优化黑曲霉菌丝球形成条件提高豆制品废水处理效率

豆制品废水的处理是豆制品厂的一个重要环节。利用黑曲霉在培养过程中形成的菌丝球处理豆制品废水具有安全性好、菌体回收简单、成本低等优点。本实验中以察氏培养基为基础研究了黑曲霉菌丝球的形成条件,并评价了对豆制品废水的处理效果。结果表明在黑曲霉孢子浓度为7.23×10~3/L~8.68×10~6/L、初始pH 3.5~pH 7.5、葡萄糖浓度为0 g/L~30 g/L的条件下都可以形成茵丝球。在豆制品废水中黑曲霉孢子浓度为1.45×10~4/L~7.23×10~5/L、pH 3.7~pH 6.6均可以形成茵丝球,而且在初始pH 5.6时经过72 h的培养豆制品废水变得澄清,COD下降了56.34%。本研究表明利用黑曲霉在豆制品废水中形成菌丝球的方式是一种有潜力的处理方式。     

黑曲霉RAF106菌丝球形成的影响因素及对结晶紫的吸附作用

【背景】黑曲霉（Aspergillus niger）作为一种代表性丝状真菌已被广泛用于酶制剂、有机酸、抗生素等高价值代谢产物的工业生产、食品发酵、环境治理等行业,其代谢能力、发酵性能等与菌体形态密切相关。然而,黑曲霉对染料、重金属等的吸附能力与菌体形态的关系鲜有报道。【目的】探究黑曲霉菌丝球形成的影响因素及其对结晶紫的吸附作用。【方法】以从普洱茶分离的黑曲霉RAF106为研究对象,实时监测马铃薯葡萄糖培养液中黑曲霉菌丝球的形成过程;探究培养液的初始pH （4.0-10.0）、培养温度（25-45°C）、孢子接种量（5×10⁴-5×10⁶个/m L）、摇床转速（140-220 r/min）、碳源（葡萄糖、蔗糖、果糖、乳糖、醋酸钠）和氮源（硝酸钠、胰蛋白胨、酵母提取粉、氯化铵）对菌丝球形成的影响;以结晶紫为对象,研究不同菌体形态及菌丝球大小对黑曲霉吸附废水染料能力的影响。【结果】在黑曲霉RAF106中,孢子聚集、菌丝聚集均可形成菌丝球;菌丝球的大小与培养液初始p H、孢子接种量成反比,与摇床转速无关;当温度低于35°C时,菌丝球大小与温度成正比,...     

同步糖化发酵菊芋生产酒精

以黑曲霉A-15形成的菌丝球作为载体对酿酒酵母C-15进行固定化,研究各种因素对黑曲霉A-15菌丝球吸附率的影响。结果表明:在40℃、80 r/min、菌种个数混合比例为1∶10时,菌丝球对酵母的吸附可达到66.9%;以菊粉为底物,利用混合菌丝球进行同步糖化与发酵,30℃发酵48 h,发酵醪酒精体积分数达到12.8%,并且混合菌丝球可以耐受19%的酒精。     

酶水解菊芋糖浆发酵生产琥珀酸的初步研究

用产菊粉酶的一株黑曲霉菌株进行产酶发酵条件和水解条件研究,在30℃,pH 6.0,摇床转速200 r/min,发酵时间为3 d的最适产酶条件下,酶活可以达到45.9 U/mL.以总糖含量为85.2 g/L的菊芋粉为初始底物,最适酶水解条件为温度50℃,加黑曲霉培养液的量为10%(v/v),水解12 h后,水解率达到99.6%.用此酶解液在5 L搅拌发酵罐中进行琥珀酸发酵,初始还原糖浓度53.5 g/L,36 h发酵产琥珀酸43.8 g/L,琥珀酸产率0.83 g/g,糖利用率99.0%,琥珀酸生产强度1.22 g/(L·h).     

