Microorganisms

Microbes too small to be seen with the naked eye aggregations or colonies can be seen without the aid of a microscope

Microbes are found almost anywhere are more abundant than any other life form they are forms on which all others depend.

Recycle elements required for life N - Nitrogen O - Oxygen P - Phosphorus S - Sulfur C - Carbon

Microbes produce food fuel air

4 major categories bacteria fungi protists viruses

Pathogens disease causing agents AIDS - Acquired Immune Deficiency Syndrome Botulism - food poisoning Tuberculosis Polio

Pathogens Typhoid Fever Syphilis

Disease Microbes cause disease by directly damaging tissues and weakening bodily functions or by producing toxins that do.

Pathogenic microbes the proportion of pathogenic microbes on earth is very small

Producers produce carbohydrates break down starch into sugar convert sugars into alcohol

Water Dwelling microbes algae and bacteria largest producers of carbon containing compounds through photosynthesis

Some microbes are unable to take in Carbon Dioxide from the air. They get Carbon from bicarbonate in the water

Ion an atom that carries a positive (+) or a negative (-) charge carries the charge because it has gained or lost one or more electrons

Microbes use CHOs (carbohydrates) synthesized during photosynthesis (Ps) to make cell structures and as an energy source Provide food for larger organisms Replenish Oxygen supply

Single Celled Fungi Yeasts Producers in wine making, bread baking or beer brewing. Convert sugar to alcohol in fermentation process

Cheese Making bacteria convert lactose (milk sugar) to lactic acid

Contribute to production of food and other substances by their enzymes

Enzymes organic molecules that speed up biochemical reactions without being used up or becoming part of the end product. A catalyst - causes a reaction to take place

Examples foods medicines vitamins leather processing textile production

Decomposers and Recyclers worlds greatest recyclers Keep elements like C and N cycling through the environment Used to treat sewage, clean up toxic wastes, processing materials

Recyclers more than one type of bacterium is needed to convert atmospheric N into a form useable by plants. Requires three different chemical reactions.

Production through decomposition Methane - decomposition of organic matter Methanogens - swampy areas, land fills, digestive tract of ruminants.

Production through decomposition Linen fabric is made from flax stems Stems are immersed in water Bacterium digests pectin that makes the stalks stiff

Linen Fabric Production remainder is washed dried and spun into thread and then woven into fabric

Basic features of MOs (microorganisms) 4 major groups –bacteria, fungi, protists, viruses Viruses are not made up of cells and are not considered organisms by many microbiologists.

Bacteria, fungi and protists have a cellular structure, a membrane surrounding cytoplasm

Protists have an inner compartment nucleus DNA in non circular chromosomes unicellular or multicellular protozoans, algae, others resemble fungi

Fungi have cellular structure non circular chromosomes in fungi with many cells, walls between cells are sometimes not complete cytoplasm and nuclei can stream from one cell to another within slender filaments of cells called hyphae

Fungi have cellular structure non circular chromosomes in fungi with many cells, walls between cells are sometimes not complete

Fungi cytoplasm and nuclei can stream from one cell to another within slender filaments of cells called hyphae

Yeasts unicellular

Molds have many cells

Fungi visible to the naked eye –mushrooms –bracts –puffballs –toadstools

Viruses not cellular particles made up of nucleic acid and protein Include short length of DNA or RNA - never both!

Viruses On their own they cannot reproduce at all Inject their nucleic acid into a host cell

Viruses Injected DNA or RNA tricks host cell into using the viruses chemical instructions to make substances needed for the virus to reproduce

Viruses Host cell is damaged when newly reproduced virus particles break out of cell (lyse)

What does it take to keep a microbe alive? Lots of variation in environmental and nutritional condition requirements

Nutritional needs energy sources basic elements to make and replace cell structures

Heterotrophs organic compounds to meet energy needs Carbon source to make own organic molecules get energy from sugars, starches, fats and other organic compounds

Saprobes live in soil, get nutrients from dead organic matter Clostridium botulinum - botulism, food poisoning

Autotrophs build their own organic compounds if they have an available source of inorganic compounds

Phototrophs generate their own food using sunlight and inorganics such as carbon dioxide

Chemotrophs dont require sun get energy from carbon dioxide, salts, water and others

Nitrosomonas bacteria live in soil use ammonia (NH4) as energy

hetero, chemo and phototrophs use energy from the environment light and heat energy from the sun energy stored in chemical bonds or organic or inorganic compounds

Six major elements in cells C - Carbon H - Hydrogen N - Nitrogen O - Oxygen P - Phosphorus S - Sulfur

Also - K- potassium Ca - Calcium Fe - Iron Na - Sodium

Trace elements Co - Cobalt Zn - Zinc Mo - Molybdenum Cu - Copper Mn - Manganese Si - Silicon

hetero, chemo, and phototrophs some require organic compounds that they cannot make themselves must be added to culture in isolation - called growth factors Vitamins

Microbial nutrition in the lab hardened gel - called agar nutrients are added to the agar called growth medium

Pure Cultures Grow only one kind of microbe Must use aseptic technique to avoid contaminating the culture

Mixed cultures may be grown on selective media nutritious to some and not to others allows researchers to isolate a certain species of microbe

Environmental conditions for microbial growth Oxygen - require Oxygen - aerobic some microbes live in Oxygen poor environment - anaerobic

Anaerobic processes fermentation O2 atoms in compounds are rearranged and made available to microbes

Anaerobes made up of molecules containing O2 but dont produce free or gaseous O2

Anaerobes free oxygen may be toxic

pH favorable range acidophillic - acid loving used in mining operations. Oxidize Cu, Fe and other metal sulfides in the process of pulling out the ore

Temperature 37 degrees C (98 degrees F) some can survive a wide range of temps ranging from 32 degrees F to 212 degrees F

Moisture dissolve minerals, ions, gases and organic compounds

Moisture in extremely dry conditions microbes form spores that hold the genetic information and some cytoplasm.

Spores when moisture is added the spore breaks down and bacteria resume their normal activity

Salt concentrations most microbes cant survive in high salt or sugar concentrations

Microbe sex or - how microbes reproduce process is known as binary fission

Binary fission increase in size, extend cell wall material down center and divide in two.

Speed of reproduction in 24 hours some species of bacteria can go from one cell to 16,777,216 cells

Single celled protists have a more difficult reproductive process DNA in nucleus is fist replicated then divided into 2 identical sets (mitosis)

continued cytoplasm of cell then divides to form 2 identical daughter cells.

Fungi reproduce by a number of methods yeasts - budding - cytoplasm pinches off on one side of cell to form a new cell or fuses with another cell

Fungi after fusing with a cell, nuclei fuse and divide to form spores when released from the cell

Yeast spores become cells on their own

Many celled fungi hyphae or filaments fuse to form sporagia cases in which nuclei from 2 parent molds excahange pieces of chromosomes a type of sexual reproduction

Microbial populations can and do change over time bacterial populations adapt to changes in the environment

Mutations change in DNA alteration of base sequence occur spontaneously

Genetic recombination exchanging or recombining genetic information two bacterial cells become connected by a thin strand of cell material called a pilus

Genetic recombination DNA can travel from one microbe to another gene enters a microbe that did not initially have it