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1.
利用改进后的菌种分离方法．从印染厂废水中分离得到球衣细菌菌株．初步研究了该菌株的菌落及形态特征、生理生化特性、生长条件，生长曲线，以及菌种的保藏方法等． 相似文献
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董亚宁 《马钢职工大学学报》2013,(2):36-39,51
通过对合肥四方化肥厂曝气池和沉淀池中活性污泥的处理,进行菌种分离、筛选、鉴定,以及测定phen-10菌株的酚降解能力,旨在找到一些对酚处理效果好的优势菌株,并记录优势菌株的最佳生长条件,为今后的进一步研究提供依据。 相似文献
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从土壤中分离得到产壳聚糖酶细菌Yg,利用紫外线对Yg菌种诱变并改变菌种的生活环境,获得4株产壳聚糖酶能力不同的菌株。其中1,2,4号菌株的产酶活性较原菌种提高了近3倍。 相似文献
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从土壤中分离得到产壳聚糖酶细菌Yg,利用紫外线对Yg菌种诱变并改变菌种的生活环境,获得4株产壳聚糖酶能力不同的菌株。其中1,2,4号菌株的产酶活性较原菌种提高了近3倍。 相似文献
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目的：分离筛选出高效降解毒死蜱菌株,明确其生物学分类地位,并优化其降解条件.方法：采取平板划线和摇瓶复筛法从农药厂土壤样品中分离得到高效降解毒死蜱菌株,并通过16S rRNA序列测定和同源性分析对其进行鉴定;运用HPLC法检测降解菌株对毒死蜱的降解效果,研究其在不同培养基、接种量、温度及pH条件下的降解能力.结果：从农药厂土壤样品中筛选得到一株能够以毒死蜱为唯一碳源生长的高效降解菌株OP7,经16S rRNA基因序列聚类分析,将其初步鉴定为粪产碱杆菌(Alcaligenes faecalis).进一步的降解条件优化结果显示,菌株OP7降解毒死蜱的最佳培养基是10%LB、最适接种量为3%(v/v)、最适温度为35℃、最适初始pH为9.0.结论：本研究结果表明菌株OP7有望成为新的菌种资源并应用于环境中毒死蜱污染物的生物修复. 相似文献
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采集9份绵阳及周边地区环境中的土壤样品,共分离出64株霉菌菌株,对其是否抑制金黄色葡萄球菌、铜绿假单胞菌、大肠杆菌的生长进行了研究。其中有14株霉菌对受试菌种有抑制作用。这为进一步的研究提供了有价值的资料。 相似文献
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我们用自己设计、筛选的培养基和菌种分离培养方法从南京、淮南、合肥和蚌埠等地生产的酸乳中筛选出优良酸乳生产菌株 ,并按伯杰氏细菌学鉴定手册和乳酸菌特有生理生化指标对其进行鉴定。在确认菌株菌名为嗜热链球菌和保加利亚杆菌情况下 ,按照生产南瓜酸乳需要 ,对菌种分别进行驯化。 相似文献
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[目的]建立一种简便有效的保存菌种的方法。[方法]用脱纤维绵羊全血保存甲型链球菌等10种菌株,两年内多次复苏检查。[结果]各冻存菌株均可正常生长。[结论]用脱纤维绵羊全血保存菌种是一种简便易行又有效的保种方法,适合各基层教学或科研单位采用。 相似文献
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1前言穿刺培养是微生物教学中重要实验内容,也是常规菌种鉴定中重要手段。通过穿刺培养,不仅可以判断菌株的好氧性与厌氧性,运动情况以及菌株是否发酵产酸等。还可以从运动情况推测菌株是否长有鞭毛。但仅参考书上已有实验操作内容,实验很难成功。关键在于能否掌握其核心技术。笔者在进行一组混合菌种分离、鉴定时,发现营养培养基的选择和加入琼脂量的多少是影响穿刺培养实验成功与否的两个关键因素。2两个关键因素2.1关键因素一———营养培养基的选择培养基选择不当即使菌株长有鞭毛也看不到根须状扩散生长。笔者先后采用三种培养基做穿刺… 相似文献
10.
