Microbiology

Learn about viruses, bacteria, and more!

Microbes are an important of life on earth. They influence everything from plant growth through to gut digestion and disease mechanisms in humans. Understanding the general classifications and anatomy of significant microbes is useful for the both the general and professional learner.

In this course, you will develop a broad based understanding of the science of microbiology . You will explore microbiology and its relationship to:

• human, animal and plant disease
• routine functions in biology (e.g. absorption of nutrients, immunology, managing waste, etc)
• farming - horticulture, agriculture
• food industries - food treatment, storage, preservation, etc.
• environmental management

You'll also discuss different practical applications of microbiology.

Lesson Structure

There are 8 lessons in this course:

1. Scope and Nature of Microbiology
   • Why study microorganisms
   • Bacteria
   • Actinomycetes
   • Fungi
   • Viruses
   • Other multicellular microscopic organisms - nematodes, mites
2. Microscopes
   • Types - light, electron and helium ion microscopes
   • Types of light microscope - stereoscope, compound microscope, confocal microscope
   • Electron microscopy - scanning election microscope, transmission electron microscope
   • Helium ion microscope
   • Preparing samples for microscopy
   • Case study - diagnosis of plant disease
   • Selecting pathogen for verification
   • Preparation of pathogens
   • Culture methods and isolation techniques
   • Inoculation
3. Cultures
   • Types of culture - pure, mixed, contaminated
   • Types of glassware
   • Sterilisation
   • Autoclaves
   • Arnold steam sterilisation
   • Dry heat sterilisation
   • Disinfection
   • Filtration sterilisation
   • Low temperature sterilisation
   • Radiation
   • What is used in media
   • Types of media - synthetic, complex, enrichment, selective, differential etc
   • Common examples - MacConkey's agar, Mannitol salt agar
   • Preparing agar plates
   • Streak plate method
   • Pour plate method
   • Staining
   • Maintaining cultures
   • Aseptic technique
   • Preserved cultures
   • Factors affecting microbial growth -pH, temperature, oxygen, moisture, pressure, vitamins, radiation, carbon, nitrogen, etc
   • Stages in development of a plant disease
   • Virus replication cycle
   • The microbiology laboratory
   • Setting up a simple home laboratory
   • Starting out
4. Microbial Taxonomy
   • What is taxonomy - varying opinions
   • Morphology
   • Prokaryotes and eukaryotes
   • Bacteria - Eubacteriales, Pseudomonadales, Clamidobacteriales, Spirochaetales, etc
   • Archaea - Crenarchaeota, Euryarchaeota, Korarchaeota
   • Viruses - ICTV, Baltimore classification
   • Fungi -Oomycotes, Zygomycota, Ascomycota, Basidiomycota, Deuteromycota
   • Others - Helminths,Arthropods
   • Good and bad microorganisms
   • Good things that microorganisms do
   • Bacteria
5. Viruses
   • Virus structure
   • Anatomy of a virion - nucleic acids, capsid, capsomeres, envelopes
   • The infected cell
   • Virus reproduction
   • The infectious cycle
   • Attachment
   • Penetration
   • Un-coating
   • Replication
   • Assembly
   • Release
   • Virus taxonomy
   • Animal viruses
   • Prototype classification
   • Viral diseases
   • Crystallisation of viruses
   • Transmission - body fluid, vector
   • Viral diseases in humans
   • Control and treatments - vaccines, drugs, hygiene
   • Case Study - human swine flu
   • Viral disease in plants - including different specific examples
   • Viral diseases in animals - including different specific examples
6. Other Microbes
   • Fungus biology
   • Case study - candida
   • Protists
   • Plant like protists - Euglenophytes, Chrysophytes, Diatoms, Dinoflagellates
   • Fungus like protists
   • Animal like protists -Amoebae (pseudopods), Flagellates, Ciliates, Sporozoa
   • Helminths
7. Immunology
   • Types of immunity - Acquired Immunity, Active Immunity, Passive Immunity
   • Antitoxins
   • Agglutinins
   • Precipitans
   • Antigens
   • Antibodies
   • Titre
   • Antiserum
   • Immunisation -Sub-unit vaccines, Inactivated vaccines, Live, attenuated vaccines, Toxoid vaccines, Conjugate vaccines
   • General immune response
   • Recognition of self or non self
   • Specificity
   • Heterogeneity
   • Memory
   • Herd immunity
   • Immunological disorders
   • Autoimmune disease
8. Applied Applications
   • Agriculture and horticulture applications
   • Mycorrhizae -Ectomycorrhizae, Endomycorrhizae, Ectendomycorrhiza
   • Soil biological management
   • Nitrogen cycle - Ammonification,Nitrification, Denitrification, Nitrogen Fixation, Immobilisation
   • Improving soil biology
   • Rhizobium Bacteria and Soil Fertility
   • The Rhizobium Bacteria
   • Microbiology and Plant Pathology
   • How Bacteria, Fungi and other Microorganisms Infect Plants
   • Lifecycle of Nematodes
   • Fungi
   • The Role of Insects in the Spread of Disease
   • Food Technology Applications
   • Food microbiology - yeast, algae
   • Microbes - food spoilage factors pH, water, oxygen, food structure
   • Reducing food spoilage
   • Environmental Applications
   • Water disposal
   • Environmental cleanup
   • Reducing greenhouse gases
   • Biological pesticides
   • Water analysis
   • Industrial Microbiology - production, mining
   • Pharmaceuticals
   • Drug therapies
   • Antibiotics, vaccines
   • Obtaining steroids from microorganisms
   • Microbes in Humans
   • Hospital acquired infections
   • Infection control
   • MRSAs
   • Virology
   • Animal/Human interactions -zoonoses
   • Microbiological health management in animals

Each lesson culminates in an assignment which is submitted to the school, marked by the school's tutors and returned to you with any relevant suggestions, comments, and if necessary, extra reading.

