prevent the action of, or otherwise exert a controlling effect on any harmful organism by chemical or biological means. Examples ...


3

According to the Hanahan transformation protocol (one of the highest competencies published), a transformation of 200µl will contain $1×10^8 - 1.7×10^8$ cells. Assuming that the pBR322 plasmid is used, 1ng of plasmid will convert to 0.36fmol of plasmid, or $6×10^8$ plasmid copies. As we can clearly see, even at very low quantities of DNA used, there are ...


2

The bacterial spores you are referring to are called endospores. The spore is formed during unfavorable conditions, by duplication of the bacterial chromosomes, and consequent envelopment by various membranes and protective coatings (while still within the original cell). The spore is dormant and remains so as the outer cell degrades during harsh conditions, ...


2

I think this is mostly a semantic differentiation, when you look up definitions for antibiotics you can find very narrow which only include the classic and modern antibiotics, while others include almost everything which has an bacteriocidal (or also anti-fungal) effect, regardless of the mechanism. The Wikipedia article on antibiotics contains the ...


1

Autotrophs: Organisms that can synthesize organic carbon from inorganic carbon (carbon fixation). Nitrogen fixation is not considered an essential condition to qualify as autotrophs. True autotrophs can fix both carbon and nitrogen (Some algae. This true autotrophs is not an actual terminology). Aerobes are organism that require oxygen for metabolism; it is ...


1

According to the Wikipedia section on bacterial capsules, they're made of the same thing: When the amorphous viscid secretion (that makes up the capsule) diffuses into the surrounding medium and remains as a loose undemarcated secretion, it is known as slime layer. Todar's Online Textbook of Bacteriology synonymizes "slime layer" and "biofilm": A ...


1

dd3 summed up the 1st part of your q nicely.....now 'bout the second part...bacterial spore-s (not necessarily endospores only...but akinets & spores produced by actinomycets) are produced by simple mitosis...so the genetic make-up stays the same as the parent cell.....so if you were a spore-forming bacteria, the spore would be essentially you..in ...


1

Yes there are many such mechanisms. One of the simplest, but perhaps most easily overlooked, is metabolism. Conjugation requires ATP. In environments with low levels of nutrients, heterotrophs might not have enough "extra" ATP to fuel the conjugation process. Note that both donor and recipient need to expend ATP in conjugation. The donor needs to make ...


1

In bacteriophage, the viral capsules serve as vectors for other DNA so frequently that there is a common name for this: transduction. The image below, from the Wikipedia, illustrates the basic process. Here a phage, with pink DNA, accidentally packages up other DNA -- in this case, from the bacterium -- in one of the capsules and thereby serves as a vector ...


1

Contrarily to the main opinion expressed so far, I would say that, in theory, it is possible that an Influenza virus can be a vector for another virus. Here is a paper about using influenza virus as vector for a variety of genes. The same method can be leveraged to engineer an Influenza virus particle that contains, for example, genes coming from another ...



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