WARM UP: What is a microbe? What are the four types of microbes we will be studying? Before we get started: check your agar plates. Make observations on your lab sheet. Return your agar plate to the incubator. DO NOT OPEN THE LID!!!!!!! 1

2 Introduction to Bacteria 2 TYPES OF BACTERIA: Bacteria -Get food from an outside source Blue-green Bacteria -Make their own food

3 BACTERIA Bacteria - small one celled monerans  Bacteria like a warm, dark, and moist environment They are found almost everywhere: -water-air -soil-food -skin-inside the body -on most objects

4 Spiral: spirilla rod-shaped: bacilli, bacillus Round: cocci 3 Shapes of Bacteria Bacteria are classified by shape into 3 groups:

1. The coccus The cocci are spherical or oval bacteria having one of several distinct arrangements based on their planes of division. a. Division in one plane produces either a diplococcus or streptococcus arrangement. b. Division in two planes produces a tetrad arrangement. 5

1. The coccus d. Division in random planes produces a staphylococcus arrangement. An average coccus is about micrometer (µm) in diameter. (A micrometer equals 1/1,000,000 of a meter.) 6

2. The rod or bacillus Bacilli are rod-shaped bacteria. Bacilli all divide in one plane producing a bacillus, streptobacillus, or coccobacillus arrangement. a. bacillus: single bacilli 7

2. The rod or bacillus b. streptobacillus: bacilli arranged in chains c. a coccobacillus: oval and similar to a coccus An average bacillus is µm wide by µm long 8

3. The spiral Spirals come in one of three forms, a vibrio, a spirillum, or a spirochete. a. vibrio: a curved or comma-shaped rod b. spirillum: a thick, rigid spiral 9

3. The spiral c. spirochete: a thin, flexible spiral Spirals range in size from 1 µm to over 100 µm in length. 10

11 3 Shapes of Bacteria Bacillus anthracis – (bacillus) Neisseria meningitidis (coccus) Leptospira interrogans – (spirilla)

12 7 Major Structures of a Bacteria Cell Capsule Cell wall Ribosomes Nucleoid Flagella Pilli Cytoplasm

13 Capsule 7 Major Structures of a Bacteria Cell  keeps the cell from drying out and helps it stick to food or other cells

14 Cell wall 7 Major Structures of a Bacteria Cell  Thick outer covering that maintains the overall shape of the bacterial cell

15 Ribosomes 7 Major Structures of a Bacteria Cell  cell part where proteins are made  Ribosomes give the cytoplasm of bacteria a granular appearance in electron micrographs

16 Nucleoid 7 Major Structures of a Bacteria Cell  a ring made up of DNA

17 Flagella 7 Major Structures of a Bacteria Cell  a whip-like tail that some bacteria have for locomotion

18 7 Major Structures of a Bacteria Cell Amimation of E.coli

19 Pilli 7 Major Structures of a Bacteria Cell  hollow hair-like structures made of protein  allows bacteria to attach to other cells.  Pilli-singular  Pillus-plural

20 Cytoplasm 7 Major Structures of a Bacteria Cell  clear jelly-like material that makes up most of the cell

21 Binary Fission- the process of one organism dividing into two organisms Fission is a type of asexual reproduction Reproduction of Bacteria How?... The one main (circular) chromosome makes a copy of itself Then it divides into two Asexual reproduction- reproduction of a living thing from only one parent

WARM UP: What are the three shapes of bacteria? What are the 7 major structures of the bacteria? DON’T FORGET TO CHECK YOUR AGAR PLATES! DO NOT OPEN THE LIDS! 22

23 BINARY FISSION Bacteria dividing Completed Reproduction of Bacteria

24 The time of reproduction depends on how desirable the conditions are Bacteria can rapidly reproduce themselves in warm, dark, and moist conditions Some can reproduce every 20 minutes (one bacteria could be an ancestor to one million bacteria in six hours) Reproduction of Bacteria

25 Bacterial Cell & Nucleiod DNA Ring DNA replication Cell wall synthesis Cell separation

26 Bacteria Survival Endospore- a thick celled structure that forms inside the cell they are the major cause of food poisoning they can withstand boiling, freezing, and extremely dry conditions it encloses all the nuclear materials and some cytoplasm allows the bacteria to survive for many years

27 Bacillus subtilis Endospore-the black section in the middle  highly resistant structures  can withstand radiation, UV light, and boiling at 120oC for 15 minutes. Bacteria Survival

28 Bacteria Survival – Food sources parasites – bacteria that feed on living things saprophytes – use dead materials for food (exclusively) decomposers – get food from breaking down dead matter into simple chemicals important- because they send minerals and other materials back into the soil so other organisms can use them

29 Harmful Bacteria some bacteria cause diseases Animals can pass diseases to humans Communicable Disease – Disease passed from one organism to another This can happen in several ways: Air Touching clothing, food, silverware, or toothbrush Drinking water that contains bacteria

Human tooth with accumulation of bacterial plaque (smooth areas) and calcified tartar (rough areas) Harmful Bacteria

31 Helpful Bacteria Decomposers help recycle nutrients into the soil for other organisms to grow Bacteria grow in the stomach of a cow to break down grass and hay Most are used to make antibiotics Some bacteria help make insulin Used to make industrial chemicals

E.coli on small intestines Helpful Bacteria

33 Used to treat sewage Organic waste is consumed by the bacteria, used as nutrients by the bacteria, and is no longer present to produce odors, sludge, pollution, or unsightly mess. foods like yogurt, cottage & Swiss cheese, sour cream, buttermilk are made from bacteria that grows in milk Helpful Bacteria

34 Controlling Bacteria 3 ways to control bacteria: 1) Canning- the process of sealing food in airtight cans or jars after killing bacteria endospores are killed during this process 2) Pasteurization- process of heating milk to kill harmful bacteria 3) Dehydration- removing water from food Bacteria can’t grow when H 2 O is removed example: uncooked noodles & cold cereal

35 Controlling Bacteria Antiseptic vs. Disinfectants Antiseptic- chemicals that kill bacteria on living things means – “against infection” Examples: iodine, hydrogen peroxide, alcohol, soap, mouthwash Disinfectants- stronger chemicals that destroy bacteria on objects or nonliving things

36 BLUE-GREEN BACTERIA Autotrophs – make their own food through photosynthesis  commonly grow on water and surfaces that stay wet…such as rivers, creeks and dams  larger than most bacterial cells  Some live in salt water, snow, and acid water of hot springs  food source for animals that live in the water

37 BLUE-GREEN BACTERIA Blooms- occur when the bacteria multiplies in great numbers and form scum on the top of the water  can be toxic to humans and animals

Bacillus anthracis - rod, vegetative stage prokaryote (bacterium) Image Number: 21185A

Neisseria meningitidis - coccus prokaryote (bacterium) Image Number: 97214E

Leptospira interrogans - spiral shaped prokaryote (spirochete)

41 Ecoli movement animatoin ges/jjani_qt/ecoli_qt.html