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

Name element playing significant role in nitrogen fixation, An element play...

An element playing significant role in nitrogen fixation is : 1.  Molybdenum 2. Copper 3. Manganese 4. Zinc An element playing significant role in nitrogen fixation

Hypertensive emergencies, Hypertensive emergencies should be treated within...

Hypertensive emergencies should be treated within one hour. Hypertensive urgencies may be treated more slowly. The term accelerated malignant hypertension is used when retinal haem

How much time is required for a single cell, How much time is required for ...

How much time is required for a single cell of Detoxivicatium completeium to grown into a population large enough to fill the volume of the earth?

Adolescence, ADOLESCENC E  - It is the period of growth from the onset ...

ADOLESCENC E  - It is the period of growth from the onset of puberty to the completion of growth & maturity. It extends between 12- 20 yrs. It is a period of rapid physical

Animal tissue, Animal Tissue A tissue is a group of cells that are si...

Animal Tissue A tissue is a group of cells that are similar in structure, origin and function. Tissue word coined by Bichat (Father of Histology). Histology term

What is the clitellum of earthtworms, Q. What is the clitellum of earthtwor...

Q. What is the clitellum of earthtworms and where it is located? The clitellum is a special region of the annelid constituted by rings (metameres) with reproductive function. I

Metanephridia - excretion, Normal 0 false false false E...

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

What is cold-shortening, What is cold-shortening It is important to poi...

What is cold-shortening It is important to point out that over-effective chilling of hot carcasses can lead to toughness. If the temperature of the meat (muscles) can be reduce

Show endocrine glands involved in the menstrual cycle, Q. What are the endo...

Q. What are the endocrine glands involved in the menstrual cycle? What are the hormones in action? The endocrine glands that secrete hormones involved in the menstrual cycle ar

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