芽孢杆菌M_(50)产生β甘露聚糖酶的条件研究

从土壤中分离到９ 株产生β甘露聚糖酶的芽孢杆菌（ Ｂａｃｉｌｌｕｓ ｓｐ ．） 。Ｂａｃｉｌｌｕｓｓｐ ． Ｍ５０２５０ｍ Ｌ三角瓶摇瓶培养试验,以４ ％ 的魔芋粉为碳源,１－０ ％ （ ＮＨ４）２ＳＯ４ 为氮源,０－３５ ％Ｎａ２ＣＯ３ ,３０ ～３４ ℃培养６０ｈ 产酶达到高峰。酶活力为１８０ ～２００ｕ／ｍ Ｌ。１００Ｌ 罐发酵,在３０ ～３２ ℃,１∶０ ．７５ｖｖｍ 通气量,２００ｒ／ｍｉｎ 条件下,发酵液酶活力高达３３０ｕ／ｍ Ｌ。酶的最适反应温度和ｐＨ 分别为５０ ℃和６－０ ,低于５０ ℃,ｐＨ５ ．０ ～７ ．０ 酶稳定。Ｆｅ^３＋ 、Ａｌ^３＋ 、ＥＤＴＡ、Ｈｇ^２＋ 对酶有抑制作用,而Ｂａ^２＋ 、Ｍｎ^２＋ 对酶有激活作用。发酵粗酶液对苎麻精干麻精练,显示对精干麻的半纤维素残胶具有降解作用。     

一株产虾青素的黄杆菌CF-60的研究

从土壤中分离到一株黄杆菌（Ｆｌａｖｏｂａｃｔｅｒｉｕｍｓｐｐ）Ｃ_Ｆ－６０,该菌的生长需Ｍｇ^２＋存在,ＭｇＳＯ_４·７Ｈ_２Ｏ的最适浓度为０．２％;蛋白胨是该菌株生长的最好氮源,它不能利用无机氮。种龄超过９６ｈ的菌体不能在新鲜培养基中生长。经５４ｈ的２Ｌ恒化器发酵,生物量达６．８ｇ／Ｌ,色素产量为１０．６ｍｇ／Ｌ。该菌产生的类胡萝卜素成分简单,主要成分的含量为９０．３％,该成分经初步鉴定是分子结构中含有羰基和羟     

利用糖蜜发酵生产生物降解塑料PHB的研究

由Ａｌｃａｌｉｇｅｎｅｓｌａｔｕｓ经单菌落分离,从中筛选到一株高效利用糖蜜产聚羟基丁酸（ＰＨＢ）的优良菌株１０１８。在６Ｌ台式发酵罐（Ｎ.Ｂ.Ｓ）中,进行了该菌利用甜菜糖蜜和甘蔗糖蜜积累ＰＨＢ的分批补料培养的研究。结果表明,培养５４ｈ左右发酵液中细胞干重达７０～８５ｇ／Ｌ,ＰＨＢ含量占细胞干重的６０％～７０％,生产强度１．０ｇＰＨＢ／Ｌ／ｈ以上;发酵液经非有机溶剂提取制得ＰＨＢ产品,纯度９５％,提取收率８０％以上。     

真养产碱菌利用甜菜糖蜜发酵产聚β－羟基丁酸的研究

探讨了以廉价原料甜菜糖蜜培养真养产碱菌（Ａｌｃａｌｉｇｅｎｅｓｅｕｔｒｏｐｈｕｓ）Ｈ１６生产聚β－羟基丁酸（ＰＨＢ）的可行性。对培养基优化试验表明,菌体产量可达２０ｇ／Ｌ,ＰＨＢ产量达９．８ｇ／Ｌ,糖转化率为２７．５％。用２升自控发酵罐进行验证,在良好的供氧条件和特定的ｐＨ值自控条件下发酵周期从４８小时缩短到４０－４２小时,菌体和ＰＨＢ量都有提高。菌体最高产量２６ｇ／Ｌ,ＰＨＢ最高产量１３ｇ／Ｌ,糖转化率为２０．４％。ＰＨＢ占细胞的含量,摇瓶和罐上结果都在５０％左右。     

雨生红球藻混合营养与异养培养研究*

研究雨生红球藻混合营养生长与异养生长对碳源及碳源浓度的需求,并对两种生长型进行比较。结果表明,乙酸钠较葡萄糖等其他碳源更能维持红球藻进行混合营养生长与异养生长。红球藻混合营养型生长与异养型生长的适宜乙酸钠浓度范围分别是０．５～１．０ｇ／Ｌ和１～１．５ｇ／Ｌ。混合营养型及异养型的平均生长速率分别是０．７２ｄ^－１和０．５３ｄ^－１,培养８ｄ的细胞干重分别是０．６５ｇ／Ｌ和０．３２ｇ／Ｌ。与光养型（对照）相比,混养型的各种生长指标均明显提高,异养型则下降。     

葡萄酒苹果酸-乳酸发酵接种时间选择的研究*

分别在佳利酿葡萄汁酒精发酵前期（第Ⅰ阶段）、中后期（第Ⅲ阶段）和结束时（第Ⅲ阶段）接种酒明串珠菌（Ｌｅｕｃｏｎｏｓｔｏｃ ｏｅｎｏｓ）３１ＤＨ,进行苹果酸－乳酸发酵（ＭＬＦ）接种时间选择的研究,结果表明;不同阶段接种经ＭＬＦ后总酸降幅均为２．６ｇ／Ｌ;挥发酸含量上升且第Ⅰ阶段＞第Ⅱ阶段＞第Ⅲ阶段;挥发酯以第Ⅱ阶段含量最高,为０.３７ｇ／Ｌ,同其他两阶段含量相比较,差异显著（ａ＝０．０５）;接种时间影响着接种后菌群成活率和迟滞期的长短;接种酒明串珠菌３１ＤＨ进行 ＭＬＦ应以第ⅢＳ阶段为宜。根据     

