The Effect of Organic Carbon Sources on the Growth, Chlorophyll, Protein, Lipid, and Carbohydrate Content of Chlorella vulgaris in Outdoor Cultivation Mohamed Amar Naqqiuddin, Chan Pek Yoke, Hishamuddin Omar, and Ahmad Ismail. Department of Biology, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang Selangor, Malaysia Corresponding author:
[email protected]
INTRODUCTION Chlorella vulgaris has been studied thoroughly as it is beneficial as food, feed, oil and others. Organic materials were utilized by active transportation when it occurred at very low concentration. Organics carbon sources can be absorbed to supply energy sources for faster cell growth. Uniquely, Chlorella vulgaris are able to grow in heterotrophic conditions using organic carbon sources for energy. Goats and chickens dung can also enhanced the growth of Chlorella sp. at concentration 1% and 10% respectively using proper dilution techniques (Phang, 1990). According to (Cid et al., 1992), the composition of carbohydrate with addition of glucose was at 48.5 pg/cell compared to in controlled conditions shown 6.5 pg/cell. Chlorella vulgaris grown autotrophically may synthesis protein in the dark condition by using acetate as a carbon sources media (Laliberte and Hellebust, 1989). In the latest studies, Chlorella vulgaris was grown mixotrophically with industrial dairy waste (cheese whey) as organic carbon sources (Abreu et al., 2012). The primary objective of this study is to investigate the effects of organic carbon sources on the growth of outdoor cultivated Chlorella vulgaris. METHODOLOGY Commercial fertilizer were prepared as the culture media and organic carbon sources supplement like glucose, acetate, brown sugar and POME were added respectively.
Chlorella vulgaris was cultured in outdoor condition in aquarium tanks. Growth parameters were determined: pH, optical density, temperature, dry weight and total chlorophyll.
After 7 days, the culture was replicated into 5 tanks with same volume of each culture. On the 8th day, sample collected for biochemical analysis.
Determination of: Cell count Vollenweider (1974); Total chlorophyll Strickland and Parsons (1968);Total lipid Bligh and Dyer (1959); total protein Bradford (1976); and carbohydrate Kochert (1978).
RESULT 10.00
Acetate 0.5g/L Glucose 0.5g/L Brown sugar 0.3 g/L Control
8.00 6.00 4.00 2.00 0.00 1
2
3
4 5 Day
6
7
8
Figure 1: Growth of Chlorella vulgaris in control and media treated with different organic carbon sources supplements.
1.80 1.60 1.40 1.20 1.00 0.80 0.60 0.40 0.20 0.00
POME 1ml/L Acetate 0.5g/L Glucose 0.5g/L Brown sugar 0.3 g/L Control
1
2
3
4 5 Day
6
7
Dry Weight (%)
POME 1ml/L Total Chlorophyll a (mg/l)
Cell count (x million)
12.00
70 60 50 40 30 20 10 0
Protein Carbohydrate Lipid
8
Figure 2: Total chlorophylla of Chlorella vulgaris in control and media treated with different organic carbon sources supplements.
Organic Carbon Sources
Figure 3: Protein, lipid and carbohydrate content in control and media treated with different organic carbon sources supplements.
From several series of test conducted, the best growth were observed and recorded from each concentration of the supplements added to the standard fertilizer medium. The most suitable concentration added of POME supplement was at 1 ml/L, acetate at 0.5 g/L, glucose at 0.5 g/L and brown sugar at 0.3 g/L. The temperature of culture was within 28°C - 34°C. The cell count constantly increased until day 7 reach about 6.75 million cell, however the cell count drop afterwards. In comparison of these treatments, the best growth was showed with the addition of acetate reached the highest cell count at 10.78 million cells on the last day of cultivation. The second best growth showed by glucose reached at 9.86 million cells in the end of cultivation. Total chlorophylla was highest at 1.6 mg/L for culture treated with glucose. In addition, treatment with acetate 0.5g/L showed highest total protein and carbohydrate content.
REFERENCES
CONCLUSION
1. Abreu, A.P., Fernandes, B., Vicente, A.A., Teixeira, J. and Dragone, G. (2012). Mixotrophic cultivation of Chlorella vulgaris using industrial dairy waste as organic carbon source. Journal of Bioresource Technology. 118. pp. 61-66. 2. Cid, A., Abalde, J. and Herrero, C. (1992). High yield mixotrophic culture of the marine microalgae Tetraselmis suecica (Kylin) Butcher (Prasinophyceae). Journal of Applied Phycology. 4(1) : 31-37. 3. Laliberte, G. and Hellebust, J.A. (1989). Heterotrophic growth of Chlorella autotrophica on acetate or ethanol. Journal of Phycology. 25 (2) :10. 4. Phang, S.M. (1990). Alga Production from Agro-Industrial and Agriculture Wastes in Malaysia. Ambio. 19 : 8.
Acetate and glucose were found to be more favorable to Chlorella vulgaris. Treatment with organic carbon sources as supplements can enhanced the growth of Chlorella vulgaris and the protein and carbohydrate contents in outdoor condition. Overall, highest percentage of protein and carbohydrate (% per dry weight) were obtained with acetate treatment.
ACKNOMLEDGEMENT
Million thanks to our supervisor Dr. Hishamuddin Omar for his guidance and to those who have contribute in this project.
