海洋微生物的化學生態學效應及其機制

高海春++蔣耀明

摘 要：我們從海洋微生物中分離、篩選具有各種生態學效應的次生代謝產物，根據次生代謝產物的化學性狀和生態學效應分門別類，從重要門類中挑選典型代表在分子生物學水平上進行系統地研究，揭示其作用機制。在原工作基礎上，進一步完成了對8株抗海洋生物病原細菌和抗海洋污損生物幼蟲附著的活性菌株中活性次生代謝產物的研究，共分離鑒定了100余個次生代謝產物，發現39個新化合物和20多個具有抗污損、抗菌、海蝦幼蟲致死活性的化合物；初步闡明了一個具有強抗藤壺幼蟲附著的生物堿抗附著的作用機制；對16個活性菌株的發酵液粗提物和活性化合物進行了抗海洋污損生物附著的野外海上掛板實驗，發現2個具有顯著海上抗污損能力的活性物質。以S.oneidensis為模型菌株，深入研究微生物生態群落的形成機制及其調控。找到了細菌組裝鞭毛絲的2個亞基的主要差異，并發現糖基化對鞭毛絲亞基的功能至關重要；明確了細菌對不同氧化還原環境的適應性來自呼吸調控系統的轉換，并進一步研究了硝酸/亞硝酸呼吸途徑的調控機制；深入研究了細菌響應青霉素類抗生素的分子機制，表明青霉素通過一條全新的信號通路調控β-內酰胺酶基因的表達。我們還對S.oneidensis MR-1是如何應答由H2O2引起的氧脅迫進行了研究，發現在這種細菌中，氧化應答機制和E.coli等一些研究過的菌株中有著明顯的區別。

關鍵詞：次生代謝產物 抗污損活性物 硝酸/亞硝酸呼吸 鞭毛 氨芐抗性 氧脅迫

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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