Cyanobacterium Synechocystis sp. PCC 6803 lacking adc1 gene produces higher polyhydroxybutyrate accumulation under modified nutrients of acetate supplementation and nitrogen-phosphorus starvation

Suthira Utharn; Panutda Yodsang; Aran Incharoensakdi; Saowarath Jantaro

doi:10.1016/j.btre.2021.e00661

Cyanobacterium Synechocystis sp. PCC 6803 lacking adc1 gene produces higher polyhydroxybutyrate accumulation under modified nutrients of acetate supplementation and nitrogen-phosphorus starvation

Biotechnol Rep (Amst). 2021 Jul 25:31:e00661. doi: 10.1016/j.btre.2021.e00661. eCollection 2021 Sep.

Authors

Suthira Utharn^{1

2}, Panutda Yodsang^{1

3}, Aran Incharoensakdi¹, Saowarath Jantaro¹

Affiliations

¹ Laboratory of Cyanobacterial Biotechnology, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
² Program of Biotechnology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
³ King Mongkut's University of Technology Thonburi Residential College, Ratchaburi, 70150, Thailand.

Abstract

Increased polyhydroxybutyrate production in cyanobacterium Synechocystis sp. PCC 6803 lacking adc1 gene (Δadc1) is first-timely reported in this study. We constructed the mutant by disrupting adc1 gene encoding arginine decarboxylase, thereby exhibiting a partial blockade of polyamine synthesis. This Δadc1 mutant had a proliferative growth and certain contents of intracellular pigments including chlorophyll a and carotenoids as similar as those of wild type (WT). Highest PHB production was certainly induced by BG₁₁-N-P+A condition in both WT and Δadc1 mutant of about 24.9 %w/DCW at day 9 and 36.1 %w/DCW at day 7 of adaptation time, respectively. Abundant PHB granules were also visualized under both BG₁₁-N-P and BG₁₁-N-P+A conditions. All pha transcript amounts of Δadc1 mutant grown at 7 days-adaptation time were clearly upregulated corresponding to its PHB content under BG₁₁-N-P+A condition. Our finding indicated that this adc1 perturbation is alternatively achieved for PHB production in Synechocystis sp. PCC 6803.

Keywords: ADC, arginine decarboxylase; Adc1 mutant; DCW, dry cell weight; DMF, N,N-dimethylformamide; HPLC, high pressure liquid chromatography; Nutrient deprivation; PCR, polymerase chain reaction; PHAs, polyhydroxyalkanoates; PHB, polyhydroxybutyrate; Polyhydroxybutyrate; Synechocystis sp. PCC6803; TAE, Tris-acetate-ethylene diamine tetraacetic acid; TCA, tricarboxylic acid; h, hour(s).