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

Enlist the modalities available for hand wash, Q. Enlist the modalities ava...

Q. Enlist the modalities available for hand wash? Modalities available for hand wishing are a) 2-4% Chlorhexidine b) 0.3-1 %Triclosan c) 0.6% Parachlorometaxylenol (PC

Mammalian testis, Normal 0 false false false EN-IN X-...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

What is the association between inflammation and fever, What is the associa...

What is the association between inflammation and fever? In the tissue region where inflammation happens bacterial toxins, cytokines, prostaglandins, interleukins and endothelin

Patterns of ageing and death, Patterns of Ageing and Death Plants and...

Patterns of Ageing and Death Plants and their parts develop continuously from germination until death. The latter part of the developmental process, which leads from maturity

Define the disturbances in fluid balance, Define the Disturbances in Fluid ...

Define the Disturbances in Fluid Balance? The correct functioning of cells and tissues depends on appropriate concentrations of nutrients; so any abnormal loss or accumulation

List the five functions controlled by hypothalamus, List the five functions...

List the five functions controlled by hypothalamus. Hypothalamus controls many important functions which are as follows: a) Blood pressure control b) Hunger and thirst

Determine about the klove grooved pegboard test, Determine about the Klove ...

Determine about the Klove Grooved Pegboard Test The subject must place pegs shaped like keys into a board having recesses that are oriented in randomly varying directions. The

Define the process of digestion of proteins, Define the Process of Digestio...

Define the Process of Digestion of Proteins? The daily protein intake (of about 50-100 g) and the protein of enzymes, sloughed (bled or drop off) epithelial cells and mucins, w

Infectious bursal disease, I nfe c tio u s bursal disease Infectio...

I nfe c tio u s bursal disease Infectious bursal disease (popularly known as Gumboro disease) is an acute contagious disease of young chicks caused by an RNA virus, a memb

Are birds rare in polar regions, How different are reptiles and birds conce...

How different are reptiles and birds concerning the maintenance of body temperature? Are birds rare in polar regions? Reptiles are heterothermic, i.e., they do not control thei

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