组织与原生质体培养

924098玉蝉花的离体繁殖〔英〕/Yabuya,T.…/Eup-hytiea一1991,57(i)一77~81仁译自DBA,1992,11(8),92一04510习 将玉蝉花(I:葱5 e.sata)23个变种和1个野生种的花萃培养在含1 mg/l NAA、1 mg/l BA、309/1蔗糖和109/l琼脂的固体MS培养基上。试验了下列培养基改变的情况:全或半量MS培养基;固体(109/l琼脂)或液体(滤纸桥法)培养基,蔗糖浓度为30、eo和909/l:活性炭(109/l)。所有培养物保存在25℃、光下。有3个变种显示明显的苗诱导率,但它们发根效果不佳。结果表明,补加1mg/1 NAA、img/1 BA、309/l蔗糖和109/l琼脂的半量MS培养基最适于…     

组织与原生质体培养

923701凤梨种质的离体贮截〔英〕/Zee,F.T一/H。-r tscience一1992,27(i)一5了一55〔译自DBA,1992,11(7),92一03861〕 在初始培养基(MS盐+Zmg/l BA+2 mg/lNAA+309/l蔗糖)上培养温室生长的成熟凤梨(A林“”as co,05“s)腋芽部分。3周后,将绿色未污染的芽转至无植物生长因子的保存培养基上 (ll,4MS)。在液体增殖培养基上继代培养小植株 (1/4MS+Zmg/l BA)。之后,将小植株移至保存培养基上,直至基叶长到7~9 cm,并测定在下述条件下贮存的情况:空管;无菌蒸馏水;1/2MS+。g/1琼脂,MS+99/l琼脂,i/4MS+309/l蔗糖十99/l琼脂。培养条件为25…     

林生地霉培养基形态学观察及生理学实验

目的观察林生地霉在5种不同培养基中的形态;通过一些常规的生理学实验,初步了解林生地霉的生理学特征。方法将林生地霉分别接种在沙堡培养基(SDA)、马铃薯葡萄糖琼脂(PDA)、麦芽汁琼脂(MEA)、玉米粉琼脂(CMA)和察氏琼脂(CZA)平皿培养基上,置37℃和27℃温箱培养2周,每天观察菌落生长情况。通过芽管试验、厚壁孢子试验、硝酸盐同化试验、放线菌酮耐受试验、尿素酶试验、糖发酵试验及API20C酵母系统等初步了解林生地霉的生理学特性。结果菌落在PDA、SDA和MEA培养基上生长较快、较好,在其他培养基上生长较差。芽管试验、硝酸盐同化试验、糖发酵试验均阴性;厚壁孢子试验、放线菌酮耐受试验阳性;尿素酶试验弱阳性;API20C酵母系统鉴定中葡萄糖、甘油、木糖、山梨醇为阳性,余为阴性。结论PDA、SDA和MEA较适合林生地霉生长;尿素酶试验可作为地霉属属内鉴定的参考依据。API20C鉴定结果及厚壁孢子试验可为其与毛孢子菌属的属间鉴别提供依据。     

国家标准测定食品细菌总数培养基的改进研究

应用我国国家标准营养琼脂（GB4789 2－94简称NA）与美国食品药品管理局（FDA）标准平析以（简称SA）两种培养基对动植物食品中细菌总数进行检测对比,结果表明FDA标准平板比GＢ营养琼脂效果较好,前比后的检出率高出２３．９％,且菌落大而明显,为此,对这两种培养基进行优化筛选试验,并优选出Ｃ８培养基,扩大试验结果表明C8培养基的检出率较GB营养琼脂及FDA标准平板分别高出35．8％和9．5％。     

花生愈伤组织的诱导和再生体系的建立

以花生下胚轴为外植体,MS和1/2 MS为基本培养基,用不同浓度的激素及琼脂对愈伤组织诱导及分化的影响进行了试验,确定MS 6-BA 3.0 mg.L-1 NAA 0.4 mg.L-1 0.7%琼脂为诱导愈伤的最佳培养基。提高琼脂浓度可有效抑制玻璃化和褐化的发生,且琼脂浓度越大,愈伤组织越易分化出丛生芽。丛生芽在1/2 MS NAA1.0 mg.L-1 0.7%琼脂培养基上生根率最高,达95%以上。     

