Contamination by bacteria

Groundwater can be contaminated by bacteria and other pathogens that seep from septic tanks, bro-... 

All stored containers, whether at room temperature, 4°C, or below freezing, must be properly sealed. This reduces contamination by bacteria and vapors in the laboratory air (C02, NH3, HC1, etc.). Volumetric flasks, of course, have glass stoppers, but test tubes, Erlenmeyer flasks, bottles, and... 

Contaminations by bacteria or fungus are easily monitored in plant tissue cultures. Furthermore, these contaminants are usually not potent pathogens to human beings. 

Water. A laboratory engaged in careful electrochemical work with aqueous solutions or in trace analysis will need facilities for the preparation and storage of highly purified water. Water commonly is contaminated with metals in both dissolved cationic form and in the form of colloidal or particulate matter that is not ionized appreciably.70 Frequently it also is contaminated by bacteria and by organic impurities that cannot be removed by ordinary or oxidative distillation because of the steam volatility of the impurities.71... 

The vitamin B12 that occurs in nature is produced almost entirely by bacterial synthesis in animals but not in humans (Battersby, 1994). The richest dietary sources of vitamin B12 are organ meats, such as fiver and kidney. Lesser amounts are present in shellfish, chicken, fish, muscle meats, and dairy products (the principal source in lacto-vegetarians). Plants contain no vitamin B12 unless they are contaminated by bacteria, and foods that contain microorganisms often provide the only source of vitamin B12 for strict vegetarians, such as the vegans of southern India. 

From Consumer Reports "Nearly half the fish we tested was contaminated by bacteria from human or animal feces... for nearly 25 percent of our samples the bacteria count exceeded the upper limits of our test methods."... 

Production was also examined on a 5000 L scale in the same way. However, damage due to stirring was found, which was fundamentally the same as on the 100 L scale. Although there was basically no problem concerning the scale-up of the fixed bed reactor and the actual production, the reaction was contaminated by bacteria which in fact degraded the calcium alginate beads during the production [9]. Fixation by acrylamide could be achieved however, scale-up was difficult, and an optical purity decline was sometimes observed. It was considered that acrylamide... 

Sharpe AN, Woodrow MN, Jackson AK. 1970. Adenosine triphosphate (ATP) levels in foods contaminated by bacteria. J Appl Bacteriol 1970 33 758-67. 

Recall Of the two principal polymers used in column chromatography and electrophoresis, which one would be most immune to contamination by bacteria and other organisms ... 

Bacteria like to eat the same kinds of things we do, so they get into a lot of our food. They also need water to survive, so they find moist environments particularly hospitable. Dry foods, such as salt, sugar, and rice, are rarely contaminated by bacteria. Just because there is bacteria in a given food, howevei doesn t mean that we ll get sick if we eat it. Much depends on the type of bacteria and — most important — the quantity. It usually takes a large number of bacteria to cause illness. 

We have used Hybond N FP nylon membranes (Amersham Int., Amer-sham, UK) extensively. Other types of membranes, however, might work as well. After hybridization, store the blots wet in a closed plastic box containing 2X SSC at 4°C (renew the solution once a month). They will remain in good condition for reprobing over several years (moist in a drawer they would easily become contaminated by bacteria and fungi that destroy the DNA). 

Transfusion of bank blood contaminated by bacteria (gram negatives, Pseudomonas, etc.)... 

There is comparatively less chance of contamination by bacteria and yeast due to low availability of water. 

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