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

Explain scope of food science and technology as a subject, Explain Scope of...

Explain Scope of Food Science and Technology as a Subject? Food science and technology has developed as a discipline to systematically organize and link various kinds of knowle

Etiology of constipation, Q. Etiology of constipation? The etiology and...

Q. Etiology of constipation? The etiology and management of two distinct disorders of the bowel viz., diarrhoea and constipation. We small continue our discussion on certain ot

Explain the clinical features of ps and vsd, Explain the Clinical Features ...

Explain the Clinical Features of PS and VSD ? Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

What do you mean by binomial system in binomial nomenclature, Q. What do yo...

Q. What do you mean by Binomial system in binomial nomenclature? In the previous sections we have outlined the concepts of binomial nomenclature at International level and the

Optical defects of eye, Give an introduction for optical defects, of eye fo...

Give an introduction for optical defects, of eye for an assignment?

Cloning, there are a restriction map of a plasmid and a human gene of known...

there are a restriction map of a plasmid and a human gene of known sequence. Your task is to clone the human liver cDNA for this gene so that the start codon is closer to the EcoRI

Define the assessment of copper status in humans, Define the Assessment of ...

Define the Assessment of Copper Status in Humans? A reliable index to assess marginal copper status is currently not available. However, severe copper deficiency may be detecte

How hiv infection works, How do antibody-based tests detect how HIV infecti...

How do antibody-based tests detect how HIV infection works? After the infection by the HIV the immune system starts the production of antibodies (primary immune response) again

What are mycorrhizas, What are mycorrhizas? How does each participant benef...

What are mycorrhizas? How does each participant benefit in this ecological interaction? Mycorrhizas are mutualist ecological interactions among fungi and some plants roots. Fun

Characteristics of river systems, Characteristics of River Systems Th...

Characteristics of River Systems The basic function of the rivers is to convey surplus rain water from land to sea. Annually the rivers carry fresh water, equivalent to 25 cm

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