土豆汤琼脂培养基培养分枝杆菌的研究

本文报道了一种土豆汤琼脂培养基系统,试验过的16株各群分枝杆菌都能在该培养基上生长。大多数分枝杆菌在土豆汤琼脂培养基上的初生长时间快于罗氏培养基。分枝杆菌H_(37)R_v、鸟型,胃型、堪萨斯、脓肿、不产色和偶发等标准株,在一些土豆汤琼脂培养基上产生两种不同的菌落。初步的研究表明,土豆汤琼脂培养基还可用于胸水、痰内结核杆菌的培养。土豆汤琼脂培养基系用传统的琼脂培养基制作方法,价格低廉,适合在发展中国家的实验室和国内医院检验科推广使用。     

实验14 M13克隆和DNA顺序分析

一、制备感受态受体菌 1.配制M13(单链DNA噬菌体)宿主菌E.coliK12 JM103的基本琼脂培养基。JM103的基因型是[△(lac pro)thi,str A,supE,end A,sbc B15,hsdR4,F′tra D36,pro AB,lac I~qz M15]。基本琼脂培养基的配制如下: (1)2×Bacto琼脂:15克琼脂粉溶于450毫升水,高压蒸汽灭菌。 (2)2×盐溶液:K_2HPO_4 10.5克,KH_2PO_4 4.5     

制备酵母菌实验材料的简易方法

笔者在实验中发现了以下制备酵母菌实验材料的简易方法。1　实验器材1 .1　药品 :玉米粉、琼脂、蔗糖和酵母粉。1 .2　器材 :小三角烧瓶 (带棉塞 )、烧杯、漏斗和电炉。1 .3　仪器 :培养箱、高压灭菌锅。2　操作步骤1 )先将三角烧瓶 (带棉塞 )、漏斗用报纸包好 ,然后进行高压灭菌 (1 2 1℃维持 2 0～ 3 0min)。2 )配制玉米粉培养基 ,方法如下 :A .蔗糖 1 3g +琼脂 1 .5g+水 80mL ,倒入大烧杯中煮沸 ,使琼脂溶解。B .玉米粉 1 7g+水 80mL倒入另一烧杯中调匀。当A中的琼脂溶解后 ,将B倒入A中 ,煮沸后移去电炉。待稍冷却后往培养基中加入 1 …     

洗衣粉S.S.琼脂培养基的初步应用报告

分离肠道病原菌的培养基种类繁多,但效果却不一致,其中效果较满意者当推3号胆盐S.S.琼脂及去氧胆酸钠-牛胆酸钠琼脂(简称郑氏S.S.琼脂)。我院试用的洗衣粉-去氧胆酸钠琼脂(简称洗衣粉S.S.琼脂)效果又较前者为优,这种培养基对肠道病原菌不但有很高的阳性检出率,而且痢疾杆菌在这种培养基上呈特殊的粘性菌落,可以在分离培养基上初步鉴别痢疾菌和沙门氏菌菌落,使肠道培养基更趋于完善。     

分枝杆菌全合成琼脂培养基的研究

本文报道了一种适合常见致病分枝杆菌生长的全合成固体琼脂培养基体系。它为实验室研究分枝杆菌的营养生理、生化特性、遗传变异、药理和耐药机制提供了一种新工具,也为研制更加满意的分枝杆菌培养基创造了条件。试验过的大多数非典型分枝杆菌,在全合成琼脂培养基上比在罗氏培养基上生长快,生长量少于或等于罗氏培养基。标准牛型株的细胞群体中,仅有少量细胞能在全合成琼脂培养基上生长。鸟型．胞内和偶发等分枝杆菌标准株在全合成琼脂培养基上产生两种不同的菌落。     

