2644 - CSUN ScholarWorks - California State University, Northridge

Journal of Student Research Abstracts · 33
gellate, to represent marine life. I hypothesized that if car wash detergent is harmful to the health of marine
life, then the colony of Pyrocystis lunula to which the car wash detergent is added will produce less intense
blue-green bioluminescence when agitated than a colony to which plain salt water is added. To answer my
question, I prepared a 150 ml solution of salt water containing two drops of car wash detergent. This solution
served as the polluted water and simulated the concentration of car wash detergent that can be found in parts
of the ocean. The· experiment was then carried out in a dark room at 8:30a.m., two hours into the dinoflagellate's
night cycle when bioluminescence is at its peak. I filled each of the wells of the microwell plate with
equal volumes of dinoflagellates. I then placed two drops of plain salt water (control) into twelve of the wells
and two drops of the polluted salt water (experimental) into the other twelve wells. Each microwell was then
stirred to agitate the dinoflagellates. I recorded the brightness of each well's bioluminescence on a scale from
0 (no bioluminescence produced) to -5 (bright blue-green bioluminescence produced). The average measured
bioluminescence for the dinoflagellates in the plain salt water was 4.83, compared to 3.29 for the dinoflagellates
in the polluted salt water. I then ran the t-test, which resulted in at value of 7.7 and probability of less
than 0.1% that my results were due to chance variation alone. This allowed me to reject the Null Hypothesis
and conclude that the brightness of blue-green bioluminescence produced by the dinoflagellates in the car wash
water was significantly less than the brightness of blue-green bioluminescence produced by the dinoflagellates
in the plain salt water. Furthermore, since the rule regarding the health of dinoflagellates is brighter bioluminescence
is better and dinoflagellates are a representation of marine life, I concluded that car wash detergent
is harmful to the health of marine life.
2709
THE EFFECTS OF THE LICHEN CLADINA RANGIFERINA UPON E. COLI AND
B. CERUES.
Nicholas R. Chladek and Steve DeGusta (instructor). John F. Kennedy High School, 6715 Gloria Drive,
Sacramento, CA 95831.
The principle objective of this experiment was to determine if the lichen Cladina rangiferina produces an
antibiotic that effectively inhibits the growth of the bacteria E. coli and B. cereus. Lichen contains a fungus;
and fungus are known to produce antibiotics. This experiment tested whether the fungus in the lichen Cladina
rangiferina produces an effective antibiotic against the growth of B. cereus and E. coli. The effective diameter
for inhibition of bacterial growth is five millimeters for the radius, or 12 millimeters for the diameter of circle
of inhibition surrounding the lichen-extract disks. The lichen extract was made from a 0.5-gram portion from
the body of the lichen that was then ground using a mortar and pestle, and finally added to 10 ml of methyl
alcohol (100%). The extract was added to filter paper disks, made using a standard hole punch; and methanol
was added to control filter paper disks as a control. B. cereus was aseptically transferred to a nutrient agar test
tube, then spread onto a petri dish. The dish was separated into four equal sections by using a permanent marker
to draw four quadrants. Two control disks were added to two quadrants, and the two experimental disks were
added to the two remaining quadrants. The same process was repeated using E. coli. The lichen-extract disks
consistently exhibited circles of inhibition, in both E. coli and B. cereus, that were 12 millimeters in diameter.
After using the t-test, I confirmed that any methanol remaining on the control disks did not inhibit either E.
coli or B. cereus (p