Describe the morphological characteristics, Biology

Assignment Help:

Q. Describe the Morphological Characteristics?

One of the first steps in the identification of bacteria in food is microscopic examination to ascertain the shape, size, aggregation, structure and staining reactions of the bacteria present. The following characteristics may be of special significance:

Encapsulation: The presence of capsules or slime may account for sliminess or ropiness of a food. Most capsules are polysaccharides of dextrin; dextran or levan and they serve as a source of reserve nutrients and increase the resistance of bacteria under adverse conditions.

Formation of Endospores: Bacteria of genera Bacillus, Clostridium, Sporosarcina etc have the ability to form endospores. Endospores are formed at an intracellular site and are resistant to heat, ultraviolet light and desiccation. Lysis of the vegetative cell releases the free endospore, which may remain dormant with no detectable metabolism for years. Sporulation usually appears in the late logarithmic phase of growth, possibly because of nutrient depletion or product accumulation. The acquisition of heat resistance is closely related to the formation of dipicolinic acid and the Ca2+ uptake. Germination is favoured by conditions that are favourable for growth.

Formation of Cell Aggregates: It is characteristic of some bacteria to form long chains or of others to clump under certain conditions. It is more difficult to kill all bacteria in intertwined chains or sizable clumps than to destroy separate cells.


Related Discussions:- Describe the morphological characteristics

Some common air pollutants: hydrocarbon, Hydrocarbon (HC): Hydrocarbons ...

Hydrocarbon (HC): Hydrocarbons such as methane, ethylene, acetylene is present in air. Most of these are low molecular weight gases and liquids at ordinary temperature. Sour

What is pulmonary embolism surgery indications, What is Pulmonary Embolism ...

What is Pulmonary Embolism Surgery Indications ? Indications for Surgery :  Acute pulmonary embolism with haemodynamic instability and hypoxaemia is nearly always fatal. Mor

Explain heat preservation - method of food preservation, Explain Heat Prese...

Explain Heat Preservation - Method of Food Preservation? The process of heating was used centuries before its action was understood. Food is heated up or cooked. Heat kills mi

Research, i want to online research biology projects

i want to online research biology projects

Define the intradermal dye test, Define the Intradermal Dye Test? The r...

Define the Intradermal Dye Test? The rate of decolouration of a small quantity of the dye, 2, 6- dichlorophenol injected intradermaly is an index of the ascorbic acid nutrition

Define influence of gardening on the development of botany, Define Influenc...

Define Influence of Gardening on the Development of Botany? The influence of gardening on the development of botany may be seen in the work of John Gerard (1545-1612). Gerard p

Carbohydrate metabolism, CARBOHYDRATE METABOLISM The endproducts of car...

CARBOHYDRATE METABOLISM The endproducts of carbohydrate digestion absorbed into the blood and taken to  the liver by  hepatic portal vein  are four  monosaccharide sugar  ( C 6

What are the substances that are constitute the chromatin, Q. What are the ...

Q. What are the substances that are constitute the chromatin? What is the difference between chromosome and chromatin? The chromatin, dispersed in the nucleus, is a set of fila

Which molecules has more direct effect, Which of the following molecules ha...

Which of the following molecules has more direct effect in learning and memory? A) norepinephrine B) epinephrine C) glutamate D) acetylcholine E) glycine Please leave justification

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd