Preparation of Photo-Bioelectrochemical Cells With the RC-LH Complex From Roseiflexus castenholzii
Roseiflexus castenholzii is an ancient green non-sulfur bacteria that absorbs the solar energy through bacteriochlorophylls (BChls) bound in the only light harvesting (LH) complex, and transfers to the reaction center (RC), wherein primary charge separation occurs and transforms the energy into elec...
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Published in | Frontiers in microbiology Vol. 13; p. 928046 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
Frontiers Media S.A
16.06.2022
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Subjects | |
Online Access | Get full text |
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Summary: | Roseiflexus castenholzii
is an ancient green non-sulfur bacteria that absorbs the solar energy through bacteriochlorophylls (BChls) bound in the only light harvesting (LH) complex, and transfers to the reaction center (RC), wherein primary charge separation occurs and transforms the energy into electrochemical potentials. In contrast to purple bacteria,
R. castenholzii
RC-LH (
rc
RC-LH) does not contain an H subunit. Instead, a tightly bound tetraheme cytochrome
c
subunit is exposed on the P-side of the RC, which contains three BChls, three bacteriopheophytins (BPheos), two menaquinones, and one iron for electron transfer. These novel structural features of the
rc
RC-LH are advantageous for enhancing the electron transfer efficiency and subsequent photo-oxidation of the
c
-type hemes. However, the photochemical properties of
rc
RC-LH and its applications in developing the photo-bioelectrochemical cells (PBECs) have not been characterized. Here, we prepared a PBEC using overlapped fluorine-doped tin oxide (FTO) glass and Pt-coated glass as electrodes, and
rc
RC-LH mixed with varying mediators as the electrolyte. Absence of the H subunit allows
rc
RC-LH to be selectively adhered onto the hydrophilic surface of the front electrode with its Q-side. Upon illumination, the photogenerated electrons directly enter the front electrode and transfer to the counter electrode, wherein the accepted electrons pass through the exposed
c
-type hemes to reduce the excited P
+
, generating a steady-state current of up to 320 nA/cm
2
when using 1-Methoxy-5-methylphenazinium methyl sulfate (PMS) as mediator. This study demonstrated the novel photoelectric properties of
rc
RC-LH and its advantages in preparing effective PBECs, showcasing a potential of this complex in developing new type PBECs. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 Reviewed by: Lijin Tian, Key Laboratory of Photobiology, Institute of Botany (CAS), China; Wenda Wang, Institute of Botany (CAS), China; Qiang Wang, Henan University, China This article was submitted to Microbial Physiology and Metabolism, a section of the journal Frontiers in Microbiology Edited by: Weimin Ma, Shanghai Normal University, China |
ISSN: | 1664-302X 1664-302X |
DOI: | 10.3389/fmicb.2022.928046 |