Annual Report 2011–12

28 開拓人類知識的版圖 This example shows that similarity in appearances between animals can be a deceptive indicator of relatedness. True crabs and crab-like anomurans are examples of parallel evolution, which refers to the independent evolution of similar characteristics. This study was published in Systematic Biology , the top journal in the field of evolutionary biology, in August 2011. Student Project Harnessing Bacterial Power At CUHK, we strive to provide students with opportunities to participate in research and help them to develop their research skills. A genetic engineering team formed by undergraduate students of science and engineering at CUHK has devised a new way of generating electricity with solar energy and bacteria. Their creative project won a gold medal, the Best BioBrick Measurement Approach and the Best New BioBrick Part (Natural) awards at the iGEM (International Genetic Engineered Machine) Asia Regional Jamboree in October 2011. Halorhodopsin is a light-driven ion pump that can be found in halobacteria. When activated by light, halorhodopsin transports surrounding chloride ions into cells of the bacteria. The CUHK team made use of this characteristic of halorhodopsin to make BioBrick parts that can alter chloride ion concentration by light. In synthetic biology, BioBrick parts are standard biological parts similar to electronic components or Lego bricks. The BioBrick parts developed by the CUHK team have two potential applications. They can be used to make a ‘mixing-entropy battery’ that takes advantage of the salinity difference between seawater and freshwater to produce electricity. They can be also used to desalinate seawater to make drinkable water by controlling halorhodopsin with light to absorb chloride ions of seawater into bacteria. Their ideas, if realized, can help address two pressing environmental issues: water and energy. 學生研發創意細菌發電技術 中大也致力為本科生提供機會，培養他們 的研究能力。理學院及工程學院本科生組 成的基因工程隊伍，就研究出新的發電方 法──太陽能加細菌，在 2011 年 10 月的國 際遺傳工程機器設計競賽（ iGEM ）亞洲區 比賽中贏得金獎，並獲頒最佳零件實驗量 度及最佳生物新天然零件兩項大獎。 嗜鹽細菌中有一種氯視紫紅質 （ halorhodopsin ），這種蛋白質是光驅動 的氯離子泵，在受光刺激後，會將周遭的氯 離子輸送進細菌的細胞內。中大隊伍利用 氯視紫紅質這種特性，開發出利用外部光 源改變細胞內氯離子濃度的生物零件。 所謂生物零件，是合成生物學中標準化的 組件，概念就像積木或電子零件一樣，可以 用來組裝合成生物。 中大隊伍研製的生物零件有兩大應用前 景，一是可用作「混合熵電池」，即利用鹹 淡水之間的含鹽量差異來發電；另外是用 於海水化淡，以光線控制細菌吸收海水中 的氯離子，降低海水鹽分供人飲用。這些 構思如能實現，可以為人類改善水源和能 源兩大環境問題。