A cyanobacterium that contains chlorophyll f – a red‐absorbing photopigment

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 748 nm was identified as due to Chl f. The results suggest that Chl f is a red-light inducible chlorophyll.

Chlorophyll f-driven photosynthesis in a cavernous cyanobacterium

“…Chlorophyll f has been found in cyanobacteria originating from aquatic/wet environments: the filamentous Halomicronema hongdechloris from stromatolites in Australia (Chen et al, 2012), a unicellar morphotype (Strain KC1) from Lake Biwa in Japan (Akutsu et al, 2011;Miyashita et al, 2014) and a filamentous Leptolyngbya sp. strain (JSC-1, Gan et al, 2014) from a hot-spring and in a unicellular Chlorogloeopsis fritschii strain from rice paddies (Airs et al, 2014).…”

Introductory Chapter: Chlorophyll Molecules and Their Technological Relevance

“…These microorganisms demonstrate considerable biocatalytic potential in biotechnological processes due to their robustness and require nutritional simplicity [18]. Chlorophyll-a is present in all organisms that perform photosynthesis and chlorophyll-b oxygen (Figure 1), which are the most abundant pigment in green algae, is found in higher plants in nature, and other similar structures are used as accessory pigments in photosynthetic process, called chlorophyll-c, chlorophyll-d, chlorophyll-e, and chlorophyll-f [6][7][8]13]. These speciic pigments present in the cells of the photosynthetic organisms inluence eiciency of dispersion of light, because each species has its own distinct characteristic pigment [9].…”

“…Basically, chlorophyll molecules are conjugated tetrapyrroles to which a cyclopentanone ring jointly with the third ring linked together by bridges methylene, with the central atom, magnesium (Figure 1). This structure also contains at the C-17, a propionic acid chain esteriied with the phytol, diterpene alcohol [3,[6][7][8].…”

Novel chlorophylls and new directions in photosynthesis research

“…The sequences are aligned with multiple sequence alignment tools (Clustal W). The alignment was then manually edited based on the alignment of Chen et al (2012). The evolution distance was calculated with Kimura 2-parameter model with 10 000 repeats using MEGA 5.0.…”

“…The sequence data of Cyanobacterium strain KC1 is kindly provided by Professor Hideaki Miyashita. The other strains are downloaded from NCBI as described by Chen et al (2012). that long wavelength light (>700 nm) contains low energy photons and is not sufficiently energetic to oxidise water (Blankenship and Prince 1985;Chen and Blankenship 2011).…”