Class Note for MIC 205A at UA
Popular in Course
Popular in Department
This 9 page Class Notes was uploaded by an elite notetaker on Friday February 6, 2015. The Class Notes belongs to a course at University of Arizona taught by a professor in Fall. Since its upload, it has received 14 views.
Reviews for Class Note for MIC 205A at UA
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 02/06/15
Microbial Growth Growth of Microbes Increase in number of cells not cell size One cell becomes colony of millions of cells Growth of Microbes Control of growth is important for infection control growth of industrial and biotech organisms Factors Regulating Growth Nutrients Environmental conditions temperature pH osmotic pressure Generation time Chemical Requirements 1 water Elements C 50 of cells dry weight HONPS Trace elements Organic Source of energy glucose Vitamins coenzymes Some amino acids purines and pyrimidines Nutritional Categories Carbon sources CO2 autotroph organic heterotroph Energy sources sunlight phototroph organic chemotroph A Chemoheterotroph would Derive both carbon and energy from organic compounds A Chemoorganic autotroph would be Derives energy from organic compounds and carbon source from inorganic compounds A related ancient group Lithoautotroph Neither sunlight nor organics used rather it relies totallyon inorganics Nutritional Categories Saprobe lives on organic matter of dead organisms Parasite lives on organic matter of living host pathogens Movement of Water Osmosis Diffusion of Water lsotonic same solutes inside and outside no water movement Hypotonic more solutes inside water enters cell Hypertonic more solutes outside water leaves cell Movement of Molecules Facilitated dif Jsion higher to lower concentration carrier molecule Active transport lower to higher takes energy Group translocation lower to higher with chemical change Bulk transport endocytosis phagocytosis pinocytosis Facilitated Diffusion Outside cell cell Active Transport Lower to higher solute concentration Requires ATP Group Translocation Mum mm x g g I 5 Emil mmm 9mm nmlm i gt Phagocytosis amp Endocytosis unarmwa l39mocylvsix V mmmnmm Environmental Factors Influencing Growth Temperature OZ pH Osmotic Pressure Others radiation atmospheric pressure Temperature Optima Psychrophiles coldloving Mesophiles moderate temperature loving Thermophiles heatloving Each has a minimum optimum and maximum growth temperature Hale a Growlh I Fsycnropmie Mesaphiie Opt mum Thermophile Maximum 45455 0 5w157075303540455055506570755115590 Temperalure c Temperature Optima Optimum growth temperature is usually near the top of the growth range Death above the maximum temp comes from enzyme inactivation Mesophiles most common group of organisms 40 F 5 C slows or stops growth of most microbes Oxygen Requirements Obligate aerobes require 02 Facultative anaerobes can use 02 but also grow without it Obligate anaerobes die in the presence of OZ Oxygen Tolerance Aerotolerant do not use 02 but can grow when it is present Often ferment glucose to lactic acid Microaeroghiles require 02 but grow only in concentrations lower than air Classifylhe Growth in each tube Aerololeranl anaerobe Facultative anaerobe Microaerophile obligate aerobe obligate anaerobe Classifylhe Growlh in each tube Aerololeranl Toxic Forms of Oxygen Singlet oxygen lOZ very reactive Toxic Forms of Oxygen Peroxide anions 0239 HZOZ broken down by catalase and peroxidase Hydroxyl radical OH39 very L Superoxide free radicals 0239 anaerobes Neutralized by superoxide Microaerophile dismutase SOD obligate aerobe obligate anaerobe LeEkZEi eiv quot Catalyst ehamnei Cunlalns pallacium pallets which scavenge excess oxygen l Hubheigaskel l Ora quot2 ll pmmeeeieiighiseei l 2 A 39 39 1 Pelii dishes Oulei lid lniioi lid Gas geiiEielei envelope Water is added o chemicals in envelope ic generale H2 and co Hzcomblnes reactive l with oxygen in chem eiio mime l r Ho whlch I5 Vlslhle as lb i mndensallon an the walls clllie Ahaeioliic indieaicislhp mamaquot iiieiiiyiene blue becomes colorless iii absence olOzl b H Candle Jar p r Most bacteria grow between pH 65 and 75 xi Acid below pH 4 good gages 41 preservative for pickles sauerkraut 2 i l high 002 3 LC 7 am Cheeses Q Acidophiles can live at low pH pH Many bacteria and viruses survive low pH of stomach to infect intestines Helicobacter pylori lives a in stomach under mucus layer Osmotic Pressure Bacteria 8090 water High salt in surrounding environment leads to water loss and plasmolysis Cell s plasma membrane shrinks cell growth inhibited Drying and High Osmolarity Salted sh jerky honey sweetened condensed milk are preserved by pulling water out of bacteria Hypotonic medium low osmolarity may lyse bacteria without cell walls Ecological Associations Symbiotic close nutritional relationship Mutualism both bene t Commensalism commensal bene ts host not harmed Parasitism parasite bene ts host harmed Measuring Bacterial Growth Bacterial Division Bacteria divide by binary fission Alternative means Budding Conidiospores filamentous bacteria Fragmentati on Generation Time Time required for cell to dividefor population to double Average for bacteria is 13 hours E coligeneration time 20 min 20 generations 7 hours 1 cell becomes1 million cells Plotting growth on graphs 0 45W 9 4000 l E 7 3mm m l7 r Vlmlmber 5 mm mm oleells 5 ulcells 4 2mm x 1530 mg i 2 o a 5 32 c N berm 2 1000 um llenelalions 2 J 4 5 5m Emmi 2 2 2 2 25 a D W m M W la Phases of Growth ag phase making new enzymes in response to new medium og phase exponential growth Desired for production of products Most sensitive to drugs and radiation during this period Phases of Growth Stationam ghase nutrients becoming limiting or waste products becoming toxic death rate division rate Death phase death exceeds division Measuring Growth Direct methods count individual cells Indirect Methods measure effects of bacterial growth Turbidity Metabolic Activity Dry Weight Microbe of the Week Therm us aquaticus A chemotrophic thermo bacterium from Yellow Thrives at 70 C 160 A Gram negative cell with a a think PG cell wall The source of several enzymes used in biotechnology that operate at high temperature Microbe of the Week Thermus aquaticus Taq DNA polymerase is used in the Polymerase Chain Reaction PCR for amplifying detecting and profiling DNA J
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'