Ester production in E. coli and C. acetobutylicum

Genetic engineering has improved the product yield of a variety of compounds by overexpressing, inactivating, or introducing new genes in microbial systems. The production of flavor-enhancing ester compounds is an emerging area of heterologous gene expression for desired product yield in Escherichia coli. Isoamyl acetate, butyl acetate, ethyl acetate, and butyl butyrate are reported here to be produced by expressing Saccharomyces cerevisiae genes ATF1 or ATF2 and the strawberry gene SAAT in E. coli when the appropriate substrates are provided. Increasing the concentration of alcohol added to the reaction generally resulted in increased ester production. ATF1 expression was found to produce more isoamyl acetate and butyl acetate than ATF2 expression or SAAT expression in the strains and culture conditions examined. Additionally, SAAT expression resulted in greater isoamyl acetate and butyl acetate production than ATF2 expression. Butyl butyrate is produced by cell-free extracts of E. coli harboring SAAT but not ATF1 or ATF2.     

Quinua and Relatives (Chenopodium sect.Chenopodium subsect.Celluloid)

Traditionally viewed as an Andean grain crop,Chenopodium quinoa Willd. includes domesticated populations that are not Andean, and Andean populations that are not domesticated. Comparative analysis of leaf morphology and allozyme frequencies have demonstrated that Andean populations, both domesticated(quinua) and free-living(ajara), represent an exceptionally homogeneous unit that is well differentiated from allied domesticates of coastal Chile(quingua) and freeliving populations of the Argentine lowlands(C. hircinum). This pattern of relationships indicates that Andean populations represent a monophyletic crop/weed system that has possibly developed through cyclic differentiation (natural vs. human selection) and introgressive hybridization. Relative levels of variation suggest that this complex originated in the southern Andes, possibly from wild types allied withC. hircinum, with subsequent dispersal north to Colombia and south to the Chilean coast. Coastal populations were apparently isolated from post-dispersal differentiation and homogenization that occurred in the Andes. Other data point toward a center of origin in the northern Andes with secondary centers of genetic diversity subsequently developing in the southern Andes and the plains of Argentina. Comparative linkage of South American taxa, all tetraploid, with North American tetraploids of the subsection will eventually clarify this problem. While the possibility of a direct phyletic connection betweenC. quinoa and the Mexican domesticate(C. berlandieri subsp. nuttalliae,) cannot be excluded, available evidence indicates that the latter represents an autonomous lineage that is associated with the basal tetraploid, C. b. subsp.berlandieri, through var.sinuatum, whereas South American taxa show possible affinities to either var. zschackei or var.berlandieri. An extinct domesticate of eastern North America,C. b. subsp.jonesianum, represents either another instance of independent domestication, possibly from subsp. b. var.zschackei, or a northeastern outlier of subsp.nuttalliae.     

两种广西特有报春苣苔属(苦苣苔科)植物传粉生物学研究

通过野外观察和室内试验,对两种广西特有的桂林小花苣苔和阳朔小花苣苔的传粉生物学进行比较研究。结果表明:两种报春苣苔属植物花期从7月底至8月初;单花花期内花粉具有较高的活性,最高可达92.6%和94.5%;柱头可授性最高时可达90%和95%;花粉/胚珠比率(P/O)分别为110.28±17.45和229.65±18.00;柱头与花药之间存在着空间隔离,可防止自花授粉;在单花花冠裂片张开后第3天,花药开始散粉,但雌蕊在花朵刚开始开放时已伸长,待第3天时柱头已伸长到位于花冠筒口部,高于花药,便于接受异花花粉;该两种植物均不存在无融合生殖现象;两种报春巨苔属植物均高度自交亲和,但很难发生自发的自花授粉,必须依靠外力,因此传粉媒介对于结实率有重要影响,自然条件下基本不发生自花授粉;在自然状态下结实率明显低于两种人工授粉的结实率;小蜂和淡脉隧蜂是目前已知仅见的两种传粉者。     