金针菇菌丝体深层培养工艺研究

在1．8L气升式发酵反应器中,研究了金针菇菌丝体深层培养工艺条件及其特性。结果表明：金针菇菌丝体深层培养可采用玉米、黄豆和糖蜜等廉价原料作主要碳氮源;最适需氧量为1．0—2．0×10^-7mol O₂／ml·min·atm,培养24—72h内,菌丝球生长遵循立方根规律·即x^1/3,=0．786+0．027t。在最佳发酵条件下,摇瓶培养4天,茵丝干重达24．4mg／ml在反应器培养4天,菌丝干重为25．7mg／ml。     

黑曲霉菌丝球吸附毕赤酵母的条件优化

丝状真菌菌丝球吸附单细胞微生物是菌丝球应用的一个重要方面。本文以黑曲霉和毕赤酵母为目标菌株探讨了影响吸附的主要因素。结果表明p H 4.0、10 mmol/L磷酸缓冲液、6.48×1010/L毕赤酵母为较优的吸附条件,吸附率达91.41%。分别添加钠、钙、镁、铝四种金属离子均会降低菌丝球吸附毕赤酵母的吸附率。本研究结果为丝状真菌菌丝球吸附单细胞微生物的应用研究提供基础。     

海藻酸钙固定赤霉菌菌丝产素的研究

将赤霉菌丝固定在海藻酸钙微球中进行连续发酵,考察产赤霉素情况。对海藻酸钠和钙盐浓度固定赤霉菌菌丝的微球稳定性进行初步研究,讨论了固定不同菌龄的赤霉菌微球在不同葡萄糖浓度下的产素能力及菌丝生长能力。实验表明:菌丝微球较稳定的固定条件是菌丝8 g/L、海藻酸钠浓度3 g/L和钙离子浓度3 mol/L;摇瓶发酵72 h,90 h的菌丝微球中菌丝营养生长基本停止,当培养液葡萄糖浓度为2 g/L时,赤霉素终浓度为1 145.5 μg/ml,比生产速率为4.61×10^-3/h;在该条件下固定菌丝球的床层式连续发酵,赤霉素比生产速率为4.82×10^-3/h,是相应分批发酵过程中最大赤霉素生产速率的1.87倍。     

溶氧对Blakeslea trispora分批发酵生产β-胡萝卜素的影响

在摇瓶和5 L发酵罐中研究了溶氧 (DO) 对Blakeslea trispora分批发酵生产β-胡萝卜素的影响,总结了5 L发酵罐中β-胡萝卜素发酵过程中溶氧的变化规律.结果表明,当500 mL摇瓶装液量为50 mL,转速为240 r/min条件下发酵生产β-胡萝卜素产量最大,达到3.416 g/L; 5 L发酵罐中,在搅拌转速为1 000 r/min,通气量为1.5 vvm的条件下,β-胡萝卜素的产量可达到3.712 g/L,略高于摇瓶,这可能是由于5 L发酵罐中的气液传递和混合状况好于摇瓶,促进了产物的合成.     

S-腺苷甲硫氨酸和谷胱甘肽联产发酵的环境条件

在5 L发酵罐中,研究pH、搅拌转速和温度等环境条件对产朊假丝酵母CCTCC M209298联产发酵合成S-腺苷甲硫氨酸(SAM)和谷胱甘肽(GSH)的影响,发现酵母细胞生长、SAM和GSH合成各自需要最适的pH、搅拌转速和培养温度。以SAM和GSH联产量最大化为目标,获得了较为合适的联产发酵条件:pH 5.0,搅拌转速350 r/min,温度30℃。在此环境条件下,结合不低于35%的溶氧体积分数,分批培养产朊假丝酵母24 h,最终SAM和GSH联产产量可达到579.6 mg/L。     

新月弯孢霉菌丝球对染料脱色作用的研究

研究了新月弯孢霉Curvularia lunata JQH-100液体培养时产生的菌丝球对多种染料的脱色能力。结果表明,多种染料在24h内的脱色率均达到80%以上,且菌丝球稳定性良好,可重复使用6次;以菌丝球对孔雀绿脱色效果为优化指标,正交实验优化获得制备菌丝球的最佳条件为:葡萄糖20g/L、硫酸铵5g/L、马铃薯200g/L、KH2PO43g/L、MgSO45mg/L、CuSO40.5mg/L、VB15mg/L及pH5、摇床转速120r/min。在上述优化后的基础培养基(不含MgSO4、CuSO4)中分别添加微量元素Cu2+、Mn2+、Mg2+或Ca2+制备的菌丝球,对孔雀绿脱色能力增强;添加Fe2+制备的菌丝球,对孔雀绿脱色能力下降;分别添加Zn2+、Al3+或Na+制备的菌丝球对孔雀绿脱色能力与对照相近。应用优化后培养条件制备的菌丝球处理含多种染料的混合废水,也获得了较好的脱色效果。     

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.