Predation of magnetotactic bacteria by tetrahymena pyriformis – a model ciliate

• Main Author: Ng, Jessica Pei Zhen
• Other Authors: Cao Bin
• Format: Final Year Project
• Language: English
• Published: 2018
• Subjects: DRNTU::Science::Biological sciences
• Online Access: http://hdl.handle.net/10356/74349
• Institution: Nanyang Technological University

Parasitic protozoans which cause waterborne diarrheal diseases remain a concern to human health in the 21st century. Currently, issues eliminating parasitic protozoans arise from its alternating lifecycle between the trophozoite and cyst stage. Particularly, the cyst form increases their resistance to conventional removal and current strategies such as sand-filtration is inefficient due to a tedious maintenance regime. Hence, a prey-predator relationship between protozoa and bacteria is proposed as a novel strategy to overcome current limitations eliminating harmful protozoans from water treatment plants. As a proof-of-concept, the protozoa, Tetrahymena pyriformis (T.pyriformis) and magnetotactic bacteria, Magnetospirillum magnetotacticum (MS-1) were selected as models to prove the feasibility of magnetically isolating protozoans which have fed on the magnetic bacteria. In this study, growth optimizations were conducted on both MS-1 and T.pyriformis. The conditions required to achieve the highest magnetic responses from MS-1 were determined. Lastly, grazing assays between T.pyriformis and MS-1 were also conducted in conjunction with fluorescent staining and microscopy. Overall, T.pyriformis have shown to phagocytose MS-1 specifically, demonstrating the possibility of implementing such strategy in water treatment facilities.