BIO 208 Unit 1 - The Microbial World and You
Unit One – The Microbial World and You.
Lecture 1 we begin our discussion on microbiology. CH1: pp 1-6 Microbes in Our Lives (in
detail) and pp. 16-21 Microbes and Human Welfare (skim)
I. What Is Microbiology
biology –
micro A. What Are Microbes?
 Microbes are:
bacteria
Domain Bacteria
archaea
Domain Archaea
protists
algae
Domain Eukarya
fungi
B. Where Are Microbes Found?
C. What Do Microbes Do?
Why don’t microbes take over the planet?
1.
2.
1
BIO 208 Unit 1 - The Microbial World and You
D. Why Should We Study Microbiology?
 Relationship to other disciplines:
 Human disease
 Plant/animal/fish/ disease
 Human (and plant, animal, fish, insect, etc) health
 Food and drink production and safety
 Chemical products
 Biotechnology
 Bioremediation
 We are microbial ecosystems!
Assignment to complete before next class:
•
•
Surf through course blackboard and web site linked there
Email your TA
– Subject line “BIO 208 Assignment 1”
– Tell your TA 2 things you noticed on the course BB/web site that you think will be
helpful, useful, or were interesting to you.
2
BIO 208 Unit 1 - The Microbial World and You
Lecture 2 - We will be talking about how Microbiology emerged as a modern science. CH 1:
pp. 6-11 Brief History of Microbiology and pp. 405-406 Etiology of Infectious Disease.
II. How Did Microbiology Become A Science?
A. Discovery of Microbes
1. Ancient Chinese
2. Romans (1st Century BC)
*3. Antoni van Leeuwenhoek (1673) – “animalcules”
B. Battle Over Spontaneous Generation
1. Redi (1668)
2. Needham (1745) versus Spallanzani (1765)
*3. Louis Pasteur (1861) -
4. Tyndall (1877) -
3
BIO 208 Unit 1 - The Microbial World and You
C. Germ Theory of Disease – Diseases are caused by microbes
1. Bassi (1835) –
2. Berkeley (1845) –
*3. Semmelweis (1840s) – childbed fever (Streptococcus agalactiae)
*4. Pasteur (1865) –
*5. Lister (1867) –
*6. Robert Koch (late 1880s) – one specific microbial agent causes one specific disease
1876 – Bacillus anthracis – anthrax
1882 – Mycobacterium tuberculosis – tuberculosis (TB)
1883 – Vibrio cholera - cholera
Koch's postulates – described on pp. 405-406
1. associate 2. isolate 3. inoculate 4. re-isolate -
D. Microbial Effects on Matter (not in your text so take good notes)
1. Schwann (1837) –
2. Pasteur (1857-1860) –
3. Winogradsky and Beijerinck (1887-1905) –
 microbes are involved in C, N, and S biogeochemical cycles in soil and aquatic
environments
 bacteria have modes of metabolism very different from that of eukaryotes
Assignment to complete before next class (will not be collected)
•
•
CH 1 Chapter end study questions:
– Review: 1, 4, 5j, m, n, p, 6, 8
– Multiple choice: 1-3
– Critical thinking: 2
– Clinical applications: 2
Answers are available at The Microbiology Place (http://www.microbiologyplace.com/
see inside cover of your text)
4
BIO 208 Unit 1 - The Microbial World and You
In Lecture 3 and 4 we will talk about how microorganisms are classified, some of the
similarities and differences among the major groups of microbes, and how we see
microorganisms using microscopes.
III. How Are Microorganisms Classified?
A. Nomenclature (p.6)
B. Phylogenetic Relationships (pp. 273-282)
1978 – 3 Domains – Carl Woese (1978, 1990)
Domain -
1. Domain Eukarya
a. Kingdom Protista
1. Unicellular algae – Ex Spirogyra
2. Protozoa – Ex. Paramecium
b. Kingdom Fungi
Morphology types:
1. Yeasts – Ex. Saccharomyces
2. Molds – Ex. Rhizopus
3. Mushrooms
5
BIO 208 Unit 1 - The Microbial World and You
Domains Bacteria and Archaea
What do they have in common?
What are the differences?