武模戈 《濮阳职业技术学院学报》2015,(3):158-160
供试的6种香菇菌株拮抗实验结果表明,Le1和Le3为同一品种;Le2、Le5和Le6为同一品种;Le4为一个品种。采用平板培养法测定所供菌株的生长速度和生长势,Le3菌丝生长速度最快,用菌种瓶栽培实验结果与平板培养法结果一致。综合各个方面因素,Le3适宜作为推广菌种。 相似文献
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在实验室水培条件下,研究了槐叶萍、满江红、浮萍等水生植物对Cd^2＋的累积吸收能力。用原子吸收分光光度法对三种植物的水培液中Cd^2＋的浓度进行了测定。结果表明Cd^2＋在2～20mg·L^-1的浓度范围内,三种植物对Cd^2＋的累积吸收量随着浓度的增加而增加,槐叶萍累积吸收能力大于满江红,满江红优于浮萍;在40～100mg·L^-1的浓度范围内,三种植物对Cd^2＋的累积吸收量则随着浓度的递增而大幅降低,槐叶萍对Cd^2＋的去除效果较其它两种植物为佳。因此,在治理轻度镉污染水体时,三种植物均是较好的备选植物,而在治理重度镉污染水体时。应首选满江红。 相似文献
13.
The Egger-Miller information hypothesis was tested in a nonoverlapping compound stimulus CER situation. During CER training, S2, the so-called redundant stimulus, acquired greater suppression qualities than S1. However, following CER training, subjects were exposed to test situations in which the independent suppression qualities of S1 and S2 were assessed. S1 was followed by a trace interval, S2 was presented alone, or the S1–S2 sequence was reversed. Results of all test conditions showed minimal suppression to S2, while suppression to S1 was maintained or facilitated. It was suggested that S2, although a redundant predictor of shock occurrence, provides information as to “when” shock is due. 相似文献
14.
Pigeons learned to peck a keylight (S2) when it was paired with a stimulus (S1) that already evoked keypecking. Control procedures showed that S2 acquired control over responding because it was paired with S1 and because S1 had a conditioning history, thereby supporting the claim that S2 was a second-order conditioned stimulus. Second-order conditioning occurred as rapidly when S1 was a keylight as when it was a tone. Test procedures showed that after second-order conditioning, responding to S2 was markedly debilitated by the extinction of responding to S1, indicating that the ability of S2 to evoke a response importantly depends upon the continued ability of S1 to do so. Our demonstration that directed motor action in the pigeon is susceptible to second-order conditioning suggests a new interpretation of conditioned reinforcement in instrumental learning. Our demonstration that the effectiveness of S2 depends upon the continued effectiveness of S1 indicates that S-S associations are formed in this version of the second-order conditioning experiment. 相似文献
15.
A second-order autoshaping procedure was used to examine the effects of three variables on the amount of information that could be learned about the stimulus properties of a reinforcer. All three experiments paired several keylight S2s with different keylight S1s and then carried out discriminative autoshaping with those S1s. Learning about the stimulus properties of S1 was inferred from changes in the response to its paired S2 when that S1 was changed in value. The sensitivity of S2 to changes in S1 was investigated as a function of number of S2-S1 pairings (Experiment 1), partial reinforcement (Experiment 2), and temporal distance between S2 and S1 (Experiment 3). Each experiment found evidence of a selective change in responding to an S2 as a function of the treatment of its S1. However, the amount of that change was not affected by any of the three variables studied. Those results imply that, within the ranges used here, none of these variables changes the degree of learning about the stimulus properties of a reinforcer. 相似文献
16.
