Microbiology

Other Chemical Agents Those Used Against Microbial Life

There are microorganisms all around us. Of course some are habitual to the common chemicals they may encounter every day life. But some chemical agents are hares to the microorganisms. And microorganisms shows a quick response against them, because chemicals are added in evaluated concentration, they win and kill the microorganisms by one or more way.

Here we would discuss and see some commonly used chemical agents those are used to kill microorganisms on a large scale.

Chlorine And Chlorine Compounds

Chlorine is the most widely used disinfectant. It may be used in gaseous or in certain chemical combination.

The compressed gas in liquid form is almost universally employed for the purification of municipal water supplies. 

Chlorine gas is hard to handle so, it is used in large plants only where it can be controlled by special equipment.

There are many compounds of chlorine available those are easy to handle then free chlorine, under proper conditions of use, are equally effective as disinfectant. Hypochlorites is one of the compound in this category. Calcium hypochlorite also known as chlorinated like, and sodium hypochlorite are some popular compounds in this category.

The chloramines represent another category of chlorine compounds used as disinfectants, sanitizing agents, or antiseptics.

Practical Applications

Semmelweis is credited with having used hypochlorite in 1846 to 1848. Medical students were required to wash their hands and soak them in a hypochlorite solution before examining patients.

Chlorine compounds are widely used in controlling microorganisms. Major applications are in water treatment, in the food industry, for domestic uses, and in medicine.

Products containing calcium hypochlorite are used in to sanitization of dairy equipment and eating utensils in restaurant. Solution of sodium hypochlorite of a 1% concentration are used for personal hygiene and as a house hold disinfectant. Higher concentration as of 5% to 12% are also employed as household bleaches and disinfectant.

The amount of hypochlorite added should provide a residual concentration of approximately 1 mg per liter of free chlorine.

Chlorine compounds have been used to disinfect open wounds, to treat athlete’s foot, to treat other infections, and as a general disinfectant.

Mode Of Action

The antimicrobial action of chlorine and it’s compounds comes through the hypochlorous acid formed when free chlorine is added in water.

Similarly, hypochlorite and chloramines undergo hydrolysis, with the formation of hypochlorous acid.

The hypochlorous acid formed in each instance is further decomposed.

The oxygen released in this reaction (nascent oxygen) is a strong oxidizing agent, and through its action on cellular constituents, microorganisms are destroyed.

Heavy Metal And Their Compounds

Most of the heavy metals, either alone or in certain compounds, exert a detrimental effect upon microorganisms. The most effective is mercury, silver and copper. 

Mode Of Action

Heavy metal and it’s compound have antimicrobial activity by binding cell proteins and inactivating them.

High concentration of slats if heavy metals like mercury, copper, and silver coagulate cytoplasmic proteins. Resulting in damage or death of the cell.

Gaseous Agents

Certain kind of medical devices that need to be available in a sterile condition are made of materials that are damaged by heat. Examples include syringes, blood transfusion apparatus, and catheterization equipment.

The main agents currently used for gaseous sterilization are ethylene oxide, beta-propiolactone, and formaldehyde.

Reference: Microbiology Pelczar

Gaurav Singh

Editor in Chief Medical Microbiology & Recombinant DNA Technology (RDT) Labs - RDT Labs Magazine

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