2. Domain Bacteria
Ex. Escherichia coli
3. Domain Archaea
Ex. Halobacterium salinarium
Comparing general characteristics of the 3 Domains
Domain
has a nucleus?
DNA packaged with histones?
arrangement of membrane
type of phospholipids
has peptidoglycan?
FA = fatty acids
Eukarya
yes
yes
bilayer
FA
no
Archaea
no
yes
bilayer or
monolayer
No FA
no
C. What do we do with:
1. Viruses -
2. Prions –
 BSE (bovine spongiform encephalopathy = mad cow disease)
 Creutzfeldt-Jacob Disease (CJD and nvCJD)
 Kuru
Bacteria
no
no
bilayer
FA
yes
6
BIO 208 Unit 1 - The Microbial World and You
7
IV. Observing Microbes With Microscopes
CH 3 p. 55 Units of Measurement and pp. 55-65 The Instruments
A. What problems need to be overcome to see a microorganism?
B. Units of measurement (you should be very comfortable with these; and converting back
and forth)
1m
1 mm (millimeter) = 0.001 or 10-3 m
1 m (micrometer) = 0.000001m or 10-6 m
1 nm (nanometer) = 0.000000001 m or 10-9 m
C. Properties of Light in Relation to Microscopy
1. Light - waves (wavelength = )
2. Resolution – ability to see 2 things that are close together as 2 separate & discrete things
visible light  = 550 nm
resolution maximum = 200 nm (0.2 m)
ultraviolet light  = 100-400 nm
resolution max. = 100 nm
electrons  = 0.005 nm
resolution max. = 0.2 nm
3. Refraction – bending of light as it passes from one medium to another of a different density.
BIO 208 Unit 1 - The Microbial World and You
D. Microscopy
1. Light Microscopy (LM) magnification resolving power a. Bright field
b. Dark field
Ex.
c. Phase-contrast
d. Fluorescence
Ex.
8
BIO 208 Unit 1 - The Microbial World and You
2. Electron Microscopy (EM) a. Transmission Electron Microscopy (TEM)
r.p. = 0.2nm
mg = 10,000-100,000x
b. Scanning Electron Microscopy (SEM)
r.p. = 20nm
mag. = 1,000-10,000x
Comparison of LM and EM
Light Microscopy
Electron Microscopy
Illumination
Light
Electrons
Objective Lens
Glass
Electromagnetic
Ocular Lens
Glass
Electromagnetic Projector
Visualize
Through eye piece
On view screen
Assignment to complete before next class
 CH 10: Multiple Choice 3, 4
 CH 3: Review 1, 4, 6, 7, 8, 9
I expect that you will do these assignments as they are assigned. This will help you keep up
with the material so that you will be prepared for tests. But I will not collect these assignments.
I expect that as a college student you will be self-motivated and not have to have due dates and
grades to force you to keep up and be prepared.
We will not cover Ch. 2 so if your Chemistry is not so fresh please review Ch. 2 on your own.
9
BIO 208 Unit 1 - The Microbial World and You
In Lectures 4 and 5 we will cover the anatomy of Bacteria and Archaea
You may want to bring your text to class with you so you can look at and mark figures that we
go over.
V. Functional Anatomy of Cells – CH 4
A. Bacteria and Archaea
1. Composition -
2. Size -
Ex. Thiomargarita namibiensis – “sulfur pearl of Namibia”
3. Shape and arrangement
a. cocci -
b. rods -
c. spirals -
10
BIO 208 Unit 1 - The Microbial World and You
4. Internal Structures
those common to all Bacteria and Archaea
a. cytoplasm -
b. nucleoid (= nuclear region)
c. ribosomes -
those found only in some Bacteria and Archaea
d. plasmids -
e. inclusions -
f. endospores –
Exs. Bacillus anthracis
Clostridium botulinum
function Processes of sporulation (spore formation) – Fig. 4.21 p. 97.
and germination.
