Done by : Renad Abu Rumman

Corrected by : Shady Soghayr

ممكن تفقد البكتيريا هذه الطبقه عند التعرض لظروف مختبريه

S layer is different from slime layer

sex pili (common pili) :help in genetic transfer between

(donors(male)/recipients(female).

The number of flagella is important in the activity of motile.

Structure of flagellum :

1- Filament 2- Hook 3- Basal body:

* It differ from gram positive or negative. It differs according to the basal body and the number of rings * Gram Positive : 2 rings embedded within the plasma membrane. * Gram Negative : 4 rings " 2 in Cell wall (includes 1 in peptidoglycan and 1 in outer membrane) - 2 in plasma

membrane. Endospore formation الابواغ الداخليه

Dormantساكن , tough, non-

reproductive structure

germination vegetative cells.

Spore forming genera: Clostridium (very dangerous bacteria).

Resistance to UV and radiation, desiccation, lysozyme, temperature, starvation, and chemical disinfectants

Relationship to disease

Sporulation: Endospore formation

Germination: Return to vegetative state N: *More pathogenic than other bacteria why? Because it is resistance to environment conditions (PH, temperature). Additional Q: Is it the spore formation of the bacteria need to reproduction?

No, why? Because the spore form from vegetative cell (mother cell) under abnormal conditions (sporulation) and it may be return to vegetative state under perfect conditions (germination) that’s mean there is no increasing in the number of cells.

:اذا كانت تحمل ذلك في جيناتها الا spores اجيمكن للخليه انت لا

. Cell can product spore genetically only

Spore can stay 100,000 years so we use it as biological

weapon.

No water in spore so there's no metabolizing activity

(dormant stage).

Resting stage during “lean or stressful times”.

Resistant protein coat!

Develop in different locations of vegetative cell:

Free ; sub-terminal; central; terminal

some of the central type form swelling in the cell e.g (c) .

location of spore is important in the lab for differentiations.

عملية صبػ الابواغ صعبه نستخدم الحراره لادخالها واذا صبغت صعب نزيل الصبغه

*The position of the spore Is important in the lab and it is used as a

diagnostic criteria to differentiate between different clostridium

*when we stain the spores we use temperature and other factors and

once the spore are stains we cannot exert them from the spores

Fulton Stain: –Schaeffer

Young (24 h) Old (96 h)

No spore spore (blue)

Forespore (الابواغ الاوليه) has two plasma membranes and

peptidoglycan form between them.

Sporulation : the vegetative cell ( mother ) disappear , spore

only exist but before that the DNA replication then a copy of

it move to the spore , the spore have a copy of the DNA of

the mother cell so it can stay at dormant stage ( save

bacteria from extinction).

The spore coat Form ( outer ). Depending on the species, the endospore might be located

terminally (at one end), sub terminally (near one end, or

centrally inside the vegetative cell.

When the endospore matures, the vegetative cell wall ruptures

(lyses), killing the cell, and the endospore is freed.

Most of the water present in the forespore cytoplasm is

eliminated by the time sporulation is complete, and

endospores do not carry out metabolic reactions.

The highly dehydrated endospore core contains only DNA,

small amounts of RNA, ribosomes, enzymes, and a few

important small molecules. The latter include a large amount of

an organic acid called dipicolillic acid which is accompanied by a

large number of calcium ions.

Because of dipicolillic acid and calcium ions it doesn't pigment unless

we increase the temperature

Endospores can remain dormant for thousands of years. An

endospore returns to its vegetative state by a process called

Germination.

Sporulation in bacteria is not a means of reproduction. This

process does not increase the number of cells.

Cytoplasm

Composed largely of water, together with proteins, nucleic

acid, lipids and small amount of sugars and salts

Ribosomes: numerous, 15-20nm in diameter with 70S;

distributed throughout the cytoplasm; sensitive to

streptomycin and erythromycin site of protein synthesis

Plasmids: extra chromosomal genetic elements

Inclusions: sources of stored energy, e,g volutin

Plasmid

Plasmids are small, circular/line, extra chromosomal,

double-stranded DNA molecules. They are capable of self-

replication and contain genes that confer some properties,

such as antibiotic resistance, virulence factors. Plasmids

are not essential for cellular survival.

Inclusions are aggregates of various compounds that are

normally involved in storing energy reserves or building

blocks for the cell. Inclusions accumulate when a cell is

grown in the presence of excess nutrients and they are

often observed under laboratory conditions.

End of the chapter

granulose