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1.
高效聚磷菌的诱变选育及特性研究   总被引:1,自引:0,他引:1  
实验采用15 keV不同剂量的低能氮离子束注入G菌,选育出两株高效聚磷菌K1、K2。其聚磷率明显高于实验出发菌,为G菌的1.43倍~3.89倍。经多次传代实验表明这两株菌遗传稳定性较好。根据生理生化及生长实验,这两株菌被鉴定为假单胞菌属细菌(Pseudom onas spp),K1、K2两株菌的最适生长条件为:温度为30℃;pH分别为6和8。菌量OD值(optim al density)在λ为218 nm、220 nm时,分别为0.6和0.4。K1菌在3天时繁殖量达到最大,K2菌在4天时繁殖量达到最大。  相似文献   

2.
我们利用制糖车间的废蜜作为原料,选用川柠1-2号柠檬酸生产菌,因陋就简、土法上马,进行了浅盘发酵柠檬酸的生产实验。一开始使用抽屉铺塑料布作发酵盘,用砖头支起一口大锅当杀菌锅,通过反复实践把又粘又黑的废糖蜜制成了国家需要的柠檬酸。为了扩大生产的需要,我们又改变了密封式无菌发酵的工艺,进行了浅盘开放式发酵柠檬酸的试验生产,取  相似文献   

3.
报道了核菌纲(Pyrenomycetes)炭角菌目(Xylariales)炭角菌科(Xylariaceae)炭墩菌属(Kretzschmaria)3个种:焦里炭墩菌K.deusta,亮色炭墩菌K.lucidula和垫状炭墩菌K.pavimentosa。其中前两种为中国新记录种。文中根据国内采集的材料对其宏观和微观特征进行了描述及图示。  相似文献   

4.
本文报道了核菌纲炭墩菌属的3个种,其中米勒炭墩菌K.milleri和夏威夷炭墩菌K.sandvicensis为中国新记录种。螺纹炭墩菌K.zonata过去仅在中国台湾省有记载,现在我国其他省份也发现该种。米勒炭墩菌采自湖南省,其主要特征是具有开放的子囊壳孔口;夏威夷炭墩菌采自云南省和湖南省,此菌牙缝长度接近孢子全长易于识别;螺纹炭墩菌K.zonata采自云南省、海南省和浙江省,其孢子较黑且较小。本文对此3个种的形态进行了描述,并提供了子座照片和显微照片。  相似文献   

5.
目的:研究营养要素对原油降解菌生长的影响.方法:通过紫外分光光度计于600nm处测量菌体OD值检测6种碳源、5种氮源、无机离子含量和氯化钠含量对原油降解菌K5生长的影响.通过正交实验确定了原油降解菌K5生长的最佳营养条件.结果:当蔗糖含量0.6%、硫酸铵含量0.2%、氯化钠含量0.6%、微量元素含量0.1%时,原油降解菌生长得最好.结论:确定了原油降解菌K5生长的最佳营养条件,并且发现了培养基中的氮源和碳源对菌体生长量的影响最大以及不同微量元素对菌体生长量有不同程度的促进或抑制作用.  相似文献   

6.
为研究大肠杆菌(Escherichia coli)和肺炎克雷伯氏菌(Klebsiella pneumoniae)混菌体系,构建了基于抗生素筛选的2株重组菌。将携带卡那霉素抗性基因的载体pET-28a转化到肺炎克雷伯氏菌中,获得重组菌K.pneumoniae(pET-28a);将携带氯霉素抗性基因cm的重组载体pET-cm(卡那霉素和氯霉素双抗性载体)转化到大肠杆菌中,获得重组菌E.coli(pET-cm),在卡那霉素抗性培养基中单独培养及混合培养上述两株重组菌。结果发现:单独培养条件下,E.coli与K.pneumoniae的相对菌体密度为57.87%;混合培养条件下,E.coli与K.pneumoniae的相对菌体密度为1.94%;E.coli和K.pneumoniae相对于各自单独培养的存活率分别为2.57%和76.60%。上述结果表明,K.pneumoniae为混菌体系的优势菌,可强烈抑制E.coli的生长。  相似文献   

