Frustule characteristics of Nitzschia palea (Kützing) W. Smith under varied light qualities and silicate concentrations

• Main Author: Casiano, Katrina Marie D.
• Format: text
• Language: English
• Published: Animo Repository 2018
• Subjects: Biology
• Online Access: https://animorepository.dlsu.edu.ph/etd_bachelors/18557
• Institution: De La Salle University

Nitzschia palea is a benthic pennate diatom distinguished by its lanceolate valves, rounded apices, and fibulae. Pure cultures of N. palea were obtained from the Microalgae Systematics and Applied Phycology Research Unit (MSAPRU) of De La Salle University-Manila. The cultures were grown under various light qualities (red, green, blue, and white) and silicate concentrations (1x [0.81M] NaSiO3 and 2x [1.62M] NaSiO3) in Binangonan Rizal SEAFDEC Philippines (BRSP) media for 30 days to assess effects on frustule length, width, and foramen density. Live samples of N. palea were viewed under a light microscope to assess its length and width. The diatom samples were then cleaned using Hot HCl and KMnO4 method to leave only the diatom frustule intact. Cleaned diatom samples were dried on sectioned Whatman glass microfiber filter grade GF/C at 60˚C for 24 hours. The samples were viewed and photographed under a high vacuum scanning electron microscope for length, width, and foramen density. The photographed scanning electron micrographs were analyzed using the ImageJ program. Results showed that the length and width of N. palea was higher in concentrations of silicate and under all light qualities, although not statistically significant (p˃0.05). Also, various light qualities and silicate concentration did not affect the foramen density.