酵母菌HL的批次发酵及发酵动力学初探

在摇瓶培养的基础上,对酵母菌Ｌｉｐｏｍｙｃｅｓ ｓｔａｒｋｅｙｉ ＨＬ进行了小型发酵罐的分批和分批补料发酵及其发酵动力学的初步研究。结果表明,通过后期补料既可明显地延长菌体脂类合成期,减缓油脂比合成速率的降低,又可增加菌液的细胞密度,最终提高了整个发酵罐的油脂产量和平均容量产率。发酵结果如下：发酵时间１２０ｈ;油脂产量１１.０ｇ／Ｌ;菌体生物量１９．４ｇ／Ｌ。油脂百分含量 ５６．５％,显然比分批培养８４ｈ所得的１１．２ｇ／Ｌ细胞生物量和 ６.１ｇ／Ｌ油脂产量分别增长了７３％和８０％。此外,通     

不同种子预处理方法对提高三树种幼苗耐盐性的效应

刺槐（ＲｏｂｉｎｉａｐｓｅｕｄｏａｃａｃｉａＬｉｎｎ．）、湿地松（ＰｉｎｕｓｅｌｉｏｔｉＥｎｇｅｌｍ．）和侧柏〔Ｐｌａｔｙｃｌａｄｕｓｏｒｉｅｎｔａｌｉｓ（Ｌ．）Ｆｒａｎｃｏ〕种子经０３％ＣａＣｌ２,２５０μｇ／ｇＨ３ＢＯ３和２５０μｇ／ｇ多效唑（ＭＥＴ）浸种２４ｈ,然后测定幼苗的耐盐性。结果表明,在０．３％ＮａＣｌ胁迫条件下,不同种子预处理方法对种子发芽率、平均苗高、根茎比、简易活力指数（ＳＶＩＳ）以及幼苗中Ｎａ＋与Ｋ＋的累积量、Ｎａ＋／Ｋ＋比及游离脯氨酸含量有较大影响。树种不同,处理效果也存在明显差异。湿地松以０．３％ＣａＣｌ２,侧柏以２５０μｇ／ｇＨ３ＢＯ３浸种处理效果最好,显著提高种子发芽率、平均苗高、根茎比和ＳＶＩＳ,降低幼苗Ｎａ＋吸收量和Ｎａ＋／Ｋ＋比,缓解盐胁迫逆境。３种种子预处理方法均降低刺槐种子发芽率、平均苗长和ＳＶＩＳ,但提高刺槐幼苗游离脯氨酸含量和幼苗根茎比,减少幼苗对Ｎａ＋的吸收,降低Ｎａ＋／Ｋ＋比     

高产油脂酵母菌选育及摇瓶发酵条件的研究

经紫外线和ＥＭＳ复合诱变选育出一株高产油脂的优良酵母菌株,命名为Ｌｉｐｏｍｙｃｅｓ．Ｓｔａｒｋｅｙｉ　ＨＬ。通过摇瓶培养,对各项与菌体产油脂相关的因素作了单因子实验,确定了摇瓶发酵培养的最佳产油脂条件：碳源,废糖液１６５．７ｍｌ／Ｌ;氮源,硫酸铵１．０８ｇ／Ｌ;Ｃ／Ｎ：６１：１;培养温度为２８℃;接种量１０％;发酵时间９６ｈ; ｐＨ５．０。最后可得油脂产量 ５．９ｇ／Ｌ;菌体生物量 １１．０ｇ／Ｌ;油脂含量 ５３．６％。对菌体内油脂组成进行了气相色谱与质谱分析,结果如下：软脂酸３３．２％,棕     

菜心下胚轴原生质体培养和植株再生

以萌发３—４ 天（长约４ ｃｍ ）的菜心（Ｂｒａｓｓｉｃａ ｃａｍｐｅｓｔｒｉｓ ｖａｒ．ｐａｒａｃｈｉｎｅｓｉｓ）无菌苗苍白下胚轴为材料,酶解分离原生质体。经纯化的原生质体,在含０．５ ｍ ｇ／ＬＺＴ、０．５ ｍ ｇ／Ｌ２,４－Ｄ、１．０ ｍ ｇ／ＬＮＡＡ 和０．４ ｍ ｏｌ／Ｌ葡萄糖的Ｋ８ｐ 培养基中,进行微滴培养。在起始培养１４—１８小时,原生质体再生新的细胞壁。３６ 小时再生细胞开始第一次分裂。第三天分裂细胞频率可达３５％ 。培养第８—９ 天,可见含８—１６个细胞的小细胞团,植板率为１５％ —１８％ 。３ 周后将发育成直径为２ ｍ ｍ 的白色小愈伤组织,转到含０．３ ｍ ｇ／Ｌ ２,４－Ｄ并用ｇｅｌｒｉｔｅ半固化的培养基上,增殖成４—５ ｍ ｍ 直径的愈伤组织。在ＭＳ＋ ３．２（或１．６） ｍ ｇ／Ｌ ＢＡ＋ １．６（或０．８） ｍ ｇ／ＬＺＴ＋ ０．０１ ｍ ｇ／Ｌ ＮＡＡ＋ ０．１ ｍ ｇ／ＬＧＡ３ 和０．２％ 蔗糖的分化培养基上,获得芽的分化。切下约２ ｃｍ 长的芽苗,转移到含０．２ ｍ ｇ／ＬＩＡＡ 和２％ 蔗糖的培养基上,生根形成完整植株     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.