Title Page
Contents
ABSTRACT 8
Chapter 1. Introduction 10
Chapter 2. Materials and methods 13
2.1. Experimental setup, fish, and rearing conditions 13
2.2. Water quality analysis 16
2.3. Fish growth 16
2.4. Microbial analysis in breeding water and fish guts 16
2.5. Statistical analysis 17
Chapter 3. Results and Discussion 18
3.1. Effects of BFT system on water quality 18
3.2. Fish growth performance 22
3.3. Effects on rearing water and fish gut microbial diversity 26
3.4. Effects on microbial distribution in rearing water and fish gut 34
Chapter 4. Conclusion 45
References 46
Appendix 52
Abstract (in Korean) 53
Table 1. Growth performance of eel (Anguilla japonica) and catfish (Silurus asotus) in the BFT treatement and control. 24
Table 2. Alpha-diversity indices of gut in eels and catfish. 30
Table 3. Alpha-diversity indices of rearing water in eels and catfish. 31
Fig. 1. The scheme of BFT aquaculture system. 15
Fig. 2. Changes in nitrogen compound concentration in breeding water during the experiment period of eels. 20
Fig. 3. Changes in nitrogen compound concentration in breeding water during the experiment period of catfish. 21
Fig. 4. Effect of BFT system on fish growth performance. 25
Fig. 5. Rarefaction curve (Chao 1) of the water and guts microbial community on BFT system in eels. 28
Fig. 6. Rarefaction curve (Chao 1) of the water and guts microbial community on BFT system in catfish. 29
Fig. 7. The similarity of the bacterial community in eels. 32
Fig. 8. The similarity of the bacterial community in catfish. 33
Fig. 9. Relative abundance of eels in phylum level. 39
Fig. 10. Relative abundance of catfish in phylum level. 40
Fig. 11. Shared and unique species in eels displayed by Venn diagram. 41
Fig. 12. Shared and unique species in catfish displayed by Venn diagram. 42
Fig. 13. Differentially changed bacterial community in eels at LDA〉4.0 level displayed by LEfSe analysis. 43
Fig. 14. Differentially changed bacterial community in catfish at LDA〉4.0 level displayed by LEfSe analysis. 44