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Ch. 26 - Applied and Industrial Microbiology
Bauman - Microbiology with Diseases by Taxonomy 6th Edition
Bauman6th EditionMicrobiology with Diseases by TaxonomyISBN: 9780134832302Not the one you use?Change textbook
Chapter 26, Problem 4

Potable water is allowed to have ________coliforms per 100 ml of water tested.

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1
Understand that coliform bacteria are used as indicator organisms to assess the microbial quality of potable (drinking) water, as their presence suggests possible contamination by fecal matter.
Recall that regulatory standards for potable water set a maximum allowable limit for coliform bacteria to ensure safety and prevent waterborne diseases.
Identify that the standard for potable water typically requires zero coliform bacteria per 100 ml sample, meaning no coliforms should be detected in a 100 ml water sample.
Recognize that this zero-tolerance standard helps ensure that the water is free from fecal contamination and safe for human consumption.
Summarize that the allowable number of coliforms per 100 ml of potable water is zero, reflecting strict microbiological safety standards.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Coliform Bacteria

Coliforms are a group of Gram-negative, rod-shaped bacteria commonly found in the environment, including soil and water, and in the intestines of warm-blooded animals. They are used as indicator organisms to assess the microbial quality of water because their presence suggests possible contamination by fecal matter and potential pathogens.
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Water Quality Standards for Potable Water

Potable water standards define acceptable limits for microbial contamination to ensure safety for human consumption. Regulatory agencies, such as the EPA or WHO, set maximum allowable levels of indicator organisms like coliforms, often requiring zero coliforms per 100 ml to minimize health risks from waterborne diseases.
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Indicator Organisms in Water Testing

Indicator organisms, such as total coliforms and fecal coliforms, are used in water testing to detect contamination because they are easier to identify than specific pathogens. Their presence indicates potential fecal pollution and the possible presence of harmful microorganisms, guiding water treatment and safety assessments.
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