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Introduction to MicrobiologyIntroduction to Microbiology

Department of Applied ScienceDepartment of Applied Science

King Saud University/ Community King Saud University/ Community

CollegeCollege

By: Murad SawalhaBy: Murad Sawalha



OutlineOutline

s What is Microbiology?What is Microbiology?

s CategoriesCategoriess Why we study microbiology?Why we study microbiology?

s Careers of microbiologyCareers of microbiology

s

The metric system The metric system



What is Microbiology?What is Microbiology?

s Micro means very small, can seen only byMicro means very small, can seen only bya microscope (an optical instrument useda microscope (an optical instrument usedto observe very small object)to observe very small object)

s Microbiology: is the study of very smallMicrobiology: is the study of very smallliving unicellular organisms, theseliving unicellular organisms, theseorganisms called microorganisms ororganisms called microorganisms ormicrobes.microbes.

s Microorganisms are ubiquitous (they areMicroorganisms are ubiquitous (they arevirtually everywhere).virtually everywhere).

s The discipline is just over a century old. The discipline is just over a century old.

s Has given rise to molecular biology andHas given rise to molecular biology and



Cont.Cont.

s Pathogens: Disease causingPathogens: Disease causingmicroorganisms (3% of microbes.microorganisms (3% of microbes.

s

Non-pathogens: microorganisms that doNon-pathogens: microorganisms that donot cause disease (vast majority).not cause disease (vast majority).--

Some of these are beneficial to us &Some of these are beneficial to us &

some have no effect on us at all.some have no effect on us at all. --Microorganisms that help us calledMicroorganisms that help us calledmicrobial allies.microbial allies.

- Microorganisms that harm us- Microorganisms that harm us

called microbial enemies.called microbial enemies.



CategoriesCategories

s Cellular microorganisms are divided into:Cellular microorganisms are divided into:

1) Eucaryotes: organisims having a true1) Eucaryotes: organisims having a true

nucleus, such Algae, fungi, & Protozoa.nucleus, such Algae, fungi, & Protozoa.

2) Procaryotes: organisims lacking a true2) Procaryotes: organisims lacking a true

nucleus, such as archaeans, & Bacteria.nucleus, such as archaeans, & Bacteria.

s Viruses are not consider to be cells (a cellular),Viruses are not consider to be cells (a cellular),

most scientists do not consider viruses to bemost scientists do not consider viruses to beliving organisims, they consider them asliving organisims, they consider them as

infectious agents or infectious particles, ratherinfectious agents or infectious particles, rather

than microorganisims.than microorganisims.



Why study MicrobiologyWhy study Microbiology

(reasons)?(reasons)?

s We have, living on & in our bodies (e.g.,We have, living on & in our bodies (e.g.,

on our skin & in our mouth & in ouron our skin & in our mouth & in our

mouth) - 500 to 1000 differentmouth) - 500 to 1000 differentspecies of microorganisms live on and inspecies of microorganisms live on and in

our bodies. -our bodies. -

These microbes called our indigenous These microbes called our indigenousflora, mostly beneficial for us.flora, mostly beneficial for us.

s Some of the organisms that colonize ourSome of the organisms that colonize our

bodies are known as opportunisticbodies are known as opportunistic





s Microorganisms are essential for life.Microorganisms are essential for life.

- Example: Some microbes produce oxygen- Example: Some microbes produce oxygen

by the process known as photosynthesis.by the process known as photosynthesis.s Many microorganisms are involved in theMany microorganisms are involved in the

decomposition of dead organisms and thedecomposition of dead organisms and the

waste products of living organisms, they calledwaste products of living organisms, they called

decomposers or saprophytes.decomposers or saprophytes.- Example: breakdown dead &- Example: breakdown dead &

dying organ materials (plants & animals) intodying organ materials (plants & animals) into

nitrates, phosphates, and other chemicalnitrates, phosphates, and other chemical

necessary for the growth of plantsnecessary for the growth of plants





s Some microorganism are capable of Some microorganism are capable of decomposing industrial wastes (oils fordecomposing industrial wastes (oils for

example).example).s Many microorganisms are involved inMany microorganisms are involved in

elemental cycles (carbon, nitrogen,elemental cycles (carbon, nitrogen,oxygen, sulfur, & phosphorus cycles).oxygen, sulfur, & phosphorus cycles).

s Algae and bacteria serve as food for tinyAlgae and bacteria serve as food for tinyanimals.animals.

s Some microorganisms live in theSome microorganisms live in the

intestinal tracts of animals, they aid inintestinal tracts of animals, they aid in





s Many microorganisms are essential inMany microorganisms are essential in

various food and beverage industries,various food and beverage industries,

while other are used to produce certainwhile other are used to produce certainenzymes and chemicals.enzymes and chemicals.

s Certain bacteria and fungi produceCertain bacteria and fungi produce

antibiotics that are used to treat patientsantibiotics that are used to treat patientswith infectious diseases.with infectious diseases.

s Microbes are essential in the field of Microbes are essential in the field of

genetic engineering.genetic engineering.





s For many years, microbes haveFor many years, microbes have

been used as “cell models”.been used as “cell models”.

s Microorganisms cause twoMicroorganisms cause twocategories of diseases: infectiouscategories of diseases: infectious

diseases and microbialdiseases and microbial

intoxicationsintoxications

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