ABSTRACT
An increasing number of Lesbians are choosing to have children. Do nurses interact with the couples differently during the childbirth experience?
Subject(s)
Homosexuality, Female/psychology , Labor, Obstetric/psychology , Adult , Female , Humans , Interview, Psychological/methods , Jurisprudence , Middle Aged , Nurse Midwives , Nurse-Patient Relations , Pregnancy , Social Support , Spouses/psychologyABSTRACT
Xenobiotic transformation by Streptomyces griseus (ATCC13273) is catalysed by a cytochrome P-450, designated cytochrome P-450soy. A DNA segment carrying the structural gene encoding P-450soy (soyC) was cloned using an oligonucleotide probe constructed from the protein sequence of a tryptic peptide. Following DNA sequencing the deduced amino acid sequence of P-450soy was compared with that for P-450cam, revealing conservation of important structural components including the haem pocket. Expression of the cloned soyC gene product was demonstrated in Streptomyces lividans by reduced CO:difference spectral analysis and Western blotting. Downstream of soyC, a gene encoding a putative [3Fe-4S] ferredoxin (soyB), named ferredoxinsoy, was identified.
Subject(s)
Cytochrome P-450 Enzyme System/genetics , Ferredoxins/genetics , Gene Expression Regulation, Bacterial , Genes, Bacterial , Glycine max/genetics , Streptomyces griseus/genetics , Amino Acid Sequence , Base Sequence , Biodegradation, Environmental , DNA, Bacterial/isolation & purification , Ferredoxins/biosynthesis , Genetic Vectors , Molecular Sequence Data , Oligonucleotide Probes , Peptide Fragments/isolation & purification , Plant Proteins, Dietary/genetics , Sequence Homology , Glycine max/enzymology , Streptomyces griseus/enzymologyABSTRACT
Two recombinant strains of Streptomyces griseus have been developed to report on the activation of promutagenic chemicals. This activation is monitored by reversion of the bacterial test strains to a kanamycin-resistant phenotype. Strain H69 detects point mutations and was reverted at an increased frequency by acetonitrile, 2-aminoanthracene, 1,2-benzanthracene, benzidine, benzo(a)pyrene, 9,10-dimethyl-1,2-benzanthracene, and glycine. The second strain, FS2, detects frame shift mutations and was reverted at an increased frequency by 1,2-benzanthracene, benzidine, and glycine. Compounds such as butylated hydroxytoluene, catechol, chlorobenzene, hydroquinone, potassium chloride, phenol, cis-stilbene, trans-stilbene, and toluene did not elicit positive responses in either strain. In addition, these strains are capable of detecting direct-acting mutagens such as N-methyl-N'-nitrosoguanidine and ICR-191, providing further evidence of their promise for detecting a wider range of mutagens. To our knowledge, this is the first report of bacterial strains capable of activating promutagenic compounds and detecting their mutagenic metabolites without the benefit of an exogenous activation system such as the rodent liver homogenate (S9).
Subject(s)
Genetic Engineering , Mutagens/analysis , Streptomyces griseus/genetics , Genetic Markers/genetics , Mutagenicity Tests/methods , Mutation/genetics , Phenotype , Plasmids/genetics , Transformation, Genetic/geneticsABSTRACT
The bacterium Zymomonas mobilis is a potentially useful organism for the commercial production of ethanol as it is capable of more than double the rate of alcohol production by yeast. However, industrial application of this bacterium has been restricted in part due to the disadvantages of its limited substrate range (glucose, fructose and sucrose) and by-product formation. Progress in strain improvement and genetic manipulation of this ethanologen is reviewed. Methodologies for gaining reproducible gene transfer in Z. mobilis have recently been developed. Genetic modification has led to its growth on the additional substrates lactose and mannitol. Additionally, a range of by-product negative mutants have also been isolated. Further interest has focused on transfer of Z. mobilis genes to other fermentive organisms in order to gain enhanced product formation. Overall, these genetic approaches should lead to development of novel strains of Z. mobilis and other genera, capable of the use of starch, cellulose and xylan in a manner attractive for industrial ethanol production, besides facilitating over production of products from E. coli strains with enhanced capability to grow at high density.
ABSTRACT
Wild-type strains of Zymomonas mobilis exhibit multiple antibiotic resistance and thus restrict the use of many broad-host-range plasmids in them as cloning vehicles. Antibiotic-sensitive mutants of Z. mobilis were isolated and used as hosts for the conjugal transfer of broad-host-range plasmids from Escherichia coli. Such antibiotic-sensitive strains can facilitate the application of broad-host-range plasmids to the study of Z. mobilis.
ABSTRACT
Fifteen Frankia strains from five different plant species were analyzed by two-dimensional polyacryl-amide gel electrophoresis to determine their relatedness by comparing the polypeptide patterns obtained. Three major subgroups (A, C, and D) were found in the Alnus-Comptonia-Myrica cross-inoculation group. An isolate from Purshia tridentata had a unique protein pattern and represents a distinct group of frankiae. Members of group A were isolated from root nodules of Alnus incana subsp. rugosa and Alnus viridis subsp. crispa. Group C organisms were from A. incana subsp. rugosa and Comptonia peregrina nodules, and group D organisms were from A. incana subsp. rugosa, A. viridis subsp. cripsa, and Myrica pensylvanica root nodules. Isolates from each gel group were obtained at several widely separated geographical locations. The results indicate that two-dimensional polyacrylamide gel electrophoresis is useful for identifying Frankia isolates.