7.
目的:了解肺炎克雷伯菌强毒性血清型K1、K2、K54和K57型菌株在我国重庆、北京、深圳三地的分布及流行趋势。方法:采用PCR对310株肺炎克雷伯菌临床分离株进行血清型K1、K2、K54和K57检测。结果:310株菌中,K1、K2、K54和K57血清型分别占14.2%、9.4%、6.5%和4.2%;来自呼吸系统标本分离株中的K1血清型菌株在4种检测的强毒血清型中占首位,为呼吸系统总数的17.4%。结论:310株肺炎克雷伯菌的4种强毒性血清型中,K1血清型菌株所占比例高,较为流行。  相似文献   

8.
抗生素发酵废菌渣的无害化及资源再利用研究进展   总被引:2,自引:0,他引:2  
抗生素发酵每年产生大量有毒菌渣,处理不当将导致环境和健康问题。概述近来抗生素菌渣无害化处理及重新用作发酵培养基氮源,生产能源、饲料、可降解生物薄膜、石膏缓凝剂等资源化利用研究进展,提高抗生素危废菌渣的无害化处理及资源化利用效率。  相似文献   

9.
一组鸡源乳酸菌产乳酸及其耐受特性研究*   总被引:3,自引:0,他引:3  
研究了12株(K9、D17、C1、C12、D11、D14、C2、D9、K6、C21、D1和D7)分离自肉鸡肠道的乳酸菌的产乳酸能力及其中3株产酸能力强的菌株的耐受特性。12株乳酸菌产乳酸结果表明:12h内,K6产乳酸速度最快,其次为K9和C1,24h时,D17乳酸浓度最高,48h时C1终乳酸浓度最高。K9、D17和C1的耐受试验结果表明:C1菌株耐酸能力最强,pH2时,C1菌株培养3h后还能检测到活菌,D17和K9菌株培养1h后就已经检测不到活菌。在胆盐浓度0.08%-0.40%范围内,C1、D17和K9均有一定的耐受能力,随着胆盐浓度的升高,C1、D17和K9的存活数呈现缓慢的下降趋势。3株菌中D17耐热能力最强,经80%处理后仍有10^4.9/mL存活数,而K9和C1已检测不到活菌;C1对热最敏感,65℃处理后存活数由10^8/mL降为10^3/mL。  相似文献   

10.
一株新的具有脱色能力的琼脂分解菌   总被引:2,自引:0,他引:2  
本文报道了一株具有脱色能力的琼脂分解菌的分离、脱色现象及细菌学鉴定结果。该菌株分离自琼脂生产工厂周围的土壤中。它能在琼脂培养基上脱除废糖蜜的黑褐色色素,能分解淀粉和琼脂,利用纤维素生长,液化明胶。培养新分离菌不需要生长因子,不产生吲哚、硫化氢、荧光色素及扩散性色素。新分离菌是假单胞菌属的一个新种,定名为井式假单胞菌(Pseudo-monas wellantypicum n.Sp.)。  相似文献   

11.
The present paper deals with the infrageneric classification, phylogeny and geographic distribution of the genus Lomatogonium. A cladistic analysis was undertaken to establish the taxa and to evaluate the relationships between the taxa. The PAUP computer program was used in this analysis. The most parsimonious tree (Cladogram) of the rotate-corolla group of subtribe Gentianinae shows that Lomatogonium is closely related to Lomatogoniopsis and Swertia, but distantly to Veratrilla. Among them, Swertia is more primitive than Lomatogonium and hence Sect. Swertia was selected as the outgroup to polarize the character states of ingroup (Lomatogonium). A data matrix of 29 charaters of Lomatogonium was made for constructing the cladogram. Two most parsimonious trees were formed one of which, with the lowest f value, was at last selected as a shortest tree. In this tree 18 species fall into three groups, i.e. Sect. Sarcorhizoma, Sect. Lomatogonium and Sect. Pleurogynella. The former comes at a lower level with more plesiomorphies while the latter at a higher level with more apomorphies. Lomatogonium is distributed in the northern temperate zone. However, 16 species are centred in Asia and two extend to Europe, or further to the Arctic region, but none has been found from Africa, Australia and South erica. The analysis of distribution pattern of species shows that the Qinling-Hengduan Mountain region is both the frequence and diversity centers of Lomatogonium. From the cladogram of Lomatogonium (Fig. 5 ), L. perenne appears to occupy the most plesiomorphic node. This is an indication that it is the extant species closest to the ancestral form and it also implies that the ancestral species may reside in the habitat of this species (the Qinlin-Hengduan Mountain region). On the other hand, a umber of species of Swertia Sect. Swertia also occur in this region today, which indicates that the Qinlin-Hengduan Mountain region may well be the original center of Lomatogonium. From the distribution pattern of L. rotatum, it can be concluded that the time of the origin dates back at least before the Pliocene. After emergence, this genus had first developed and dispersed in the original center and adjacent region, then diverged into two lineages. One gave rise to the widespread species (northern temperate distribution species L. carinthiacum and L. rotatum), and the other formed the Himalayan species.A taxonomic revision of the whole genus Lomatogonium is presented. In this paper, one new section (Sect. Sarcorhizoma), one new species (L. zhongdianense S. W. Liu et T. N. Ho) and one new variety (L. forrestii var. densiflorum S. W. Liu et T. N. Ho) are described. The key to the species is given. Type studies are made for all the taxa.  相似文献   