11
BIO 208 Unit 1 - The Microbial World and You
5. Plasma membrane (= cytoplasmic membrane)
found in all cells
Archaea
glycerol – O – branched lipid
Bacteria
glycerol – O – C – CH3 – fatty acid
O
a. Function of plasma membrane
1) simple diffusion –
2) facilitated diffusion –
3) active transport –
4) group translocation –
Transport Compare and Contrast
Simple
Property
Diffusion
Carrier mediated
No
Can concentrate inside
No
Energy expended
No
Substance modified
No
during transport
Facilitated
Diffusion
Yes
No
No
No
Active
Transport
Yes
Yes
Yes
No
Group
Translocation
Yes
Yes
Yes
Yes
12
BIO 208 Unit 1 - The Microbial World and You
6. Cell Wall – Fig. 4.13 p. 86.
found in almost all Bacteria and Archaea have
Exceptions: Mycoplasma (Bacteria)
Thermoplasma (Archaea)
a. Functions -
1) Bacteria – divide into 2 groups based on a cell wall molecule called
peptidoglycan (old name = murein)
Gram positive
Gram negative
2) Archaea – do not have peptidoglycan, some have similar molecule called
pseudomurein, or chondroitin sulfate, or protein.
13
BIO 208 Unit 1 - The Microbial World and You
7. Structures External to Cell Wall
These external structures are found in many but not all Bacteria and Archaea
a. glycocalyx -
functions
i.
ii.
iii.
b. flagella function -
c. axial filament –
function Ex. Treponema pallidum
d. fimbriae function Ex. Neisseria gonorrhoeae
e. pili function –
Our next topic is Eukaryotic cell evolution, if you do not feel very comfortable with Eukaryotic
cell anatomy, then please read and study pp. 98-106 The Eukaryotic Cell before the next class.
14
BIO 208 Unit 1 - The Microbial World and You
Our focus in Lecture 6 is how the Eukaryotic cell evolved.
Your textbook does not contain much information on this topic; lecture will be your primary
source of information.
B. The Eukarya
1. Compare/contrast with Bacteria and Archaea
a. Major differences
b. Similarities
2. Origins of the Eukarya (p. 106 and lecture)
a. History of evolution of cells and cellular based life
Symbiosis = living together
Endosymbiont = living inside
15
BIO 208 Unit 1 - The Microbial World and You
b. Theory of Serial Endosymbiosis - Lynn Margulis
*Eukarya evolved as a result of multiple mergers of Bacteria and Archaea.
How Eukarya may have evolved – in reverse chronological order (starting with
most recent evidence)
1. Cholorplasts Evidence:
a. same size as cyanobacteria
b. surrounded by a membrane
c. have their own DNA
d. contain 70S ribosomes
e. have same pigments as cyanobacteria
All organisms with chloroplasts have mitochondria – therefore, mitochondria evolved
as organelles before chloroplasts did
2. Mitochondria Evidence:
a. same size as proteobacteria
b. surrounded by a membrane
c. have their own DNA
d. contain 70S ribosomes
e. grow and divide on their own schedule
f. some modern Eukarya do not have mitochondria but do have bacterial
endosymbionts
3. Flagella and cilia 4. Centrioles Evidence for 3 & 4:
 “docking”
 flagella and centrioles of Eukarya have DNA and RNA
 there are protists that have flagella but do not have mitochondria
5. Nucleus Evidence:
 nuclear envelope is a lipid membrane
 Archeae have histones for organizing DNA, so do Eukarya
 some Archeae have no cell walls, only a plasma membrane.
16
BIO 208 Unit 1 - The Microbial World and You
The evolution of Eukarya from multiple mergers of Archaea and Bacteria = The Theory of Serial
Endosymbiosis
Putting it together in chronological order:
1. Archaea attacked by spirochetes
2. Archaea surrounded its DNA with membrane  evolved into a nucleus
3. Captive internal spirochetes evolved into centrioles
4. Endosymbiotic proteobacteria evolved into mitochondria
5. External spirochetes evolved into flagella and cilia
6. Endosymbiotic cyanobacteria evolved into chloroplasts
Assignments to complete before Test 1.
CH 4:
-
Review: 2, 3, 4, 5, 6, 7a, b, c, d, e
Multiple Choice: 1, 6, 7, 8, 9
Critical Thinking: 2, 3
Clinical Applications: 2
This ends the lecture material for Test 1.
17