Tag: useful microorganisms

Fermentation is a metabolic process that converts sugar to acids, gases or alcohol. It occurs in yeast and bacteria, and also in oxygen-starved muscle cells, as in the case of lactic acid fermentation.

Pasteurization is the technique of heating milk at a high temperature ( 75$^0$ C) for a short period of time (15 s) and again cooling down quickly. It kills bacteria that may be in the milk, to ensure its safe consumption. Also, it increases the lifespan of milk. Therefore, pasteurisation is a 'sterilisation technique'.

Phenol usually in low concentrations is used in household used for cleaning and disinfecting purpose.Chloroform can't be used for disinfecting utensils as it is an anesthetic drug and causes dizziness.Isopropanol is a flammable reagent and also can't be used as a cleaning product.Butanol is usually used in painting or other work as thinner and also its fumes are harmful if inhaled and may cause slight irritation. so this also can't be used for disinfecting utensils. So, the correct answer is'5% of phenol'

The yeast is a type of fungal species which have unicellular cells. These cells are known to perform anaerobic fermentation of the sugars and produce alcohol and carbon dioxide. The organism respires anaerobically and breaks down the fermentable sugars in the absence of oxygen.

Gamma rays are used for sterilization of pharmaceutical products after their production as to prevention the growth of any microorganism that may be present in the product. It is also used for sterlization of food product to kill any harmful bacteria or other organism that are present in the food, it won't make the food radioactive. Gamma rays act as a ionising radiation and it will inhibit the growth of microorganism. So it can be used to sterilize culture media. So, the correct answer is 'Both A and C'

Hops used to provide a distinct flavour to beer are actually the flowers of Humulus lupulus

Aseptic culture means culture which takes place in the absence of harmful microbes or other contaminants. During tissue culture, the cells are kept under the aseptic condition to avoid contamination caused by microbes because the microbes inhibit the growth of the cell and utilize the nutrients provided for the plants in the media for their growth as they have the ability to multiply fast. The aseptic condition during culture can be maintained by the process of heating, fumigation of lab, autoclave apparatus before use, wiping the apparatus with alcohol, performing the experiment in the laminar air flow under HEPA filters. 

Louis Pasteur is credited with discovering that yeast is responsible for fermentation, transforming the understanding of the process from a chemical reaction to a biological one.

Zymase is the enzyme complex that catalyse the fermentation of sugar into ethanol and $CO _2$. It occur naturally in the yeast. Zymase activity varies as among the yeast strains.