Aims

• Discuss the nature and scope of microbiology and its potential application to human life and society.
• Determine appropriate tools for studying microorganisms, and how to utilise those tools in a variety of different contexts.
• Describe how to culture different microorganisms in a laboratory.
• Differentiate between different types of microorganisms.
• Determine appropriate ways of finding and applying current information to differentiate between microorganisms you are not familiar with.
• Explain the taxonomy, function and significance of a range of different types of bacteria.
• Explain the taxonomy, function and significance of a range of different types of viruses.
• Explain immunity in plants, animals and humans.
• Identify and explain different practical applications for an understanding of the applications of microbiology.

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How are Bacteria Different?

Bacteria can be good or bad; useful to man, or harmful to man. It all depends upon what type of bacteria you are considering. This course helps you to understand those differences, and understand how we can differentiate between different types of bacteria.

Bacteria occur everywhere in our world in huge numbers: from inside our bodies to across the surface of every living and non living thing on our planet.

Bacteria have the same structures as a normal cell, including: a cell wall, nuclear material, cytoplasm and various membranes, such as mitochondria, endoplasmic, reticulata, plasma membrane; they also have a slime layer (capsule), flagella and some but not all can have spore formation.

The ‘slime layer’ can vary in thickness and texture - if it is thick and firm enough, it is called a capsule. When chains or clumps of bacteria form the whole chain or clump can be surrounded by a slime layer. At times this layer can become a solid gelatinous mass (called a zooglea).

Flagella are outgrowths of cytoplasm that extend through the cell wall. They are appendage-like structures used for movement.

Bacteria can either reproduce by splitting, or by spores.

Spore formation is regarded as a resting stage. Under favourable conditions the internal protoplasm can form a ‘knot’ and surround itself with a wall. Bacterial spores are generally more resistant to being degraded than other types of organisms. To completely destroy bacterial spores may require boiling under pressure (as in a pressure cooker).

Classification of bacteria is based upon:

1. Morphology - the form of the cell.
2. Presence or absence of flagella.
3. Reaction to certain stains.
4. Mode of nutrition.

There are two broad groups:

• Heterotrophs -these cannot make their own food. They are either parasites, feeding off living things, or saprophytes, feeding off dead things.
• Autotrophs have chlorophyll-like pigments that allow them to make their own food.

 

This Course is Only the Beginning -But a very important Beginning

Microbiology is the study of tiny living things that cannot be seen by the unaided human eye. This includes both helpful and unhelpful organisms, small animals and plants, bacteria, fungi, viruses and algae. It includes organisms that contribute in a very positive way to our health and well being, and others that can kill us.
Microorganisms are found everywhere - inside and outside of the human body, and within all other animals and plants.
Some microorganisms are very simple, single celled organisms; but others are multicellular organisms.

Why Study Microorganisms?

• They impact directly upon our health and well being.
• They impact upon the quality of physical world we live in.
• They impact upon the other living organisms we depend upon: everything from crops and farm animals to our pets.
• Studying them can give us insights into all life.
  
  

Given the scope and nature of microbiology, this course cannot hope to teach you about every type of microorganism.  There are in fact so many different microorganisms that microbiology experts don’t know even a fraction of what is to be learned.

This is however such an important subject because microorganisms have a huge impact upon both us and the world around us.
The starting point is to become aware of the scope and nature of these organisms, to understand how they can be examined and the general characteristics of different types of microorganisms. The bulk of this course focuses on giving you that broad foundation, with a particular focus on some of the more significant types.  Toward the end of the course you will explore some of the practical applications for microbiology.

WHO USES MICROBIOLOGY?

Microbiologists work with microbiology all day every day, commonly working in laboratories. Their work can involve routine laboratory diagnostics, or production of microbiological products, through to cutting edge research.  Other professions also apply a knowledge of microbiology on a day to day basis.

This course can be a first step toward becoming a microbiologist. It may also be a step toward being a better farmer, food processor, health or veterinary professional or horticulturist.

Microbiologists are hired across all these fields, but may also have input into areas such as patent law (especially in the case of genetically engineered organisms and structures), policy change (as understanding of microbe function and transmission is required in implementing some health policies), humanitarian causes (ensuring potable water, testing and implementing sanitation measures to reduce disease in the developing world), even climate change (using microbes to help reduce pollution). The following pages explore just a few of the real-world applications of microbiology.

Microbes need to be managed in a variety of situations including:

• In the human and animal body - deterring or killing pathogenic microbes (diseases), encouraging/maintaining beneficial organisms (probiotics).
• In soil – soil health in agriculture and horticulture is dependent upon balance/presence of certain microbes - e.g. mycorrhizae and rhizobia. In plant tissue to prevent or deter disease.
• In scientific research/laboratory and pathology testing.
• In commerce - e.g. brewing, wine making, mushroom production; production of medicines/health products, bread etc.
• In bio remediation e.g. microbes used to manage oil spills, pollution, degrading of organic compounds etc.