posted on 2021-11-03, 22:03authored byHaixiang Liu, Haotian Bai, Neng Yan, Tin Yan Wong, Dongfeng Dang, Jen-Shyang Ni, Jacky W. Y. Lam, Henry Lam, Ryan T. K. Kwok, Wen-Xiong Wang, Ben Zhong Tang
Light
utilization is the vital first step of photosynthesis for
photoautotrophic organisms. Boosting the growth and yield of photosynthetic
organisms is critical in sustainable food and biofuel production in
a photobioreactor. In this contribution, we improved the light quality
of cyanobacteria by the addition of aggregation-induced emission luminogens
(AIEgens), which could absorb the ultraviolet/blue light and emit
the green/yellow light into the culture medium, thus effectively converted
the light to a more usable range. Our designed AIEgens formed highly
bright luminogenic aggregates in the exposure medium and dispersed
around the cells, which effectively modified the wavelength and spatial
distribution of the light source. The photosynthesis parameters of
AIEgen-treated cyanobacteria, including the maximum photosynthetic
quantum yield, the effective photochemical quantum yield of photosystem
II, and the relative electron transport rate, were significantly improved
with the application of our AIEgens. Specifically, after 14 days of
incubation, we demonstrated that the AIEgens boosted the cell density
of cyanobacteria by 5-fold and the lipid contents by 5- to 6-fold.
Furthermore, cyanobacteria continued to grow under UV light irradiation
in the presence of AIEgens, highlighting the important role of AIEgens
in light conversion to improve light quality. Our study demonstrated
the potential application of AIEgens in a photosynthetic biofactory
without genetic modification of photosynthetic organisms.