| 摘要: |
| 热球菌目古菌是深海热液区极端高温环境下的主要古菌类群，其具有丰富的胞外水解酶系以获得营养物质。本研究对来源于深海热液区的太平洋古球菌Palaecoccus pacificus DY20341T 的高温淀粉酶系进行了分析。基于酶活测定、SDS-PAGE复性胶检测和保守位点、结构域、信号肽等序列分析，解析其种类及特点。结果显示，菌株DY20341T 的高温淀粉酶系包括胞外淀粉酶(PAP00275)、胞外环糊精葡糖基转移酶(PAP01075)、胞内淀粉酶(PAP09095)和胞内4-α-葡聚糖转移酶(PAP09225)。4种酶在60~110 ℃温度范围具有酶活性，且100 ℃时酶活性最高。研究表明，DY20341T 含有多个耐高温淀粉酶及转运系统，有助于其在深海热液区适应高温和摄取营养，是一种重要的环境适应机制。 |
| 关键词: 海洋生物学 深海热液区 太平洋古球菌 高温淀粉酶 适应机制 |
| DOI：10.3969/J.ISSN.2095-4972.2021.03.007 |
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| 基金项目:福建省教育厅中青年教师教育科研资助项目(JT180305)；自然资源部第三海洋研究所基本科研业务费专项资金资助项目(海三科2017003) |
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| Amylase analysis of hyperthermophilic archaeon Palaecoccus pacificus DY20341T from deep sea hydrothermal fields |
| HU Junxi,ZHANG Jing,ZENG Xiang |
| (School of Biological Science and Biotechnology, Minnan Normal University, Zhangzhou 363099, China;Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, MNR, Xiamen 361005, China) |
| Abstract: |
| The hyperthermo-piezophilic heterotrophic archaeon Thermococcales including Palaeococcus spp., are an important order in deep sea hydrothermal fields as the group contains versatile extracellular hydrolases for nutrient absorption.This study analyzed the thermostable activity and sequence of its amylase to understand the adaptation mechanism of Palaecoccus pacificus DY20341T in hydrothermal fields. Enzyme activities were investigated by DNS method and Native-PAGE. The conserved sites, domains and signal peptide were further analyzed by sequence analysis. Four amylase were found in the genome of P.pacificus DY20341T, i.e. extracellular α-amylase (PAP00275), extracellular cyclodextrin glucanotransferase (PAP01075), intracellular α-amylase (PAP09095) and intracellular 4-α-glucanotransferase (PAP09225) with their conserved domains. The crude amylase showed a good stability in temperatures of 60-110 ℃, with the highest activity at 100 ℃. It shows that as an important environmental adaptation mechanism the strain DY20341T can increase the amylase numbers with characters of high temperature tolerance and enzyme synergy to help it adapt to high temperature and limited nutrients in deep-sea hydrothermal environments. |
| Key words: marine biology deep sea hydrothermal field Palaeococcus pacificus thermostable amylase adaptation mechanism |