Goldfish trained to discriminate between signals paired with shock (S?) and signals paired with shock omission (S+) with a linear presentation procedure, originally learned (OL) to control the signal state of a shuttle box and showed a decided preference for the S+ signal. In Experiment 1, following OL, groups had one OL signal replaced (S+ or S?), both signals replaced (S+ and S?), or the OL signals reversed (S+ and S? reversed) and were then tested in a transfer training procedure. In transfer, groups with one signal replaced maintained discriminated performance at OL levels; the S+ replaced group was slightly superior to the S? replaced group on the first day of transfer. With both OL signals replaced, discrimination dropped to chance performance levels, whereas, with OL signal shock pairing reversed, discrimination performance dropped below chance levels. In Experiment 2, following OL, extinction procedures consisted of turning off the shocker (0% shock) or of shocking 100% or a random 25% of the trials. A fourth extinction procedure (R,) retained the trial start response-dependent shock-omission contingency, but shock differentiating the S+ and S? signals was eliminated entirely. Extinction of the S+/S? discrimination was measured both during extinction training per se and with reversal retraining of the S+/S? discrimination later. Groups for which the OL S+ was paired with shock during extinction extinguished on both measures, but groups for which the OL S? was paired with shock omission did not extinguish, especially as shown by the reversal test procedure. Theoretical implications and the implications for several conditioning procedures are discussed. 相似文献
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Paul Craddock Jessica S. Wasserman Cody W. Polack Thierry Kosinski Charlotte Renaux Ralph R. Miller 《Learning & behavior》2018,46(2):171-181
Second-order conditioning (SOC; i.e., conditioned responding to S2 as a result of S1–US pairings followed by S2–S1 pairings) is generally explained by either a direct S2→US association or by an associative chain (i.e., S2→S1→US). Previous research found that differences in responses to S2 after S1 was extinguished often depended on the nature of the S2–S1 pairings (i.e., sequential or simultaneous). In two experiments with human participants, we examined the possibility that such differences result from S1 evoking S2 during extinction of S1 following simultaneous but not sequential S2–S1 pairings. This evocation of S2 by S1 following simultaneous pairings may have paired the evoked representation of S2 with absence of the outcome, thereby facilitating mediated extinction of S2. Using sequential S2-S1 pairings, both Experiments 1 and 2 failed to support this account of how extinction of S1 reduced responding to S2. Experiment 1 found that extinguishing S1 reduced responding to S2, while extinguishing S2 had little effect on responses to S1, although forward evocation of S1 during extinction of S2 paired the evoked representation of S1 with absence of the outcome. In Experiment 2, evocation of S2 during S1 nonreinforced trials was prevented because S2–S1 pairings followed (rather than proceeded) S1-alone exposures. Nevertheless, responding to S2 at test mimicked S1 responding. Responding to S2 was high in the context in which S1 had been reinforced and low in the context in which S1 had been nonreinforced. Collectively, these experiments provide additional support for the associative-chain account of SOC. 相似文献
18.
美苏《雅尔塔秘密协定》满足了苏联在远东的利益要求，换得苏联出兵东北，消灭了日本关东军。可以说，苏军进入东北与美苏黑幕交易有直接关系。战后，因美国插手中国事务，美苏冷战已露端倪，苏联从东北撤军问题一波三折，这也与美国的态度和做法有关。美国的压力又是苏联最终实现撤军的重要原因之一。 相似文献
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The signaling function of the second-order CS (S2) was manipulated in second-order autoshaping by arranging a partial reinforcement schedule. S2 was paired with a well-conditioned first-order CS (SI) on a continuous reinforcement or a 25% reinforcement schedule in different groups. Schedule of reinforcement did not influence the number of S2-S1 pairings required to establish keypecking to S2. However, in the postacquisition sessions, responding to S2 was initially weaker but persisted for many more sessions on the 25% schedule than on the 100% schedule. The data indicate that S2-S1 pairings are responsible both for the acquisition of second-order keypecking to S2 and for the subsequent conversion of S2 into an inhibitory stimulus. 相似文献
20.
Geoffrey Hall 《Learning & behavior》1973,1(2):157-160
Rats were trained to criterion (CT) and overtrained (OT) on a horizontal against vertical stripes discrimination in the jumping stand. A change in response strategy, from inspecting both stimuli to inspecting just the S?, was observed during overtraining. Replacing the S? with a novel stimulus disrupted performance in the OT Ss, but replacing the S+ did not. Performance in the CT Ss was disrupted, but not very severely, both when the S+ was replaced and when the S? was replaced. These results suggest that OT Ss in the jumping stand come to rely especially upon the S?. The overtraining effects found here are compared with those found in other types of apparatus. 相似文献