Effect of N-deprivation, light cycle and trehalose on arthrospira platensis glycogen production and glycogen synthase modeling

Name: Nat-Anong Mudtham

LCSH: Kasetsart University -- Theses. M.S. (Animal Health Technology) 2020

Classification :.LCCS: QR99.63

LCSH: Kasetsart University. Department of Veterinary Technology -- Theses

LCSH: Cyanobacteria

LCSH: Glycogen

LCSH: Trehalose

LCSH: Biomass energy

Abstract: The glycogen product of Arthrospira platensis was promising as a source for bioethanol. A. platensis could assemble glycogen under the optimal photoperiod and nitrate-deprived medium (-N). In the present research, cells were grown in different photoperiod cycle (24:0 hr, 12:12 hr, 0:24 hr (light:dark cycles)), nitrate concentration (control (2.5 g/L), 50% (1.25 g/L), 25% (0.625 g/L), and 0% (0 g/L)) and trehalose concentration (0.003M, 0.03M and 0.3M). Biomass, chlorophyll a, glycogen content, and transcriptional expression of glgA gene encoding glycogen synthase and its activity were investigated. Additionally, the 3D structural modeling was analyzed to provide insight data and predict the metabolic changes. The results showed, A. platensis biomass increased corresponding to an increase duration of light exposure. Besides, carbohydrate contents in particular glycogen (474±3.4 mg/L) were found to be higher in cells grown in -N medium under continuous illumination (24:0 hr). Interestingly, 0.003M trehalose supplementation could alleviate the effects of nitrate deprivation. Higher concentration than 0.3M caused growth rate reduction. Furthermore, A. platensis glycogen synthase exhibited the highest activity (89.15 µmol/min/mg protein) in -N medium supplemented with 0.003M trehalose. RT-PCR revealed that glgA transcript was significantly increased when cells grown in -N medium supplemented with 0.003M trehalose. The 3D structural model of ApGS could explain substrate binding and catalytic mechanisms. His-166, Arg-307, and Lys-312 were critical catalytic residues in the transglycosylation. The overall results demonstrated that nitrate deprivation, light, and trehalose supply were factors for enhancing glycogen production in A. platensis

Kasetsart University. Office of the University Library

Address: Bangkok

Email: tdckulib@ku.ac.th

Name: Wuttinun Raksajit

Role: Thesis Advisor

Created: 2020

Modified: 2026-06-24

Issued: 2026-06-24

วิทยานิพนธ์/Thesis

application/pdf

URL: https://www.lib.ku.ac.th/KUthesis/2563/nat-anong-mud-all.pdf

CallNumber: QR99.63 .N37

eng

DegreeName: Master of Science

Level: Master's Degree

Descipline: Animal Health Technology

Grantor: Kasetsart University

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