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Chlorophyll (Chl) f was reported as the fifth Chl in oxygenic photoautotrophs. Chlorophyll f production expanded the utilization of photosynthetically active radiation into the far‐red light (FR) region in some cyanobacterial genera. In this study, 11 filamentous cyanobacterial strains were isolated from FR‐enriched habitats, including hydrophyte, moss, shady stone, shallow ditch, and microbial mat across Central and Southern China. Polyphasic analysis classified them into the same genus of Leptodesmis and further recognized them as four new species, including Leptodesmis atroviridis sp. nov., Leptodesmis fuscus sp. nov., Leptodesmis olivacea sp. nov., and Leptodesmis undulata sp. nov. These cyanobacteria had absorption peaks beyond 700 nm due to Chl f production and red‐shifted phycobiliprotein complexes under FR conditions. All but L. undulata produced phycoerythrin and showed varying degrees of a reddish‐brown to dark green color under white light conditions. However, the phycoerythrin contents were sharply decreased under FR conditions, and these three Leptodesmis species appeared green. In summary, the Leptodesmis genus contains diverse species with the capacity to synthesize Chl f and is likely a ubiquitous group of Chl f‐producing cyanobacteria. [ABSTRACT FROM AUTHOR]

Chlorophyll (Chl) f was recently identified in a few cyanobacteria as the fifth chlorophyll of oxygenic organisms. In this study, two Leptolyngbya‐like strains of CCNU0012 and CCNU0013 were isolated from a dry ditch in Chongqing city and a brick wall in Mount Emei Scenic Area in China, respectively. These two strains were described as new species: Elainella chongqingensis sp. nov. (Oculatellaceae, Synechococcales) and Pegethrix sichuanica sp. nov. (Oculatellaceae, Synechococcales) by the polyphasic approach based on morphological features, phylogenetic analysis of 16S rRNA gene and secondary structure comparison of 16S‐23S internal transcribed spacer domains. Both strains produced Chl a under white light (WL) but additionally induced Chl f synthesis under far‐red light (FRL). Unexpectedly, the content of Chl f in P. sichuanica was nearly half that in most Chl f‐producing cyanobacteria. Red‐shifted phycobiliproteins were also induced in both strains under FRL conditions. Subsequently, additional absorption peak beyond 700 nm in the FRL spectral region appeared in these two strains. This is the first report of Chl f production induced by FRL in the family Oculatellaceae. This study not only extended the diversity of Chl f‐producing cyanobacteria but also provided precious samples to elucidate the essential binding sites of Chl f within cyanobacterial photosystems. [ABSTRACT FROM AUTHOR]

A few groups of cyanobacteria have been characterized as having far‐red light photoacclimation (FaRLiP) that results from chlorophyll f (Chl f) production. In this study, using a polyphasic approach, we taxonomically transferred the Cf. Leptolyngbya sp. CCNUW1 isolated from a shaded freshwater pond, which produces Chl f under far‐red light, to the genus Kovacikia and named this taxon Kovacikia minuta sp. nov. This strain was morphologically similar to Leptolyngbya‐like strains. The thin filaments were purplish‐brown under white light but became grass green under far‐red light. The 31‐gene phylogeny grouped K. minuta CCNU0001 into order Synechococcales and family Leptolyngbyaceae. Phylogenetic analysis based on 16S rRNA gene sequences further showed that K. minuta CCNU0001 was clustered into Kovacikia with similarities of 97.2–97.4% to the recently reported type species of Kovacikia muscicola HA7619‐LM3. Additionally, the internal transcribed spacer region between 16S–23S rRNA genes had a unique sequence and secondary structure compared with other Kovacikia strains and phylogenetically related taxa. Draft genome sequences of K. minuta CCNU0001 (8,564,336 bp) were assembled into one circular chromosome and two circular plasmids. A FaRLiP 20‐gene cluster comprised two operons with the unique organization. In sum, K. minuta was established as a new species, and it is the first species reported to produce Chl f and for which a draft genome was produced in genus Kovacikia. This study expanded our knowledge regarding the diversity of Chl f‐producing cyanobacteria in far‐red light‐enriched environments and provides important foundational information for future investigations of FaRLiP evolution in cyanobacteria. [ABSTRACT FROM AUTHOR]

