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2017 IWA Symposium of Lake and Reservoir Management
Shanghai, China, 22-26 May, 2017
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Detection of cyanotoxins in Laguna Lake, Philippines using ELISA and qPCR
Ricardo F. de Leon, Jr.1, 2, Delia B. Senoro1,3,*, Tsair-Fuh Lin4, Yi-Ting Chiu4, Yi-Hsuan
Chen4, Anna DG Binayug1,3
1
Environmental Engineering Graduate Program, Mapúa Institute of Technology, Intramuros,
Manila 1002, Philippines;
2
Department of Physics, Mapúa Institute of Technology, Intramuros, Manila 1002,
Philippines;
3
Sustainable Development Research Office, Mapúa Institute of Technology, Intramuros,
Manila 1002, Philippines;
4
Global Water Quality Research Center, Department of Environmental Engineering, National
Cheng Kung University, Tainan 70101, Taiwan
Presenting Author: Ricardo F. de Leon, Jr.
Keywords: Microcystins; Laguna Lake; cylindrospermopsins
Introduction
Cyanobacteria such as microcystis and cylindrospermopsis pose serious problems to
drinking water and the public health due to its cyanotoxins (Lone et al., 2015). Chronic
exposure to cyanotoxins would affect the health of public by targeting human kidney and liver
(AWWA 2016). Hence, reliable detection and quantification of the cyanotoxins are important
in Laguna de Bay and the public health. These bacteria are highly adaptive organisms that can
adjust to changing environmental conditions (Davis et al., 2009). Laguna is the biggest inland
water in the Philippines.
Materials and Methods
The study was carried out in Laguna Lake with a total surface area of 900 square
kilometers. It is the primary raw water source for domestic supply at the western part of Metro
Manila. The lake is located 13 degrees 55’ to 14 degrees 50’ N latitude and 20 degrees 50’ to
121 degrees 45’ E longitude at 15 kilometers southeast of Manila. Surface water were manually
collected using a stainless steel retractable sampler and stored in an ice chest prior to treatment
and analysis from August 18 to 21, 2016. Thirty four sampling stations were included in the
study for the whole lake. Figure 1 shows the exact location of the sampling points. Portable
enzyme-linked immunosorbent assay (ELISA) was used to detect cyanotoxins. Cell number in
the water samples was determined by portable quantitative real-time PCR (qPCR) to distinguish
whether cyanobacteria species in Laguna Lake is toxic or non-toxic, and odorous or nonodorous.
Figure 1 Map of Laguna Lake showing
the locations of the sampling points. Red
dots showing the sampling points.
2017 IWA Symposium of Lake and Reservoir Management
Shanghai, China, 22-26 May, 2017
____________________________________________________________________________________________________
Results and Discussion
The ELISA results showed the highest recorded total microcystins and
cylindrospermopsins concentration is near at San Cristobal, Laguna (Figure 2) and a thermal
power plant (Figure 3), respectively. This could be associated with historical excessive load of
nitrogen and phosphorus at San cristobal river system (Gacelo, 2006) and power plant water
abstraction for industrial cooling. This process recycled water back to the lake resulting to
thermal pollution (LLDA, 2016).
(g/L)
10
5
0
1 2 3 4 5 6 7 8 9 10111213141516171819202122232425262728293031323334
sampling stations
Figure 2 Total microcystins concentration (g/L) detected in the water samples of Laguna
Lake
(g/L)
0.15
0.1
0.05
0
1 2 3 4 5 6 7 8 9 10111213141516171819202122232425262728293031323334
sampling stations
Figure 3 Total Cylindrospermopsins concentration (g/L) detected in the water samples of
Laguna Lake
Conclusions
Dominant species of cyanotoxins in the water column at Laguna Lake, Philippines are
microcystins and cylindrospermopsins at the south and central bay of the lake. The results of
the quantitative assessment and determination of the type of cyanobacteria present in the lake
will aid in providing information for bioremediation options.
References
AWWA, 2016. Managing Cyanotoxins in .Drinking Water: A Technical Guidance Manual for Drinking Water
Professionals. Water Research Foundation
Davis, T. W., Berry, D. L., Boyer, G. L. and Gobler, C. J., 2009. The effects of temperature and nutrients on the
growth and dynamics of toxic and non-toxic strains of Microcystis during cyanobacteria blooms. Harmful
Algae, vol. 8, 715–725.
Gacelo E. P., 2006. Dynamics of Water Quality of the San Cristobal river systems, Laguna, Philippines. University
Library, University of the Philippines at Los Banos, Philippines.
LLDA, 2016. Exisiting Lake Uses. Laguna Lake Development Authority, National Ecology Center, Quezon City,
Metro Manila, Philippines
Lone, Y., Koiri, R. K., and Bhide, M., 2015. An overview of the toxic effect of potential human carcinogen
Microcystin-LR on testis. Toxicol. Reports, vol. 2, 289–296.