Cyanobacteria Oxygen Production Through Photosynthesis
Date Performed: September 2, 2014
I. Introduction
a. Background
Cyanobacteria or blue green algae are renowned for their tolerability and susceptibility even in wide range of environmental conditions, a characteristic of many primitive organisms. CNB are believed to be the agents of autotrophic origin of life thus they probably represent the survivors of the earliest photosynthetic plants, along with photosynthetic and chemosynthetic bacteria. CNB fossilized remains have been found in middle Precambrian rocks, and they may have appeared much earlier (Humm and Wicks 1980).
b. Objectives
This experiment aims to find out the oxygen production of cyanobacteria in selected sample areas.
The experiment will also introduce the use of dissolved oxygen meter in determining oxygen production.
II. Materials and Methods
Water Samples
Fresh or Tap H2O
(BOD) bottle
Dissolved Oxygen (DO) Meter
Micropipette
1. All the needed materials were prepared.
2. Freshwater or tap water was added into the BOD bottle.
3. The initial dissolved oxygen was measured using a DO meter.
4. With the use of a micropipette, a predefined volume of the water samples acquired in different locations was added into four different BOD bottle with H2O. Water samples were obtained from different areas (Pond, Britanico Bridge Stream, Bentoy’s Place Canal and Hatchery Canal) before the lab.
5. The containers were kept in a well-lighted place.
6. The dissolved oxygen in every sample was measured after three hours.
7. After twenty four hours, the dissolved oxygen in the samples was measured again.
8. All the readings were recorded and tabulated.
III. Results and Discussion
Table 1. Dissolved Oxygen Readings
Time
Water (Control)
Stream
Pond
Hatchery Canal
Bentoy’s Canal
9:00 AM
0 ppm
4.5 ppm
5.6 ppm
4.1 ppm
1.2 ppm
12:00 PM
0 ppm
4.5 ppm
4.4 ppm
4.6 ppm
4.3 ppm
9:00 AM (Next Day)
0 ppm
4.82 ppm
5.8 ppm
6.75 ppm
5.2 ppm
Figure 2. Trends
Cited: Martinez MR. 1984. A checklist of Blue-Green Algae of the Philippines. National Institutes of Biotechnology and Applied Microbiology (Biotech) UPLB. 1p. Humm, HJ, Wicks, SR. 1980. Introduction and Guide to the Marine Blue Green Algae. John Wiley & Sons, Inc. 2 p.