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1.
欧文氏菌和棒杆菌的属间隔合研究   总被引:7,自引:0,他引:7  
研究了用原生质体融合技术获得欧文氏菌和棒杆菌的融合细胞,串联发酵D-葡萄糖产生2-酮基-L-古龙酸的第一步发酵菌株欧文氏菌SCB247经0.8mg/mL溶菌酶酶解0.5h后,原生质体的形成率和再生率分别为99.8%和27.8%。第二步发酵菌株棒杆菌SCB3058经预处理后由1.3mg/mL溶菌酶酶解2h,原生质体的形成率和再生率分别为99.5%和56.3%,用携带氨苄青霉素抗性标记的SCB247和  相似文献   

2.
对革兰氏阳性的地衣芽孢杆菌(Bacilluslicheniformis)H19和革兰氏阴性的2-酮基-L-古龙酸产生菌S19的原生质体的制备条件进行了研究,并采用聚乙二醇作诱导剂进行了两菌株的原生质体融合,用链霉素作为抗性标记对融合子进行了选择。从17株产生2-酮基-L-古龙酸的融合子中选出了一株连续传代八次产酸高且产量稳定的融合子15号。融合子15号具有两个亲本菌株所具有的一些特性。  相似文献   

3.
采用紫外照射,化学诱变和原生质融合等方法选育到一株性状更优良的突变株SCB329,并与新筛选的一株芽孢杆菌SCB933搭配组成新的组合菌系,产酸小菌SCB329与其亲本菌株氧化葡萄糖酸杆菌性状相似,伴生大菌SCB933属苏芸金芽孢杆菌(B.thurngiensis),新组合菌系列L-山梨糖的发酵液提取后经纸层析,元素分析和红外吸收光谱等项鉴定,其发酵产物克系2-酮基-L-古龙酸,对新组合菌系的生物  相似文献   

4.
新组合菌系氧化葡萄糖酸杆菌SCB329-苏芸金芽杆菌SCB933能在较长时间内保持高的转化活力且具有极强的抗杂菌污染的特性。在一次投糖分批发酵的基础上,探索在控制溶氧、PH,温度等条件下,分批加入L-山梨糖发酵生产2-酮基-L-古龙酸新工艺。采用新工艺,既充分利用了菌系的优良特性,又避免了高糖浓度可能对菌系造成的不良影响。L-山梨糖最终浓度达到14%(W/V),产酸120-135g/l,转化率90  相似文献   

5.
大叶紫花苜蓿愈伤组织原生质体再生植株   总被引:15,自引:0,他引:15  
大叶紫花苜蓿下胚轴诱导的愈伤组织在继代培养基上生长快速,易于分散。继代第12d的愈伤组织原生质体的得率为6.5×107/g鲜重。原生质体培养基为SH基本培养基,含有1.0mg/L2,4-0、0.5mg/LBA、2.0g/LCH、2%蔗糖、6%葡萄糖、5mmol/LMES,培养密度为1.0×105/mL。培养至第12d时的原生质体再生细胞植板率为3.7%。由原生质体形成的小愈伤组织在含2.0mg/L2,4-D的MS固体培养基上大量增殖。增殖的愈伤组织转移至2.0mg/L2-ip+0.1mg/LNAA的B5培养基上,形成体细胞胚并发育成完整植株。  相似文献   

6.
百脉根愈伤组织原生质体再生植株   总被引:1,自引:0,他引:1  
百脉根无菌苗幼茎在含2.0mg/L-,2,4-D,0.1mg/L2-ip的MS培养基上诱导和继代培养愈伤组织。选取绿色松散颗粒愈伤组织分离原生质体。原生质体培养在调整珠KM8P,V-KM,MS和SH培养基上「含300mg/L,CH,2%CW,2%蔗糖,6%葡萄糖,2.0mg/L,2,4-D,0.5mgg/L,BA,5mmol/L MES」,原生质体再生细胞均能分裂,并形成小愈伤组织,但以KM80为  相似文献   

