红曲霉AS 3.3491葡萄糖淀粉酶形成的研究

对红曲霉AS3．3491供给易利用碳源,葡萄糖淀粉酶的形成受咀遏,cAMP可使之解阻遏。易利用碳源的迅速利用使培养液pH显著下降,实验发现各种提高培养液pH值的方法都能促进葡萄糖淀粉酶的形成。同时发现该菌株的五种类型的葡萄糖淀粉酶是随培养液pH的逐渐回升陆续形成的,且各型酶的出现都与培养液的一定pH值相关联。文中讨论了该菌株中葡萄糖淀粉酶形成的调控机制。     

葡萄糖淀粉酶研究进展

葡萄糖淀粉酶研究进展杨依军,李多川,沈崇尧（北京农业大学植物科技学院．北京１０００９４）葡萄糖淀粉酶（ＧｌｕｃｏａｍｖｌａｓｅＥ·Ｃ３．２．１．３）,又称淀粉葡萄糖苷酶（Ａｍｙｌｏｇｌｕｃｏｓｉｄａｓｅ）或γ－淀粉酶（γ－ａｍｙｌａｓｅ）,简称糖化酶...     

提高黑曲霉产葡萄糖淀粉酶活力的研究

本研究所设计新型结构的20M~3发酵罐,其搅拌电动机的功率较低,为22千瓦。发酵液的投料浓度略增高,为原发酵液增加含糖量<2％。在这种发酵条件下,以黑曲霉UV11 AN5—1变异菌株产葡萄糖淀粉酶的活力,平均达14601单位/毫升,最高达15115单位/毫升,提高产率41.2％。发酵周期平均为107.2小时,每小时产酶活力为136.2单位/毫升。生产1罐葡萄糖淀粉酶,可降低耗电量679.2千瓦,年产300罐,可降低耗电量20.38×10~4千瓦。     

植物类异戊二烯生物合成途径的调节

主要介绍植物中通过甲羟戊酸形成类异成二烯的生物合成途径,参与酶和基因调节的研究进展,并指出通过基因工程技术生产这些重要化合物的前景。     

用葡萄糖酶电极法测定葡萄糖淀粉酶活性的研究

利用固定化葡萄糖氧化酶酶膜和过氧化氢电极组成酶电极测定葡萄糖淀粉酶的活性单位。用已知单位的葡萄淀粉酶作为测定标准定标后,在仪器上直接测出被测样品的葡萄糖淀粉酶活性单位,测定时间１４０ｓ,操作周期３ｍｉｎ,连续１０次测定ＣＶ值为０.６７％,５０～５００ｕ／ｍｌ的范围内线性良好,ｒ＝０.９９９９。     

红曲色素的两种新结构

从中国科学院微生物研究所保藏红曲菌中,筛选得到一株高产红色素的红曲菌菌株(AS.3.4617)。经鉴定属于红色红曲菌(Monascus anka Sato).通过有机溶剂的萃取和两次硅胶柱层析,从该菌株中分离得到两种色素样品,高压液相色谱测定为纯色素样品。通过元素组成分析,核磁共振谱,快离子轰击,质谱和高分辨质谱分析确定,这两种色素与已知的六种红曲菌色素不同,为新发现的红曲菌色素,它们可能的分子式为:C_(25)H_(31)O_5N和C_(23)H_(27)O_5N。     

紫红曲有性阶段的研讨

紫红曲因在其菌丝体及孢子生长过程中,具有合成某些药用及色素物质功能而被重视。这些物质在东方国家中早被用于医疗及食物染色方面。本文在阐明该菌闭襄壳内数目众多的子囊孢子系来自多数子囊,其子囊壁在发育早期即已消失。具8个子囊孢子的单一子囊的确时有发生,所以红曲属名拉丁文原意“单一子囊”,虽然有时极易被置凝,但基本是正确的。此菌之另一显著特性为一次性结合可产生多数产囊丝钩及发育后的闭囊壳。此现象导致孢子形成以子囊孢子数目远超过分生孢子。     

固定化红曲生物反应器发酵红曲色素的研究

对采用气升式生物反应器,以海藻酸钠为载体包理固定红曲（MonascusPurpureus）发酵生产红曲色素进行了研究。结果表明,最佳发酵条件为：发酵培养基pH值5～6;发酵温度30℃;通气量0．35vvm;固定化细胞粒子接入量20％;发酵周期为50h左右。     