12.
Ten years after the large-scale tsetse control campaigns in the important cattle rearing areas of the Faro and Deo Division of the Adamaoua Plateau in Cameroon, the seasonal distribution and abundance of tsetse flies (Glossina spp.) were determined. During a period of 12 consecutive months (January-December 2005), the tsetse population was monitored along four trap transects consisting of a total of 32 traps and two flyround transects traversing the study area, which comprised the tsetse-infested valley, a buffer zone and the supposedly tsetse-free plateau. Throughout the study period, a total of 2195 Glossina morsitans submorsitans and 23 Glossina tachinoides were captured in the traps and 1007 G. m. submorsitans (78.8% male flies) were captured along the flyround transects. All G. tachinoides and almost all G. m. submorsitans were captured in the valley. Five G. m. submorsitans were captured in traps located in the buffer zone, whereas no flies were captured in traps located on the plateau. The index of apparent abundance (IAA) of G. m. submorsitans was substantially higher in the areas close to game reserves. In the remaining part of the valley, where wildlife is scarce and cattle are present during transhumance (dry season), the IAA of tsetse was substantially lower. In this part of the valley, the abundance of tsetse seemed to be associated with the presence of cattle, with the highest IAA during transhumance when cattle are present and the lowest apparent abundance during the rainy season when cattle have moved to the plateau. It is concluded that the distribution of tsetse in a large part of the valley undergoes substantial seasonal changes depending on the presence or absence of cattle. The repercussions of those findings for the control of tsetse in the valley and the probability of reinvasion of the plateau are discussed.  相似文献   

13.
Microctonus hyperodae is a solitary endoparasitoid of the Argentine stem weevil, Listronotus bonariensis. Early investigation into the biology of the parasitoid indicated that there was no discrimination between parasitized and unparasitized hosts. However, dissection data from two experiments were analyzed according to three mathematical models. Model I was based on the Poisson distribution and assumed random selection of hosts. The host discrimination model (model II) assumed that parasitized hosts had reduced attractiveness to searching parasitoids. A competition model (model III) made the assumption that competition between the early immature parasitoid stages led to premature mortality, which was not accounted for in the dissection results. The dissection data indicated statistically significant departure from the Poisson model. Results from the laboratory experiment indicated that host discrimination explained the results more accurately than parasitoid larval competition. Models II and III both provided adequate fits to the field data, although the departure from the observed data was greatest for the competition model. Both intra- and inter-ecotypic host recognition were evident, and there was some indication that clonal recognition took place. This is the first evidence of host discrimination by a member of the genus Microctonus. It has provided further indication of the success of M. hyperodae as a biological control agent.  相似文献   

14.
Research on the influence of sea level variations on the benthic faunas have been carried out in the Upper Ordovician of Sardinia. Study of the depositional facies and sequence analysis of the upper part (Lower Ashgill) of the Portixeddu Formation led to the identification of the sedimentary environments. Cystoids and crinoids are associated to bryozoans and brachiopods in most levels. The numerical analysis of associations and megaguilds shows that crinoids and cystoids have a higher frequency in the proximal and median facies of the upper offshore. The columnal association characterized by Conspectocrinus celticus and the coronoid Mespilocystites tregarvanicus has been discovered in the upper part of the formation. This material and complementary samples from Upper Ordovician of Sardinia and Kabylia (Algeria) bring additional data on the systematic and show the wide distribution of this fauna outside of the Ibero-armorican domain. The distribution of this echinoderm association supports a palaeogeographical position of the Ibero-armorican domain and Sardinia within the north gondwanan margin during the Lower Palaeozoic.  相似文献   

