嗜酸乳杆菌固态发酵的初步研究

研究了嗜酸乳杆菌在 4种不同固态基质 (豆渣、麦麸、芋艿渣、纤维素 )中的生长情况 ,结果显示 :1)豆渣作为基质时嗜酸乳杆菌生长最佳 ,最高活菌数可达 1.6 45× 10 9cfu/g ,麦麸次之 ,达 3.2× 10 8cfu/g ,纤维素最差 ,仅为 2 .1× 10 7cfu/g ,并且豆渣固态培养基优于对照的 3种液体培养基 ;2 )豆渣的含水量以 75 %左右为宜 ;3)通过加入可中和所产酸量的CaCO3 ,并用缓冲液代替水配制培养基 ,结果发现用pH 6 .0的缓冲液配制的培养基 ,培养后活菌量可达 2 .12 4× 10 9cfu/g ,,比对照用自来水提高了 4.2倍 .     

杂色云芝产漆酶的发酵条件研究*

本文对杂色云芝（Coriolus versicolor）产漆酶的发酵条件作了研究。结果表明摇瓶实验产漆酶（Laccase）的最佳培养基成分为：可溶性淀粉 2g/L, NH4Cl 24mmol/L, 微量元素混合液 7ml/L, pH3.0柠檬酸—Na2HPO4缓冲溶液 0.01mol/L, KH2PO4 1.4×10-2 mol/L, MgSO4·7H2O 2.03×10-3mol/L, CaCl2·2H2O 6.8×10-4 mol/L, VB1 2.97×10-6 mol/L, 吐温80 4.0g/L, 愈创木酚0.01mmol/L, CuSO4 ·5H2O 0.005mmol/L,最佳发酵条件为培养基初始pH3.0, 菌体生长6d,培养基装量为250ml三角瓶中25ml培养液,25℃条件下振荡培养(150r/min)9d。     

用微载体悬浮培养大量生产高活性鼠干扰素

用自制的MC-1型微载体进行悬浮培养,当其浓度为5mg/ml时,可较好地用以培养和增殖鼠L929细胞。当接种细胞量为30×10~4/ml左右时,一般在3天即可增殖至1×10~6细胞/ml。用25IU/ml鼠IFN起动12—24小时,用NDV作诱生剂,并采用环己亚胺(20μg/ml)和放线菌素D(2μg/ml)进行超诱导,IFN产量可高达1×10~6IU/ml左右,比活接近1.3×10~5IU/ml蛋白。尽量去除培养基,加胰酶—柠檬酸盐消化和高速搅拌,使细胞从载体上分离,再加新鲜培养基和微载体的方法进行扩大生产看来是可行的。这些实验表明采用微载体悬浮培养细胞的技术将更适于IFN的工业化生产。     

解脲脲原体生物学特性的研究

本文研究了4株解脲脲原体的生物学特性,发现解脲脲原体在不含血清的液体培养基中加有青霉素3.1×10³—1.2×10⁴u/ml即可生长2—4代;在半固体培养基培养时,除指示剂变色外无肉眼可见生长现象。解脲脲原体不同株对醋酸铊敏感性不一,当浓度<0.1mg/ml时,无抑制生长作用。     

金龟子绿僵菌原生质体形成和再生的研究

用0.5%纤维素酶和0.5%蜗牛酶的混合酶液,以0.6mol/L KCl为渗透压稳定剂,pH6.5时,30℃处理菌龄为24小时的金龟子绿僵菌3-4小时,可从1克湿菌丝获得5×10⁷个以上的原生质体。原生质体在祭氏培养基上再生率仅为0.1—1.2%。但原生质体先在液体中培养再转移到固体平皿上,再生率可提高到8%。实验还观察和确证了原生质体的形成及其再生。     

空肠、结肠弯曲菌产生的霍乱样毒素

<正>我们的实验室工作证实了Ruiz—palacios等的结论:空肠弯曲菌产生一种霍乱样毒素。 临床、食品和动物的空肠、结肠弯曲菌分离物可在酪蛋白氨基酸/酵母浸液肉汤,布鲁氏肉汤或含灵古霉素的布鲁氏肉汤中,于37℃的85％氮、10％Co_2和5％氧的静止气层下震荡培养生长过夜。培养基不加辅助营养成份或血清,其最终细菌浓度为5×10~8～5×10~9个/ml。     