建兰根状茎增殖条件的研究

研究了建兰两个栽培品种的根状茎在固体及液体两种培养方式,以及培养基中有无激素和不同激素浓度配比对增殖及分化的影响。根状茎在液体培养基上的生长量都大于固体培养基上的生长量。根状茎在无激素的培养基上也能增殖。加入激素有促进作用。合适的激素浓度及配比因品种而异。     

Comparison of Mycobacterial Cultures on Agar and Lowenstein Medium

In a comparison of Lowenstein's medium with two agar media, 7H10 without and with the addition of Triton WR 1339, 4,100 sputa were planted on all three, yielding 803 (19.6%) positive cultures. The addition of Triton WR 1339 to the 7H10 medium made it possible to observe the cord formation directly on the isolation plates and did not alter, in any respect, the results obtained with the basic 7H10 medium. The agar media produced much earlier and more positive cultures than Lowenstein's medium. A greater number of cultures showed drug resistance on Lowenstein's medium as compared with the agar media.     

Medium for presumptive identification of Yersinia enterocolitica.

A medium, lysine-arginine-iron agar, was developed for the presumptive identification of Yersinia enterocolitica isolates. This medium was a modification of lysine-iron agar and allowed for the testing of five biochemical characteristics in a single tube medium. The reactions of Y. enterocolitica on this medium were reliable and distinctive. The medium significantly simplified the identification of Y. enterocolitica isolates.     

Evaluation of several selective media for recovery of Aeromonas hydrophila from polluted waters.

Eleven media were studied for their suitability in the selective isolation of Aeromonas hydrophila. Preliminary results showed that five of them (inositol-brilliant green-bile salts agar, bile salts-brilliant green agar, Rimler-Shotts agar, xylose-sodium deoxycholate-citrate agar, and dextrin-fuchsin-sulfite agar) allowed the growth of several microorganisms that are usually present in the same samples in which A. hydrophila is found. Six media (mA agar, modified Rimler-Shotts agar, DNase-toluidine blue-ampicillin agar, Pril-xylose-ampicillin agar, MacConkey-trehalose agar, and starch-bile salts agar) were selected for evaluation as recovery selective media on the basis of their efficiency in the isolation of A. hydrophila from natural water samples. mA agar showed the best recovery rate and also an acceptable specificity, but its selectivity was low. Another medium that can be considered is DNase-toluidine blue-ampicillin agar, which showed good accuracy, but its specificity was low.     

Evaluation of several selective media for recovery of Aeromonas hydrophila from polluted waters

Eleven media were studied for their suitability in the selective isolation of Aeromonas hydrophila. Preliminary results showed that five of them (inositol-brilliant green-bile salts agar, bile salts-brilliant green agar, Rimler-Shotts agar, xylose-sodium deoxycholate-citrate agar, and dextrin-fuchsin-sulfite agar) allowed the growth of several microorganisms that are usually present in the same samples in which A. hydrophila is found. Six media (mA agar, modified Rimler-Shotts agar, DNase-toluidine blue-ampicillin agar, Pril-xylose-ampicillin agar, MacConkey-trehalose agar, and starch-bile salts agar) were selected for evaluation as recovery selective media on the basis of their efficiency in the isolation of A. hydrophila from natural water samples. mA agar showed the best recovery rate and also an acceptable specificity, but its selectivity was low. Another medium that can be considered is DNase-toluidine blue-ampicillin agar, which showed good accuracy, but its specificity was low.     

Evaluation of Chromocult enterococci agar for the isolation and selective enumeration of Enterococcus spp. in broilers

AIMS: To investigate the productivity and specificity of a new chromogenic enterococci selective medium (Chromocult enterococci agar) recently developed by Merck. METHODS AND RESULTS: The study was carried out comparing Chromocult enterococci agar with MRS agar (Merck), a basal lactic acid bacteria medium in current use. A total of 216 faecal samples from poultry were collected and enterococci populations were counted. Likewise, 100 randomly selected strains were identified for each medium. The differences found between the two media were analysed and discussed. CONCLUSIONS: A good sensitivity of 98% was obtained for Chromocult agar and all false-positive isolates obtained were identified as Leuconostoc spp. However significant differences (P<0.01) were obtained between the enterococci species isolation rates identified from these two media, suggesting the poor growth of some species in Chromocult enterococci agar. Viable counts of Enterococcus spp. obtained with MRS agar were significantly higher than those obtained with Chromocult enterococci agar. SIGNIFICANCE AND IMPACT OF THE STUDY: The use of chromogenic media for microbiological analysis is increasing. Independent studies are important to evaluate newly developed chromogenic media.     