Presence of Rhizobium Etli bv . Phaseoli and Rhizobium Gallicum bv . Gallicum in Egyptian Soils

Seven bean rhizobial strains EBRI 2, 3, 21, 24, 26, 27 and 29 identified as Rhizobium etli, and EBRI 32 identified as Rhizobium gallicum, isolated from Egyptian soils and which nodulated Phaseolus vulgaris efficiently, were subjected to hybridization with a nifH probe in order to estimate the copy number of this gene. Seven strains (EBRI 2, 3, 21, 24, 26, 27 and 29) which were only able to nodulate Phaseolus vulgaris, contained three copies of the nifH gene, consistent with their identification as Rhizobium etli bv. phaseoli. Only one strain (EBRI 32) which nodulated both Phaseolus vulgaris and Leucaena leucocephala, had one copy of nifH gene. This confirmed the classification of this strain as Rhizobium gallicum bv. gallicum.     

Genome constitutions of Pseudoroegneriageniculata, P. geniculata ssp. scythica and P. geniculata ssp. pruinifera (Poaceae: Triticeae) revealed by genomic in situ hybridization

Genomic constitutions of three taxa of Pseudoroegneria á. L?ve, P. geniculata, P. geniculata ssp. scythica, and P. geniculata ssp. pruinifera, were characterized using genomic in situ hybridization (GISH). The results indicated that ploidy level and genomic constitution in the three Pseudoroegneria taxa studied were as follows: P. geniculata (2n = 4x = 28; genomic formula StSt ^g ), P. geniculata ssp. scythica (2n = 4x = 28; genomic formula ESt), and P. geniculata ssp. pruinifera (2n = 6x = 42; genomic formula EESt). P. geniculata ssp. scythica and P. geniculata ssp. pruinifera should be transferred to Trichopyrum á. L?ve following L?ve’s principles and treated as T. scythicum and T. pruiniferum, respectively.     

应恢复赤车属头序赤车组和头序赤车

头序赤车的特征在于其具花序托和总苞的雌头状花序,根据此一特征即可将它与赤车属的其它所有种区别开.因此,在2002年被错误归并为异名的此赤车属进化种,以及根据其建立的单种进化组头序赤车组在该文中予以恢复.     

Cardenolides from Asclepias asperula subsp. Capricornu and A. Viridis

6′-O-(E-4-hydroxycinnamoyl) Desglucouzarin, the first cardenolide containing a cinnamoyl ester moiety, has been isolated from the ethanolic extract of the milkweed, Asclepias asperula. In addition, five known cardenolides were isolated and identified from A. asperula and A. viridis.     

应恢复赤车属头序赤车组和头序赤车

头序赤车的特征在于其具花序托和总苞的雌头状花序,根据此一特征即可将它与赤车属的其它所有种区别开。因此,在2002年被错误归并为异名的此赤车属进化种,以及根据其建立的单种进化组头序赤车组在该文中予以恢复。     

福贡银莲花(毛茛科)与光叶银莲花属于同一分类实体

通过标本检查,发现福贡银莲花(Anemone yulongshanica W.T.Wang var.glabrescens W.T.Wang)(毛茛科)与光叶银莲花(A.obtusiloba D.Don ssp.leiophylla W.T.Wang)没有本质区别,应属于同一分类实体,故将前者处理为后者的异名。     