The textbook explanation that P680 pigments are the red limit to drive oxygenic photosynthesis must be reconsidered by the recent discovery that chlorophyll f (Chlf)‐containing Photosystem II (PSII) absorbing at 727 nm can drive water oxidation. Two different families of unsymmetrically substituted Zn phthalocyanines (Pc) absorbing in the 700–800 nm spectral window and containing a fused imidazole‐phenyl substituent or a fused imidazole‐hydroxyphenyl group have been synthetized and characterized as a bioinspired model of the Chlf/TyrosineZ/Histidine190 cofactors of PSII. Transient absorption studies in the presence of an electron acceptor and irradiating in the far‐red region evidenced an intramolecular electron transfer process. Visible and FT‐IR signatures indicate the formation of a hydrogen‐bonded phenoxyl radical in ZnPc II‐OH. This study sets the foundation for the utilization of a broader spectral window for multi‐electronic catalytic processes with one of the most robust and efficient dyes. [ABSTRACT FROM AUTHOR]

We report production of chlorophyll f and chlorophyll d in the cyanobacterium Chlorogloeopsis fritschii cultured under near-infrared and natural light conditions. C. fritschii produced chlorophyll f and chlorophyll d when cultured under natural light to a high culture density in a 20 L bubble column photobioreactor. In the laboratory, the ratio of chlorophyll f to chlorophyll a changed from 1:15 under near-infrared, to an undetectable level of chlorophyll f under artificial white light. The results provide support that chlorophylls f and d are both red-light inducible chlorophylls in C. fritschii . [ABSTRACT FROM AUTHOR]

Abstract: A Chl f-containing filamentous cyanobacterium was purified from stromatolites and named as Halomicronema hongdechloris gen., sp. nov. after its phylogenetic classification and the morphological characteristics. Hongdechloris contains four main carotenoids and two chlorophylls, a and f. The ratio of Chl f to Chl a is reversibly changed from 1:8 under red light to an undetectable level of Chl f under white-light culture conditions. Phycobiliproteins were induced under white light growth conditions. A fluorescence emission peak of 748nm was identified as due to Chl f. The results suggest that Chl f is a red-light inducible chlorophyll. [Copyright &y& Elsevier]

Inside Back Cover: Phthalocyanine as a Bioinspired Model for Chlorophyll f-Containing Photosystem II Drives Photosynthesis into the Far-Red Region (Angew. Bioinspired models, chlorophyll f, far-red region, photosystem II, phthalocyanine Keywords: bioinspired models; chlorophyll f; far-red region; photosystem II; phthalocyanine EN bioinspired models chlorophyll f far-red region photosystem II phthalocyanine 12607 12607 1 05/20/21 20210525 NES 210525 B Chlorophyll b f (Chl I f i )-containing Photosystem II absorbing in the far red has transgressed the red limit of photosynthesis locked by chlorophyll I a i at 680 nm and drives water oxidation at 727 nm. [Extracted from the article]

Keywords: bioinspired models; chlorophyll f; far-red region; photosystem II; phthalocyanine EN bioinspired models chlorophyll f far-red region photosystem II phthalocyanine 12715 12715 1 05/20/21 20210525 NES 210525 B Das Chlorophyll f b (Chl I f i ) enthaltende Photosystem II, das im fernen Rot absorbiert, überwindet das "rote Limit" der Photosynthese, das vom Chlorophyll I a i bei 680 nm festgelegt ist, und vermittelt die Wasseroxidation bei 727 nm. Innenrücktitelbild: Phthalocyanine as a Bioinspired Model for Chlorophyll f-Containing Photosystem II Drives Photosynthesis into the Far-Red Region (Angew. Bioinspired models, chlorophyll f, far-red region, photosystem II, phthalocyanine. [Extracted from the article]