三烯霉素J——来自深海细菌Ochrobactrum sp.的新安莎霉素

目的探究深海来源细菌Ochrobactrum sp. OUCMDZ-2164中的细胞毒活性代谢产物。方法利用硅胶柱色谱、凝胶柱色谱和高效液相色谱等手段对发酵产物进行分离纯化,运用紫外、红外、质谱、核磁共振及圆二色谱等方法鉴定化合物的结构,采用MTT和细胞计数试剂盒-8(CCK-8)法分别评价化合物对乳腺癌MCF-7细胞和肺癌A549细胞及慢性髓性白血病K562细胞的增殖抑制活性。结果从细菌Ochrobactrum sp. OUCMDZ-2164的发酵产物中分离获得了4个化合物,分别鉴定为3-O-去甲基三烯霉醇(1)、flazin(2)、flazin-3-carboxylicacid(3)和胸腺嘧啶(4)。化合物1在10μmol/L浓度下对MCF-7细胞的增殖抑制率为61.5%。结论化合物1为新的安沙霉素类化合物,命名为三烯霉素J,其具有一定的乳腺癌细胞毒活性。     

基于OSMAC策略对深海来源真菌Acrostalagmus luteoalbus SCSIO F457化学多样性的初步研究

摘要：目的 采用单菌多次级代谢产物（OSMAC）策略对1株采自南海深海2 801 m沉积环境的白黄笋顶孢霉属真菌Acrostalagmus luteoalbus SCSIO F457进行化学多样性的初步研究。方法 通过在不同培养基、不同pH与不同盐度条件下对菌株进行培养调控并筛选2种适宜发酵条件进行小规模发酵。采用硅胶柱层析、葡聚糖凝胶层析、半制备高效液相等色谱学方法对发酵产物进行化学分离,利用NMR、MS等波谱学技术并结合文献鉴定化合物结构,并对化合物进行初步抗氧化和抗菌活性测试。结果 从菌株SCSIO F457的发酵产物中共新增分离鉴定11个单体化合物,包括paulownin（1）、cyclo(L-Phe-L-Pro)（2）、cyclo(L-Tyr-L-Pro)（3）、cyclo(L-Val-L-Pro)（4）、cyclo(D-Ile-L-Pro)（5）、cyclo(D-Leu-L-Pro)（6）、1-methyoxy-4-(2-hydroxy)ethylbenzene（7）、2-(4-hydroxyphenyl)-ethanol（8）、1-phenylbutane-2,3-diol（9）、3-methoxy-2-methyl-4H-pyran-4-one（10）及3-(hydroxy-acetyl)-1H-indole（11）,化合物7表现出较弱的1,1-二苯基-2-苦基肼（1,1-Diphenyl-2-picryl-hydrazyl, DPPH）自由基清除活性。     

南海深海沉积环境来源真菌Aspergillus flavus SCSIO F025的次生代谢产物及活性研究

目的 对采集自南海中部1781 m沉积环境的1株曲霉属真菌Aspergillus flavus SCSIO F025进行次生代谢产物及活性研究。方法 通过优化培养条件对菌株进行规模发酵,发酵产物采用硅胶柱层析、Sephadex LH-20、HPLC等色谱学方法进行化学分离,利用NMR、MS等波谱学技术并结合文献进行化合物的结构鉴定,应用纸片扩散法及DPPH自由基清除法对化合物进行初步抗氧化和抗菌活性测试。结果 从菌株SCSIO F025中分离鉴定5个单体化合物：penicillivinacine(1),arthrographol(2),dehydroxypaxilline(3),ditryptophenaline(4),kojic acid(5)。其中化合物1和2为首次从黄曲霉中分离得到。化合物1对溶藻弧菌和藤黄微球菌有弱的抑制活性,化合物2表现出显著抗氧化及溶藻弧菌和藤黄微球菌抑制活性,化合物3对溶藻弧菌和肺炎克雷伯杆菌有抑制活性。     

Cell proliferation at 122 degrees C and isotopically heavy CH4 production by a hyperthermophilic methanogen under high-pressure cultivation

