News » Chapter 7 Control of Microbes

The domestication of microbes: A. oryzae case

Contributed by tanidjaja on Aug 07, 2013 - 03:41 PM

Since the beginning of the civilization, humans have domesticated not only animals and plants, but also different kinds of microbes to produce beer, wine, cheese, yogurt, soy sauce, and more. Although researchers have studied the plant and animal domestication comprehensively, it is still a mystery on how domestication changes microbial behavior on a genetic scale. In this article, researchers at Vanderbilt University try to compare the genetic profiles between Aspergillus oryzae, the domesticated microbes, with its wild type relative, Aspergillus flavus to unveil the mystery of microbial domestication.

A Shot in the Arm for New Antiobiotics

Contributed by samaaronson on Jul 24, 2013 - 03:13 PM

    The ability of bacteria to develop resistance to antibiotics has posed as an ongoing obstacle for the medical community.  Antibiotic resistance becomes evolutionarily favorable when the resistant microbes are able to thrive within a community.  This in turn creates a pressure to maintain these mutated microbes and weed out the susceptible ones.  Since mutated organisms are less fit, when resistance is no longer needed the original strain can thrive once again.  


    Overuse of certain antibiotics is to blame for this dilemma, however antibiotics are often the only known treatment for certain illnesses.  Recently, scientists at Harvard University’s Wyss Institute for Biologically Inspired Engineering have discovered a new way of engineering antibiotics to trick the already resistant bacteria.  Silver has been very useful for certain medical tools such as catheters and tracheal tubes due to the low infection rate however until recently no one understood why this was the case.  Ruben Morones-Ramirez, Ph.D. investigated the mechanism in which silver affects bacteria and discovered that silver has many properties that alter the bacteria.  Firstly, silver creates more reactive oxygen species in the bacteria which in turn damages both enzymes and DNA.  It also affects the membrane by making it leakier and therefore weaker.  


The Rise of Antibiotic Resistance: Ways of Mitigating

Contributed by gsims on Jul 18, 2013 - 06:55 PM

Antibiotic resistance in both pathogenic and nonpathogenic bacteria is becoming an urgent topic in human health. According to the Center for Disease Control and Prevention, antibiotic resistance is developing in more and more bacteria. Resistance has been the cause of over 90,000 deaths nationwide, typically from patients with preexisting autoimmune diseases. Studies have been done to determine why more bacteria are acquiring resistance genes and the origin of these genes.

Drug Resistance Loiters on Antibiotic-Free Farms

Contributed by laurenbruehl on Jul 10, 2013 - 07:11 PM

Scientists have found, to their surprise, that after two and a half years of being antibiotic free, pigs that were involved in a Canadian study carried bacteria that were still resistant to antibiotics. Scientists originally hypothesized that the antibiotic resistant mutation would be associated with some sort of fitness disadvantage, like many similar mutations. If this had been true, the bacteria would have been likely to lose their resistance when no longer in the presence of antibiotics.

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