Glycogen Production in Marine Cyanobacterial Strain Synechococcus sp. NKBG 15041c

Amr Badary; Shouhei Takamatsu; Mitsuharu Nakajima; Stefano Ferri; Peter Lindblad; Koji Sode

doi:10.1007/s10126-017-9792-2

Glycogen Production in Marine Cyanobacterial Strain Synechococcus sp. NKBG 15041c

Mar Biotechnol (NY). 2018 Apr;20(2):109-117. doi: 10.1007/s10126-017-9792-2. Epub 2018 Jan 12.

Authors

Amr Badary^{1

2}, Shouhei Takamatsu^{1

2}, Mitsuharu Nakajima^{2

3}, Stefano Ferri^{2

4}, Peter Lindblad⁵, Koji Sode^{6

7

8}

Affiliations

¹ Department of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan.
² JST, CREST, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan.
³ Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, 3-8-1 Harumi-cho, Fuchu, Tokyo, 183-8538, Japan.
⁴ Department of Applied Chemistry and Biochemical Engineering, Shizuoka University, 3-5-1 Johoku, Naka-Ku, Hamamatsu, Shizuoka, 432-8561, Japan.
⁵ Department of Chemistry, Ångström Laboratory, Uppsala University, Box 523, SE-751 20, Uppsala, Sweden.
⁶ Department of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan. sode@cc.tuat.ac.jp.
⁷ JST, CREST, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan. sode@cc.tuat.ac.jp.
⁸ Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, 3-8-1 Harumi-cho, Fuchu, Tokyo, 183-8538, Japan. sode@cc.tuat.ac.jp.

PMID: 29330710
DOI: 10.1007/s10126-017-9792-2

Abstract

An important feature offered by marine cyanobacterial strains over freshwater strains is the capacity to grow in seawater, replacing the need for often-limited freshwater. However, there are only limited numbers of marine cyanobacteria that are available for genetic manipulation and bioprocess applications. The marine unicellular cyanobacteria Synechococcus sp. strain NKBG 15041c (NKBG15041c) has been extensively studied. Recombinant DNA technologies are available for this strain, and its genomic information has been elucidated. However, an investigation of carbohydrate production, such as glycogen production, would provide information for inevitable biofuel-related compound production, but it has not been conducted. In this study, glycogen production by marine cyanobacterium NKBG15041c was investigated under different cultivation conditions. NKBG15041c yielded up to 399 μg/ml/OD₇₃₀ when cells were cultivated for 168 h in nitrogen-depleted medium (marine BG11_ΔN) after medium replacement (336 h after inoculation). Cultivation under nitrogen-limited conditions also yielded an accumulation of glycogen in NKBG15041c cells (1 mM NaNO₃, 301 μg/ml/OD₇₃₀; 3 mM NaNO₃, 393 μg/ml/OD₇₃₀; and 5 mM NaNO₃, 328 μg/ml/OD₇₃₀) under ambient conditions. Transcriptional analyses were carried out for 13 putative genes responsible for glycogen synthesis and catabolism that were predicted based on homology analyses with Synechocystis sp. PCC 6803 (PCC6803) and Synechococcus sp. PCC7002 (PCC7002). The transcriptional analyses revealed that glycogen production in NKBG15041c under nitrogen-depleted conditions can be explained by the contribution of both increased carbon flux towards glycogen synthesis, similar to PCC6803 and PCC7002, and increased transcriptional levels of genes responsible for glycogen synthesis, which is different from the conventionally reported phenomenon, resulting in a relatively high amount of glycogen under ambient conditions compared to PCC6803 and PCC7002.

Keywords: Bioprocess; Carbohydrate production; Glycogen; Marine cyanobacteria; Synechococcus.

MeSH terms

Biofuels
Glycogen / biosynthesis*
Nitrogen / metabolism*
Seawater
Synechococcus / genetics
Synechococcus / growth & development
Synechococcus / metabolism*
Transcription, Genetic
Transcriptome

Substances

Biofuels
Glycogen
Nitrogen