This exercise allows students to investigate the genetic control of a biosynthetic pathway: the production of the red pigment prodigiosin by the bacterium Serratia marcescens. The students perform feeding trials with mutant strains to examine the genetic control of this biosynthetic pathway. Auxotrophic strains of the bacteria which are blocked at different places in the pathway exhibit different colors, the wild-type is a deep red color. Pairwise feeding trials enable the students to determine which strains are blocked at which point in the pathway. Students will then use an explanatory system to determine the pathway's shape and learn about its genetic control.

A laboratory exercise to investigate immune response to bacterial infection using tobacco hornworms.

Recovery of Escherichia coli from a rectal swab begins a series of procedures combining mastery of technique with productive experiments. After isolating his/her own E. coli strain, each student recovers a unique coliphage from raw sewage and determines its host range, thereby revealing the genetic individuality of each bacterial and viral isolate. Colonies of virus-resistant mutants can often be recovered in regions where sensitive bacteria have been destroyed. After antibiotic sensitivity testing of E. coli isolates, a variety of antibiotic resistant mutants can be recovered, thus yielding genetically marked strains for future bacterial genetics experiments.

Soil contains a wider variety of microorganisms than in other types of environments. Many kinds of bacteria, algae, protozoans, yeasts, molds, and microscopic worms are present in soil. Bacteria are the dominant species found in soil and many of the biological changes that occur in soil are due to bacteria. These biological changes include fixation of nitrogen for photosynthetic plants, and the recycling of other important biological elements from the decomposition of plants and animals. This laboratory exercise involves isolating an unknown bacterium from soil, maintaining a pure culture of the microbe, determining the staining, cultural, and physiological characteristics of the organism, and narrowing the identification of the bacterium to a specific microbial group.

This is an interactive learning adventure for middle school students and has accompanying classroom activities and magazines. In this challenge, students will perform experiments to identify the germ responsible for a fungal disease. Students will follow rules or postulates worked out by Dr. Koch in the late 1800s for establishing whether a specific germ causes a particular infectious disease: 1. The suspected pathogen must be present in every case of the disease; 2. The suspected pathogen must be isolated from the host and grown in pure culture; 3. The disease must be reproduced when a pure culture of the suspected pathogen is inoculated into a healthy susceptible host; 4. The same pathogen must be recovered from the newly infected host. The Germ Theory of Disease holds that germs or microorganisms cause infectious diseases.

Funded through the National Center for Research Resources and the National Institute of Allergy and Infectious Diseases.

Using simple microbiological techniques, this exercise will introduce students to the variety of bacterial type present in their mouths. Enriched, selective, and differential media will be used to isolate the major aerobic and anaerobic species. Visual observations of the bacteria enhance the students' appreciation for the complex microbial world of the mouth. Note: This workshop is not included in the published proceedings volume because it was not submitted by the author.

This workshop demonstrates on-line use of the national electronic bulletin board, complete with electronic mail started in 1987 by the National Association of Biology Teachers. Once on-line, 14 special interest areas are available, such as AP- Biology, magazine and book reviews, ABT Journal, NABT membership services, question and answer forum, software reviews, and swap/sale of used equipment. Also available for downloading onto your computer are extensive files of labs, graphics, and handouts. Discussions of this and other databases will emphasize the power of these new professional communication tools. Note: This workshop is not included in the published proceedings volume because it was not submitted by the author.

This exercise is used to demonstrate the sodium requirement for substrate accumulation of gram-negative marine bacteria by using a radio-labelled substrate. It may also demonstrate that freshwater bacteria do not require sodium for substrate accumulation.

Two strains of Escherichia coli are grown in broth and plated out at intervals. A population growth curve is plotted for each strain. The two strains are then grown together for several days in different types of broth. Students from each day's laboratory plate out the mixed culture on selective media. Data are pooled. Population curves are plotted for the two strains in competition. With different conditions, it is possible to observe competitive displacement of one strain by another.

This textbook has evolved from online and live-in-person lectures presented in my bacteriology courses at the University of Wisconsin-Madison. Its contents are suitable for reading or presentation in courses or course modules concerning general microbiology and medical bacteriology at the college and advanced high school levels of education. For teachers, instructional materials are available that accompany many chapters and topics. These include lecture outlines, notes, powerpoint presentations, and examination questions that compose a study guide

Creation and characterization of mutants is the basis for any genetic analysis. This exercise demonstrates a simple, safe procedure for transposon mutagenesis of Rhodobacter sphaeroides, a purple non-sulfur photosynthetic bacteria. Students perform the mutagenesis by mating a transposon-carrying plasmid from Escherichia coli to R. sphaeroides and then selecting for the drug resistance carried on the transposon. Only R. sphaeroides carrying the transposon in the chromosome survive the selection. Transposon carrying mutants are then scored for various phenotypes. The metabolic diversity of R. sphaeroides allows the isolation of nutritional, photopigment, and photosynthetic mutants. Further analysis of mutants is possible.