We have developed a technique for cultivation of chemolithoautotrophs under high hydrostatic pressures that is successfully applicable to various types of deep-sea chemolithoautotrophs, including methanogens. It is based on a glass-syringe-sealing liquid medium and gas mixture used in conjunction with a butyl rubber piston and a metallic needle stuck into butyl rubber. By using this technique, growth, survival, and methane production of a newly isolated, hyperthermophilic methanogen Methanopyrus kandleri strain 116 are characterized under high temperatures and hydrostatic pressures. Elevated hydrostatic pressures extend the temperature maximum for possible cell proliferation from 116°C at 0.4 MPa to 122°C at 20 MPa, providing the potential for growth even at 122°C under an in situ high pressure. In addition, piezophilic growth significantly affected stable carbon isotope fractionation of methanogenesis from CO₂. Under conventional growth conditions, the isotope fractionation of methanogenesis by M. kandleri strain 116 was similar to values (−34‰ to−27‰) previously reported for other hydrogenotrophic methanogens. However, under high hydrostatic pressures, the isotope fractionation effect became much smaller (<−12‰), and the kinetic isotope effect at 122°C and 40 MPa was −9.4‰, which is one of the smallest effects ever reported. This observation will shed light on the sources and production mechanisms of deep-sea methane.     

深海放线菌Micrococcus sp. R21的次生代谢产物研究

研究一株来源于西太平洋深海沉积环境(-6 310 m)的放线菌菌株Micrococcus sp. R21的抗肿瘤活性次生代谢产物。结合运用用硅胶, 凝胶柱色谱等方法从其菌液的乙酸乙酯萃取物中分离鉴定了8个化合物, 通过核磁数据结合其他波谱数据鉴定其结构分别为:环(4-羟基-L-脯-L-亮)二肽(1), 及环(L-脯-L-甘)二肽(2), 环(L-脯-L-丙)二肽(3), 环(D-脯-L-亮)二肽(4), N-β-乙酰色胺酸(5),邻羟基苯甲酸(6), 2-苯基乙酸(7)。其中化合物 1 对小鼠单核巨噬细胞白血病细胞RAW264.7显示出较好的生长抑制活性(IC₅₀=9.1 μmol·L^-1), 提示 1 可能是该菌抗肿瘤的活性成分。     

深海鱼油改善小鼠记忆功能的实验研究

目的通过小鼠实验探讨深海鱼油改善记忆功能的作用。方法 120只雄性SPF级昆明种小鼠随机分为溶剂对照组及深海鱼油低、中、高4个剂量组。每日分别灌胃给予0、0.15、0.30和0.60g/kg BW的深海鱼油,连续30天。于末次给药后次日进行跳台试验、避暗试验和水迷宫试验,并记录相应的指标。结果深海鱼油中剂量组小鼠的跳台试验潜伏期延长,深海鱼油中剂量组小鼠的水迷宫试验到达终点的时间缩短(P<0.05)。避暗试验中,各剂量组与对照组之间的各项指标的差别均无统计学意义(P>0.05)。结论深海鱼油具有辅助改善小鼠记忆的功能。     

Deep ocean communities impacted by changing climate over 24 y in the abyssal northeast Pacific Ocean

