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Growth Human Terms: Growth = __________ Microorganism Terms: Growth = __________ Growth Binary Fission – bacteria reproduce __________ : Chromosome __________ Cell __________ Plasma membrane __________ in at center __________ __________ distributes evenly Cell wall thickens to separate dividing cells Growth Binary fission – gives __________ to bacteria The first bacterium ________ _______ It __________ and becomes a new, young cell again The original __________ (billions of years old) is still among us Growth Reproduction: __________ __________ 20 Generation 21 Generation 22 Generation 23 Generation Generation Time Time between _______ __________ when bacteria grows and develops its unique features Also called “________ _________” A determining factor in the __________ of time that passes between entry of an organism into our bodies and the __________ of disease symptoms Growth Each microorganism has it’s own characteristic __________ __________ Range: Usually 1 to 3 __________ __________ 20 minutes (E. coli) __________ 33 hours (T. pallidum syphilis) BACTERIAL GROWTH IS LOGARITHMIC Growth Growth Rates If after 48 hours of __________, a colony is pinpoint size, __________ GT is indicated. If after 48 hours, the __________ is ¼” wide, __________ GT is indicated. Growth Example E. coli has a 20 minute __________ __________ under ideal conditions: Time # of Bacteria 0 1 1 hour 8 2 hours 64 3 hours 512 10 hours > 1 billion 36 hours Cover face of the earth Growth Growth Rates Exponential growth signifies ideal __________ and maximum __________ But the __________ __________ of bacteria is never fully realized due to environmental __________ Growth Phases Many dynamics __________ the population of bacteria over the course of __________ A certain population’s history may begin when: Several bacteria enter the __________ __________ tract Several bacteria are transferred to a tube of __________ __________ in a lab Growth Phases Lag Phase: First few hours of __________ __________ Period of __________ to new environment If an __________, WBC’s can be __________ some cells If in a lab, some cells may die from __________ __________ Growth Phases The activity of the remaining cells is intense as they: Store __________ Synthesize __________ Prepare for __________ __________ But the curve remains at a __________, where the number of cells reproducing __________ the number of cells dying Growth Phases Log Phase: Also called “__________” phase The mass of each cell increases __________ and __________ follows As each generation time passes, the number of bacteria __________ and the graph rises __________ Growth Phases In humans, disease symptoms arise during the __________ __________ Bacterial population is high enough to __________ __________ Fever, __________, tissue damage arise In a lab, visible signs of growth will be seen: colonies will appear on ________ ________ broth media will become __________ Growth Phases Research experiments are usually done during the __________ __________ because the population of bacteria is at its __________ __________ Growth Phases Stationary Phase: Period of __________ __________ numbers Reproduction rate = __________ __________ No change in total number of __________ Growth Phases Stationary Phase: In humans: the __________ __________ may be destroying the bacteria antibiotics have been __________ In the lab: nutrients are becoming __________ __________ __________ are building up oxygen or water could be in __________ __________ Growth Phases Decline Phase: Environment becomes progressively __________ and exerts its __________ __________ pH is changing oxygen and nutrients are __________ accumulation of __________ Growth Phases Decline Phase: Number of cells __________ __________ the number of new cells formed Spore forming species will start to produce __________ Flagellated species will try to __________ to a new location For other species, culture death is __________ Things That Affect Growth Temperature Different species grow at different temperatures __________ – grow best between 0oC and 20oC __________ – grow best between 20oC and 40oC __________ – grow best between 40oC and 90oC Things That Affect Growth Temperature Most bacteria are __________, especially __________ __________ that grow in the human body (37oC) When the body’s temperature rises to 40oC (104oF) there is a slightly _________ affect on bacterial ________ The lab incubator is set at 37oC to __________ bacterial growth Things That Affect Growth Temperature Some __________ can grow at refrigerator temperatures and cause __________ __________ Staphylococci can grow in the refrigerator and deposit their __________ on cold cuts, salads and leftovers If these foods are eaten without further cooking, __________ __________ can result Things That Affect Growth Temperature __________ outbreak in a restaurant in 1991 Restaurant employee prepared Caesar salad dressing which contains raw egg It may have remained at room __________ too long before being