7.
芽孢杆菌M50产生β—甘露聚糖酶的条件研究   总被引:16,自引:0,他引:16  
从土壤中分离到9株产生β-甘露聚糖酶的芽孢杆菌(Bacillus sp.)。Bacillus sp.M50250mL三角瓶摇瓶培养试验,以4%的魔芋粉为碳源,1.0%(NH4)2SO4为氮源,0.35%Na2CO3,30~34℃培养60h产酶达到高峰。酶活力为180~220u/mL。100L罐发酵,在30~32℃,1:0.75vvm通气量,200r/min条件下,发酵液酶活力高达330u/mL。  相似文献   

8.
L-异亮氨酸产生菌选育的研究   总被引:6,自引:0,他引:6  
以黄色短杆菌(Brevibacteriumflavum)ATCC14067为出发菌株,经硫酸二乙酯(DES)、紫外线(UV)和亚硝基胍(NTG)逐级诱变处理,α-氨基-β-羟基戊酸(AHV)、S-2-氨基乙基-L-半胱氨酸(AEC)、磺胺胍(SG)、乙硫氨酸(Eth)、α-氨基丁酸(α-AB)、异亮氨酸氧肟酸(IleHx)等氨基酸结构类似物及琥珀酸为碳源平板定向筛选,获得一株L-异亮氨酸高产菌ZQ-4(AHV~γ、AEC~γ、SAM~γ、SG~γ、Eth~γ、α-AB~γ、IleHx~γ)在含13.5%葡萄糖培养基中,摇瓶发酵72h、L-异亮氨酸积累可达2.8-3.0%。  相似文献   

9.
L-异亮氨酸产生菌选育的研究   总被引:3,自引:0,他引:3  
以黄色短杆菌(Brevibacteriumflavum)ATCC14067为出发菌株,经硫酸二乙酯(DES)、紫外线(UV)和亚硝基胍(NTG)逐级诱变处理,α-氨基-β-羟基戊酸(AHV)、S-2-氨基乙基-L-半胱氨酸(AEC)、磺胺胍(SG)、乙硫氨酸(Eth)、α-氨基丁酸(α-AB)、异亮氨酸氧肟酸(IleHx)等氨基酸结构类似物及琥珀酸为碳源平板定向筛选,获得一株L-异亮氨酸高产菌ZQ-4(AHV~γ、AEC~γ、SAM~γ、SG~γ、Eth~γ、α-AB~γ、IleHx~γ)在含13.5%葡萄糖培养基中,摇瓶发酵72h、L-异亮氨酸积累可达2.8-3.0%。  相似文献   

10.
无花果曲霉原生质体形成与再生条件的探讨   总被引:7,自引:1,他引:6  
根据正交试验得出无花果曲霉原生质体形成的最佳条件,用1%的混合酶液(0.5%纤维素酶+0.25%蜗牛酶+0.25%溶菌酶)作用无花果曲霉菌体细胞,原生质体产量达3.2×107个·ml-1,渗透压稳定剂为0.6mol·L-1KCl于0.2mol·L-1PO3+4(pH5.8)中,酶解时间和酶解温度分别为3.0h、30℃.比较不同酶解时间、再生稳定剂和碳源等因素对原生质体再生的影响,可确定最佳再生条件,再生率达30%以上.  相似文献   

11.
The objective of this study was to isolate and screen the highly efficient copper-removing microorganisms from the petroleum hydrocarbon (PH)-contaminated sites in the Amazonian rain forest in Ecuador. Two bacterial strains (strain UEAB3 and UEAB6) have shown 100% microbial resistance on the nutrient medium containing 100 mM of MgCl2, FeCl3, and Al2(SO4)3 separately. Though these two strains were less tolerant of ZnCl2 and CuSO4.5H2O, they have proven 100% resistance at the lower concentrations of these two metals. According to atomic absorption spectroscopy (AAS) analysis, the filamentous fungi (strains UEAFr and UEAFg) were significantly (p<0.05) effective at bacteria in the biosorption (97–100%) of copper (5 mg L?1) over 7 d. As per 16/18S rDNA sequences, UEAB3, UEAB6, UEAFr, and UEAFg were Bacillus thuringiensis, Bacillus cereus, Geomyces pannorum, and Geomyces sp., respectively. From these results, it can be comprehensively concluded that the isolated microbial cultures had a capacity to remove the copper metal from the liquid medium.  相似文献   

