005 Microbes, the little guys_Bacillus thuringiensis and its role in agricultural biotechnology

With the Earth's population continuing to increase there is an increasing demand for food. But how can food production become more efficient? One answer to that question is transgenic crops. Transgenic crops are crops that contain DNA from two different organisms. Usually the genome of the target organism is supplemented with a gene or multiple genes from another organism.

One  transgenic crop that has been developed to reduce crop losses due the pest such as the European Corn Borer and the Cotton Bollworm is Bt crops. Bt crops such as Bt Corn and Bt Cotton, contain the cry gene/s from the bacterium Bacillus thuringiensis. This gene codes for a Crystal protein that once ingested by insects, breaks down in their hindgut and lyses the cells lining their gut. This cellular breakdown of the digestive system of the insect by the Bt toxin kills the insect and therefore reduces crop losses due to the action of pest species.

As with all things genetically modified there are both ethical and scientific issues to contend with. Ethical issues aside, the real problem of Bt crops is natural resistance in the pest population and the potential effects on non-target organsism.

Join us as we explore the world of Bt crops, which continues to help increase crop yields by controlling pest population.

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002 Microbes, the little guys_SAR11 the most abundant microbe on the planet!

This episode delves inside the world of SAR11. The most abundant microbe in the Oceans, and in fact on the Planet! Only discovered in 1990 by Stephen Giovannoni et. al., this microbe has already had its genome sequenced. SAR11 plays an important role as not just the garbage cleaner and elemental recycler of the oceans, but is also involved in the carbon cycle. The high abundance of SAR11, 25% in some oceans means that this tiny microbe with a tiny genome can effect the global carbon cycle and thus is important to study in reference to climate change.