15.
We describe a new genus and species of the diatom family Stephanodiscaceae with light and scanning electron microscopy from Libo Small Hole, Libo County, Guizhou Province, China. Edtheriotia guizhoiana gen. & sp. nov. has striae across the valve face of varying lengths, and are composed of fine striae towards the margin and onto the mantle. Many round to stellate siliceous nodules cover the exterior of the valve. External fultoportulae opening are short tubes; the opening of the rimportula lacks a tube. Internally a hyaline rim is positioned near the margin. Marginal fultoportulae possess two arcuate opercles. Areolae have domed cribra on the valve face. Those near the margin do not open to the interior. One to three sessile to slightly‐raised rimportulae are placed on the valve face towards the margin; they do not terminate shortened striae towards the center of the valve. This suite of features distinguishes this group from other known genera in the Stephanodicaeae. Cyclotella shanxiensis is transferred to Edtheriotia, making the new combination E. shanxiensis (Xie & Qi) Kociolek et al. comb. nov. It differs from E. guizhoiana by the presence of open pores near the margin of the valve. Features of the new genus are compared and contrasted with others in the Family Stephanodiscaceae. The two species of the genus, unlike most in the family, are known only from rivers and ponds from China and Japan.  相似文献   

16.
The Lias and Dogger series in the southern Paris Basin outcrops are precisely dated following the ammonite biozonation scale. In these series, the depositional environment context is accurately identified and thus various isopic zones can bee recognized. From the outcrop study, the depositional sequence and the tectonics events are also distinguished. The poorly dated subsurface data should be not anymore interpreted as diagraphic signatures, with the traditional peak to peak correlation. They now need to be analysed according to the geodynamic evolution of each isopic zone. The Liassic transgressive series (in the Armorican continent) and the Dogger platforms numerous carbonate bodies are correlated at biostratigraphic scale, throughout the whole southern Paris Basin. Subsequently, paleogeographic maps are established and based on depositional sequences. The basin evolution image changes radically. This shows clearly that the complexes carbonate bodies layout prohibits any depositional environment interpretation and any isopach mapping at geological stage level. If not, the carbonate platforms of different age would be amalgamated, without any connection with the reality. Over the time, paleogeographic maps show syn-sedimentary short wavelength deformations, more or less well expressed according to the local sedimentary context. During the Lias and the Dogger, three steps can be distinguished in the southern Paris Basin. Hettangian to Lower Aalenian, the progressive increase in accommodation drives to total immersion of the continental areas; the maximum of accommodation during the Middle Toarcian entails uniform sedimentary conditions. However, short wavelength deformations persist. The major accidents defining the isopic zones are mainly North-South oriented. Middle Aalenian to Middle Bathonian, isopic zones are contrasted, controlled by the North-South accidents but also the North West-South East ones ; the variable accommodation allowed the development of regional sedimentary gaps and shallow limestone progradations on a marly area (so called “Sillon marneux”) ; tectonics events correspond to the Tethyan and the North Sea riftings influences. Upper Bathonian to Upper Oxfordian, the North West-South East tectonics accidents are particularly active; this tectonic phase could be associated to the thermal event, described in the Paris Basin and announcing the Malm depositional environment.  相似文献   

17.
The development of the egg-apparatus (consisted of an egg cell and two synergids) of rice ( Oryza sativa L. ) was studied at the uhrastructural level. The walls of the egg cell and synergids, immediately after their formation, possessed numerous plasmodesmata. Plasmodesmata were also present on walls between the egg cell and synergids. During the enlargement phase of the egg cell and synergids, the walls at the tip region began to loosen and vesiculate. By the time the embryo sac became mature, the part of the wall of the egg cell and synergids, facing the chalaza, disappeared. Consequently, the tip regions of the egg cell and synergids were only protected by a plasma membrane. When the embryo sac reached full maturity, the upper and middle region of the wall of the synergids broke up into pieces. At that time one synergid began to degenerate. Plasmodesmata persisted at the hook region of the wall of both the egg cell and synergids. Most plastids in the egg cell contained starch grains that persisted throughout the period of the embryo sac development. Starch grains in the plastids of the synergids appeared only before the time when the two polar-nuclei moved into the region above the egg-apparatus. They then disappeared and did not appear again until the embryo sac had reached full maturity. The size and location of the vacuoles in the egg cell were different from those in the synergids. The time of formation was also different. Vacuoles in the egg cell formed late in comparison with the synergids. Vacuoles in the chalazal region of the egg cell (especially at the early stage of the embryo sac development) were much larger than those in the micropylar region. Vacuoles in the synergids tended to concentrate mainly in the chalazal region. There was a peak period of lipid formation in the two synergids. The peak appeared when the embryo sac neared maturity. At the early stage of development, the nuclei of the synergids were elliptical in shape and were situated at the central region near the micropyle. The shape of the nuclei at the late stage of development became less regular and tended to move more towards the micropylar region. Changes in the uhrastructure of the egg cell and synergids of rice appeared to be closely related to the metabolic processes controlling the embryo sac formation and development.  相似文献   

