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

In hormonal terms why does menses occur, In hormonal terms why does menses ...

In hormonal terms why does menses occur? Menses is the endometrial monthly desquamation that happens as the estrogen and progesterone levels fall after the regression of the co

Explain about common congenital heart diseases, Explain about common congen...

Explain about common congenital heart diseases ? Congenital Heart Disease is commonly classified as acyanotic and cyanotic. Acyanotic Left to right shunts Obstructive Lesion

Preparing financial statements from the work sheet, When the work sheet is ...

When the work sheet is finished all the essential information to prepare the statement of retained earnings, income statement and balance sheet is readily available. Currently you

Coniferous forest - ecosystem, Coniferous forest - Ecosystem Cold regi...

Coniferous forest - Ecosystem Cold regions with high rainfall and strongly seasonal climates with long winters and fairly short summers are characterised by boreal coniferous

What is the phase of the menstrual cycle, In general what is the phase of t...

In general what is the phase of the menstrual cycle when copulation may lead to fecundation? Although this is not a rule, to be effective fecundation in general must happen wit

Bacteria - type of microorganisms, Q. Bacteria - type of microorganisms? ...

Q. Bacteria - type of microorganisms? Many of us know bacteria only as "germs," invisible to naked eyes that can invade our bodies and make us sick. Few know that many bacteria

What is normalisation of inverted t-waves?, Q. What is Normalisation of Inv...

Q. What is Normalisation of Inverted T-Waves? In patients with flat or inverted T-waves at rest, the evolution to an upright T-wave has been considered by some to be a sign of

Regulation of respiration in a child, Describe the factors that are involve...

Describe the factors that are involved in the regulation of respiration in a child who decides to hold his/her breath for as long as possible.

Chemical equation of the aerobic cellular respiration, Q. What is the chemi...

Q. What is the chemical equation of the aerobic cellular respiration? The chemical equation of the aerobic cellular respiration is given below: C 6 H 12 O 6 + 6 O 2 + 36 A

Human eye, Who first discovered eye anatomy?

Who first discovered eye anatomy?

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