Donato Research Group:  Biochemistry

Background

Bacteria play a role in almost all processes at work on the planet. From global warming to feeding the hungry to treating disease, many of the challenges that face us, as well as the potential solutions to these problems, can be traced back to bacteria. Despite their abundance (it is estimated that approximately 90% of the cells in the human body are bacterial!) and importance, little is known about the overwhelming majority of bacteria. After all, less than 1% of bacteria, are readily culturable under standard laboratory conditions; leaving the rest of the bacterial community virtually unexplored. However, advances in technology coupled with increased interest and funding are enabling researchers to unlock the secrets of the microbial world.

Our group focuses on probing the uncultured majority of bacteria to identify and characterize the enzymes responsible for enabling bacteria to survive under stressful conditions. We use functional metagenomics to circumvent the need to culture these bacteria in our search for genes of interest. The word “metagenomics” refers to the composite snapshot of the genetic components of an entire assemblage of organisms. Taking a metagenomic approach entails directly cloning DNA from the bacteria present in a given sample, without the need for amplification. Since there is no bias introduced through culturing, we have access to all of the genes (and the enzymes they encode) in all of the bacteria in the sample. Through functional screens, specific phenotypes are then selected in an effort to identify gene products with desired biochemical function.

Antibiotic Resistance

Health depends on a delicate balance between the body and its resident microbes. There is growing evidence that many human diseases are caused by bacterial residents of the human body. In addition to infectious diseases, these include chronic inflammatory diseases, autoimmune diseases, and certain cancers. Therefore, a robust arsenal of antibiotics and ways to manage resistance are likely to be of increasing importance in medical practice.

In the fight against bacterial pathogens, one of the most important weapons available to physicians is a broad range of chemotherapeutic agents. However, a significant limitation to successful use of these drugs is the development of antibiotic resistance. This generates a serious need for new antibiotics to overcome resistance as well as a need to develop new strategies to manage resistance. To design more effective antibiotics, we must first understand the molecular mechanisms and environmental conditions that give rise to antibiotic resistance.

We will use the inherent diversity in microbial communities along with the tools of modern genomics to identify and characterize potential sources of antibiotic resistance. This information will be a valuable resource to aid in the development of new drugs and to prolong the useful lives of existing drugs by anticipating and managing resistance.

Surviving Other Stresses

Antibiotics represent just a few of the many potentially lethal chemicals that bacteria face. We administer antibiotics with the hope in mind that these chemicals will kill off microbial pests. On the other hand, many bacteria are beneficial to us. Their ability to detoxify the toxic chemicals in their natural habitats greatly impacts our daily lives. Our group uses functional metagenomics to identify the enzymes that enable bacteria to thrive under toxic conditions in an effort to understand the roles these molecular machines play in their host organisms.

Joining the Donato Lab

If exploring the molecular diversity of the bacterial world interests you and you would like to join our group, please contact me at dona1145@stthomas.edu.

Recent Publications

Please click the following link to see recent publications from Dr. Donato