有机溶剂微扰葡萄糖淀粉酶时的紫外、荧光和红外光谱

本文结果表明:(1)酶体系中随有机溶剂含量增加,紫外吸收亦随之增加,表明芳香氨基酸更充分地暴露,分子更趋于伸展;(2)酶的荧光发射随有机溶剂量增加而稍有变化,但当溶剂量达到一定值时[对乙二醇为35％(V/V)],荧光发射强度显著增加,表明酶分子构象受溶剂影响有一个极限值;(3)酶的傅立叶红外光谱表明,有机溶剂侧链的疏水性愈强,微扰后C=O,C—N,O—H等共价键的吸收峰变得愈宽,愈强,肽链愈伸展。     

红曲色素提取条件及结构表证

以乙醇为溶剂,从红曲中提取红曲色素。探讨了提取条件对提取率的影响,并用FTIR和UV对色素结构进行了表征。结果表明,最佳乙醇浓度为70％～80％,在此条件下提取5次,提取率可达到90％。在提取的头一小时内,浸出速率较高,提高温度有利于提高提取液浓度和降低乙醇用量。增大乙醇对红曲的用量比例,虽然有利于提高浸出率,但是会明显增加乙醇耗量。     

THE REGULATION OF RNA SYNTHESIS AND PROCESSING IN THE NUCLEOLUS DURING INHIBITION OF PROTEIN SYNTHESIS

The effect of protein synthesis inhibition by cycloheximide on nucleolar RNA synthesis and processing has been studied in HeLa cells. Synthesis of 45S RNA precursor falls rapidly after administration of the drug. However, the nucleolar content of 45S RNA remains relatively constant for at least 1 hr because the time required for cleavage of the precursor molecule into its products is lengthened after treatment with cycloheximide. The efficiency of transformation of 45S RNA to 32S RNA remains constant with approximately one molecule of the 32S RNA produced for each cleavage of a molecule of 45S RNA. However, shortly after the cessation of protein synthesis the formation of 18S RNA becomes abortive. The amount of 32S RNA present in the nucleolus remains relatively constant. After long periods of protein synthesis inhibition the 28S RNA continues to be synthesized and exported to the cytoplasm but at a greatly reduced rate. When the protein synthesis inhibitor is removed, a prompt, although partial, recovery in the synthesis rate of 45S RNA occurs. The various aspects of RNA synthesis regulation and processing are discussed.     

超声波对红曲菌的诱变筛选及发酵过程在线处理

以红曲菌为出发株 ,经超声波诱变 ,获得一株高产菌株 ,并对该菌株在液态深层发酵过程中 ,进行超声波在线处理 ,结果表明 :红曲色素和MonacolinK的产量都有明显提高 ,分别达 29.74%和 39.96%。     

REGULATION OF PROTEIN SYNTHESIS IN THE VENOM GLAND OF VIPERID SNAKES

Morphological changes in the venom gland of V. ammodytes were studied after the removal of the venom from the gland lumina (milking) It was found that the height of the secretory cells was changed during the secretory cycle. The patterns of the rough endoplasmic reticulum and of the Golgi complex were changed as well Milking induced an increased incorporation of [¹⁴C]amino acids into total and venom proteins In V ammodytes, during the first day after milking, 25% of the total counts in protein were precipitable by anti-venom serum, while at 8 days, 80% of the proteins synthesized were venom proteins At this stage, the incorporation was 10- and 20-fold that of unmilked glands for total and venom proteins, respectively. Venom was accumulated (secreted) in the gland lumina of V. ammodytes at a relatively high rate up to 2 wk after milking and leveled off afterwards. Intact glands and gland slices of V ammodytes and V palaestinae, taken from snakes a few days after milking, incorporated [¹⁴C]amino acids into proteins in vitro at a rate higher than that of unmilked glands. The activity of two exportable enzymes (phosphodiesterase and benzoyl arginyl ethyl esterase) was assayed in gland homogenates of V. ammodytes. It was found that 2–3 wk after milking, the intracellular level of these enzymes was up to 2-fold that of unmilked glands.     

利用粉丝废液固定化红曲发酵生产红曲色素的研究*

对以粉丝生产废液为主要培养基,以聚乙烯醇海藻酸钠双载体固定红曲Monascuspurpureus,采用气升式生物反应器重复发酵生产红曲色素进行了考察研究.试验结果表明:粉丝生产废液经适当补加营养盐可作为发酵生产红曲色素的良好培养基,其最佳发酵条件为:发酵培养基初始pH值为5~6;发酵温度为30℃;固定化细胞粒子接入量为20%,通气量为0.35vvm,发酵周期为50h左右。