Interaction between Rhodobacter sphaeroides and Harmful Algal Bloom (HAB) causing dinoflagellate Amphidinium carterae

JEC JOSE MIGUEL C. CABALFIN1, JOSEPH DINESH H. LAMZON1, VAUGHN REMOS M. SERRA1, HAROLD P. MEDIODIA1, and DEMY D. CATEDRAL2
1Philippine Science High School – Western Visayas Campus, Brgy. Bito-on, Jaro, Iloilo City 5000, Department of Science and
Technology Philippines – Science Education Institute, Philippines
2Southeast Asian Fisheries Development Center/ Aquaculture Development, Tigbauan, Iloilo City


Abstract
The present study hopes to develop a further understanding regarding algal-bacteria interactions as an option for bioremediation. After the use of chemicals against the events of the red tide proved to be impractical due to its detrimental effects on the aquatic ecosystem, recent studies focused on bioremediation. To examine the algal – bacteria interactions, an in vitro co-culture system consisting of marine bacteria Rhodobacter sphaeroides and HAB – causing dinoflagellate Amphidinium carterae were used as the model organisms. The population count of each species in the co-culture were monitored for 14 days as well as positive (pure A. carterae) control and negative (pure Rb. sphaeroides) control. The co-culture system used for investigating the interactions was established based on the interdependence of the two organisms and later the bacteria would prevail over the dinoflagellate. The results of the population count shows an inverse progression on the growth between the two organisms. Furthermore, the analysis of the populations trend suggests that the bacteria growth was suppressed due to allelopathic interactions by the dinoflagellate specifically the production of toxins and chemical compounds detrimental to the growth of the bacteria proving that the bacteria was ineffective to mitigate the growth of the dinoflagellate.

Keywords: Bioremediation, mitigate, co-culture, dinoflagellate, harmful algal blooms


Identification of microalgae isolated from floating plastics found along Iloilo estuary and cultured in CM and F/2 media

FRENSEL MAE R. YEBAN, CATHY LYN P. BARANDA, VINCE ROLLY P. ANTENOR, and RAMON ANGELO N. SINCO
Philippine Science High School – Western Visayas Campus, Brgy. Bito-on, Jaro, Iloilo City 5000, Department of Science and Technology – Science Education Institute, Philippines


Abstract
Microalgae has been considered as a microorganism having potential to degrade plastic. This organism was able to attach itself to a substratum, forming a biofilm. It is vital to determine the microalgae present thriving in the surrounding environment, as the organism’s characteristics contribute to its biofilm-formation properties. In this study, suspended plastics in the Iloilo river were collected. The microalgal organisms in the plastics were scraped, cultured, serially diluted, and identified. After identification, the genus-level taxonomic identification of isolates was analyzed, and the most common genus were named. From the data acquired, Nitzschia sp. was the most prevalent in all of the samples collected and was seen both in CM and F/2 media. Following Nitzschia sp. is Navicula sp., with six (6) samples containing such. Most of the Navicula sp. were found in Conditioned media. Anabaena sp. were present in five of the samples identified.

Keywords: plastic, biodegradation, microalgae, Nitzschia sp., Navicula sp.


Comparison of Phytoplankton Abundance and Diversity in Selected Sites Along Iloilo-Guimaras Strait near Panay Energy Development

LANEL ROSE C. CORDOVA, CLOYD IAN T. DEMANDANTE, KRISTEL JOYCE T. OCCEÑA, and ANDREA LUCYLE M. BELA-ONG
Philippine Science High School – Western Visayas Campus, Brgy. Bito-on, Jaro, Iloilo City 5000, Department of Science and Technology – Science Education Institute, Philippines


Abstract
Phytoplankton community diversity in selected sites along Iloilo-Guimaras Strait near Panay Energy Development Corporation (PEDC) coal-fired power plant in Brgy. Ingore, La Paz, Iloilo City was compared with those from two other areas one kilometer away from the plant. The vertical tow method was applied during sampling, with the use of a plankton net (25 μm). Water physical parameters including turbidity, pH, temperature, and salinity were also measured. It was found that the most abundant phytoplankter for all sampling stations was the Cyanophyta (A 36.5%, B 25.4%, and C 46.3%). The Shannon-Wiener and Simpson’s diversity indexes both indicate that the sampling station closest to PEDC had the most diverse hytoplankton community. Water pH was the only parameter that showed statistically significant difference (One-way ANOVA p < 0.05). The operation of PEDC coal-fired power plant, particularly the high water turbulence that it generates, causes nutrient circulation, which in turn favors the growth of certain phytoplankton species in the Iloilo-Guimaras Strait. Certain modifications in methods are recommended including the use of Sedgewick-Rafter chamber and the increase of number of repetitions of the counting procedure per sample. It is recommended that similar studies be conducted at another power plant in the Philippines, considering treatment facilities and chemical parameters, or conducting at different times of the day.


