Roberto Kolter


Department of Microbiology and Molecular Genetics
Harvard Medical School
Building D1, Room 219
200 Longwood Avenue
Boston, MA 02115
Tel: (617) 432-1776
Fax: (617) 738-7664
Email: rkolter@hms.harvard.edu
Web Page: The Kolter Lab Page
12 postdoctoral fellows, 2 graduate students


In the natural setting, and within the human host, microbes seldom encounter conditions that are propitious for unrestricted growth. Rather, they must survive in environments where most of the time they are faced with limiting amounts of essential nutrients and stressful stimuli. The myriad of survival strategies that microorganisms have evolved to cope in the environment is reflected in the richness of diversity found in the microbial world. Our laboratory studies several of these microbial survival strategies. Two of the current projects are: the study of surface-associated microbial communities known as biofilms and the ways in which interspecies interactions influence microbial development in communities.

 

Bacterial Biofilms. Most bacteria are capable and most likely prefer to exist in surface associated communities (biofilms). Biofilm formation is a complex developmental process which is regulated by environmental signals and bears many similarities to the development of multicellular organisms. Single motile planktonic cells can differentiate into many different types of non-motile cells when they become members of a sessile community. A trademark of a mature biofilm is that the cells are encased in an extracellular matrix, that can be composed of polysaccharides, proteins and even nucleic acids. Currently, we are focusing our attention on several key questions regarding the cell fate determination during biofilm development using Bacillus subtilis as the model system. What genes regulate matrix production? What extracellular signals determine cell fate? What molecular mechanisms allow for the co-existence of different cell types within a biofilm?

 

Interspecies Interactions. On a global scale, the interactions between microbes of different species, be they bacteria, archaea or eukarya, far out-number microbial interactions with humans. Contacts amongst microbes have certainly influenced the evolution of numerous aspects of microbial physiology, including developmental strategies such as the ability to form biofilms. Our laboratory has developed a number of dual species model systems in which to study the molecular mechanisms that underlie diverse microbial interactions. In addition, we have developed high throughput screens to identify interspecies interactions that result in interesting phenotypic changes mediated by small molecule natural products.

 

References:

BBS webpage updated 12/02/2009