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1.
To date, a number of bacteriophages (phages) infecting Acinetobacter species have been reported and characterized. However, Acinetobacter phages which infect A. soli have not been investigated yet. Here, we report the complete genome sequence of Acinetobacter phage phiAC-1, which belongs to the Myoviridae, infecting Acinetobacter soli strain KZ-1.  相似文献   

2.
Archaeobotanical studies were undertaken at the Yuergou site, which is located in the Turpan basin in Xinjiang, China, and which has been dated to around 2300–2400 years b.p. Altogether 21 taxa were identified. Four cereal remains were identified, Triticum aestivum, Hordeum vulgare var. coeleste, Panicum miliaceum and Setaria italica. The first three were probably cultivated while the last one may not have been grown deliberately, but probably grew together with plants of P. miliaceum. A fruit stone of Ziziphus jujuba (Chinese date) was discovered, which showed that this may have been cultivated around the site during that time. Charcoal of Picea sp. was found, from wood which must have been used as fuel by the indigenous people. Fifteen taxa of wild plants were also identified, most of which can be considered as weeds, and which grew near the site. Burs of Xanthium strumarium were discovered. As nearly all of them were broken, the seeds may have been used by the ancient inhabitants. Since most of the cereal remains consisted of chaff, they must represent by-products. Furthermore, grains of Echinochloa crus-galli may also have been exploited as complementary food resources. All the above indicate that both cultivated and wild plants were used for cereals, fuel, or other purposes, and plant resources played important roles in the daily life of the ancient inhabitants of the Yuergou site.  相似文献   

3.
φ80 transducing phages for the proC2, phoA and phoB genes of Escherichia coli have been obtained. Two mutants have been isolated, in which the brnQ, phoA, proC, phoB (and possibly phoR) genes have been deleted. Derivatives of a phoA, phoB deletion strain which are lysogenic for a φ80phoA transducing phage make only very low levels of alkaline phosphatase activity. These results are in agreement with a positive control mechanism for the regulation of alkaline phosphatase synthesis.  相似文献   

4.
A number of abnormal polypeptides which are products of the lacZ gene in Escherichia coli have been characterized. A variety of experiments indicates that one class of at least nine different fragments arises from premature termination of protein synthesis. They have been detected as products of protein synthesis both in vitro and in vivo, although the percentage of fragments made in vitro is greater than that in vivo. The percentage of total Z gene-encoded protein which is found as fragments is estimated to be roughly 23% in vivo. This means that about 31% of the total number of β-galactosidase monomers synthesized are prematurely terminated molecules. The average molecular weight of the polypeptides produced is 91,000. This corresponds to a termination event occurring on the average once every 3200 codons. The sites at which termination occurs appear to be specific and are located primarily near the 3′-end of the gene.Polypeptides synthesized in vitro and in vivo from templates containing mutations in the Z gene have also been compared. Most of the mutationally generated fragments synthesized in vitro are stable, unlike their in vivo counterparts, which are often rapidly degraded. One fragment, however, generated by an early amber mutation in the Z gene, is degraded in the in vitro system. The mechanism of degradation appears to be specific for small abnormal polypeptides. Internal reinitiation polypeptides generated by nonsense mutations, which have been found in vivo, are not detected in the in vitro protein synthesis system under the conditions used here.  相似文献   

5.
《Phytochemistry》1986,25(5):1143-1150
A GC/MS examination of extracts of Lycopodium clavatum var. borbonicum and L. deuterodensum revealed alkaloids which had not been previously observed in these species. New alkaloids have been found in L. australianum and in L. fastigiatum, two species which had not been investigated before.  相似文献   

6.
The culture media from gametophore over-producing mutants of the moss Physcomitrella patens have been examined for their cytokinin content. Two cytokinins have been detected, one of which has been identified as N6-(Δ2-isopentenyl) adenine (2iP).  相似文献   

7.
Literature on the occurrence and toxicology of Alternaria mycotoxins shows that a wide range of Alternaria metabolites have been described although relatively few have been fully characterised. It has been reported that about half of the wild-type Alternaria cultures tested are highly toxic to mammals or birds but the compounds responsible have rarely been identified. Very little information is available on the nature or incidence of Alternaria mycotoxins in commodities grown in the UK. Preliminary results of an investigation of UK foods demonstrate the presence of several cytotoxic compounds in an ethyl acetate extract from an A. alternata culture. A toxic fraction has been isolated which appears to contain a compound not previously identified as an Alternaria mycotoxin.  相似文献   

8.
《Carbohydrate research》1986,147(2):191-203
Complexes between borate ion and cyclohexane-cis-1,2-diol, cyclohexane-cis,cis-1,3,5-triol, and myo- and epi-inositol have been investigated by 11B-n.m.r. spectroscopy. Three different complexes of myo-inositol have been identified. Formation constants have been determined for the borate complexes of each cyclitol. Where the complex is formed from the less-stable chair conformer, MNDO calculations have been performed to determine the enthalpies of inversion. For myo-inositol, an iterative method of calculation gave a set of constants which provided a good match with experimental data and supported the proposed formulation of its borate complexes.  相似文献   

9.
Malouetine and funtumafrine C have been isolated from the leaves of Malouetia brachyloba, indicating that this species is not very different from M. bequaertiana. Five conanine derivatives have been extracted from the leaves of M. heudelotii, a species which does not contain any alkaloid with a quaternary ammonium function.  相似文献   