The deep ocean, covering a vast expanse of the globe, relies almost exclusively on a food supply originating from primary production in surface waters. With well-documented warming of oceanic surface waters and conflicting reports of increasing and decreasing primary production trends, questions persist about how such changes impact deep ocean communities. A 24-y time-series study of sinking particulate organic carbon (food) supply and its utilization by the benthic community was conducted in the abyssal northeast Pacific (∼4,000-m depth). Here we show that previous findings of food deficits are now punctuated by large episodic surpluses of particulate organic carbon reaching the sea floor, which meet utilization. Changing surface ocean conditions are translated to the deep ocean, where decadal peaks in supply, remineralization, and sequestration of organic carbon have broad implications for global carbon budget projections.Contemporary climate change marked by increasing water temperature, density stratification, and acidification is impacting the world ocean. These changes are especially evident in oceanic surface waters and coastal areas (1), where surface water production of organic carbon and trophic exchanges are affected. However, little is known of how these changes influence the food supply to the deep ocean. Can we expect decreased production of organic carbon produced in the upper ocean, and thus less food delivered to the sea floor? Because the deep ocean occupies the vast majority of the world, such answers are critical to evaluating impacts of climate variation on the global carbon cycle, particularly regarding long-term carbon sequestration.A major unknown component of the global carbon cycle is the amount of organic carbon that reaches the deep ocean and its ultimate utilization or long-term sequestration in the sediments. This supply starts with primary production by phytoplankton in surface waters. There is no consensus on whether phytoplankton biomass is decreasing as a result of a reduction in upwelled nutrients, caused by warming surface waters and increasing stratification (2). In open ocean areas, these conditions can lead to a decrease in primary production by phytoplankton (1, 3) and a geographic expansion of oligotrophic (low chlorophyll) waters (3). In contrast, along-shore winds and increased land–sea temperature disparities are leading to increased nutrient supply and primary production in coastal upwelling areas (1, 2, 4–6). A portion of the organic carbon produced in surface waters is exported to the deep ocean by a variety of mechanisms, including mineral ballasting, aggregation, fecal pellet production, and sinking or vertical migration of large zooplankton (7–12).How do such conditions impact the food supply to the deep ocean, which relies on surface water primary production? Previous studies have shown an unexpected shortage of food reaching deep ocean depths to sustain benthic communities over an 18-y period, with carbon utilization consistently exceeding local supply over that time scale (13, 14). New technology added to long time-series studies now allows us to compare high-resolution measurements of food supply and benthic community carbon consumption to trends over the past 24 y to resolve the question of food shortage, and to examine how it might be changing in the context of global warming. We set out to test the hypothesis that food produced in and settling from overlying surface waters cannot sustain benthic community utilization on multiyear to decadal scales at an abyssal station in the northeast Pacific. To test this hypothesis, we used a combination of autonomous instrumentation on the sea floor and water column, along with satellite-derived measurements, to estimate sinking particulate food as organic carbon reaching and being used by deep-sea communities. These studies were conducted as part of an ongoing 24-y time series at Station M, where measurements of deep-sea processes, combined with atmospheric and surface ocean conditions, have been monitored since 1989 (15). Overlying waters at this abyssal site (∼4,000-m water depth) show strong seasonal primary production corresponding to upwelling events within the California Current.     

A novel indole alkaloid from deep-sea sediment metagenomic clone-derived Escherichia coli fermentation broth

To explore secondary metabolites in deep-sea sediment metagenomic clone-derived Escherichia coli fermentation broth, different kinds of chromatography methods were used in the isolation procedures, while the structures of the isolated compounds were assigned based on the MS analysis and their ¹H and ¹³C NMR spectra including 2D NMR techniques such as COSY, HMQC, and HMBC experiments. As a result, a novel compound was isolated and characterized as N-{1-[4-(acetylamino)phenyl]-3-hydroxy-1-(1H-indol-3-yl)propan-2-yl}-2,2-dichloroacetamide (1). In addition, eight known compounds were also obtained. Fatty acid amide hydrolase and monoacylglycerol lipase were used to screen analgesic activity, and the new compound showed analgesic activity to some extent in pharmacological test.     

Corrosion Properties of Mn-Based Alloys Obtained by Aluminothermic Reduction of Deep-Sea Nodules

Deep-sea manganese nodules are polymetallic oxidic ores that can be found on a seabed. Aluminothermic reduction is one of the possibilities of manganese nodules processing. This process obtains the polymetallic alloy with a high content of Mn and a varying content of Al, depending on the ratio between aluminum and nodules. The corrosion behaviors of three experimental Mn-based alloys produced by aluminothermic reduction with a content of Mn > 50 wt % were studied. The electrochemical testing in potable water and model seawater was used to explain the corrosion mechanism of Mn-based alloys. The results showed that the corrosion rate of experimental Mn-based alloy decreases with the increase in aluminum content in both potable water and model seawater. It was observed that the uniform corrosion of experimental Mn-based alloys is changed with an increase in aluminum content in alloy to localized corrosion, which was caused by microcells in an environment of model seawater. In contrast, the formation of a semi-protective layer of corrosion products was observed on the surface of Mn-based alloys with a higher content of aluminum in potable water. Moreover, the pitting corrosion of tested Mn-based alloys was observed neither in potable water nor in model seawater.