Simplified Thermonuclease Test for Rapid Identification of Staphylococcus aureus Recovered on Agar Media

A simplified thermonuclease test that identifies colonies of Staphylococcus aureus 5 h after recovery on various agar media is described.     

Comparison of media for enumeration of coliform bacteria and Escherichia coli in non-disinfected water

In this work alternative media for detection and enumeration of E. coli and coliform bacteria were compared to the reference method ISO 9308-1 (LTTC) using non-disinfected water samples with background flora. The alternative media included LES Endo agar medium (LES Endo), Colilert-18 with 51-well Quanti-tray (Colilert), Chromocult Coliform agar (CC), Harlequin E. coli/Coliform medium (HECM) and Chromogenic Escherichia coli/Coliform medium (CECM). A total of 110 samples of groundwater, bathing water and spiked water was used. Our results revealed that confirmation of coliform bacteria counts is necessary, not only on lactose-based LTTC and LES Endo media, but also on the chromogenic agar media tested, due to the growth of oxidase positive colonies. LTTC and CC media also allowed the growth of some morphologically typical coliform colonies containing gram-positive bacteria. The recovery of coliform bacteria was lower on LES Endo than on LTTC. In most cases Colilert, CC, HECM and CECM gave higher coliform counts than LTTC. The use of the LTTC medium led to higher E. coli counts than obtained with any of the alternative mediums. There are three explanations for this: (1) high sensitivity of LTTC, (2) false positives on LTTC or (3) false negatives especially with Colilert, but also with chromogenic agar media. Although LTTC was found to be a very sensitive medium, the high degree of background growth of non-disinfected waters disturbed substantially the use of it. In conclusion, our results suggest that Colilert, CC and CECM are potential alternative media for detection of coliform bacteria and E. coli from non-disinfected water.     

New Quantitative, Qualitative, and Confirmatory Media for Rapid Analysis of Food for Clostridium perfringens

A selective and differential medium, Shahidi-Ferguson Perfringens agar (SFP agar), and a confirmatory medium, lactose-motility agar (LM agar), were developed for the enumeration and identification of Clostridium perfringens in foods. These media provide a rapid, specific, and direct diagnosis of C. perfringens. SFP agar contains sodium metabisulfite and ferric ammonium citrate to demonstrate H(2)S production and egg yolk to demonstrate lecithinase production by C. perfringens. On SFP agar, C. perfringens produces black colonies, 2 to 3 mm in diameter, surrounded by zones of opaque precipitate. The typical colonies are confirmed on LM agar. Enumeration and identification are completed within 48 hr. All of the ingredients of SFP agar are stable to heat and storage conditions. SFP agar also contains two antibiotics, kanamycin and polymyxin B, which are inhibitory to many bacteria commonly occurring in foods. A comparative study of SFP agar and noninhibitory media showed that SFP agar did not inhibit any of the 16 strains of C. perfringens tested. Recovery of C. perfringens added to foods averaged 90.6% for SFP agar as compared with 69.8% for sulfite polymyxin-sulfadiazine (SPS) agar (BBL) and 60.2% for SPS agar (Difco). The colonies on the SFP agar, were much larger and were consistently black. Of 464 food samples tested, C. perfringens was found in 27 samples with SFP agar and in 5 samples with SPS agar (Difco), with a recovery ratio considerably higher on SFP agar. SFP agar is a more specific presumptive medium for the enumeration of C. perfringens and in conjunction with LM agar should save considerable time, effort, and materials toward the final identification of the species.