徐闻8种珊瑚共附生真菌的分离及初步鉴定

从徐闻珊瑚保护区的8种珊瑚中分离共附生真菌,以获得珊瑚共附生可培养真菌的多样性信息。选用5种培养基,采用平板涂布法培养分离共附生真菌,并进行形态鉴定。8种珊瑚共分离121株真菌,鉴定了其中97株真菌,分属于14个属,青霉属和枝孢霉为优势种属,其次是曲霉属和木霉属。二异角孔珊瑚上分离出22株,数量最多;盔型珊瑚上分离菌株数量最少仅8株。除优势种属外,不同珊瑚样品上真菌种类分布有较大差异,炭角菌属和葡萄穗霉菌属均来源于盔形珊瑚,镰刀菌属在盔形珊瑚和角孔珊瑚上较为常见,盔形珊瑚样品上还分离出2株散囊菌属,1株节菱孢属,因此盔形珊瑚的种群最为丰富;不同培养基分离真菌的能力不同,淀粉培养基分离的菌株最多占所有分离菌株的30.6%,CDA培养基最少,但种类特异。     

拮抗香蕉枯萎病菌海洋细菌的筛选和鉴定

从93份中国南部海域近海海泥样品中分离出1800多株海洋细菌,以对峙培养法,测定海洋细菌对香蕉枯萎菌的拮抗作用,再以琼脂划线培养法(agar streak)测定菌株的抑菌活性,结果表明:约55.6%的菌株对香蕉枯萎菌有一定的拮抗作用,其中58株菌株抑制香蕉枯萎菌生长所形成的抑菌带宽度大于10.0mm,抑菌作用较好,复筛后其中13个菌株形成的抑菌带宽在15.0mm以上。经反复转接和对峙培养,筛选出拮抗效果好、抑菌活性稳定的菌株TC-1,初步鉴定为芽孢杆菌属的细菌,TC-1对14种病原微生物都有较好的抑菌效果。     

化学诱导对2株海洋真菌次级代谢产物及其生物活性的影响

【目的】以2株海洋真菌为研究对象,探究不同种类及浓度的化学表观遗传修饰剂对其次级代谢产物化学多样性和生物活性的影响。【方法】基于化学表观遗传修饰策略,采用两种不同的化学表观遗传修饰剂5-氮杂胞嘧啶核苷(5-azaC)和丁酸钠,分别对Penicillium sp.019和Aspergillus terreus ZN4-5-4两株海洋来源真菌进行表观遗传修饰。通过观察真菌在培养基中的生长状态变化,并根据薄层层析(TLC)指纹图谱、高效液相色谱(HPLC)图谱、乙酰胆碱酯酶(AChE)抑制、1,1-二苯基-2-三硝基苯肼(1,1-Diphenyl-2-picryl-hydrazyl,DPPH)自由基清除和卤虫致死活性筛选模型等技术手段,从中筛选出代谢产物丰富、AChE抑制活性与抗氧化活性产物丰富且毒性小的发酵培养条件。【结果】添加1 mmol/mL的丁酸钠诱导剂可使菌株019和ZN4-5-4的次生代谢产物的种类增加,且同时能提高该菌株次级代谢产物的AChE的抑制活性和DPPH自由基清除活性。因此,确定菌株019和ZN4-5-4的最优发酵条件均是添加浓度为1 mmol/mL丁酸钠的PDB培养基。【结论】化学表观遗传修饰策略指导下,添加诱导剂5-azaC或者丁酸钠对2株海洋真菌次生代谢产物的产生有影响。     

海洋真菌来源丁内酯I的单胺氧化酶抑制活性及结构类似物虚拟筛选

【目的】为研究海洋土曲霉(Aspergillus terreus)C23-3的次级代谢产物中的单胺氧化酶抑制剂及其抑制作用类型,借助计算机模拟方法探讨同类型化合物对单胺氧化酶的潜在抑制活性及构效关系,以开发单胺氧化酶抑制剂。【方法】采用活性引导下的色谱方法分离纯化得到活性化合物,采用核磁共振、质谱、圆二色谱分析鉴定其结构,采用酶标比色法评价化合物对单胺氧化酶抑制作用。使用Autodock vina对其结构类似物进行抑制单胺氧化酶活性虚拟筛选。【结果】1)分离鉴定得到一个具有单胺氧化酶抑制活性的化合物丁内酯I;2)丁内酯I对单胺氧化酶A和单胺氧化酶B的抑制作用为可逆非竞争性抑制,对单胺氧化酶A的半抑制浓度(IC₅₀)为21.45μmol/L,抑制常数K_i=6.27μmol/L;对单胺氧化酶B的IC₅₀为24.16μmol/L,K_i=12.61μmol/L;3)分子对接显示丁内酯I可与单胺氧化酶形成多个氢键,五元内酯环为α,γ?二芳基取代、含有苯并吡喃或苯并呋喃基团的aspvinone类丁内酯化合物在虚...     

