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1.
Twenty-one individuals each of the species great tits (Parus major), blue tits (Parus caeruleus), marsh tits (Parus palustris), blackbirds (Turdus merula), songthrushes (Turdus philomelos), tree sparrows (Passer montanus) and house sparrows (Passer domesticus) were conditioned to a keypeck response by means of food reinforcement. The site where the reward was given was then changed. The number of reinforcements were then counted until the keypeck response followed immediately (within 10 seconds) on three successive occasions, and a comparison was made between species. Of the species studied the blackbird needed significantly fewer instances of reinforcement in order to re-establish an immediate keypeck response. A significant difference was also seen between the performance of the great tit and marsh tit, as well as between the blue tit and the marsh tit. No significant difference was found between the performance of the house sparrow and the tree sparrow.  相似文献   

2.
Foreign DNA has been introduced into the genome of bacteriophage Ø3T, producing a specialized transducing bacteriophage containing the genetic information encoding α-amylase from BacillusamyloliquefaciensH. Genetic and physical studies demonstrated that the gene(s) is inserted into the bacteriophage genome. These bacteriophage carrying the gene(s) encoding α-amylase lysogenized and replicated in Bacillussubtilis with normal efficiency. In these lysogens, the gene(s) encoding α-amylase appears to map near the bacteriophage attachment site rather than the chromosomal amyE locus. This method of construction of specialized bacteriophage should be applicable to the cloning of other genes for which no primary selection exists.  相似文献   

3.
The effect of a deficiency in DNA polymerase on recombination in Bacillussubtilis has been studied. It is concluded that the major DNA polymerase of B.subtilis is not required for recombination, and that the recombination deficiency of a previously described DNA polymerase-deficient mutant is actually due to a rec mutation. Genetic crosses imply that this recombination deficiency is not recA or recB.  相似文献   

4.
A soluble, cytochrome P-450-containing system from Bacillusmegaterium which catalyzes the monohydroxylation of long-chain saturated fatty acids has now been found to convert palmitoleic acid to 9,10-epoxypalmitate and 9,10-dihydroxypalmitate in addition to the expected isomeric mixture of monohydroxypalmitoleic acids.  相似文献   

5.
Acrystalliferous strains of Bacillusthuringiensis subsp. kurstaki were isolated at a high frequency following heat treatment of spores. Spores of these strains lacked a 130,000 dalton glycoprotein, the major component common to both parasporal crystals and coats and were nontoxic to tobacco hornworm larvae. Moreover, the deficiency of this glycoprotein resulted in lysozyme sensitivity of the spores of some mutants and the presence of new spore coat proteins in others. All nontoxic acrystalliferous mutants lacked the complete array of at least six plasmids present in the wild type, implying a relationship between presence of plasmid(s) and toxicity. The unique capacity of this species to alter the surface coating of spores which appears to be related to crystal formation may provide flexibility for germination and growth in diverse soil environments.  相似文献   

6.
A soluble epoxide hydrase which catalyzes the hydration of 9,10-epoxypalmitic acid has been partially purified from cell-free preparations from Bacillusmegaterium ATCC 14581. The hydrase can be cleanly separated from a soluble cytochrome P-450-dependent monooxygenase complex, previously demonstrated in this bacterium, that can catalyze the epoxidation of palmitoleic acid.  相似文献   

7.
Cyclic AMP was not found in vegetative cells or sporulating cells or dormant spores of Bacillusmegaterium using an assay which would have detected an invivo concentration of 1 – 2 × 10?9 M. Adenyl cyclase and cyclic AMP phosphodiesterase were also not detected in sonicates of vegetative or sporulating B.megaterium cells.  相似文献   

8.
N-(5-dimethylamino-1-napthalene sulfonyl)-3-aminobenzene boronic acid (Dns-PBA) and N,N′-bis-3(dihydroxylborylbenzene)adipamide (Bis-PBA) were synthesized. The former is found to reversibly associate with Bacillussubtilis, apparently through boronate diester linkages with carbohydrates on the cell surface. The latter displays the lectin-like property of agglutinating red blood cells.  相似文献   

9.
10.
Uracil-DNA glycosylase of Bacillussubtilis is involved in repair of deaminated cytosine residues of DNA. Survivals of SPO2 phage after treatment with bisulfite and weak alkali are considerably higher in wild type strains than in urg mutants, which are deficient in the enzyme activity, whereas survivals of bisulfite/alkali-treated PBS1 phage in the two types of cells are essentially the same. The spontaneous mutation frequency of a urg mutant is three fold higher than is that of a wild type strain.  相似文献   

11.
Two new nucleotides have been found in the formic acid extracts of Escherichiacoli, Clostridiumbotulinum, Bacillussubtilis and Rhodospirillumrubrum isolated during log phase growth. In E.coli the compounds are present at all times during cell growth but increase in amount during interruption of aeration and transition to stationary phase. They migrate close to ppGpp during one dimensional chromatography on PEI cellulose but are clearly separated from ppGpp by paper chromatography. The compounds are unstable on PEI cellulose and purification was effected by chromatography on A25 Sephadex ion exchange columns. Preliminary characterization indicates that the predominant compound is a dinucleoside polyphosphate and that both compounds contain a modified adenosine nucleoside.  相似文献   