served Within 3 days, 15 people were __________ with diarrhea, fever, cramps and __________ Things That Affect Growth Oxygen __________ bacteria – require __________ to grow __________ bacteria – require an oxygen-free environment to grow Includes __________ species that cause tetanus and botulism __________ bacteria – grow in either the presence or __________ of oxygen includes many staphylococci, streptococci and bacilli Things That Affect Growth pH Bacteria have a __________ internal environment Will tolerate a pH range of __________ Human blood and tissues have a pH of __________ Provides a __________ environment for disease causing bacteria to __________ Things That Affect Growth pH Certain bacteria are __________ __________ Useful in the food and dairy __________ Lactobacillus and Streptococcus produce the acid that converts: milk to __________ __________ to sour cream milk curds to __________ These bacteria __________ __________ __________ to good health even when eaten in large quantities Things That Affect Growth pH Most bacteria do not grow well under __________ __________ Stomach’s __________ __________ prevents disease Certain __________ __________ are hardly ever contaminated with bacteria Citrus fruits __________ Tomatoes Things That Affect Growth Pattern of Nutrition Bacteria (like us) need: __________ __________ to serve as energy sources and as raw materials for synthesis of cell __________ Things That Affect Growth Pattern of Nutrition Two patterns for obtaining nutrition: __________ – can make their __________ food using inorganic carbon, water and sun’s energy __________ – obtain preformed organic molecules from the __________ for structural components and energy ○ __________ – feed exclusively on dead organic matter such as rotting wood ○ __________– feed on living organic matter such as human tissues Things That Affect Growth Bacterial Cultivation In the lab, bacteria are grown in: __________ __________ containing water, beef extract and peptone (protein supplement) __________ __________ – contains the same, plus agar, a polysaccharide derived from marine algae *Most bacteria __________ __________ in these Things That Affect Growth Bacterial Cultivation Some bacteria require __________ or __________ media The streptococci that cause strep throat and scarlet fever grow well when __________ __________ is added to the media __________ __________– heated before solidification to disrupt the red blood cells and release __________ Sometimes called __________ __________ Things That Affect Growth Bacterial Cultivation __________ __________– contain ingredients to __________ the growth of certain bacteria in a mixture while __________ the growth of others __________ salt agar – high salt content __________ the growth of most bacteria, but allows for staphylococci to grow __________ methylene blue agar – contain dyes that __________ Gram-positive bacteria, but __________ growth of Gram-negative Things That Affect Growth Bacterial Cultivation __________ __________– makes it easy to distinguish colonies of one organism from __________ of another on the same plate MacConkey’s agar contains __________ __________ as well as lactose Colonies of bacteria that __________ __________ are red Colonies of bacteria that __________ ferment lactose are colorless Things That Affect Growth Bacterial Cultivation __________ __________– not chemically defined Exact components and quantities are not known Some bacteria will only grow on natural media __________ __________ - chemically defined The nature and amount of each component is known Things That Affect Growth Intermicrobial Relationships __________ – situation in which two populations of organisms interact in a __________ and __________ association Benefits obtained may involve: food __________ support Things That Affect Growth Intermicrobial Relationships __________ – symbiosis that benefits both populations Bacteria living on roots of plants: Bacteria trap __________ for plants to synthesize __________ __________ Plants provide a __________ environment and __________ __________ for bacteria Things That Affect Growth Intermicrobial Relationships __________ – one population receives benefit from the relationship while the other is not __________ or __________ Bacteria that inhabit human skin: __________ has a place to live and food We are not helped or __________ in any way Things That Affect Growth Intermicrobial Relationships __________ – two populations live together and accomplish what neither could alone __________ __________ – two populations of bacteria (usually rods and spirochetes) must be present for __________ of the __________ __________ to occur Things That Affect Growth Intermicrobial Relationships __________– symbiosis is beneficial to one population (__________) but harmful to the other (__________) The bacteria of all human diseases are __________ Applications Industrial: __________ __________ products Penicillin Wine Beer Alcohol Vinegar Pickles Cheese Medical: Phases of disease parallel __________ __________ of pathogen