盐酸普鲁卡因诱导下海洋真菌Hypocrea lixii次级代谢化学成分

【目的】通过化学诱导方法从一株海洋真菌Hypocrea lixii中获得多样化的活性小分子化合物。【方法】对菌株在盐酸普鲁卡因的化学诱导作用下进行固体发酵,代谢产物采用硅胶减压柱层析、Sephadex LH-20以及pHPLC等手段分离纯化,对化合物运用NMR、MS等波谱学技术并比对文献进行结构鉴定,采用Ellman比色法及DPPH自由基清除法对化合物进行初步抗乙酰胆碱酯酶(AChE)和抗氧化活性测试。【结果】从海洋真菌Hypocrea lixii在盐酸普鲁卡因诱导下的发酵提取物中分离得到4个异黄酮类化合物,包括6'-O-crotonylgenistin(1)、Genistein(2)、Daidzein(3)和Genistin(4),以及对氨基苯甲酸甲酯(5)、对羟基苯丙酸(6)和胞嘧啶(7),其中化合物1和6为该种中首次报道,化合物5为生物转化来源首次报道,化合物2~4可能源自培养基。在100μmol/L剂量浓度下,化合物1~4对AChE的抑制以及DPPH自由基的清除活性均较弱,化合物5和6显示了相对强的AChE抑制活性,抑制率分别为40%和38%。【结论】盐酸普鲁卡因对该菌次级代谢产生了显著的影响,为深入研究该菌株化学诱导次级代谢产物提供基础。     

海洋经济与海洋环境保护协调发展的初步探讨——大连海域案例研究

21世纪是开发和利用海洋的新世纪。在开发利用海洋的过程中出现了海洋经济发展与海洋环境保护之间的不协调性、不同步性。以大连为个案，运用耦合机制对海洋环境与海洋经济的协调发展进行初步探讨，并提出相应对策和建议。     

海洋经济与海洋环境保护协调发展的初步探讨--大连海域案例研究

21世纪是开发和利用海洋的新世纪.在开发利用海洋的过程中出现了海洋经济发展与海洋环境保护之间的不协调性、不同步性.以大连为个案,运用耦合机制对海洋环境与海洋经济的协调发展进行初步探讨,并提出相应对策和建议.     

海洋治理概念内涵的演化研究

海洋治理是指为了维护海洋生态平衡、实现海洋可持续开发,涉海国际组织或国家、政府部门、私营部门和公民个人等海洋管理主体通过协作,依法行使涉海权力、履行涉海责任,共同管理海洋及其实践活动的过程。海洋治理在实践需求、管理主体、管理对象、管理手段、管理层次等方面深化了海洋管理、海洋综合管理、海洋行政管理的内涵。     

一株产植酸酶菌株的分离鉴定及其产酶特性

<正>植酸酶(phytase)是催化植酸和植酸盐水解成肌醇和磷酸(或盐)的一类酶的总称,是一类特殊的酸性磷酸酶。饲料中添加植酸酶可改良磷酸盐的生物利用度,减少无机磷的添加,缓解我国磷资源缺乏、磷供应不足的局面;消除植酸的抗营养作用,     

大口黑鲈肠道益生菌的分离与鉴定

【目的】分离鉴定大口黑鲈（Micropterus salmoides）肠道益生菌,评估分离菌用作饲料添加剂的益生潜力。【方法】采集大口黑鲈肠道样本,采用稀释涂布法分离细菌,经16S rRNA序列比对和生化试验鉴定种属,并进行抗逆性能、黏附能力、溶血活性和药敏特性等鉴定。【结果】从大口黑鲈肠道分离菌株84株,经测序、blast比对,筛选出3株同源性最高的菌株MS-1、MS-2、MS-3,分别鉴定为地衣芽孢杆菌（Bacillus licheniformis）、解淀粉芽孢杆菌（Bacillus amyloliquefaciens）和贝莱斯芽孢杆菌（Bacillus velezensis）。3株分离菌均为γ-溶血,不具有生物膜,疏水性50%～93.3%,自凝集性43.6%～69.2%;可在pH 2.0～12.0环境和5.0 g/L胆盐中存活;经高温处理后仍可生长;3株菌对大多数抗生素敏感。【结论】芽孢杆菌MS-1、MS-2和MS-3抗逆性高,黏附性能及饲料学安全性高,可作为大口黑鲈养殖中潜在益生菌。     

