Team:SBS SH 112144/Description



Cyanobacteria are ancient phyla of photosynthetic bacteria widely spread in aquatic ecosystem. As one of the earliest forms of life, cyanobacteria are thought to lay the foundation of life on earth. What's more, they are vital fossil fuel and nitrogen fertilizer providers. However, cyanobacteria pollution nowadays has become a notorious problem:In China, cyanobacteria have invaded major water bodies, turning the lake surface into a disgusting bluish-green color.

Lake Taihu cyanobacteria pollution

Cyanobacteria is threatening human lives and the natural environment in multiple ways:

1. Their growth depletes the storage of nutrients such as nitrogen and phosphorus in the water body.

2. Large clumps of cyanobacteria would increase the opacity of water, disallowing sunlight to reach the bottom of the water, thus harm the growth of other aquatic plants and animals.

3. Cyanobacteria bloom results in hypoxia of organisms in the water, as indicated by the cyanobacteria bloom on Lake Taihu.

A boat driving on the badly polluted surface

4. Microcystis, a special type of cyanobacteria, produces a type of cyanotoxin named microcystins, which harms human liver severely.

Project Overview

We spent much time doing background research including reaching out to the public, and learned that existing methods allow us to cluster all the cyanobacteria into one little area. However, in order to deal with the salvaged cyanobacteria appropriately, we designed an experiment aiming to use a cyanophage lysozyme to degrade the cyanobacteria into their utilizable components.

Through gene amplification, we were able to obtain plasmid with lysozyme gene. And we were able to purify protein from the transformed E. coli containing such a gene. Our functional test under different environmental conditions provides us data based on which we built our models through collaborating with some collegiate teams to obtain the optimal parameters for our device. Even though due to limited time, we were not able to test all parts of our device, we were able to prove its effective lysis of cyanobacteria. The device that could potentially be configured on water-filtering ships, or launched in an aquatic environment with concentrated cyanobacteria in order to break cyanobacteria into harmless parts that could potentially be used commercially.