10.
The coral species Leptoseris troglodyta sp. n. (Scleractinia, Agariciidae) is described as new to science. It is the first known azooxanthellate shallow-water agariciid and is recorded from the ceilings of caves at 5-35 m depth in West Pacific coral reefs. The corals have monocentric cup-shaped calices. They may become colonial through extramural budding from the basal coenosteum, which may cause adjacent calices to fuse. The size, shape and habitat of Leptoseris troglodyta are unique compared to other Leptoseris species, many of which have been recorded from mesophotic depths. The absence of zooxanthellae indicates that it may survive well in darkness, but endolithic algae in some corals indicate that they may be able to get some light. The presence of menianes on the septal sides, which may help to absorb light at greater depths in zooxanthellate corals, have no obvious adaptive relevance in the new species and could have been inherited from ancestral species that perhaps were zooxanthellate. The new species may be azooxanthellate as derived through the loss of zooxanthellae, which would be a reversal in Leptoseris phylogeny.  相似文献   

11.
Flavonoid profiles of Solanum sections Petota, Basarthrum, Solanum and Androceras have all proved to be useful in the delineation of species and series boundaries. A total of sixty-four flavonols have been isolated from these four sections, forty of which have been fully characterized. Flavonol glycosides of kaempferol and quercetin are confirmed as the flavonoids characteristic of this genus but in addition methylated and acylated compounds have also been isolated. By combining existing data, it is possible to develop a phylogenetic scheme illustrating the relationship between each section on the basis of the biosynthetic complexity of their flavonol substitution patterns. Sections Petota and Basarthrum appear to be more ‘primitive’ than sections Solanum and Androceras.  相似文献   

12.
13.
(14C-Carbinol)benzyl alcohol taken up through the roots of greenbug (Schizaphis graminum) resistant barley is metabolized into a large number of radioactive compounds which have been separated by ion exchange chromatography. Two of these acidic metabolites have been identified as O-benzoyl-l-malic acid and N-benzoylaspartic acid; these identifications were confirmed by synthesis.  相似文献   

14.
Two DNA fragments which contain the Escherichia coli tryptophan promoter-operator region but lack the attenuator have been used in the construction of a series of pAT153 based plasmids suitable for the regulated expression of foreign genes in E. coli. The first, a 139-bp HhaI fragment includes 59 bp of the trp leader sequence, ending within the “attenuator peptide” coding sequence, eleven codons from the N-terminus. A fusion-type expression plasmid incorporating this fragment has been constructed. The second, a 99-bp HaeIII-TaqI fragment contains no coding sequence but includes the “attenuator peptide” SD site situated 4 bp upstream of the TaqI site. This fragment has been incorporated in expression vectors which result in the direct expression of cloned gene sequences. To further maximise expression, plasmids with directly repeating trp promoter HaeIII-TaqI units have been constructed.  相似文献   

15.
Chemical modification experiments on the tyrosyl-tRNA synthetase/tRNAtyr system of Bacillus stearothermophilus reported by Bosshard et al. (1975,1978) which have been interpreted in terms of a binding scheme with one binding site that spans two subunits have been re-evaluated by a more rigorous procedure. The results show that the experiments of Bosshard et al. are in agreement with the antico-operative binding model that has been demonstrated for the Escherichia coli system.  相似文献   

16.
17.
Pungency in peppers is due to the presence of capsaicinoid molecules, which are only produced in Capsicum species. The major gene Pun1 is required for the production of capsaicinoids. Three distinct mutant alleles of Pun1 have been found in three cultivated Capsicum species, one of which has been widely utilized by breeders. Although these mutations have been previously identified, a robust collection of molecular markers for the set of alleles is not available. This has been hindered by the existence of at least one paralogous locus that tends to amplify with Pun1. We present a suite of markers that can differentiate the four Pun1 alleles and test them on a diverse panel of pepper lines and in an F2 population segregating for pungency. These markers will be useful for pepper breeding, germplasm characterization, and seed purity testing.  相似文献   

18.
Fully subtituted di-O-acetyl-N-acetylchitosan (chitin diacetate) has been prepared by a route in which the hydroxyl groups are acetylated prior to N-acetylation. This overcomes the previously reported intramolecular steric hindrance to esterification caused by the N-acetamido group. The resultant products were of high viscosity but had a limited solubility range. Di-O-acrylcarbamate derivatives of N-acetylchitosan (chitin) have been produced by a similar route, whilst di-O-arylcarbamate-N-arylureidochitosans have been prepared directly from chitosan. These products also have limited solubility ranges and have inherent viscosities similar to that of di-O-acetylchitosan prepared from the same batch of chitosan.  相似文献   

19.
From Lathyrus odoratus treated with mercuric acetate (cotyledons, pods) or with Phytophthora megasperma var. sojae-elicitor (cotyledons) a number of fungitoxic stress metabolises have been isolated, among which are two novel α-hydroxydihydrochalcones (odoratol and methylodoratol). Their structures have been elucidated.  相似文献   

20.
A lot of Stringocephalidae have been discovered,for the first time, in the Givetian of Afghanistan. Among these we have identified: Stringocephalus aff. burtini (Defrance)), St. (Parastringocephalus) dewalense n. sp., Rensselandia aff. circularis (Holzapfel)). The locality is situated in Hazarajat, in a Devonian sequence which is more than one thousand meters thick and the age of which ranges from Gedinnian (probable) to Frasnian.  相似文献   

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