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

State the method of recombination or crossing-over, Which of the following ...

Which of the following statement is false regarding the method of recombination or crossing-over? A. Crossing-over takes place during prophase I of meiosis B. Recombination

Explain about types of insulin, Q. Explain about types of Insulin? Thre...

Q. Explain about types of Insulin? Three types of Insulin is available. The type varies in how quickly it starts working (lowering blood glucose), time of peak activity (when t

Slight or no metamorphosis, Slight or no Metamorphosis In primitive w...

Slight or no Metamorphosis In primitive wingless insects (Apterygota) such as spring tails, silver fish etc. and in secondarily apterous insects the young ones which hatch fr

ASSINMENT, HISTORY ON CLASSIFICATION IN BIOLOGY

HISTORY ON CLASSIFICATION IN BIOLOGY

How do cells obtain energy for their functioning, How do cells obtain energ...

How do cells obtain energy for their functioning? Cells obtain energy for their metabolic reactions from the breaking of organic molecules with high energetic content. This ene

Byproducts high in energy and nitrogen, Byproducts high in energy and nitro...

Byproducts high in energy and nitrogen Byproducts in this category include products such as blood meal and poultry offal meal, fish meal, extracted oilseed meals/cakes and wast

Where in leaves the photosynthetic tissue often located, Where in the leave...

Where in the leaves is the photosynthetic tissue often located? The major photosynthetic tissue is the photosynthetic parenchyma (also called as chlorenchyma, do not confuse wi

Metabolism, What is Metabolism ?  The  sum total of vital activities ( ...

What is Metabolism ?  The  sum total of vital activities ( movements , nutrition, growth, respiration, excretion , reproduction, behaviour ,etc.  Is the  life  of a living  bei

Primary egg envelopes, Primary Egg Envelopes These are the egg envelo...

Primary Egg Envelopes These are the egg envelopes which develop in the ovary between oocyte and follicle cells in the space occupied by the interdigitating microvilli. Such e

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