高海春++蒋耀明

摘 要：我们从海洋微生物中分离、筛选具有各种生态学效应的次生代谢产物，根据次生代谢产物的化学性状和生态学效应分门别类，从重要门类中挑选典型代表在分子生物学水平上进行系统地研究，揭示其作用机制。在原工作基础上，进一步完成了对8株抗海洋生物病原细菌和抗海洋污损生物幼虫附着的活性菌株中活性次生代谢产物的研究，共分离鉴定了100余个次生代谢产物，发现39个新化合物和20多个具有抗污损、抗菌、海虾幼虫致死活性的化合物；初步阐明了一个具有强抗藤壶幼虫附着的生物碱抗附着的作用机制；对16个活性菌株的发酵液粗提物和活性化合物进行了抗海洋污损生物附着的野外海上挂板实验，发现2个具有显著海上抗污损能力的活性物质。以S.oneidensis为模型菌株，深入研究微生物生态群落的形成机制及其调控。找到了细菌组装鞭毛丝的2个亚基的主要差异，并发现糖基化对鞭毛丝亚基的功能至关重要；明确了细菌对不同氧化还原环境的适应性来自呼吸调控系统的转换，并进一步研究了硝酸/亚硝酸呼吸途径的调控机制；深入研究了细菌响应青霉素类抗生素的分子机制，表明青霉素通过一条全新的信号通路调控β-内酰胺酶基因的表达。我们还对S.oneidensis MR-1是如何应答由H2O2引起的氧胁迫进行了研究，发现在这种细菌中，氧化应答机制和E.coli等一些研究过的菌株中有着明显的区别。

关键词：次生代谢产物 抗污损活性物 硝酸/亚硝酸呼吸 鞭毛 氨苄抗性 氧胁迫

Chemical and Ecological Effects of Marine Microbes Secondary Metabolism and Its Mechanism

Gao Haichun Jiang Yaoming

（Zhejiang University）

Abstract：We isolated and screened many metabolites with vary ecological effects from marine microbes， and these metabolites were classified according to their chemical characteristics and ecological effects. Some from important category were chosen for systematical study at molecular level to reveal their function mechanism. On the basis of previous work， antifouling secondary metabolites of eight bioactive marine fungal strains were investigated using a bioassay-guided procedure. Totally， over one hundred compounds were obtained from the eight fungal strains， including 39 new compounds and over 20 bioactive compounds with antifouling， antibacterial， or brine shrimp lethality bioactivities. The mode-of-action of one antifouling compound against the larval settlement of Balanus Amphitrite larvae was investigated. The antifouling potentials of 16 antifouling extracts and compounds were further evaluated in field test， and two of them displayed strong antifouling activity in a lasting four months field trial. By using S.oneidensis as a model strain， we studied the mechanism and regulation of the formation of biocommunity in microbes. We found the main differences between the 2 assembly subunits of flagellum in bacteria， and revealed that carbonylation is very important for the subunits. We identified that the fitness of bacteria to different redox environment gained from the exchange of respiration regulation system. We further studied the regulation mechanism of nitrate/nitrite respiratory pathway. We also detected the molecular mechanism by which bacteria response to β-lactam antibiotics， this demonstrated that penicillin regulated the expression of β-lactamase genes through a novel signal transduction pathway. We also studied the H2O2 caused oxidative stress response in S.oneidensis MR-1， it demonstrated that in this strain， oxidative stress response was different from that in many other previously well studied bacteria like E.coli.

Key Words：Secondary metabolites； Antifouling secondary metabolites； Nitrate/nitrite respiration； Flagellum； Anti-penicillin；Oxidative stress

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