RNAi Knock-Down of LHCBM1, 2 and 3 Increases Photosynthetic H-2 Production Efficiency of the Green Alga Chlamydomonas reinhardtii

Oey, Melanie, Ross, Ian L., Stephens, Evan, Steinbeck, Janina, Wolf, Juliane, Radzun, Khairul Adzfa, Kuegler, Johannes, Ringsmuth, Andrew K., Kruse, Olaf and Hankamer, Ben (2013) RNAi Knock-Down of LHCBM1, 2 and 3 Increases Photosynthetic H-2 Production Efficiency of the Green Alga Chlamydomonas reinhardtii. PLoS One, 8 4: e61375.1-e61375.12. doi:10.1371/journal.pone.0061375


Author Oey, Melanie
Ross, Ian L.
Stephens, Evan
Steinbeck, Janina
Wolf, Juliane
Radzun, Khairul Adzfa
Kuegler, Johannes
Ringsmuth, Andrew K.
Kruse, Olaf
Hankamer, Ben
Title RNAi Knock-Down of LHCBM1, 2 and 3 Increases Photosynthetic H-2 Production Efficiency of the Green Alga Chlamydomonas reinhardtii
Journal name PLoS One   Check publisher's open access policy
ISSN 1932-6203
Publication date 2013-04-01
Year available 2013
Sub-type Article (original research)
DOI 10.1371/journal.pone.0061375
Open Access Status DOI
Volume 8
Issue 4
Start page e61375.1
End page e61375.12
Total pages 12
Place of publication San Francisco, CA United States
Publisher Public Library of Science
Collection year 2014
Language eng
Formatted abstract
Single cell green algae (microalgae) are rapidly emerging as a platform for the production of sustainable fuels. Solar-driven H2 production from H2O theoretically provides the highest-efficiency route to fuel production in microalgae. This is because the H2-producing hydrogenase (HYDA) is directly coupled to the photosynthetic electron transport chain, thereby eliminating downstream energetic losses associated with the synthesis of carbohydrate and oils (feedstocks for methane, ethanol and oil-based fuels). Here we report the simultaneous knock-down of three light-harvesting complex proteins (LHCMB1, 2 and 3) in the high H2-producing Chlamydomonas reinhardtii mutant Stm6Glc4 using an RNAi triple knock-down strategy. The resultant Stm6Glc4L01 mutant exhibited a light green phenotype, reduced expression of LHCBM1 (20.6% ±0.27%), LHCBM2 (81.2% ±0.037%) and LHCBM3 (41.4% ±0.05%) compared to 100% control levels, and improved light to H2 (180%) and biomass (165%) conversion efficiencies. The improved H2 production efficiency was achieved at increased solar flux densities (450 instead of ~100 μE m-2 s-1) and high cell densities which are best suited for microalgae production as light is ideally the limiting factor. Our data suggests that the overall improved photon-to-H2 conversion efficiency is due to: 1) reduced loss of absorbed energy by non-photochemical quenching (fluorescence and heat losses) near the photobioreactor surface; 2) improved light distribution in the reactor; 3) reduced photoinhibition; 4) early onset of HYDA expression and 5) reduction of O2-induced inhibition of HYDA. The Stm6Glc4L01 phenotype therefore provides important insights for the development of high-efficiency photobiological H2 production systems.
Keyword Light Harvesting Complex
Chlorophyll Antenna Size
Photosystem II
State Transitions
Solar energy
Hydrogen Photoproduction
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Mathematics and Physics
Official 2014 Collection
Institute for Molecular Bioscience - Publications
 
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Citation counts: TR Web of Science Citation Count  Cited 28 times in Thomson Reuters Web of Science Article | Citations
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