12.
Problems caused by nematodes and Fusarium wilt (Panama disease) on banana plantations are responsible for yield losses and are limiting to its cultivation. In the state of Goias, there is little information about the nematode occurence on this crop, and its relation with the incidence of Fusarium oxysporum f.sp. cubense (Foc). This research had the purpose to identify the occurrence of plant‐parasitic nematodes on banana plantations and to verify its correlation with the Fusarium wilt and with the soil attributes (pH, texture, nutrients). Twelve banana orchards in the state of Goias were sampled in the municipalities of Anapolis, Caiaponia, Goiatuba, Itaguaru, Itumbiara (two areas), Jatai, Morrinhos, Ouro Verde, Palestina, Taquaral and Uruana. All sampled areas, except Morrinhos, revealed contamination with Foc, and all areas had different genera of nematodes either in the soil or in the roots samples. Meloidogyne sp., Helicotylenchus sp. and Rotylenchus sp. were the main genera of plant‐parasitic nematodes found in the samples, with Meloidogyne sp. and Rotylenchus sp. being the most dominant and abundant genera. The presence of Pratylenchus sp. increases the population levels of F. oxysporum. Helicotylenchus sp. is highly correlated with high concentrations of Mn. High population density of Meloidogyne sp. was found in irrigated areas with low concentrations of P, Ca, Mg and soil pH.  相似文献   

13.
两种陆栖等足类的种群及其分解落叶的作用   总被引:15,自引:1,他引:14  
采用固定路线进行种群数量调查,并用落叶饲养,测定食性、食量,以探讨潮虫、鼠妇在广东小良人工阔叶混交林中分解落叶的作用。结果:(1)潮虫Philoscia sp.喜湿,主要分布于低湿、荫蔽处;鼠妇Armadillo sp.耐干旱,主要分布在较高爽处。(2)两种虫的种群数量高峰均在6月份。潮虫繁殖期延长到雨季之后,鼠妇则在雨季高峰前结束。(3)对未经沤化过的落叶多选食薄且质软的。鼠妇在25℃时摄食量最大,为117.1±12.4毫克/克体重·天;潮虫在20℃时食量最大,为251.2±7.3毫克/克体重·天。 通过种群年生物量变化及不同温度下的摄食量等因素来推算林中等足类的年分解落叶量:在荫蔽潮湿的林下,其分解量最大,占凋落物的自然消耗量的11.4%。  相似文献   

14.
闫云君  李晓宇 《生态科学》2006,25(2):97-101
大型底栖动物在河流生态系统中发挥着重要作用。2003年6月至2004年6月间对汉江流域2级河流--黑竹冲河大型底栖动物群落优势种类的生产力进行了为期一周年的调查研究。结果表明,主要优势种小裳蜉(Leptophlebia sp.)和蜉蝣(Ephemera sp.)的生活史均为一年两代,蜉蝣的两个代之间界限比较明显;小裳蜉成虫羽化主要发生在秋季和冬季,而蜉蝣成虫羽化主要发生在夏季和冬季。小裳蜉和蜉蝣种群的生物量和多度均出现两次峰值。采用体长频率法(size-frequencymethod)测算的周年生产量分别为:小裳蜉,38.0362g·m-2·a-1,P/B为11.4;蜉蝣,76.0318g·m-2·a-1,P/B为11.8。  相似文献   