18.
Three species of epiphytic Dischidia have been investigated in terms of their relationship to ants on trees. Two species, D. parvifolia and D. astephana , are associated with ants and trees in montane areas. A clear association has been found between ants of the genus Crematogaster and the tree Leptospermum flavescens. This relationship is complex and probably both organisms benefit from the association. The ants live in tunnels in the wood of the major branches and the trunk, and the entire tree is occupied by one ant colony. Trees occupied by ants are maintained by the ants substantially clear of epiphytes other than the two species of Dischidia. The potential benefits to the tree and to the ants of this association are noted. The roots of D. astephana and D. parvifolia penetrate into the cavities of these ant nests and presumably gain nutrients from waste in the ant nests. Both Dischidia species are effectively scavenging upon the waste material from the ant-tree association. The leathery dome-shaped leaves of D. astephana are not vital to the development of the scavenging habit as D. parvifolia has lens-shaped leaves, but may offer some advantage to D. astephana by the uptake of nutrients from waste deposited by the ants under the dome-shaped leaves by interception of stem flow and by uptake of gaseous waste. Ants do not nest under these leaves. Seeds of these species of Dischidia are taken by ants into the central woody area of the ant nest where they germinate. Both Leptospermum and Dischidia can be visualized as showing adaptations to a nutient-deficient tropical montane environment. These adaptations are discussed as is the need for reassessment in this genus of the term 'ant-plant', and the need for wider recognition of the 1ant-tree' relationship between Crematogaster and Leptospermum.  相似文献   

19.
In the newly laid egg of the mayfly Ephemera japonica, an egg nucleus (oocyte nucleus) at metaphase of the first maturation division is in the polar plasm at the mid-ventral side of the egg, and a male pronucleus lies in the periplasm beneath a micropyle situated just opposite the polar plasm or at the mid-dorsal side of egg. The maturation divisions are typical. An extensive and circuitous migration of the male pronucleus is involved in the fertilization process: it first moves anteriad in the periplasm from beneath the micropyle to the anterior pole of the egg and then turns posteriad in the yolk along the egg's long axis to the site of syngamy, near the center of the egg. Cleavage is superficial. The successive eight cleavages, of which the first five are synchronized, result in the formation of the blastoderm, and about ten primary yolk cells remain behind in the yolk. Even in the newly formed blastoderm, the thick embryonic posterior half and the thin extraembryonic anterior half areas are distinguished: the former cells are concentrated at the posterior pole of the egg to form the germ disc, and the latter cells become more flattened, forming serosa. Time-lapse VTR observations reveal a yolk stream that is in accord with the migration of the male pronucleus in time and direction. The yolk stream is also generated in activated unfertilized eggs, and it is probable that the migration of the male pronucleus in association with the fertilization may be directed by the yolk stream. J. Morphol. 238:327–335, 1998. © 1998 Wiley-Liss, Inc.  相似文献   

20.
This paper provides a taxonomic revision of Pandanus sect. Martellidendron , which so far comprises six species of which only one is known from both staminate and pistillate plants. Research in herbaria and in the field in Madagascar has provided the data on which a revision of the unclear taxonomy of this section can be based. Based on micromorphology, architecture and phytogeography, the number of these dioecious species is reduced. One new species (P. gallinarum Callmander) from the Biosphere reserve of Mananara-North on the east coast is described, and P. karaka Martelli is transferred to this section 30 years after it was assigned to section Dauphinensia. A key to all species of subg. Martellidendron is provided. Finally, the important role of the section for the understanding of the phylogeny of the Pandanaceae is discussed in the context of Indian Ocean biogeography.  相似文献   

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