목차

1. Introduction 1
2. Materials and Methods 5
2.1 Strains, media, and culture conditions 5
2.2 Melanin synthesis inhibition test 5
2.3 Extraction and analysis of melanin 6
2.4 Characterization of melanin extracted from culture broth 6
2.5 Genome mining and heterologous expression of proteins involved in melanin biosynthesis 7
2.6 Expression and purification of the F. kingsejongi HPPD-encoding gene using E coli 8
2.7 In vitro HPPD activity assay 9
2.8 Analysis of mRNA expression level of HPPD 10
2.9 Phylogenetic analysis of HPPD 11
2.10 Batch fermentation of F. kingsejongi in a 5-L bioreactor 11
2.11 Batch fermentation of recombinant E coli expressing HPPD in a 5-L bioreactor 12
2.12 Analytical methods 12
3. Results and Discussion 16
3.1 Characteristics of the brownish-black pigment from F. kingsejongi 16
3.2 Chemical characterization of the brownish-black pigment from F. kingsejongi 19
3.3 Identification and heterologous expression of the putative eumelanin-synthesizing gene of F. kingsejongi 21
3.4 In vitro activity of purified 6×His-tagged HPPD and native HPPD in crude protein extract 26
3.5 Bioreactor batch fermentation of F. kingsejongi 30
3.6 Bioreactor batch fermentation of recombinant E coli expressing HPPD 33
4. Conclusion 36
5. References 37
ABSTRACT IN KOREAN 43