1. 毕业设计（论文）的内容和要求

1、毕业论文内容
生物表面活性素（surfactin）通常是含有七个氨基酸（glu#8211;leu#8211;d#8211;leu#8211;val#8211;asp#8211;d#8211;leu#8211;leu
）的七肽与碳的个数为13-15的β-脂肪酸组成。

它是芽孢杆菌产生的一种次级代谢产物，具有可降解，低毒的特点，在医药[1]、食品[2]、生物修复[3]、生物防治[4]等方面具有很大的潜在应用价值[5, 6]
在surfactin结构中，肽环的合成是由非核糖体肽合成酶（nrps）负责合成的[7,8]。

而β-羟基脂肪酸链参与脂肪酸的合成是以β-羟基-脂酰coa的形式被surfactin的被 srfaa的起始模块 c domain 识别并用于肽链的合成起始反应[9]。

2. 参考文献

[1] Zhai, S., Q. Shi, and X. Chen, Effect of dietary antimicrobial peptides-surfactin supplementation on parameters of intestinal health indices of genetically improved farmed tilapia (gift, oreochromis niloticus)[J]. Acta Hydrobiologica Sinica, 2016. 40(4): p. 823-829.
[2] Zhang, Y., et al., Anti-inflammatory Activity and Mechanism of Surfactin in Lipopolysaccharide-Activated Macrophages[J]. Inflammation, 2015. 38(2): p. 756-764.
[3] de Almeida Couto, C.R., et al., Response of the bacterial community in oil-contaminated marine water to the addition of chemical and biological dispersants. Journal Of Environmental Management[J], 2016. 184: p. 473-479.
[4] Jasim, B., J. Mathew, and E.K. Radhakrishnan, Identification of a novel endophytic Bacillus sp from Capsicum annuum with highly efficient and broad spectrum plant probiotic effect[J]. Journal Of Applied Microbiology, 2016. 121(4): p. 1079-1094.
[5] 翟少伟, 李剑,史庆超, 抗菌脂肽Surfactin的抗菌活性及应用[J]. 动物营养学报, 2015(05): p. 1333-1340.
[6] 任鹏举, 枯草芽孢杆菌OKB105产生的surfactin防治烟草花叶病毒病及其机理研究[J]. 中国生物防治学报, 2014(02): p. 216-221.
[7] 刘丽霞, Surfactin合成酶相关基因研究[D]. 2012, 南京农业大学.
[8] Strieker M，Tanovic 'A, Marahiel MA.Nonribosomal peptide synthetases: structures and dynamics[J]. Curr Opin Struct Biol, 2010, 20( 2): 234240．
[9] Kraas F I, Helmetag V, Wittmann M, et al. Functional dissection of surfactin synthetase initiation module reveals insights into the mechanism of lipoinitiation[J]. Chemistry amp; biology, 2010, 17(8): 872-880.
[10] Lee D S, Yamada A, Sugimoto H, et al. Substrate recognition and molecular mechanism of fatty acid hydroxylation by cytochrome P450 from Bacillus subtilis Crystallographic, spectroscopic, and mutational studies [J]. Journal of Biological Chemistry, 2003, 278(11): 9761-9767.
[11] Youssef N H, Wofford N, McInerney M J. Importance of the long-chain fatty acid beta-hydroxylating cytochrome P450 enzyme YbdT for lipopeptide biosynthesis in Bacillus subtilis strain OKB105[J]. International journal of molecular sciences, 2011, 12(3): 1767-1786.
[12] Liu Q, Lin J, Wang W, et al. Production of surfactin isoforms by Bacillus subtilis BS-37 and its applicability to enhanced oil recovery under laboratory conditions[J]. Biochemical Engineering Journal, 2015, 93: 31-37.
[10] Huo Y, Zhan Y, Wang Q, et al. Acetolactate synthase (AlsS) in Bacillus licheniformis WX-02: enzymatic properties and efficient functions for acetoin/butanediol and l-valine biosynthesis[J]. Bioprocess and biosystems engineering, 2017: 1-10.

3. 毕业设计（论文）进程安排