การควบคุมโครงสร้างและการแสดงออกของยีนไฟโคบิลิโซมของสาหร่ายเกลียวทอง (Spirulina platensis C1) โดยการขาดไนโตรเจน

Regulation of Phycobilisomes Expression of Spirulina platensis C1 by Nitrogen Deprivation

Name: กมลทิพย์ พรหมณเรศ

Organization : มหาวิทยาลัยเทคโนโลยีพระจอมเกล้าธนบุรี

keyword: platensis C1

; Arthrospira

; Nitrogen deprivation

; Phycobiliproteins

; Phycobilisomes

; Photosynthesis

; Photosystem I

; Photosystem II

Abstract: platensis C1 was grown in batch culture under illumination of 80 UE m- 2 S- 1at 35?C. The alteration of biochemical composition of S. platensis C1 nitrogen deprived cells were observed by determining the content and composition of phycobiliproteins (PBPs), chlorophyll a (Chl a), total protein and carbohydrate. In addition, the alteration of the photosynthetic activity and the regulation of PBPs gene expression were also determined by Northern analysis. It was found that the cells started to bleach at the first 24 hours and more pronounced after 72 hours of nitrogen starvation, indicating the change in pigment, and biochemical composition of nitrogen depleted cells. The content of cellular PBPs, Chl a and total protein decreased while carbohydrate increased. The 33- kDa linker polypeptide (LR33) disappeared after 48 hours of nitrogen depletion while 3.5 kb mRNA encoding a and B PC subunit, LR33 , LR34.5 and LR15 was lost after 8 hours of starvation. The 1.4 and 1.5 kb PC mRNA, and 1.4 kb AP mRNA greatly decreased at the first 8 hours of nitrogen depletion. The 1.7 kb AP mRNA and 2.9 kb Lcm97 mRNA dramatically declined during the first 16 hours of nitrogen deficient growth. The loss of LR33 and the decline in expression of PBS genes demonstrated that the structure and the synthesis of phycibilisome (PBS) were decreased. The loss of LR'I resulted in a reduction in the rod length and loss of the terminal PC hexamer of PBS rods. This phenomenon caused a decrease in PC content that corresponded with the amount of PBPs reduction. Moreover, S. platensis C1 cells accumulated carbohydrate to cope with nitrogen stress. The decrease in cellular Chl a suggested that cells stopped Chl a synthesis as shown by the decrease in Chl a per milliliter culture. The alteration in amount of PBPs and PBS structure led to the reduction of photosynthetic oxygen evolving activity (net photosynthesis). The decline of net photosynthesis was caused by changing of photosystem I1 (PS 11) activity not by photosystem I (PS I) activity. These results provide the basic knowledge of how S. platensis survives in the nitrogen starvation, contributing the valuable information to Spirulina cultivation in nitrogen limited condition. S

มหาวิทยาลัยเทคโนโลยีพระจอมเกล้าธนบุรี

Address: กรุงเทพมหานคร (Bangkok)

Email: info.lib@mail.kmutt.ac.th

Name: Dr.Supapon Cheevadhanarak

Role: Supervisor

Created: 2544

Issued: 2005-10-26

Modified: 2006-05-24

วิทยานิพนธ์/Thesis

ISBN: 9745949627

CallNumber: BIT366

tha

DegreeName: วิทยาศาสตรมหาบัณฑิต

Level: ปริญญาโท

Descipline: เทคโนโลยีชีวภาพ

Grantor: มหาวิทยาลัยเทคโนโลยีพระจอมเกล้าธนบุรี

©copyrights มหาวิทยาลัยเทคโนโลยีพระจอมเกล้าธนบุรี

ลำดับที่.	ชื่อแฟ้มข้อมูล	ขนาดแฟ้มข้อมูล	จำนวนเข้าถึง	วัน-เวลาเข้าถึงล่าสุด
1	BIT366.pdf	3.65 MB	91	2023-12-27 00:33:43
2	BIT366ab.pdf	122.2 KB	30	2021-02-20 16:03:20
3	BIT366ab.txt	5.18 KB	17	2018-05-13 04:39:36

ใช้เวลา

0.041609 วินาที