Genome analysis of mitochondria and chloroplast from red alga dulse and the relation of bioactivity × SDGs
It is found that red algae from northern Japan, such as the low-use red alga Dulse from Hokkaido, are rich in a variety of useful biochemical components. The mitochondrial and chloroplast genome structures of several species of red algae have been determined in order to understand the mechanisms by which these components are produced. Through these studies, we hope to contribute to the development of foods that improve people's health.
algae are classified more than 7,000 species in the world and have great
diversity among seaweeds. The number of species have been increasing by the new
classification method by gene marker and genome information. Genome contains
seaweed proteins information. Red algae are rich in proteins, especially Nori
possesses about 40% protein in dry weight, having great concern for new protein
sources. Proteins have a potential not only the source of amino acid but also
bioactive peptides. We here determined the complete genome structure of
mitochondria and chloroplast from Japanese dulse, which is a new bioresource in
Southern Hokkaido and attempted to elucidate of the bioactivity.
DulseRed alga dulse lives in cold region from
Iwate prefecture to Hokkaido prefecture in Japan. Dulse contains high amount of
protein like Nori. Red algae have galactan (agar and carrageenan) in their cell
wall, but dulse contains xylan as the cell wall.
Functional peptidesAngiotensin converting enzyme I (ACE) and
dipeptidyl peptidase 4 are the enzymes, which are related to blood pressure and
blood sugar. Peptides having specific structure repress rapid increases in
blood pressure and blood sugar by the inhibition of enzyme activities.
in silico analysis in
silico analysis is performed by using computer not in vivo and in vitro. In
this study, ACE inhibitory peptide information was obtained from database and
evaluated in the chloroplast proteins in Southern Hokkaido dulse. This
information is useful for exploring novel peptides and breeding of high value
Research purpose In
this study, we determined the complete mitochondria and chloroplast genome of
Southern Hokkaido dulse and explored peptides related to health functions.
Mitochondria and Chloroplast genome of Southern Hokkaido Dulse
Genome DNA was extracted from dulse
leaf, and the complete genomes were determined by next generation sequencer.
Chloroplast genome is circular structure composed of 192,409 bp containing 205
protein coding genes. Mitochondrial genome is also circular structure composed
of 31,399 bp containing 27 protein coding genes. These accession numbers were
deposited in DDBJ (ddbj.nig.ac.jp/) as chloroplast: AB807662 and
Photosynthesis is essential for the
growth of seaweed. Chloroplasts have many proteins involved in photosynthesis.
The composition of amino acids in dulse was very similar to that of chloroplast
proteins (Table 1). Therefore, peptide information that inhibits ACE was
obtained from the database and compared with the chloroplast genome proteins
(Table 2). This study is focusing on tripeptides, revealing that many peptides
are found in photosynthesis (PS) and metabolism (Meta). The data would be more
accurate by calculating the amount of each component.
Phylogenetic tree Phylogenetic tree was constructed by maximum likelihood method using successive mitochondrial gene (cox1) and chloroplast genes (psbA and rbcL). Red and blue box shows Southern Hokkaido dulse and Atlantic dulse, respectively. Chloroplast genomes were similar between them, however, these species were genetically separated in this tree.
Mitochondrial genome structures There
are two different between Southern Hokkaido dulse and Atlantic dulse. One is
intron size in ribosomal RNA large subunit. The other is the direction of two
genes (orf43 and orf44) were opposite.
The amount of protein in Southern Hokkaido dulse contains about 40% of dry weight, which is higher than the Atlantic dulse and Palmaria mollis (Devaleraea mollis). We need to investigate in future studies whether the difference from growth condition or genetics.
Dulse chloroplast proteins contain many
peptides that inhibit ACE. It is necessary to investigate the cooking methods
(peptide production by protease) for bioavailability.
Find novel peptides by in silico and in
vitro studies. Red algae mitochondria and chloroplast genomes are close.
Therefore, the novel peptides will be also found in other red algae, leading to
a comprehensive understanding of the health functionality of red algae.
Hokkaido dulse may contain more protein than overseas. Therefore, it is
expected to clarify the reason for a new protein source.