Team:SBS SH 112144/Device


Our Device

Device Design:

Cyanobacteria are detrimental to human beings and the environment. However, objectively speaking, They are also treasuries containing countless valuable components. Chlorophylls in cyanobacteria are very important research material for the study of light systems 1 and 2 as well as the general photosynthetic pathway of autotrophic organisms; ​metabolites such as steroids, free fatty acids and biocides could function antibiotics, immunosuppressant, anticancer, antiviral, anti-inflammatory medicines; and other components could be made into fertilizers, biofuels and even pieces of cosmo-technologies. With all these benefits, our device could bring huge benefit if it could successfully degrade the cyanobacteria into smaller components.

Cyanobacteria have a thick peptidoglycan layer in their cell wall, and the normal lysis mixture barely work on them. Existing physical lysis methods with beads would destroy the structure of its components such as chlorophyll, depriving their practical values. Therefore, our device equipped with the cyanophage lysozyme is an ideal choice. We have managed to culture wild cyanobacteria ​PCC 6803​ in our lab to mimic the salvaged cyanobacteria from the natural water bodies. Then, after a series of functional test and modeling, we are able to identify the best pH, temperature, enzyme concentration and reaction time for the reaction to take place. By applying the optimized parameter to the device, we are able to measure an over 70-80 percent lysis. Of course the prototype is very small, but the fact that it worked proved the practicality of the commercial application of such a device.

Device Improvement:

  • The result of the lysis could be better compared to our functional test. Therefore, during each cycle, the pump could be designed in a mode that it pumps the reaction mix into the enzyme column, stops for a while for the lysozyme to be able to fully cleave the peptidoglycan on the cell wall, then pumps the liquid out while drawing some new reaction mix into the enzyme column.
  • We suspect that exposure to the light would deteriorate the quality of chlorophylls. Therefore, the entire process of lysis and the later processing of end products should be contained in a dark environment.
  • We suspect that simply attaching the enzyme on nickel bead column would influence the activity of the enzyme. Therefore, we could change the ways we immobilize the lysozyme into cross-linking or entrapment to better retain the activity of the lysozyme.
  • Due to limited time we have, our tested device does not include parts that would help separate the different components of cyanobacteria. Future research could test the device in the following diagram which includes a sedimentation pool for extraction of larger components such as cell wall and a centrifugation component to extract the smaller metabolites and chlorophylls from the reaction mix.
The improved device