15.
目的:建立能够同时检测单孢子虫、派琴虫和折光马尔太虫的三重荧光定量PCR方法。方法:根据基因库中单孢子虫、派琴虫和折光马尔太虫的基因序列,设计3对特异性引物和3条用不同荧光基团标记的TaqMan探针,对反应条件和试剂浓度进行优化,建立能够同时检测单孢子虫、派琴虫和折光马尔太虫的三重荧光定量PCR方法。结果:该方法对单孢子虫、派琴虫和折光马尔太虫的检测敏感性分别达到40、400和40个模板拷贝数;此外抗干扰能力强,对单孢子虫、派琴虫和折光马尔太虫不同模板浓度进行组合,仍可有效地同时检测这3种原虫,对嗜水气单胞菌、荧光假单胞菌、副溶血弧菌、溶藻弧菌、河弧菌和拟态弧菌等病原体的检测结果均为阴性。结论:建立的单孢子虫、派琴虫和折光马尔太虫多重荧光定量PCR具有特异、敏感、快速、定量和重复性好等优点,可用于临床上单孢子虫、派琴虫和折光马尔太虫感染的检测。  相似文献   

16.
SYNOPSIS Four new eimerian species are described from red-backed voles. Clethrionomys gapperi in Pennsylvania. Sporulated oocysts of Eimeria clethrionomyis sp. n. are ellipsoidal, 18.8 (16.5–21.5) × 14.9 (14.0–16.5) with elongate, ovoid sporocysts, 10.6 (9.5–12.0) × 6.1 (5.5–7.0). The oocyst wall is smooth, with 2 layers, and thins, with terminal cap at one or both ends. Polar granules, dark Stieda body and sporocyst residuum are present. The occyst residuum is absent. Sporulated oocysts of Eimeria gallatii sp. n. are ellipsoidal, 27.7 (21–32) × 19.3 (17–24) with ovoid sporocysts, 13.5 (12–15) × 8.8 (8–10). The oocyst wall is smooth, 2-layered, with a micropyle and thin wall at the end opposite the micropyle. Polar granules. Stieda body and sporocyst residuum are present. The oocyst residuum is atypical, of cobwebby material. Sporulated oocysts of Eimeria pileata sp. n. are subspherical to spherical, 25.2 (20.5–29.5) × 22.5(19.5–25.5) with ellipsoidal sporocysts, 13.4(10.5–15.0) × 8.4 (7.5–9.5). The oocyst wall is rough, pitted, striated, 2-layered, with no micropyle. Polar granules, oocyst and sporocyst residuum. Stieda body and stiedal cap are present. Sporulated oocysts of Eimeria marconii sp. n. are ellipsoidal, 13.0 (10.5–15.0) × 10.6 (9.5–12.0) with elongate, ovoid sporocysts, 7.7 (7.0–8.5) × 4.2 (3.0–4.5). The oocyst wall is smooth, single-layered, with no micropyle. Polar granules, dark Stieda body and sporocyst residuum are present. There is no oocyst residuum.  相似文献   

17.
In this study we report the isolation of four denitrifying bacteria from a batch reactor, where the progress of hydrogenotrophic denitrification was examined. Only three of the strains had the ability to use hydrogen as electron donor. In the present work, kinetic batch experiments were carried out in order to study the dynamic characteristics of pure and defined mixed cultures of hydrogen-oxidizing denitrifying bacteria, under anoxic conditions, in a defined synthetic medium, in the presence of nitrates. Kinetic models were developed and the kinetic parameters were determined from the batch experiments for each bacterium separately. The behavior of mixed cultures and the interactions between the bacteria were described using kinetic models based on the kinetic models developed for each bacterium separately and their predictions were compared with the results from mixed culture experiments. The mathematical models that were developed and validated in the present work are capable of describing the behavior of the bacteria in pure and mixed cultures, and in particular, the kinetics of nitrate and nitrite reduction and cell growth.  相似文献   

