Science News
from research organizations

Biologists discover an extra layer of protection for bacterial spores

Date:
May 9, 2010
Source:
New York University
Summary:
Bacterial spores, the most resistant organisms on earth, carry an extra coating of protection previously undetected, a team of microbiologists reports. Their findings offer additional insight into why spores of the bacteria that cause botulism, tetanus, and anthrax survive methods to eradicate them.
Share:
       
FULL STORY

A spore from the bacterium Bacillus subtilis reveals bands, or protective coats, surrounding the spore’s center. The outer-most dark layer is a previously undetected extra coating of protection, which biologists have labeled the “spore crust.”
Credit: Image courtesy of Current Biology (Eichenberger et al., May 25, 2010 issue)

Bacterial spores, the most resistant organisms on earth, carry an extra coating of protection previously undetected, a team of microbiologists reports in the latest issue of the journal Current Biology. Their findings offer additional insight into why spores of the bacteria that cause botulism, tetanus, and anthrax survive methods to eradicate them.

The study was conducted by researchers at New York University's Center for Genomics and Systems Biology, Loyola (Ill.) University's Medical Center, and Princeton University's Department of Molecular Biology.

The researchers studied the spores of a non-pathogenic bacterium, Bacillus subtilis, which is commonly found in soil. Although non-pathogenic, B. subtilis spores exhibit many of the same structural features of the spore-forming pathogens. In this study, the scientists examined the proteins that comprise spores' protective layers. Previous research has shown that 70 different proteins make up these layers. Less understood is how these proteins interact to form the spores' protective coats.

To do this, the researchers examined coat formation of both normal and mutant spores. In the latter case, they removed genes for selected coat proteins, allowing them to determine which proteins were necessary in -- and extraneous to -- the formation of the spores' coats.

To observe proteins' behavior in living cells, the researchers fused the genes encoding the spores' coat proteins to a marker, a Green Fluorescent Protein (GFP). This procedure allowed them to monitor how the proteins localized to form spores' protective coats. A combination of fluorescence microscopy experiments and high-resolution image analysis enabled the researchers to overcome a theoretical limitation of light microscopy, pinpoint the location of the spores' coat proteins with a high degree of precision, and build a map of the spore coat. These experiments suggested the existence of a new outermost layer of the spore coat. They were then able to confirm the existence of this new layer using electron microscopy.

The researchers named this coat layer, located on the spores' outer surface, the "spore crust." While it has not yet been confirmed, it is possible that the spore crust is a common feature of all spore-forming bacteria, such as the botulism, tetanus, and anthrax pathogens.

The research was funded by the National Institute of General Medical Sciences, part of the National Institutes of Health.


Story Source:

The above story is based on materials provided by New York University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Peter T. McKenney, Adam Driks, Haig A. Eskandarian, Paul Grabowski, Jonathan Guberman, Katherine H. Wang, Zemer Gitai, and Patrick Eichenberger. A Distance-Weighted Interaction Map Reveals a Previously Uncharacterized Layer of the Bacillus subtilis Spore Coat. Current Biology, 2010; DOI: 10.1016/j.cub.2010.03.060

Cite This Page:

New York University. "Biologists discover an extra layer of protection for bacterial spores." ScienceDaily. ScienceDaily, 9 May 2010. <www.sciencedaily.com/releases/2010/05/100506121746.htm>.
New York University. (2010, May 9). Biologists discover an extra layer of protection for bacterial spores. ScienceDaily. Retrieved May 28, 2015 from www.sciencedaily.com/releases/2010/05/100506121746.htm
New York University. "Biologists discover an extra layer of protection for bacterial spores." ScienceDaily. www.sciencedaily.com/releases/2010/05/100506121746.htm (accessed May 28, 2015).

Share This Page: