酒精废水发酵生产白地霉（续上期）

2　结果和讨论2 1　糖蜜酒精废水稀释倍数对摇瓶发酵产率的影响 :糖蜜酒精废水虽然含有丰富有机质 ,但是也含有大量酵母的代谢废物和一些未知的毒素杂质 ,对白地霉的生长有一定影响 ,为此进行了废水的稀释倍数试验 (表 1 )。表 1　废水稀释倍数对白地霉生长的影响稀释倍数 (倍 ) 稀释后还原糖浓度 (% ) 菌丝体干重(ｇ/2 0 0ｍｌ) 菌丝体干重得率 (% )0 (对照 ) 1 60 0 760 3 80 2 1 3 3 1 12 0 5 60 3 1 2 3 1 0 2 0 5 10 41 14 0 90 0 450 5 1 0 60 82 0 411 0 0 80 0 780 3 9　　从表 1可以看出稀释 0 2倍的白地霉产量最…     

浓缩糖蜜酒精废水发酵生产白地霉

探讨了利用糖厂的浓缩酒精废水,进行白地霉摇瓶培养的一些试验条件,即浓缩废水先稀释10倍,添加0.15%麸皮发酵进行到5h时补充0.1%硫酸铵,0.05%磷酸,初始pH值调整为4.5-5.0,接种量为10%,温度28-30℃,得到了0.4-0.45%干物质发酵产率。     

降解三硝基甲苯的酵母和类酵母菌的研究

从受三硝基甲苯（TNT）严重污染的土壤和废水中分离筛选到17株可降解TNT的酵母菌和白地霉。其中6株为克鲁斯假丝酵母（Candidakrusei）,4株为橡树假丝酵母（C.quercitrusa）,一株为无名假丝酵母（C.famata）,一株为伯杰汉逊酵母（Hansenulabeijerinckii）,一株为亚膜汉逊酵母（H.subpelliculosa）,4株为白地霉（Geotrichumcandidum）。对其中6株菌进行了降解TNT的条件实验,发现降解TNT的适宜pH为7,温度为37～40℃。在含75～80mg／LTNT的培养基中,40h内能降解TNT56～74mg／L,去除率达71％～93％。在培养基中加入0．01％～0．05％的葡萄糖作碳源,或加入0.01％～0．1％的酵母膏对6株菌降解TNT的能力略有促进作用。加入铵盐作为氮源则明显抑制这些菌对TNT的降解。     

一株白地霉在低碳氮比废水中降氨氮新功能的研究

该文从垃圾渗滤液中筛选出一株低C/N营养条件下氨氮去除效果显著的菌株。ITS序列测序鉴定表明，该菌株为白地霉（Galactomyces candidum）。经不同pH、温度、C/N的培养条件下培养24 h，测定其生长密度及氨氮去除情况，结果发现，白地霉培养基最佳降氨氮条件为：pH 8.0,C/N 1.5，温度30℃，其最佳氨氮去除率可达93.1%。该文发现了白地霉在污水处理，尤其是低C/N污水处理中具有氨氮去除的新功能，为其在低C/N污水生化处理工业化应用提供了新的菌株资源和技术途径。     

白地霉ch-3脂肪酶Ⅰ基因在大肠杆菌中的表达

构建了白地霉脂肪酶Ⅰ的基因工程菌,为进一步进行蛋白质工程改造和脂肪酶应用奠定了基础。从新疆昌吉市油脂化工厂含油冻土中分离得到1株低温脂肪酶产生菌-白地霉ch-3。该菌发酵上清液中的脂肪酶最适作用温度为35℃,在0℃仍可保持66%的相对酶活力。应用PCR技术从白地霉ch-3基因组DNA中克隆得到脂肪酶Ⅰ基因lip1,将该基因与原核表达质粒载体pET-22b（＋）连接,构建重组质粒pETl-ip1,转化E.coliBL21（DE3）,酶切鉴定,筛选得到重组菌。十二烷基磺酸钠-聚丙希酰胺（SDS-PAGE）显示重组脂肪酶Ⅰ的相对分子质量约为5.8×10^4,酶活为2.73 U/mL,表明lip1基因的表达产物具有正常的生物学活性。白地霉ch-3脂肪酶Ⅰ基因lip1能够在大肠杆菌中有效地表达。     

纤维素酶水解稻草生产单细胞蛋白（SCP）：Ⅱ.稻草酶解液生产SCP的研究

从18株酵母和2株白地霉中选得两株酵母它们能较好地利用稻草酶解液生产单细胞蛋白,其菌名和编号为皮状丝孢酵母(Trichosporon cutaneum)AS 1.374,假丝酵母(Candida sp.)Y002对这两株菌的生长条件进行了研究,在pH5.0、30—32℃、糖浓度1.5—2.0％、培养36h的条件下,SCP对糖的产率可达66.6％。     

