Introduction to Microbiology

Norazli GhadinNorazli.ghadin@city.edu.my

norazlicucst.weebly.com (online note)DNEH 1292: Environmental Microbiology 1

Lecture 1

Environmental Microbiology

Assesment:Formative: 40%Midterm 20Assinment 10Lab report 10Summative 60Final Exam Theory 40

OSPE/LAB 20

Learning Outcomes…IAt the end of this section, students will have an appreciation of &/or be able to: The important developments in Microbiology Describe basic and specialised microscopy

techniques and their applications The extent of the microbial world Describe the important differences between

prokaryotes (Bacteria and Archaea) and eukaryotes

Learning Outcomes…IIAt the end of this section, students should be able to: Describe basic and specialized techniques for

quantifying microbial growth Summarize the process of bacterial and viral

reproduction and describe the dynamics of a bacterial growth curve and the plaque assay

Indicate how bacteria are divided into groups according to their phylogeny &/or metabolism

Lecture PlanScope of Microbiology Extent of the microbial worldHistory of MicrobiologyTechniques Microscopy and Staining Pure culture methods Quantitative methods Microbial growth curvePlaque assayMicrobial diversity Phylogeny Substrate utilization

ReferencesJensen, M.M. and Wright, DN. (1993) Introduction to Microbiology for the Health Sciences, 3rd. ed.Edward, A.L. (1997) 5th. Fundamentals of microbiology, Benjamin Cummings.Nestar, E.W. (1995), Microbiology : A Human Perspective, new York: Mc Graw Hill.Wesley A.V. (1992), Basic Microbiology, 7th. Ed. New York : Harper Collins.Brock T.D et al (1994), Biology of Microorganisms, 7th. Ed. Pretice Hall.Wikipedia

Introduction“microbiology’ - the study of microorganisms organisms to small to be seen with the naked eye except in large groups effects of large numbers often visible e.g., chemical reactions in soil horizons e.g., toxin and gas production in incompletely

sterilised food cans e.g., disease in animals and plants

Environmental Microbiology

Study of the composition and physiology of microbial communities in the environment.Such as Soil Water Air Sediments

Microbial World

VirusesBacteria (Eubacteria) and ArchaeabacteriaFungi (Yeasts and Molds)ProtozoaMicroscopic Algae

BenefitsMaintain balance of environment (microbial ecology)Basis of food chainNitrogen fixationPhotosynthesisDigestion, synthesis of vitaminsManufacture of food and drink

BenefitsGenetic engineeringSynthesis of chemical productsRecycling sewageBioremediation: use microbes to remove toxins (oil spills)Use of microbes to control crop pestsNormal microbiota

Harmful Effects

Cause disease (basis for bioterrorism)

Food spoilage

Pioneers of MicrobiologyRobert Hooke, UK (1665) Proposed the Cell Theory Observed cork with crude microscope All living things are composed of cells

Spontaneous generation Some forms of life could arise

spontaneously from non-living matter

Francesco Redi, IT (1668) Redi’s experiments first to dispprove S.G.

Pioneers of Microbiology

Antoni van Leeuwenhoek, DE (1673) First observed live microorganisms

(animalcules)Schleiden and Schwann, DE Formulated Cell Theory: cells are the

fundamental units of life and carry out all the basic functions of living things

Pasteur, FR and Tyndall, UK (1861) Finally disproved S.G.

Pioneers of Microbiology

Louis Pasteur (1822-1895), Chemist Fermentation (1857) Pasteurization: heat liquid enough to kill

spoilage bacteria (1864) Vaccine development – rabies Proposed the germ theory of disease Proposed aseptic techniques (prevent

contamination by unwanted microbes) Director of Pasteur Institute, Paris (1894)

Pioneers of Microbiology

Joseph Lister, UK (1867) Used phenol (carbolic acid) to disinfect

wounds First aseptic technique in surgeryRobert Koch, DE (1876) Postulates – Germ theory (1876) Identified microbes that caused anthrax

(1876), tuberculosis (1882) and cholera(1883)

Developed microbiological media & streak plates for pure culture (1881)

Branches of MicrobiologyBacteriology: study of bacteriaMycology: study of fungiImmunology: study of immunity Edward Jenner, UK: developed vaccination

(1798) Metchnikoff, RU: discovered phagocytes (1884) Paul Ehrlich, DE: theory of immunity (1890)Virology: study of viruses Beijerinck, NE: discovered intracellular

reproduction of TMV; coined the term “virus” (1899)

Branches of Microbiology

Parasitology: study of protozoa and parasitic wormsChemotherapy Treatment of disease by using chemical means Antibiotics produced naturally Synthetic drugs Paul Ehrlich (1878) – used arsenic compounds to

fight disease – ‘magic bullet’

Branches of Microbiology

Chemotherapy Alexander Fleming, Scotland (1928) discovered

penicillin Selman Waksman, Ukraine (1944) discovered

streptomycin

Problems Toxicity of drugs => Selective toxicity Resistance of bacteria to drugs

Branches of Microbiology

Recombinant DNA Technology Recombinant DNA Genetic engineering/biotechnology Microbial genetics – mechanism by which

microbes inherit genes Molecular biology – structure and

function (expression) of genes Molecular epidemiology/diagnostics

Branches of Microbiology

Biotechnology GMOs/GEMs for industrial, pharmaceutical and

agricultural applications Improvements of agriculture (plants and

animals) Gene therapy: inserting a missing gene or

replacing a defective one in human cells

Classification of Microorganisms

A. Principles of Classification and Nomenclature

B. Eukaryotic OrganismsC. Prokaryotic Organisms

Principles of Classification and Nomenclature

Taxonomy Kingdom

Phylum (pl: Phyla)

Class

Order

Family

Genus (pl: Genera)

Species (pl: Species)

Principles of Classification and Nomenclature

Nomenclature Scientific name (Systematic Name)

Binomial System of Nomenclature

Genus name + species name italicized or underlined genus name is capitalized and may be abbreviated species name is never abbreviated.

eg: Bacillus subtilisB. subtilis

Eukaryotic Organisms

Eukaryotic Kingdoms Kingdom Protista

(Protozoa and Algae)

Kingdom Fungi

Kingdom Plantae

Kingdom Animalia

Prokaryotic Organisms

Prokaryotic Kingdoms Kingdom Eubacteria Kingdom Archaeobacteria

SYMBIOSIS is the interaction between 2 different organisms living together

HOST- usually the LARGER of the 2 organisms

SYMBIONT- usually the SMALLER member

THE THREE SYMBIOTIC RELATIONSHIPS ARE...

PARASITISM MUTUALISM COMMENSALISM

PARASITISM

Is a relationship where the Symbiont lives in/on the HostThe Symbiont (or Parasite) BENEFITS The Host is HARMEDFor example, the tick in the picture above is a parasite. It benefits by extracting blood from its human host. The human is harmed because

Is a relationship between the host and a symbiont, where both organisms benefit and neither is harmed.The relationship can be long or short term.For example, in the photo above, the host flower benefits by being pollinated by the traveling butterfly. The symbiont butterfly benefits from the nectar that it extracts from the flower.

Mutualism

COMMENSALISM

Is a relationship between the host and symbiont, where the symbiont benefits and the host is neither helped nor harmed.The symbiont benefits by receiving transportation, housing, and/or nutrition.For example, in the photo above the symbiont barnacles receive transportation from the host whale. The host whale is neither helped nor harmed by the barnacles.