复轮生暗孢小克银汉霉新变种及其与原变种之间的配合

多年前分离自湖北神农架林中采回的一份土样的一株小克银汉霉Cu137最近经我们研究定名为复轮生暗孢小克银汉霉新变种(Cunninghamella phaeospora Boedijn var.multiverticillata var. nov.)。它与暗孢小克银汉霉原变种(Cunninghamella phaeospora Boedijnvar. phaeospora)的异同在于:(1)两者均具有单轴分枝、分枝单生或成对的孢子枝,不同的是新变种的孢子枝除单轴分枝外还可轮状分枝,或单轴与轮状混合分枝,轮状分枝可多达3轮,每轮由3-8分枝组成,原变种则完全不形成轮状分枝;(2)两者的孢子枝主轴上的顶生泡囊均具各种形状并略呈棱角状,但新变种的侧枝上的饱囊常常是棒形的,原变种的侧枝上的饱囊则很少棒形;(3)新变种的假根很发达,可自菌丝、匍匐菌丝、孢子枝、泡囊等部位发生,而原变种的假根一般不很发达,而且只从菌丝或甸旬菌丝发生;(4)两者的小型孢子囊在形状、大小、刺等方面一致,但新变种的小型孢子囊无色至淡褐色,原变种的小型孢子囊则为淡褐色至深褐色;(5)新变种的菌落白色,至多在老后污白色至极浅的淡褐色,原变种的菌落自始即为深灰色。除暗孢小克银汉霉原变种外,同属中还有另外三个分类群与复轮生暗孢小克银汉霉较为接近:印度小克银汉霉(Cunninghamella indica Baijal & B. S. Mehrotra)与印度刺孢小克银汉霉[Cunninghamella echinulata(Thaxt.) Thaxt. ex Blakeslee var. indica Baijal & B. S. Mehrotra]因菌落白色及孢子枝分枝棒形,轮生小克银汉霉(Cunninghamella verticillaata Paine)因孢子枝具数轮轮生分枝而与复轮生暗孢小克银汉霉这个新变种有一定的相似。但是,新变种无论是顶生泡囊还是侧生泡囊的直径都较上述三个分类群小得多;新变种的顶生饱囊往往不规则形状且略带棱角,而上述三个分类群则不是这样。还有,新变种的孢子枝分枝方式与印度小克银汉霉的颇为不同,新变种的小型孢子囊比印度刺孢小克银汉霉的小得多,其小型孢子囊主要球形至近球形,与轮生小克银汉霉的椭圆形至卵形也不一样。此外,新变种的假根系统极其发达,与同属中任何一种均不相同。将复轮生暗孢小克银汉霉新变种Cu137(+)与暗孢小克银汉霉原变种的一株分离自香港山边土壤的Cu 136(一)配合时只形成配子囊,但与原变种的模式菌株CBS 692.68(-)配合时则可形成少量的接合孢子囊。为了获得更多的接合孢子囊以观察它们是否可育的,我们将Cu 137和CBS 692.68同时接种到许多培养皿上,然后制片观察。用姆指轻轻、重复压盖玻片,可使接合孢子囊破裂以观察其内含物。结果,从100个以上的接合孢子囊中,仅在其中4个发现有接合孢子的形成,其余的都是空的和不育的。由于原变种尚未发现(+)配合型菌株,新变种则未发现(-)配合型菌株,原变种与原变种之间及新变种与新变种之间配合形成的有性型尚未获得,而且全世界均未见有报道,无法和新变种与原变种之间配合形成的有性型相比较,因此目前尚不能肯定新变种与原变种之间形成的有性型在形态上是否能代表这个种的有性型。但是,尽管如此,暗孢小克银汉霉的这两个变种之间配合形成的有性型的形态仍然是很有特征性的,足以把它与其它种的已知有性型相区别。     

Lanius collurio L. undLanius senator L.

Ohne ZusammenfassungMit Aufnahmen und Zeichnungen der Verfassers.     

Secondary metabolite profiling of Alternaria dauci, A. porri, A. solani, and A. tomatophila

Chemotaxonomy (secondary metabolite profiling) has been shown to be of great value in the classification and differentiation in Ascomycota. However, few studies have investigated the use of metabolite production for classification and identification purposes of plant pathogenic Alternaria species. The purpose of the present study was to describe the methodology behind metabolite profiling in chemotaxonomy using A. dauci, A. porri, A. solani, and A. tomatophila strains as examples of the group. The results confirmed that A. dauci, A. solani, and A. tomatophila are three distinct species each with their own specific metabolite profiles, and that A. solani and A. tomatophila both produce altersolanol A, altertoxin I, and macrosporin. By using automated chemical image analysis and other multivariate statistic analyses, three sets of species-specific metabolites could be selected, one each for A. dauci, A. solani, and A. tomatophila.     

