红树林细菌发酵产灵菌红素条件研究

采用单因素试验和L9(34)正交试验研究从红树林中分离到的一株具有产灵菌红素的海洋细菌(Flavobacterium sp.)的发酵条件。结果表明,最佳培养基配方为麦芽糖10.0g/L,蛋白胨10.0g/L,磷酸氢二钾0.25g/L,硫酸镁0.1g/L,最合适pH值为6.0,最合适的盐度为10‰,最合适的温度为27℃。     

新鲜哈密瓜汁中芽胞菌的分离鉴定及超高压对其致死效应研究

为探讨哈密瓜汁超高压杀菌的新方法,以新鲜哈密瓜为试验材料,通过形态特征的传统鉴定方法分离得到2株芽胞菌,采用细菌16SrRNA基因的通用引物进行PCR并扩增出这2株菌的16SrRNA基因全序列。测定16SrRNA基因序列,将获得的序列用blast软件与Genbank中相关菌株的16SrDNA序列进行同源性分析,结果显示两菌株均为枯草芽孢杆菌。采用100~500MPa超高压协同35~55℃处理5~20 min进行枯草芽孢杆菌的杀菌实验,结合哈密瓜汁的理化指标和最大程度保持哈密瓜汁原有特殊风味,得出45℃、300MPa、保压15min为杀菌的最优参数,能使哈密瓜汁中的枯草芽孢杆菌降低5.23个对数。     

Luffariellolide,an anti-inflammatory sesterterpene from the marine spongeLuffariella sp.

Summary Luffariellolide (2) is a sesterterpene from the Palauan spongeLuffariella sp. that has useful anti-inflammatory properties. In contrast with the irreversible action of manoalide (1) on phospholipase A₂, luffariellolide (2) is a slightly less potent but partially reversible PLA₂ inhibitor.30 December 1986Acknowledgment We thank Edward Luedtke, Elise Clason and Ellen Snideman for performing some of the assays reported above. The sponge was identified by Dr. Klaus Rützler, Smithsonian Institution, Washington, D.C. The research was supported by grants from Allergan Pharmaceuticals and the California Sea Grant College Program (Projects R/MP-30 and R/MP-31).     

Effect of iron deficiency on heterocyst differentiation and physiology of the filamentous cyanobacterium<Emphasis Type="Italic">Anabaena</Emphasis> sp. PCC 7120

The effect of iron deficiency on heterocyst differentiation and some physiological properties of the filamentous cyanobacteriumAnabaena sp. PCC 7120 was investigated. Under moderate iron limitation conditions, achieved by addition of iron chelator 2, 2′-Dipyridyl (<80 μmol/L) led to delayed heterocyst differentiation, no heterocyst differentiation was observed under severe iron limitation conditions, when the concentration of 2,2′-Dipyridyl in the medium was more than 100 μmol/L. it seemed that there are certain iron-regulated genes or operons whose function is to control heterocyst development. In addition, iron deficiency impaired the growth. Low iron cells had a decrease in the quantities of pigment content (chlorophyll and phycocyanin content), the whole cellin vivo absorbance spectra confirmed the decrease, the protein electrophoretic profiles revealed that iron-deficient cells had less protein bands, with the increase of 2,2′-Dipyridyl, the protein bands was more and more less. And differently, iron deficiency also caused an increase of ROS (Reactive Oxygen Species) and SOD activity, it suggests that iron deficiency led to oxidative stress, which generally occured under high-iron conditions. Foundation item: Supported by the National Natural Sciences Foundation of China (30070154), the Frontier Science Projects Programme of the Institute of Hydrobiology, the Chinese Academy of Sciences (220316), State Key Project on Cyanobacterial Bloom Control in Lake Danchi (K9905-35-01) Biography: Xu Wenllang (1974-), male, Ph. D. research direction: molecular genetics of eyanobacteria.     

根霉2#(Rhizopussp.2#)产酶条件研究

对影响根霉２＾＃（Ｒｈｉｚｏｐｕｓ ｓｐ．２）产生生淀粉分解酶的碳源、氮源、无机盐、温度、ｐＨ值等进行优化组合试验，摸索出了一个最佳的产酶条件，该条件为：木薯渣５％、花生麸０．７５％、尿素０．１％、Ｋ２ＨＰＯ４０．１％、ＭｇＳＯ４０．０７５％、ｐＨ值５．０、３２℃摇瓶培养９６ｈ。使用该条件可使得发酵酶液的酶活达到７．７５Ｕ／ｍＬ。     

甲烷八叠球菌(Methanosarcinasp)若干特性的研究

利用甲醇、H_2+CO_2或乙酸盐作为碳源和能源,从池塘的沉积物取样,经过反复的富集和分离,得到了甲烷八叠球菌的纯培养物。该菌在H_2+CO_2或甲醇上生长最快,1～2周出现菌落而在乙酸盐上3～4周出现菌落。菌落直径通常为1～2mm,在培养基的深层为不规则的多角形,表面菌落为圆形。菌落颜色为白至黄色。特殊的假八叠形使之很容易鉴定到属的水平。甲烷八叠球菌在液体培养基或固体培养基中均产生甲烷。酵母膏对该菌的生长具有很大的刺激作用。在420nm处该菌产生荧光。     

对混合离子分步滴定最佳酸度的讨论

用配位滴定法对混合离子进行分步滴定时,将pH_(?)定为最佳酸度范围的低限是否合理。在最佳酸度范围内有一最佳pH值能否作为一普遍规律的结论,文章从三种不同类型的实例,论证上述结论的局限性。     

广西盘蚱科一新种(蚱总科)

记述盘蚱科（Ｄｉｓｃｏｔｅｔｔｉｇｉｄａｅ）扁角蚱属（Ｆｌａｔｏｃｅｒｕｓ）一新咱，即大青山扁角蚱（Ｆｌａｔｏｃｅｒｕｓ ｄａｑｉｎｇｓｈａｎｅｎｓｉｓ ｓｐ．ｎｏｖ．）．模式标本存陕西师范大学动物所标本室。     

苹果内生细菌动态分布及其对斑点落叶病的拮抗作用

采用常规分离法对不同生长季节苹果树的不同部位进行了内生细菌分离．结果表明，内生细菌的分离几率和数量不同．通过平板对峙培养和发酵液抑菌活性测定，在所分离的118个菌株中，筛选出7株对苹果斑点落叶病菌（Alternaria alternata f．sp．Mali）具有较强拮抗作用的菌株，其中菌株B86和B91的发酵滤液在活体上对苹果斑点落叶病的防治效果显著，分别为73．72％和75．32％．两菌株培养滤液对病菌分生孢子萌发具有抑制作用，并造成芽管畸形膨大，呈泡囊状，泡囊消解破裂；两菌株产生的抑菌物质具有热稳定性．表明B86和B91菌株具有一定的生防潜力．     

红树林共生真菌Paecilomyces sp.Tree 1-7 代谢产物的研究

Paecilomyces sp.Tree 1-7是一株采自台湾海峡的红树林共生真菌。用硅胶柱色谱及重结晶等方法,并根据理化性质和光谱数据对该菌的代谢产物进行了研究,从菌丝体中分离鉴定出三个化合物,分别为alatern in(1),5,8-二羟基-4-甲基-香豆素(2),3-羟基-3,6-二甲基-2,5-哌嗪(3)。对1进行了抗人的肝癌细胞hepG2及抑制乙酰胆碱酯酶(AChE)的活性测试,结果显示,化合物1有较强的抗肿瘤活性(IC50=7.0μg/mL),及很好地抑制AChE活性(IC50=0.87μg/mL)。