Pigment Production in Freshwater Algal Strain
By Paige Smith
Isolated From Wastewater
Mentor: Dr. Yongli Zhang
Results Continued
Algal Experiment Optical Density
4
Approach
Introduction
•
•
•
•
•
Sustainable Manufacturing Connection
•
Results
Algal Experiment Cell Count
18000000
16000000
14000000
CELL COUNT (CELLS/ML)
• Manufacturing using algae is environmentally friendly
because algae is a renewable resource with a rapid growth
rate
• Marginal lands that cannot be used for traditional farming can
often be used for algal cultivation
• Algae can be grown with wastewater, providing a natural and
low-energy way to remove harmful nitrates and phosphates
• The global market for carotenoids is worth over $1.5 billion
(1)
• Research is focusing on ways to more efficiently bring the
cost of algal cultivation and harvesting down so as to make
algal products more economically competitive
Algal strain was isolated from wastewater provided by the
Detroit Wastewater Treatment Plant
Algal strain was introduced into a BG-11 medium
The samples were aerated and placed on a rotating table
A NaCl concentration of 1.2% (m/v) was introduced to half of
the samples after 10 days of growth
Daily optical density measurements were taken
Cell Count measurements were taken starting on the 13th
day
The experiment ran for 24 days
•
Carotenoids (red/orange pigments) are used in food additives,
vitamins, and fish feeds. The majority of carotenoids used in
industry are produced synthetically. This research focuses on
inducing natural carotenoid production in a freshwater strain of
green algae isolated from wastewater by exposing it to 1.2% NaCl
(m/v).
Control
12000000
Experiment
1.2% NaCl
10000000
8000000
6000000
4000000
Figure 1
Cell count
measurements
of the 1.2%
NaCl
experiment
compared to
the control
2000000
0
13
Background
14
17
18
19
20
21
24
TIME (DAYS)
• When this strain of algae was being isolated from the
wastewater, it turned orange, proving under certain
circumstances it will produce carotenoids
• Previous experiments done with green algae has shown that
under physiological stress, such as nitrogen deprivation, high
light intensity, and high salinity, some algal strains will produce
red pigment (2)
•
•
•
•
The desired pigment was not produced
The samples treated with 1.2% NaCl had significantly slower
growth than the control sample
The algae in the salt samples showed signs of dying off in less
than a week after NaCl was added
When observed under a microscope, the cells in the NaCl
samples showed distress, grouping tightly together instead of
free floating like the cells not exposed to NaCl
OPTICAL DENSITY (A)
3.5
Control
3
2.5
Experiment
1.2% NaCl
2
1.5
1
0.5
0
4
5
6
7
10
11
12
13
14
17
18
19
TIME (DAYS)
Figure 3
Control
cells
20
21
24
Salt
Added
on Day
10
Figure 2
Optical density
measurements of
the 1.2% NaCl
experiment
compared to the
control
Figure 4
Cells
exposed to
1.2% NaCl
Conclusions
When 1.2% NaCl is added to this algal strain it will not
produce carotenoids and the algae will exhibit significantly
decreased growth.
Acknowledgements
This work is supported by the NSF REU program (Award
No. 1461031). Special thanks to Dr. Kishore
Gopalakrishnan and Javad Roostaei. All work for this
project was done in the Water-Energy-Environment
Sustainability Lab (https://blogs.wayne.edu/wees/).
About Me
I am a biomedical engineering major at Miami University
in Ohio.
References
1. The Global Market For Carotenoids. BCC Research (2015)
2. Boussiba and Vonshak. Plant Cell Physiol (1991) 32 (7): 1077-1082
2016 Summer Academy in Sustainable Manufacturing
engineering.wayne.edu/sustamfg/
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