12.
The present communication describes a comparative study of some enzymatic properties of an early and a late aconitase (EC.4.2.1.3) present in Bacilluscereus T cells of 5 and 12 hr culture age, respectively. The activity of both enzymes increased linearly with increase in enzyme concentration. They demonstrated similar pH *7.5) and temperature (30 C) optima, but differed in their activation energy and affinity for substrate. Late aconitase had higher activation energy (16,100 cal) as compared to early aconitase (9,200 cal). Early aconitase showed a Km value of 100 × 10?4M for sodium citrate and 33.3 × 10?4M for isocitrate. Late aconitase exhibited 5 to 7 times greater affinity for citrate and isocitrate yielding Km values 14 × 10?4M and 7 × 10?4M, respectively. On the basis of available evidence, it is suggested that early and late aconitase present in 5 and 12 hr aged cells of Bacilluscereus T behave as isozymes, and may be designated as aconitase (EC.4.2.1.3) isozyme I and aconitase (EC.4.2.1.3) isozyme II, respectively. The significance of their plausible role during growth and sporulation has been discussed.  相似文献   

13.
α-Glucosidase was membrane bound during exponential growth of Bacilluslicheniformis but was released into the medium during stationary phase. It could be partially removed from exponential phase cells by washing with NaCl (0.5 M). α-Amylase was exclusively extracellular and could not be detected in cells. Polysomes were prepared from exponential phase cells and separated into membrane bound and soluble fractions. Invitro chain completion and immunoprecipitation showed that α-glucosidase and α-amylase were synthesized by membrane bound and not by soluble ribosomes.  相似文献   

14.
The plasma membrane-bound penicillinase of Bacilluslicheniformis749C has been purified. Amino acid analysis showed no significant differences in composition between the enzyme and exopenicillinase. Enzyme purified from cultures containing H333PO4 or [3H]-glycerol contained 33P or [3H]-glycerol activity and treatment with 8 M urea, 0.2% sodium dodecyl sulfate at 80° C did not remove the 3H-activity from the enzyme protein. Trypsin readily cleaved the glycerol-containing moiety from the enzyme protein, forming enzyme with molecular weight and heat stability like that of the exoenzyme. Phospholipase D and C also produced enzyme resembling the exo-form.  相似文献   

15.
Mutants which had a genetic character to increase the production of both α-amylase and protease simultaneously, were isolated from a transformable strain of Bacillussubtilis Marburg by NTG treatment. This mutation seems to have occurred at a single gene of the bacterial chromosome and was not linked to aro116 which was closely linked to the α-amylase gene. When this mutation and an α-amylase regulator gene (amyRh) coexisted in one strain, their synergistic effect on extracellular α-amylase production ws observed. The introduction of this mutation resulted in a loss of competence for the transformation. The SDS disc gel electrophoretic profiles of the membrane proteins from the original strain, the mutants and transformants with this mutation showed a remarkable difference in one component.  相似文献   

16.
Several tunicamycin resistant mutants were obtained from Bacillussubtilis NA64. One of them, B7 strain produced a 5-fold larger amount of α-amylase than NA64 did. Only the amount of α-amylase, among excreted proteins, was enhanced. Genetic analyses by transformation suggested that a single mutation in B7 induced both resistance to tunicamycin and hyperproductivity of extracellular α-amylase.  相似文献   

17.
A spontaneous mutant of Bacillussubtilis resistant to killing by two hydroxyphenylazopyrimidines has been isolated. The DNA polymerase III of this mutant is resistant to inhibition by these drugs. The Ki for 6-(p-hydroxyphenylazo)-uracil (HPUra) is 20 μM, about 40 times higher than the Ki of the wild-type enzyme. The mutant and wild-type polymerases behave similarly during purification, are sensitive to N-ethylmaleimide and to 0.1 M KCl, and have the same Km for dGTP (0.5 μM). The HPUra inhibition of both enzymes is attenuated competitively by dGTP. We conclude that polymerase III is the target for hydroxyphenylazopyrimidines invivo, and since the drugs specifically inhibit replicative DNA synthesis, polymerase III is necessary for DNA replication.  相似文献   

18.
The insecticidal toxin of Bacillusthuringiensis subsp. kurstaki was isolated from parasporal crystals. The toxin, which is stable for several months, is a glycoprotein with an apparent molecular weight of 68,000 that is generated upon solubilization and activation of a higher molecular weight protoxin (MWapp = 1.3 × 105) at alkaline pH. The toxin was purified by gel filtation and anion exchange chromatography and its molecular weight was established by gel filtration chromatography and SDS polyacrylamide gel electrophoresis.  相似文献   

19.
A non-alkalophilic mutant strain of Bacillusalcalophilus grows on L-malate over a pH range from 5.0 to 9.0. The mutant does not exhibit the energy-dependent efflux of Na+ that has been used to assay a Na+H+ antiporter in the wild type organism. The mutant also fails to transport α-aminoisobutyric acid, at pH 9.0, either in the presence or absence of Na+; at pH 5.5, the amino acid analogue is taken up by a Na+-independent mechanism. The properties of the mutant constitute strong evidence that the Na+H+ antiporter is involved in maintaining an acidified cytoplasm in B. alcalophilus.  相似文献   

20.
Glutamate synthase, an important enzyme in the assimilation of ammonia, was measured in cultures of Bacillussubtilis grown with different nitrogen sources. An attempt was made to correlate the specific activity to the intracellular levels of five metabolites of glutamate metabolism: aspartate, glutamate, glutamine, alanine and NH4+. An inverse relationship was found between the activity of glutamate synthase and the pool level of glutamine. We propose that the intracellular concentration of glutamine is an important element in controlling the level of glutamate synthase.  相似文献   

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