Gang of 15 Fungal Cellulases Open the Bio-Gate

The bio-gateway to abundant energy and wealth was just opened a crack. Cellulose is one of nature's favourite ways of storing solar energy. But human machines and power systems do not run well on cellulose. Naturally, a conversion from cellulose to high density liquid, solid, and gaseous forms of energy storage is vital. But, how to do it? Using clever and efficient enzymes can be a good way, but single enzymes lack the power and versatility to do everything necessary. Hence, the "gang of 15 enzymes" working together.

Researchers at the California Institute of Technology (Caltech) led by Frances H. Arnold, the Dick and Barbara Dickinson Professor of Chemical Engineering and Biochemistry at Caltech, and gene-synthesis company DNA2.0 have developed a new group of 15 highly stable fungal enzyme catalysts that efficiently break down cellulose into sugars at high temperatures for conversion into a variety of renewable fuels and chemicals.

Previously, fewer than 10 such fungal cellobiohydrolase II (CBH II) enzymes were known. In addition to their remarkable stabilities, Arnold’s enzymes degrade cellulose over a wide range of conditions. A paper on the work was published 23 March in the early edition of the Proceedings of the National Academy of Sciences.

This is a really nice demonstration of the power of synthetic biology. You can rapidly generate novel, interesting biological materials in the laboratory, and you don’t have to rely on what you find in nature. We just emailed DNA2.0 sequences based on what we pulled out of a database and our recombination design, and they synthesized the DNA. We never had to go to any organism to get them. We never touched a fungus.
—Dr. Frances Arnold

...Arnold and Caltech postdoctoral scholar Pete Heinzelman created the 15 new enzymes using a process called structure-guided recombination. Using a computer program to design where the genes recombine, the Caltech researchers mated the sequences of three known fungal cellulases to make more than 6,000 progeny sequences that were different from any of the parents, yet encoded proteins with the same structure and cellulose-degradation ability.

By analyzing the enzymes encoded by a small subset of those sequences, the Caltech and DNA2.0 researchers were able to predict which of the more than 6,000 possible new enzymes would be the most stable, especially under higher temperatures (a characteristic called thermostability). _GCC

Very clever. And this is just the beginning.

We are living in a biological world. When we start working with biology to get more of the things we want, we can begin building a veritable cornucopia of riches.