一株海洋发光细菌的分离鉴定及其发光条件的初步研究

从青岛近海海洋沉积物样品中分离出一株海洋发光细菌，命名为D40。经过形态观察以及一系列生理生化特征测试结果，确定这株菌属于弧菌属(Vibrio)的哈维氏发光弧菌(Vibrio harveyi)。同时对这株菌的发光条件和发光特点进行了初步研究，实验结果表明，细菌D40在PH7．5，温度30℃，NaCl浓度为3．0％时，发光强度最高，液体培养4h开始发光，6h后，发光达到峰值，持续发光时间可达19h。     

南沙群岛海区沉积物中可培养的非嗜压好气性异养细菌的初步调查

采用16SrRNA基因序列分析，对南沙群岛海区沉积物中分离获得的细菌进行了种类鉴定及多样性初步研究。发现沉积物中可培养的非嗜压好气性异养细菌主要为革兰氏阳性细菌，其中海洋芽孢杆菌又是最常见的种；分离获得的菌株中存在部分细菌的16SrDNA序列与发表在国际基因数据库中的16SrDNA序列表现出较大的差异，但目前尚未能直接确定其属种，说明在南海海洋沉积物中存在着我们目前还不了解的细菌多样性，而且可以通过分离培养获得其中的部分新的菌株，提示该海区沉积物中蕴藏着丰富的细菌资源。     

Extraction and physicochemical characteristics of a red pigment produced by marine bacterium strain S-9801

A red pigment that has better biological properties is produced by marine bacterium strainS- 9801. The extraction methods, physicochemical and toxicity of the pigment have been studied. Dissolubility of pigment in the five organic solvent has been tested, and ethanol is optimally chosen for extraction. Physicochemical characteristics of this pigment was stable. The absorbance of the pigment solution was no losing when put under natural light for 10 days or treated by UV for 30 minutes, color of the pigment unchanged after 100 ℃ hythere for 1 h or 80 ℃ xerother for 2 h. The median lethal dose (LD_(50) )of the rat by celiac injection was 670.04 mg/kg and minimum lethal dose of oral was greater than 2 000 mg/kg.     

太平洋双色鳗鲡(Anguilla bicolor pacifica)致病性类志贺邻单胞菌的鉴定和中药敏感性研究

从发病死亡的养殖太平洋双色鳗鲡(Anguilla bicolor pacifica)肝脏中分离到一株优势菌AMSH1,为研究其种属、毒力及中药敏感性,结合BIOLOG微生物鉴定系统和16S r DNA序列分析对该菌株进行鉴定,并通过人工回归感染试验确定其致病性。此外,还研究了10味中药单用、10种双联用和4种三联用对该菌株的体外抑菌作用。结果显示该菌株为类志贺邻单胞菌(Plesiomonas shigelloides)。经人工腹腔注射感染健康太平洋双色鳗鲡,证实该菌具有致病性,半致死量LD50为3.2×105CFU/g。药敏试验结果表明,10味中药均有较好的抑菌效果,其中五倍子(Galla chinensis)、丁香(Eugenia caryophllata)和生地榆(Sanguisorba officinalis)的效果最好,7种双联用复方和1种三联用复方均具有协同抑菌作用。本次引起太平洋双色鳗鲡发病的病原为类志贺邻单胞菌,该菌对太平洋双色鳗鲡的致病性及其中药药敏的研究属首次报道。建议选用含五倍子的中药双联用复方或三联用复方进行防治,皆绿色环保。     

Identical carbon isotope trends of carbonate and organic carbon and their environmental significance from the Changhsingian (end-Permian), Meishan,South China

High resolution carbon isotope analyses of carbonate and organic carbon from Meishan, South China showed that the variation of δ13Ccarb is marked by three large positive excursions during the Changhsingian (end-Permian). Carbon isotope stratigraphy during this stage shows three cyclic intervals in δ13Ccarb, with two cycles corresponding to the lower (Paleofusulinid minima Zone) and one corresponding to the upper Changhsingian (P. sinensis Zone). The large positive δ13Ccarb excursions indicate episodes of enhanced burial of isotopically light or-ganic carbon, presumably in response to deep-water anoxia episodically extending into shallow water with the rise of sea level. The organic carbon during the Changhsingian is distinguished into two groups, and the δ13Corg of each group parallels (separately) the more detailed profile of δ13Ccarb, strongly showing that the values of fractionation Δ13Ccab-org remain relatively constant, with only two intervals with anomaly. The enhanced fractionation Δ13Ccab-org with large negative δ13Corg excursions apparently indicates significant inputs from sulfide-oxidizing bacteria and green sulfur bacteria, notably at bed 24 just predating mass extinction. Our evidence appears to support that the ex-tended euxinic water is possible for the main pulse of mass extinction at the end-Permian.     

