The growth of a bacterial isolate will be followed as a function of time to illustrate the various phases of growth that occur in liquid culture. Intuitively one can recognize that bacterial growth via cell division in liquid media will continue to occur until: a nutrients become limiting; or b microbial waste products accumulate and inhibit growth Maier et al. To understand and define the growth of a particular microorganism, cells are placed in a flask in which the nutrient supply and environmental conditions are controlled.
If the liquid medium supplies all the nutrients required for growth and environmental parameters are conducive to growth, the increase in numbers can be measured as a function of time to obtain a growth curve. Several distinct growth phases can be observed within a growth curve Figure These include the lag phase, the exponential or log phase, the stationary phase, and the death phase.
These phases correspond to distinct periods of growth and associated physiological changes Table The mean generation time can be calculated through the use of a dilution and plating experiment.
See Section 1. Compare the difference in the shape of the curves in the death phase colony-forming units CFUs versus optical density. The difference is due to the fact that dead cells still result in turbidity.
Lag Phase Slow growth or lack of growth due to physiological adaptation of cells to culture conditions or dilution of exoenzymes due to initial low cell densities. Exponential or Log Phase Optimal growth rates during which cell numbers double at discrete time intervals known as the mean generation time Fig.
Stationary Phase Growth cell division and death of cells counterbalance each other resulting in no net increase in cell numbers.
Death Phase Death rate exceeds growth rate resulting in a net loss of viable cells. Mix thoroughly and remove 5ml and refrigerate immediately. Place the flask of E. Remove 5ml aliquots of culture every hour up to 8 hours. These cultures should be designated T0 through T8. First Period Materials 1ml aliquots of E. Each cell division results in a doubling of the cell number.
At low cell numbers the increase is not very large, however after a few generations, cell numbers increase explosively. After n divisions we have 2n cells. Make a fold dilution series: 2. For one dilution, transfer 0. If you have changed your email address then contact us and we will update your details.
Cappuccino & Sherman, Microbiology: A Laboratory Manual | Pearson
Brendecke author Sign in to write a review. Not available. This item has been added to your basket View basket Checkout. View other formats and editions.
The experiments introduce students to the activities of various organisms and the analyses used to study them. The book is organized into three thematic sections: Soil Microbiology, Water Microbiology, and Environmental Biotechnology. The first section includes experiments on the soil as a habitat for microorganisms, and introduces the main types of soil microorganisms, how they interact with the soil, and the techniques used in their analysis.
Experiments in the second section cover assays of microbial pathogens - bacteria, viruses, and protozoan parasites - used in food and water quality control as well as an exercise in applied bioremediation of contaminants in water. The final section on biotechnology includes applications of the polymerase chain reaction PCR for the detection of bacteria and the use of enrichment cultures and a computer-based, physiological test bank to isolate and identify a bacterium useful in bioremediation. Designed for maximum versatility and ease of use for both the student and instructor, each experiment is self-contained and includes theoretical, practical, and pedagogical material.
The new edition incorporates new experiments and the latest techniques. It is designed for maximum versatility and ease of use for the student and instructor. Each experiment is self-contained and includes theoretical, practical, and pedagogical material. Added to basket. Life's Engines. Paul G. Microbiology: A Very Short Introduction. Nicholas P.
- Handbook of Security and Networks.
- Environmental Microbiology.
- Adverb-Adjective Collocation in English.
Schaum's Outline of Microbiology, Second Edition. Edward Alcamo. Philosophy of Microbiology.
Environmental Microbiology: A Laboratory Manual
Maureen O'Malley. I, Superorganism. Jon Turney. Benjamin M.