This study examined the growth rate and hydrocarbon production of the algae Botryococcus braunii when grown in different mediums. Two strains of B. braunii were grown in three different liquid mediums for two months. The hydrocarbon production was measured weekly by separating the hydrocarbon biofilm from the algal cells. Only one bottle showed algal growth, while bacteria dominated the other bottles. The experiment did not provide clear results on hydrocarbon production or growth rates. Key lessons learned were that the air delivery and light intensity needed improvement, and inoculation amounts should be increased for better results.

1. Results: Dddddddddddd
Hydrocarbon Production and Growth Rate of
Botryococcus braunii
Introduction: This study revolves around Botryococcus braunii
which is an algae that produces large hydrocarbons. Botryococcus braunii
has 3 different races (A, B, L) classified separately do to the types of hydrocarbons
that they produce. We used race A (UTEX 2441 and UTEX 572.). Race A was
chosen because it was the easiest race of this algae to get ahold of. The A race
has been shown to produce Alkadienes and Alkatrienes which are more lipid
based. The B race has been shown to produce Botryococcenes which are better
for hydrocracking. The L race is shown to produce an oil not formed by the other
algae. The majority of the hydrocarbons produced by this algae are stored in a
biofilm around the outside of the algae. The importance of studying this algae is so
we can use the hydrocarbons this algae produces for a renewable fuel source. For
instance, if these hydrocarbons can be broken down in smaller chains, they can be
used for gasoline. Therefore, we would have a sustainable energy source.
Goal: This basic research will help in further our understanding of how
Botryococcus braunii grows. The first purpose is to develop a process that will
allow us to measure hydrocarbon production and grow algae in a good
environment. The second purpose is to maximize the efficiency of hydrocarbon
production and growth rate in this algae.
Method: In this study, we measured the algal cell growth and hydrocarbon
production over a 2 month period of time for this algae. The variables are that I
grow two different strains (2441 and 572.) of this algae in three different liquid
mediums (Algal Gro medium, Bristol's medium, and Modified Bold 3N medium) to
find the best combination that will maximize the hydrocarbon production and
growth. This means we have 6 different sets of variables. We grew the algae in 2
liter bottles with a bubbler supplying air constantly. The bottles were under a
industrial light always, and the light would be 12 hours on and 12 hours off. To
measure the average cell growth, we took a sample from every bottle once a week
each week to make permanent slides. Then we took 5 random pictures of the slide
through a microscope where we could count the cells. To measure the
hydrocarbon production. We took a sample from each of the bottles each week.
We then used the process of adding kerosine and blue food coloring to each
sample and mixing the samples up so we could separate the hydrocarbon biofilm
from the actual algal cells. The kerosene mixes with the biofilm and the algal cells
stay in solution with the liquid water mediums through the separation process.
From there, we just used a pipet to measure the increase in volume of the the
kerosine to measure the hydrocarbon production rate.
Conclusion: In conclusion, none of the data proved what we were hoping for,
but we learned a lot. We learned that if we were to do this experiment again, we
would change the bubbler system. We would make it a sterile system and feed the
air through the bottom of the bottles instead of the top. We would also lower the
light intensity on the bottles because most of the algae didn’t grow. We would also
increase the inoculation amount of algae in each bottle. Also, we would keep a
more up to date journal of what happens. One of the main things we would change
with this experiment is to not do this experiment because over the past couple
years, there has been more research on this algae. Other people have proven that
the best medium to grow this algae in is Chue 13 medium.
Results: The experiment ended up showing that instead of the volume of the
kerosine increasing and telling us that the hydrocarbon production was increasing,
it decreased. Therefore, the data of the hydrocarbon production was thrown out.
The growth rate results showed that only bottle number 6 (strain 2441 and algal gro
medium) produced algae that did not die out. There were no other bottles shown to
grow any algae. The assumption is that bacteria that we saw as present in all the
other bottles wiped out any of the algae present in those bottles. Bottle 6 must
have not been contaminated by bacteria. Since we had 2 separate bottles with the
same variables (strain 2441 and algal gro medium), and the second bottle never
had any algae growing. We assumed that our procedure for just growing algae
was flawed. Our data for cell growth rate must be inconclusive. Therefore, this
experiment is a learning experience.
Figure 2: The picture shows some of the algae that was present in bottle 6.
William Trevillyan, Justin Lovrien, Sanford PROMISE
Figure 5: These pictures shows bottle 11 which had no algae growing, though it
did have a lot of bacteria growing.
Figure 4: This graph shows the cell growth for algae in bottle 6 (strain 2441 and
Algal Gro Medium), which was the only bottle to have any algal cell growth.
Figure 1: The picture shows the lab where the research was conducted. If you
look closely, you can see the black straws feeding air into all 12 bottles. Notice all
of the set up is covered in aluminum foil to maximize light.
Figure 3: This a zoomed in picture of Firgure 2.