微生物絮凝剂的菌种培养及絮凝活性研究

从活性污泥中分离出具有絮凝活性的菌种作为微生物絮凝剂,通过将其对高岭土悬浊液进行絮凝活性测定,得出了适于该菌产絮凝剂的最佳培养基为：以浓度为1．5％的葡萄糖作为碳源,以NH4Q0．06％ 酵母膏0．04％相组合为氮源,以浓度0．3％的KH2PO4作为无机营养物质,其它培养条件pH值为7～8,温度为30℃,摇床转速为180r／min。并将培养好的菌液用于多种废水净化,试验结果表明：其絮凝率与去除率均达90％以上,具有较好的净化效果。     

白地霉中甘露醇的鉴定及其形成机制的研究

(1)白地霉菌絲中含有大量的多元醇,經紙层析、紙电泳及提純結晶制备衍生物等方法鉴定为甘露醇。(2)白地霉无細胞提取液中有NADP-甘露醇脫氫酶存在,催化甘露醇被NADP氧化为果糖或相反地果糖被NADPH_2还原为甘露醇。(3)白地霉无細胞提取液中有磷酸酯酶,催化果糖磷酸酯水解为自由果糖及无机磷酸。(4)白地霉中測不出果糖-6-磷酸还原酶活力。(5)确定了甘露醇的形成途径为: D-果糖磷酸→Pi→D-果糖←NADPH_2 NADP→D-甘露醇(6)D-木糖培养的白地霉适应形成了NAD-艾杜糖醇脫氫酶,催化: 木糖醇←NAD NADH_2→D-木酮糖D-山梨醇←NAD NADH_2→D-果糖     

酵母菌产麦角固醇发酵条件的研究

为了提高酵母菌麦角固醇的产量,采用摇瓶培养法,对筛选出的一株酵母菌YN2产麦角固醇发酵条件进行了研究。结果表明,酵母菌YN2产麦角固醇适宜的培养基配方为：酵母粉1％,牛肉膏2．5％,葡萄糖8％,K2HPO4 0．3％,MgSO4 0．15％,该菌株产麦角固醇最适培养条件为：培养温度28℃,起始pH6．5,发酵时间72h。在优化的实验条件下,麦角固醇含量可达2．2％,100ml发酵液中麦角固醇产量达25．30mg。     

轮梗霉原生质体的制备

本文比较了酶浓度,菌龄,渗透压稳定剂以及酶解温度和时间等因素地轮梗霉原生质体得率的影响,结果基本获得了制备原生质体的适宜条件;用0．6mol/L甘露醇稳渗剂配制成的4％纤维素酶和0．5％蜗牛酶混合酶,35℃酶解培养了30h的菌丝1．0h,即可得到较高产量的原生质体,对该生质体进行了再生实验,其再生率约为23．8％。     

Investigation of the mechanism of temperature sensitivity of the electroreceptors of ampullae of lorenzini

In experiments on Black Sea skates (Raja clavata), the potential of the receptor epithelium of the ampullae of Lorenzini and spike activity of single nerve fibers connected to them were investigated during electrical and temperature stimulation. Usually the potential within the canal was between 0 and –2 mV, and the input resistance of the ampulla 250–400 k. Heating of the region of the receptor epithelium was accompanied by a negative wave of potential, an increase in input resistance, and inhibition of spike activity. With worsening of the animal's condition the transepithelial potential became positive (up to +10 mV) but the input resistance of the ampulla during stimulation with a positive current was nonlinear in some cases: a regenerative spike of positive polarity appeared in the channel. During heating, the spike response was sometimes reversed in sign. It is suggested that fluctuations of the transepithelial potential and spike responses to temperature stimulation reflect changes in the potential difference on the basal membrane of the receptor cells, which is described by a relationship of the Nernst's or Goldman's equation type.I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. I. M. Sechenov, Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of the USSR, Leningrad. Pacific Institute of Oceanology, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Neirofiziologiya, Vol. 12, No. 1, pp. 67–74, January–February, 1980.     

Principles of organization and evolution of systems of regulation of functions

Evolution of living organisms is closely connected with evolution of structure of the system of regulations and its mechanisms. The functional ground of regulations is chemical signalization. As early as in unicellular organisms there is a set of signal mechanisms providing their life activity and orientation in space and time. Subsequent evolution of ways of chemical signalization followed the way of development of delivery pathways of chemical signal and development of mechanisms of its regulation. The mechanism of chemical regulation of the signal interaction is discussed by the example of the specialized system of transduction of signal from neuron to neuron, of effect of hormone on the epithelial cell and modulation of this effect. These mechanisms are considered as the most important ways of the fine and precise adaptation of chemical signalization underlying functioning of physiological systems and organs of the living organism