Keywords: phytoplankton, diversity, abundance, Iloilo-Guimaras Strait, coal-fired power plant


Accumulation of cadmium and lead in Enhalus acoroides (tape seagrass) species in Brgy. Alegria, Semirara Island, Caluya, Antique, Philippines

VENISE JAN C. CASTILLON, GIEBERLINE DYNE A. AMBUT, PRINCESS JOY D. TINDAN, and HAROLD P. MEDIODIA
Philippine Science High School – Western Visayas Campus, Brgy. Bito-on, Jaro, Iloilo City 5000, Department of Science and Technology – Science Education Institute, Philippines


Abstract
Seagrass meadows are a critical component of the marine ecosystems worldwide and are sensitive to changes in the environment. Semirara, Antique operates the biggest open pit coal mines in the Philippines since 1980. Heavy metals are one of the waste products from mining which can accumulate in living organisms, posing a threat to their health. In this study, seawater, sediment, and Enhalus acoroides (tape seagrass) samples were collected from Brgy. Alegria, Semirara and analyzed using Microwave Plasma – Atomic Emission Spectroscopy (MP-AES) to determine the accumulation of cadmium and lead. Results showed that concentrations for Cd and Pb in seagrass roots were as follows: Cd (<0.009) and Pb (0.061 ± 0.008) while concentrations in seagrass leave were: Cd (<0.009) and Pb (0.067 ± 0.005). Concentration of Cd decrease in the following order: seawater > seagrass leaves > seagrass roots > sediments while concentrations of Pb decrease in the order: seagrass roots > seagrass leaves > seawater > sediments.

Keywords: seagrass, cadmium, lead, Enhalus acoroides, mp-aes


DNA barcoding of molluscs (Bivalvia) in selected sites in Capiz, Philippines

ANDREA PEARL D. AREÑO1, LAURA ELYSE J. CAMBEL1, MARIENELLE S. HILAPAD1, ANDREA LUCYLE M. BELA-ONG1,
RAYMOND VINCENT F. CASTILLO2, and MARCOS B. VALDEZ JR.3
1Philippine Science High School – Western Visayas Campus, Brgy. Bito-on, Jaro, Iloilo City 5000, Department of Science and Technology – Science Education Institute, Philippines
2Department of Biology, College of Science, De La Salle University, Malate, Manila 1004, Philippines
3Department of Biological Sciences, Institute of Arts and Sciences, Far Eastern University, Sampaloc, Manila 11000, Philippines



Abstract
Molluscs exhibit complex morphological characteristics and have the same vernacular for the same species which makes species identification difficult. Using morphology as the lone identifier of species populations was found to be problematic. DNA barcoding using the CO1 gene is found to be a useful tool for species identification when traditional taxonomy is ineffective. This study aimed to contribute to the current DNA barcoding data of molluscs in the Philippines and provide identification of commercially available bivalves in Roxas City, Capiz for conservation and diversity assessment. A discordance between morphological and molecular identification was found and nine putative new species were discovered. DNA barcoding can be used for species identification, food safety, conservation management, market surveillance and discovery of putative new species of bivalves in markets in Roxas City, Capiz. In addition, combining morphological and DNA taxonomic analysis can help in conserving and monitoring of commercially-available marine species.


Keywords: DNA barcoding, bivalves, putative, mislabeling, CO1 gene


Determining the tensile strength, tear resistance, and stiffness of Adonidia merrillii (Manila palm tree) leaf sheaths

GHERVIC KYLE C. AGUILAR, BHOB ANDREEVE A. LIGNIG, ADRIAN CAHLIL EIZ G. TOGONON, XAVIER ROMY O. BRANA, and ALBERTO G. TANOY
Philippine Science High School – Western Visayas Campus, Brgy. Bito-on, Jaro, Iloilo City 5000, Department of Science and Technology – Science Education Institute, Philippines


Abstract
Use of natural plant fibers has increased in the past decades from uses such as ropes, textiles, paper-making, to reinforcement for polymer composites due to its advantages over hazardous synthetic fibers with comparable strength. Adonidia merrillii, commonly known as Manila palm tree, have not yet been fully explored of its fibrous properties. Its leaf sheaths, a fiber sheet-like material, has no known uses aside from being used as burning fuel. The research aimed to profile the mechanical properties of A.merrillii leaf sheaths such as the tensile strength, stiffness, and tear resistance, in comparison to the commercially available textile, canvas. Raw leaf sheaths were first tested to see if it can compare to textile, before applying any treatments. The leaf sheaths were washed, cut, and dried before testing. Due to limitations of the study, only the tensile and tear test yielded results. It was found out that the leaf sheath had a higher average tensile strength and stiffness than that of canvas. The leaf sheaths however were found to have weaker tearing force along the ridges. The leaf sheaths can be an alternative textile in the market.

Keywords: fiber sheet, textile, canvas, mechanical properties, testing