海洋土曲霉C23-3与不同类型海洋微生物共培养对其次生代谢产物的影响

【目的】研究海洋土曲霉C23-3与不同类型海洋微生物共培养对其次生代谢产物的影响,挖掘土曲霉菌株C23-3的次生代谢潜力。【方法】将副溶血弧菌、枯草芽孢杆菌和胶红酵母的活菌或灭活菌体分别以不同时间与土曲霉C23-3共培养;采用DPPH自由基清除法和Ellman法分别评价各提取物的抗氧化和乙酰胆碱酯酶抑制活性,采用滤纸片法比较各提取物的抗菌活性,采用HPLC指纹图谱分析各提取物化学成分的差异。【结果与结论】发现不同类型的微生物与土曲霉共培养均可激活一些原本沉默的活性次级代谢产物;菌株及共培养物的化学拮抗能力、HPLC指纹图谱中的特征代谢产物变化揭示在活菌培养体系中土曲霉占竞争优势;而且灭活菌体中可能存在某些信号物质,在12 d时对土曲霉群体自感应信号分子丁内酯-I的产生具有比活菌更强的刺激作用。研究结果为深入挖掘海洋真菌代谢潜力及抗老年痴呆等活性先导化合物的发现提供基础。     

Isolation and identification of a bacterium from marine shrimp digestive tract: A new degrader of starch and protein

It is a practical approach to select candidate probiotic bacterial stains on the basis of their special traits. Production of digestive enzyme was used as a trait to select a candidate probiotic bacterial strain in this study. In order to select a bacterium with the ability to degrade both starch and protein, an ideal bacterial strain STE was isolated from marine shrimp (Litopenaeus vannamei) intestines by using multiple selective media.The selected isolate STE was identified on the basis of its morphological, physiological,and biochemical characteristics as well as molecular analyses. Results of degradation experiments confirmed the ability of the selected isolate to degrade both starch and casein. The isolate STE was aerobic, Gram-negative, rod-shaped, motile and non-spore-forming, and had catalase and oxidase activities but no glucose fermentation activity. Among the tested carbon/nitrogen sources, only Tween40, alanyl-glycine, aspartyl-glycine, and glycyl-l-glutamic acid were utilized by the isolate STE. Results of homology comparison analyses of the 16S rDNA sequences showed that the isolate STE had a high similarity to several Pseudoalteromonas species and, in the phylogenetic tree, grouped with P. ruthenica with maximum bootstrap support (100%). In conclusion, the isolate STE was characterized as a novel strain belonging to the genus Pseudoalteromonas.This study provides a further example of a probiotic bacterial strain with specific characteristics isolated from the host gastrointestinal tract.     

Antimicrobial activities of novel cultivable bacteria isolated from marine sponge Tedania anhelans

Marine sponge Tedania anhelans distributes throughout the intertidal zone of Fujian, southeastern China, and is a potential source of natural bioactive products. The sponge harbors a large number of bacterial groups that have been identified using various techniques, including fluorescent in situ hybridization (FISH). Fractionation of dissociated sponge allowed isolation of 25 bacterial species. Based on 16S rRNA gene sequencing, phylogenetic analysis attributed most of these eubacteria to α-Proteobacteria, γ-Proteobacteria, Cytophaga/Flavobacterium/Bacteroidetes (CFB group), and the family Bacillaceae of Gram-positive bacteria. In sequence similarity, five putatively novel species were identified with less than 98% similarity to other strains in the NCBI database. Tests for antimicrobial activities were performed against Gram-positive bacteria, Gram-negative bacteria, fungi, antitumor indicators Escherichia coli 343/591 (with DNA repair deficiency), regular E. coli 343/636 (with different DNA repair capacity), and 10 bacterial isolates exhibited inhibitory bioactivities. Among these strains, three isolates were detected involving function gene NRPS-A domains, which were most closely related to the amino acid sequences of linear gramicidin synthetase and pyoverdine synthetase. These results contribute to our knowledge of the microbes associated with marine sponges and further reveal novel bacterial resources for the screening of bioactive marine natural products.     