18.
Habitually, capuchin monkeys access encased hard foods by using their canines and premolars and/or by pounding the food on hard surfaces. Instead, the wild bearded capuchins (Cebus libidinosus) of Boa Vista (Brazil) routinely crack palm fruits with tools. We measured size, weight, structure, and peak-force-at-failure of the four palm fruit species most frequently processed with tools by wild capuchin monkeys living in Boa Vista. Moreover, for each nut species we identify whether peak-force-at-failure was consistently associated with greater weight/volume, endocarp thickness, and structural complexity. The goals of this study were (a) to investigate whether these palm fruits are difficult, or impossible, to access other than with tools and (b) to collect data on the physical properties of palm fruits that are comparable to those available for the nuts cracked open with tools by wild chimpanzees. Results showed that the four nut species differ in terms of peak-force-at-failure and that peak-force-at-failure is positively associated with greater weight (and consequently volume) and apparently with structural complexity (i.e. more kernels and thus more partitions); finally for three out of four nut species shell thickness is also positively associated with greater volume. The finding that the nuts exploited by capuchins with tools have very high resistance values support the idea that tool use is indeed mandatory to crack them open. Finally, the peak-force-at-failure of the piassava nuts is similar to that reported for the very tough panda nuts cracked open by wild chimpanzees; this highlights the ecological importance of tool use for exploiting high resistance foods in this capuchin species.  相似文献   

19.
SYNOPSIS. A survey of 22 Western Painted Turtles (WPT), Chrysemys picta belli Gray; 2 Map Turtles (MT), Graptemys geographica Le Sueur; 8 False Map Turtles (FMT), Graptemys pseudogeographica Gray; 26 Illinois Mud Turtles (IMT), Kinosternon flavescens spooneri Smith; and 5 Spiny Softshell Turtles (SST), Trionyx spiniferus Le Sueur, revealed the presence of 10 species of coccidia. The species found, the shape and average length-width dimensions (in micrometers) of their oocysts, and the respective hosts from which they were isolated were as follows: Eimeria chrysemydis Deeds & Jahn, slightly pear-shaped (27.6 × 17.0), from 5 WPTs; Eimeria delagei marginata Deeds & Jahn, markedly pearshaped (22.1 × 17.6), from 2 WPTs, 1 MT, and 3 FMTs; Eimeria graptemydos sp. n., broadly ellipsoid to subspherical (12.6 × 11.4), from 10 WPTs, 2 MTs, and 5 FMTs; Eimeria lutotestudinis sp. n., broadly ellipsoid to subspherical (11.9 × 10.8), from 4 IMTs; Eimeria mascoutini sp. n., broadly ellipsoid to subspherical with outer surface of oocyst wall mammillated (14.0 × 11.9), from 2 SSTs; Eimeria mitraria (Laveran & Mesnil), asymmetrically ellipsoid, bearing 1 or 2 conical projections at the polar end and 2 or 3 at the antipolar end (10.0 × 7.6), from 7 WPTs, 1 MT, 3 FMTs, and 4 IMTs; Eimeria pseudogeographica sp. n., narrowly ellipsoid to slightly ovoid (19.5 × 13.5), from 5 WPTs and 3 FMTs; Eimeria tetradacrutata sp. n., spherical to subspherical with outer surface of oocyst wall mammillated (19.5 × 19.2), from 1 WPT; an Eimeria sp. narrowly ellipsoid, bearing 2 conical projections at the polar end and 2 at the antipolar end (23.8 × 13.2), from 1 MT; and Mantonella hammondi sp. n., conical to narrowly ellipsoid, bearing 1 conical projection at the polar end and 2 or 3 at the antipolar end (14.3 × 7.1), from 1 IMT. The overall infection rate for the 63 turtles examined was 54.0%.  相似文献   

20.
Two microorganisms (NDKK48 and NDKY76A) that degrade long-chain cyclic alkanes (c-alkanes) were isolated from soil samples. Strains NDKK48 and NDKY76A were identified as Rhodococcus sp. and Gordonia sp., respectively. Both strains used not only normal alkane (n-alkane) but also c-alkane as a sole carbon and energy source, and the strains degraded more than 27% of car engine base oil (1% addition).  相似文献   

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