Loss of Symbiodinium from bleached soft corals Sarcophyton ehrenbergi, Sinularia sp. and Xenia sp.

The deleterious effects of temperature-induced coral bleaching, a process by which corals lose their endosymbiotic algae (zooxanthellae; genus Symbiodinium) primarily at temperatures above mean yearly maximums, has not been well described for alcyonacean soft corals (Coelenterata, Octocorallia). The study of Symbiodinium cells lost from Sarcophyton ehrenbergi, Sinularia sp., and Xenia sp., which have not been compared in bleaching studies, indicate that the soft coral S. ehrenbergi released the greatest number of symbiont cells, however, it was less susceptible to heat stress surviving temperatures of 34 °C for >39 h. Sinularia sp. showed intermediate levels of bleaching tolerance to elevated temperatures, surviving prolonged exposures at 32 °C, but dying within 24 h at 34 °C. Xenia sp., however, was the most vulnerable to high heat stress maximally releasing Symbiodinium at temperatures ≤30 °C. This evidence indicates that Xenia sp. is even more susceptible to elevated temperatures than Acropora spp., previously reported to be the most vulnerable coral species to elevated temperature-induced bleaching.

Molecular analysis showed that the more resistant soft coral species (S. ehrenbergi) had the same type of Symbiodinium (clade C) as less resistant soft corals (Xenia sp.). In comparison to scleractinian corals collected from the same region that show similar bleaching resistance to high temperatures (e.g. Porities solida—more robust; Favites complanata—moderate resistance; Acropora hyacinthus—less robust), all scleractinian corals were symbiotic with Symbiodinium from clade C. A. hyacinthus, however, was found to possess multiple symbionts (clades B and C), and this represents a first report of Clade B in any Acropora species.     

Growth and isoflavonoid accumulation of Pueraria candollei var. candollei and P. candollei var. mirifica cell suspension cultures

We established cell suspension cultures derived from leaf, stem, and root calli of Pueraria candollei var. candollei and P. candollei var. mirifica using liquid Murashige and Skoog (MS) medium supplemented with 0.56 μM 6-benzyladenine (BA) and 4.52 μM 2,4-dichlorophenoxyacetic acid (2,4-D). Growth of the cell suspension cultures progressed to the stationary phase within 15–24 days. Methanolic extracts of cell suspension cultures of both varieties of P. candollei were analyzed using a validated HPLC protocol. All cell lines derived from leaf, stem, and root explants produced four major isoflavonoids: daidzein, daidzin, genistein, and genistin; these isoflavonoids were detected only in the roots of intact plants. Furthermore, the isoflavonoid contents of the cell suspension cultures were higher than those of intact plants. Thus, cell suspension culture of both varieties of P. candollei may be an effective tool for isoflavonoid production.     

Morphological, chemical and genetic differentiation of two subspecies of Cistus creticus L. (C. creticus subsp. eriocephalus and C. creticus subsp. corsicus)

Cistus creticus L., an aromatic species from the Mediterranean area, contains various diterpenes bearing the labdane skeleton. The production of essential oil from this species has potential economic value, but so far, it has not been optimized. In order to contribute to a better knowledge of this species and to its differentiation, the morphological characters, volatile chemical composition and genetic data of two subspecies (C. creticus subsp. eriocephalus and C. creticus subsp. corsicus) were investigated. The leaf trichomes were studied using scanning electron microscopy. The chemical composition of Corsican essential oil (C. creticus subsp. corsicus) has been reported using GC, GC/MS and ¹³C NMR; the main constituents were oxygenated labdane diterpenes (33.9%) such as 13-epi-manoyl oxide (18.5%). Using plant material (54 samples) collected from 18 geographically distinct areas of the islands of Corsica and Sardinia, the basis of variation in the headspace solid-phase microextraction volatile fraction and an inter-simple sequence repeat genetic analysis were also examined. It was shown that the two subspecies of C. creticus differed in morphology, essential oil production, volatile fraction composition and genetic data.