Impact of Phenanthrene on Denitrification Activity and Transcription of Related Functional Genes in Estuarine and Marine Sediments

The effects of phenanthrene(Phe)on the denitrification activity and denitrifying genes(narG,nirS and nosZ)were evaluated by dose-response experiments in sediments of Dagu River Estuary(DRE)and Jiaozhou Bay(JZB).The results showed that potential denitrification activity(PDA),N2O,NO3−and NO2−reduction rates of both areas were inhibited with an increase of Phe concentrations.The PDA,N2O,NO3−and NO2−reduction rates of both areas was highest and lowest in the control(DRE:0.453,0.427,7.439 and 3.222mgNkg−1 h−1,JZB:0.592,0.555,8.470 and 3.793mgNkg−1 h−1)and highest Phe amended treatments(DRE:0.069,0.001,4.486,and 1.563 mgNkg−1 h−1;JZB:0.114,0.024,5.527 and 2.200 mgNkg−1 h−1).The inhibition rate of PDA was highest,follow by NO2−reduction and then NO3−reduction.Moreover,with the increasing of Phe concentrations,total bacteria count and the abundance of denitrifying genes were decreased.And N2O accumulation was promoted with the addition of Phe for both areas.Based on the comparison of EC50 values,denitrifiers harboring three genes were more sensitive to Phe than PDA,and denitrifiers harboring nirS gene were more sensitive,followed by nosZ gene,and then narG gene.Furthermore,according to correlation analysis,the relative abundance of denitrifying genes was much more positively correlated with PDA,NO3−and NO2−reduction than total bacteria count.In addition,the denitrification activity and total bacteria count in JZB were more inhibited than that of DRE.This study is useful for understanding the impact of Phe pollution on denitrification in estuary and marine sediments,with profound implications for the management of aquatic ecosystems regarding eutrophication(N-removal)and greenhouse effect.     

Screening of marine fungus from Nanji Island and activity of their metabolites against pathogenic Vibrio from Pseudosciaena crocea

Seventy-eight marine fungal strains were isolated from sediment samples collected off the coast of Nanji Island,Wenzhou,Zhejiang Province,China.Antibacterial screening using the agar disc method showed that 19 of the isolated strains could inhibit at least one pathogenic Vibrio from Pseudosciaena crocea.Subsequent screening confirmed that nine strains produced antibacterial metabolites that had activity against one or several types of pathogenic Vibrio.Strain NJ0104 had the widest antimicrobial spectrum and strong activity,particularly against Vibrio parahaemolyticus-MM0810072.A preliminary study of NJ0104 antibacterial metabolites demonstrated that they had thermal stability up to 80°C,ultraviolet stability up to 40 min and pH stability between 4.0-7.0.In addition,the antibacterial metabolites were readily soluble in butanol.To identify the specific strain,the ITS-5.8S rDNA regions of NJ0104 were PCR amplified and sequenced.Based on the combination of phenotypic and genotypic data,the strain was identified as Arthrinium sp.     

中国及国际海洋科学发展态势文献计量分析

以SCIE、ESI、OA等数据库为统计分析源,对1996~2005年国际海洋科学论文产出的主题领域及国家分布、中国海洋科学论文产出的主题领域等从文献计量学的角度进行了统计分析,以揭示国际及中国海洋科学的发展现状和态势,并通过论文产出、国际1%顶尖论文数及热门论文数的统计揭示中国在国际海洋科学领域的科学影响力。     

镉和铜对海洋浮游植物的毒性效应及其机制研究进展

【目的】综述重金属元素镉Cd和铜Cu对海洋浮游植物的毒性效应研究,总结重金属对海洋浮游植物的毒性作用机制,为开展重金属对海洋浮游植物毒害机理的深入研究提供借鉴。【方法】以毒理实验中常用的重金属镉和铜为代表,总结了重金属对海洋浮游植物毒理研究的常用测试指标,归纳了重金属对海洋浮游植物光合作用、抗氧化系统等方面的毒性作用机制。【结果】重金属对海洋浮游植物毒性作用机制概括为:1)重金属替换与其结构相似的作为酶辅助因子的金属元素,使浮游植物体内某些酶失活;2)重金属直接或间接诱导活性氧的产生,使浮游植物受到氧化胁迫;3)重金属与生物大分子中的某些基团亲和性高而结合,阻断相关的生理生化过程。【结论】重金属的毒性效应因浮游植物种类不同而有所差异,今后相关研究中需更加关注重金属在多种海洋浮游植物共存环境下的毒性效应及机制,将有助于全面系统地理解重金属对海洋浮游植物的致毒机理。