一株多环芳烃芘降解菌的鉴定及其降解特性研究

从红树植物红海榄叶片中分离一株对芘具有较好降解作用的海洋细菌,命名为B11,并对其菌体特征、生长条件及降解效能等进行了系统研究。结果发现该菌株为革兰氏阴性菌,结合其生理生化特征和16S rDNA序列比对,表明此菌株属于交替单胞菌属(Alteromonas sp.)。菌株在芘的起始浓度为100 mg/L,pH为中性或偏碱性条件下,盐度35时对芘的降解作用最强。外加碳源对B11对芘的降解效果都具有一定的抑制作用,其中水杨酸的抑制作用更为显著。综合菌株B11的生长特性和降解效能,初步认为B11菌株较适合用于降解多环芳烃芘,可用于红树植物多环芳烃生态污染的原位修复。     

海洋细菌Bacillus sp. Cs-700耐受及移除铯能力研究

为了筛选可以耐受高浓度铯离子(Cs⁺)的海洋细菌并探究细菌耐受Cs⁺的机制,本研究从广西近海沉积物样品中筛选出一株能够耐受700 mmol/dm³ Cs⁺的海洋细菌,是目前已报道的可耐受最高浓度Cs⁺的细菌。通过形态学分析、16S rRNA序列分析及生理生化特性的测定,确定该菌属于芽孢杆菌属(Bacillus),故将该菌株命名为Bacillus sp.Cs-700。在添加有700 mmol/dm³氯化铯的培养基中,菌体对铯的移除率最高可达52.06%。研究结果表明Bacillus sp.Cs-700不但具有耐受高浓度Cs⁺的特性,还具有较好的铯移除能力,具有修复放射性铯污染环境的潜力。本研究可为探索海洋放射性铯的生态修复提供参考。     

南极菌Pseudoalteromonas sp.S-15-13引导糖基转移酶基因表达对环境因子变化的响应

为了探讨胞外多糖在南极微生物低温适应性中的作用与机制,克隆了南极菌Pseudoalteromonas sp.S-15-13的引导糖基转移酶(GTF)核心片段,并采用Real-Time PCR的方法研究了温度、冻融循环、盐浓度、pH等条件对该糖基转移酶基因(gtf)表达的影响。结果表明,低温有利于gtf的表达,短时的低温刺激(2℃)1 h后,gtf的表达量即上调为对照的1.5倍;而该菌经4和10℃培养24 h后gtf的表达量约为20℃时的8~12倍;经过冻融循环gtf的表达量上调,在第2个冻融循环后gtf 的表达量较对照提高了3.667倍;盐浓度对gtf的影响表现为低促高抑,即NaCl含量为6.0 %时gtf 的表达量是对照(3.0%)的3.59倍,当NaCl含量达9.0 %时gtf 表达量则显著下调;在一定范围内(pH5.0~8.0),pH的改变会促进gtf 的表达,当pH为6.0时gtf 表达量约为pH7.0时的2倍。该结果为探讨胞外多糖在南极微生物环境适应性中的作用与机制提供了科学依据。     

Study on the Flocculability of Metal Ions by Bacillus Mucilaginosus GY03 Strain

Inrecentyears,withtherapiddevelopmentofindustrialeconomy ,wastewaterisdischargedinhugevolumeandtheaccumulationofheavymetalionsinsoilsandwatersourcesisspeededuprapidly .Asaresult,waterpollutionhasbecomeadailydeterioratingproblem .Heavymetalsareeasytoenterthefoodchain ,therebyconstitutingagreatthreattothehealthofanimalsandhu manbeings .Therefore,howtoeffectivelyhandleheavymetalpollutionhasbecomeacommonat tractionformankind .Theroutineheavymetaltreatmentmethodsaremainlythechemical,phys icalandphy…