Faculty Advisor

Crusberg, Theodore C.


The goal of this project was to determine how lighting conditions affected the production of sunscreen compounds by three cyanobacteria, Scytonema, Nostoc, and Microcoleus, found in cryptobiotic crusts in the desert southwest of the United States. Cryptobiotic crusts contribute greatly to the stability and fertility of the soil. The crusts are an important carbon dioxide sink and fixer of atmospheric nitrogen. Cyanobacteria live in cooperation with lichens and mosses. The goal of this project was accomplished by growing each type of cyanobacteria under three kinds lights which produced different amounts of UV radiation. Methanol extracts of the cyanobacteria were collected and analyzed using spectrophotometry from the range of 250 nm to 700 nm. The spectra of each cyanobacteria was compared with the extracts of a native cryptobiotic crust collected from the desert southwest.


Worcester Polytechnic Institute

Date Accepted

April 2005


Biology and Biotechnology

Project Type

Major Qualifying Project



Advisor Department

Biology and Biotechnology