Hg2+、Pd2+、Cd2+和Cu2+对沼泽红假单胞菌生长及净化氮、磷能力的影响

研究了在培养基中分别添加不同浓度的重金属离子Hg2+、Pd2+、Cd2+和Cu2+作为人工配制的污水对光合细菌沼泽红假单胞菌生长与净化PO4-P和NH4-N能力的影响.实验结果表明当培养基中Hg2+的浓度达到2×10-6mol@L-1,该菌生长趋势开始减慢;当增至4×10-6mol@L-1时,生长完全被抑制.Cu2+的浓度达到1×10-6mol@L-1,该菌生长趋势也开始减慢;当增至8×10-6mol@L-1时生长完全被抑制.Cd2+的浓度达4×10-5mol@L-1时,其延缓期大大延长;增至16×10-5mol@L-4时生长完全被抑制.培养基中Pd2+的浓度达到8×10-4mol@L-1时,对该菌生长并未产生影响.当培养基中重金属离子浓度未达到完全抑制其生长时,对其净化PO4-P和NH4-N能力的影响不显著.     

鳜鱼(Sinipera chuatsi)鱼苗肠道微生态调节的研究

对鳜鱼鱼苗肠道菌进行好氧菌和兼性厌氧菌的分析鉴定 ,发现鳜苗肠道中存在哈夫尼亚菌属和气单胞菌属 ,其中哈夫尼亚菌属量为 4 .8× 10 6cfu/ g ,气单胞菌属量为 2 .4 3× 10 5cfu/ g。哈夫尼亚菌属和气单胞菌属的拮抗实验表明哈夫尼亚菌对气单胞菌的生长有一定的抑制作用。分别用哈夫尼亚菌、气单胞菌作饵料添加剂 ,前者将鱼苗成活率由 18%提高至 33%～ 4 0 % ,后者将鱼苗成活率由 18%降至 2 %～ 4 %。     

马氏钳蝎毒对大鼠神经和骨胳肌的作用

本工作在大鼠膈神经膈肌标本上观察马氏钳蝎(Buthus marensi Karsch)毒对神经、肌肉和神经肌肉接头传递的作用,结果如下:1.在蝎毒(3×10~(-5)g/ml)作用下,由吸附电极引导的膈神经单相动作电位的下降相逐渐延长,形成平台,3小时后电位时程可达100ms 以上。2.蝎毒(5×10~(-7)—6×10~(-5)g/ml)显著改变肌纤维动作电位的波形,降低肌细胞的静息膜电位。如用6×10~(-5)g/ml 浓度蝎毒处理膈肌,半小时内即可使肌纤维动作电位下降相大大延长,形成平台。一小时后膜电位由对照的78±4mV 降低至59±13mV,2小时后至55±8mV(平均值±S.D.)。3.河豚毒(3μM)可使被蝎毒降低了的肌细胞膜电位迅速复原,但随着时间的延续还可以再出现缓慢的轻度下降。4.在河豚毒(3μM)使肌细胞动作电位消失后,向溶液中加入蝎毒,半小时后将二者一并洗去,重新出现的动作电位亦带有明显的平台。5.在接头传递已被高 Mg~(++)或筒箭毒碱阻遏的标本上加蝎毒后,单个间接刺激可诱发出一串终板电位,甚至引起肌肉收缩。6.蝎毒(1×10~(-5)g/ml)明显增加小终板电位的发放频率,作用1小时后其频率可高达每秒100次以上。7.肌肉对间接刺激的收缩反应在加入蝎毒后首先增大,然后逐渐下降,在1×10~(-5)g/ml 浓度蝎毒作用下1.5—2小时传递阻遏,此时肌肉对直接刺激     

DNA重组技术：Ⅲ.重组质粒在大肠杆菌中的转化

氯化钙法是用质粒DNA转化细菌细胞,尤其是大肠杆菌细胞最常使用的方法。实验操作如下: (1) 将受体菌接种在平板培养基上划线,37℃过夜,进行活化。 (2) 挑选单菌落,接于5ml LB培养液,37℃震荡过夜。 (3) 从上述培养液中取0.5ml,转入50mlLB培养液,37期震荡培养2～4小时,到细菌密度大约为5×10~7/ml,OD_(575)约为0.8。     

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