Diversity of Cyanobacteria Synechococcus spp. based on DNA Analysis and Phycoerythrin Chromophores in the East Sea, Korea
- Abstract
- Distribution patterns and diversity of Synechococcus related to environmental factors in the East Sea were investigated using three different methods: flow cytometry, pyrosequencing for the DNA analysis, and PE chromophores excitation ratio (PUBEX:PEBEX ratio). Synechococcus distribution showed high seasonal variation with the highest value in autumn (2.6±3.3 x 103 cells ml-1) and the lowest in winter (0.2±0.1 x 103 cells ml-1). The abundance changed dynamically with season and the environmental factors influencing the distribution differently in each season. DNA analysis showed high diversity of Synechococcus with 22 clades identified. Distinct seasonal contribution of the clades were observed in which clades I and IV contributed higher (~ 50 %) in spring, whereas clade II contributed more in autumn. Based on PUBEX:PEBEX ratio, three different populations of Synechococcus were found: high PUBEX:PEBEX ratio (> 1) type that dominated the study areas and were found mostly at the deeper layers, low PUBEX:PEBEX ratio (< 1) type that was found dominated in the upper layer in autumn and spring, and PUB-lacking cells which were rare. This study is one of the few studies that used DNA analysis and PUBEX:PEBEX ratio method to understand the diversity and ecotypes of Synechococcus and the relationship with the environmental factors. Moreover, it is the only study that used natural samples where most of the studies have been using culture samples. The result showed an agreement in which PE-rich type of Synechococcus that is represented with the high occurrence of Synechococcus subcluster 5.1 dominated in the East Sea. The distribution of Synechococcus clades showed close relationship with temperature, while the distribution of PUBEX:PEBEX ratio related to the water masses and light.
- Issued Date
- 2014
- Awarded Date
- 2014. 8
- Type
- Dissertation
- Publisher
- Pukyong National University-Oceanography Department
- Affiliation
- Pukyong National University
- Department
- 대학원 해양학과
- Advisor
- Prof. Mi Ok Park
- Table Of Contents
- Abstract i
Table of Contents iii
List of Tables viii
List of Figures ix
Chapter 1. Introduction 1
1.1. Research background 2
1.2. The role of picophytoplankton 3
1.3. Synechococcus distribution 5
1.3.1. Pacific Ocean 5
1.3.2. Atlantic Ocean 6
1.3.3. East Sea 7
1.3.4. Other locations 8
1.4. Environmental factors controlling distribution of Synechococcus 10
1.4.1. Physico-chemical factors (temperature, salinity
and nutrient level) 10
1.4.2. Biological factors (specific growth rate, grazing) 14
1.5. Phycoerythrin study of Synechococcus 16
1.6. DNA study of Synechococcus 22
1.7. Research objectives 25
Chapter 2. Materials and Methods 27
2.1. Environmental characteristics of the study area 28
2.2. Sampling sites 30
2.3. Chlorophyll a analysis 32
2.4. Nutrient analysis 33
2.5. Flow cytometry analysis of Synechococcus 33
2.6. PUBEX:PEBEX ratio analysis 34
2.7. Diversity of picocyanobacteria using a molecular approach 36
2.7.1. Extraction 36
2.7.2. Purification 37
2.7.3. PCR amplification 37
2.7.4. Analysis of pyrosequencing data 38
Chapter 3. Results 40
3.1. Hydrographic conditions 41
3.1.1. Temperature 41
3.1.1.1. Surface distribution of temperature 41
3.1.1.2. Vertical distribution of temperature 43
3.1.2. Salinity 46
3.1.2.1. Surface distribution of salinity 46
3.1.2.2. Vertical distribution of salinity 48
3.1.3. Nitrate + nitrite 51
3.1.3.1. Surface distribution of nitrate + nitrite 51
3.1.3.2. Vertical distribution of nitrate + nitrite 52
3.1.4. Phosphate 55
3.1.4.1. Surface distribution of phosphate 55
3.1.4.2. Vertical distribution of phosphate 56
3.2. Chlorophyll a 60
3.2.1. Total Chlorophyll a 60
3.2.1.1. Surface distribution of total Chlorophyll a 60
3.2.1.2. Vertical distribution of total Chlorophyll a 61
3.2.2. Size fraction of Chlorophyll a 64
3.2.2.1. Surface distribution of pico-size fraction
of Chlorophyll a 64
3.2.2.2. Vertical distribution of pico-size fraction
of Chlorophyll a 65
3.2.3. Percentage contribution of pico-size fraction to total
Chlorophyll a 67
3.3. Synechococcus seasonal distribution 69
3.3.1. Surface distribution of Synechococcus cells abundance 69
3.3.2. Vertical distribution of Synechococcus cells abundance 71
3.4. Seasonal variation of PUBEX:PEBEX ratios 77
3.4.1. Surface variation of PUBEX:PEBEX ratios 77
3.4.2. Vertical variation of PUBEX:PEBEX ratios 78
3.5. Synechococcus clade distribution 84
3.5.1. Surface distribution of Synechococcus clade 84
3.5.2. Vertical distribution of Synechococcus clade 88
Chapter 4. Discussion 103
4.1. Hydrographic conditions 104
4.2. Chlorophyll a 106
4.2.1. Total Chlorophyll a 106
4.2.2. Size fraction of Chlorophyll a 108
4.3. Synechococcus abundance 110
4.3.1. Surface distribution of Synechococcus 112
4.3.2. Vertical distribution of Synechococcus 115
4.4. Surface variation of PUBEX:PEBEX ratio 119
4.5. Vertical variation of PUBEX:PEBEX ratio 121
4.6. Distribution patterns of Synechococcus clades 125
4.7. Synechococcus diversity in the East Sea 131
4.8. Future studies 135
Conclusion 136
References 139
Abstract in Korean 159
Acknowledgements 160
- Degree
- Doctor
- Files in This Item:
-
-
Download
Diversity of Cyanobacteria Synechococcus spp. based on DNA Analysis and Phycoerythrin Chromophores i.pdf
기타 데이터 / 2.91 MB / Adobe PDF
-
Items in Repository are protected by copyright, with all rights reserved, unless otherwise indicated.