Zeaxanthin belongs to the carotenoid family and is widely found in nature. It is also a natural color making corns, carrots and marigolds yellow. Moreover, zeaxanthin is an essential nutrient substance to human’s eyes, and some health supplements are made of it. Most of the green plants produce zeaxanthin as an intermediate in the carotenoid pathway. However, some cyanobacteria lack some genes and cannot produce zeaxanthin, such as Synechococcus elongatus PCC 7942. PCC7942 lacks only one gene making zeaxanthin, that is beta-carotene hydroxylase (CrtZ). To make Synechococcus elongatus PCC 7942 produce zeaxanthin, we construct a plasmid BBa_K2320022 under the control of PrbcL. After the expression of CrtZ, PCC 7942 can then be yellow.
And the crtZ what we use was a part released in iGEM (BBa_I742158).We have successfully constructed this part on our special design backbone pPIGBACK so that it can express in our microalgae and result in yellow microalgae.

Details

1. We studied Professor Chuan-Hsiung Chang’s paper(Energy Environ. Sci., 2012, 5, 8318: Enhancing CO2 bio-mitigation by genetic engineering of cyanobacteria) and decided to construct pigment plasmid with the same promoter. The natural ribosome binding site is also referred to it.

2. The intrinsic promoter of Rubisco large subunit (PrbcL) can overexpress foreign genes in the cyanobacteria. Many plants’ proteins in photosynthesis are under regulation of PrbcL. And the high activity to express foreign genes has been proved.

3. CrtZ from Pantoea ananatis is a coding sequence of igem released part (BBa_I742158). It can lead to zeaxanthin and astaxanthin. However, the wild-type Synechococcus elongatus PCC 7942 lacks it and cannot make zeaxanthin naturally.

Team:NYMU-Taipei/Composite Part

Composite Part

BBa_K2350022

Part Description

Details

Result