scholarly journals Formation of Streptomyces protoplasts during cultivation in liquid media with lytic enzyme

2021 ◽  
Vol 8 (1) ◽  
pp. 35-44
Author(s):  
Zuzana Brnáková ◽  
Jarmila Farkašovská ◽  
Annamária Rusnáková ◽  
Andrej Godány
Keyword(s):  
Recombinant Dna ◽  
Transformation Frequency ◽  
Lytic Enzyme ◽  
Liquid Media ◽  
Cultivation Medium ◽  
Protoplast Preparation ◽  
Cultivation Process ◽  
Recombinant Dna Techniques ◽  
High Sucrose ◽  
Submerged Conditions

Many streptomycetes strains are hardly or not at all transformable via protoplasts, or there is a problem with the regeneration of protoplasts. We found that protoplasts are formed directly in cultivation media under submerged conditions in the presence of lytic enzyme. Actinophage μ1/6 endolysin and lysozyme were used in this study. Streptomyces strains were cultivated in several media with glycine and lytic enzyme for 24 and 48h. The highest amounts of protoplasts (about 3 x 107 cfu/ml of cultivation medium) together with the highest regeneration (95%) and transformation frequency (about 2 x 106 – 107 cfu/μg DNA) were obtained reproducibly in YEME medium with high sucrose content. S. aureofaciens B96, as hardly transformable strain because of difficulties with protoplast preparation and their further regeneration, was used in this study. The same procedure was applied to S. lividans 66 TK24 and S. coelicolor A3(2), streptomycetes model strains, to confirm the general use of this method. Moreover, such cultivation process was appropriate for additional quick isolation of either chromosomal as well as plasmid DNA that could be further used in recombinant DNA techniques.

scholarly journals Characterization of an associated microfibril protein through recombinant DNA techniques.

1992 ◽  
Vol 267 (14) ◽  
pp. 10087-10095
Author(s):  
S.K. Horrigan ◽  
C.B. Rich ◽  
B.W. Streeten ◽  
Z.Y. Li ◽  
J.A. Foster
Keyword(s):  
Recombinant Dna ◽  
Recombinant Dna Techniques

Report of the committee on human gene mapping by recombinant DNA techniques

1984 ◽  
Vol 37 (1-4) ◽  
pp. 210-273 ◽  
Author(s):  
M.H. Skolnick ◽  
H.F. Willard ◽  
L.A. Menlove
Keyword(s):  
Gene Mapping ◽  
Recombinant Dna ◽  
Human Gene ◽  
Human Gene Mapping ◽  
Recombinant Dna Techniques

Recombinant DNA techniques; an introduction

Gene ◽  
1983 ◽  
Vol 26 (2-3) ◽  
pp. 323-324
Author(s):  
A.J. Podhajska
Keyword(s):  
Recombinant Dna ◽  
Recombinant Dna Techniques

Recombinant DNA techniques in diagnostic and preventive medicine

BioEssays ◽  
1984 ◽  
Vol 1 (1) ◽  
pp. 12-15 ◽  
Author(s):  
Stephen Hodgkinson ◽  
Peter Scambler
Keyword(s):  
Preventive Medicine ◽  
Recombinant Dna ◽  
Recombinant Dna Techniques

scholarly journals Influenza virus hemagglutinin-specific cytotoxic T cell response induced by polypeptide produced in Escherichia coli.

1985 ◽  
Vol 162 (2) ◽  
pp. 663-674 ◽  
Author(s):  
A Yamada ◽  
M R Ziese ◽  
J F Young ◽  
Y K Yamada ◽  
F A Ennis
Keyword(s):  
Influenza Virus ◽  
Recombinant Dna ◽  
Cytotoxic T Lymphocyte ◽  
Nonstructural Protein ◽  
T Cell Response ◽  
Cytotoxic T Cell ◽  
Protein Immunization ◽  
Recombinant Dna Techniques

We have tested the abilities of various polypeptides of A/PR/8/34 (H1N1) virus, constructed by recombinant DNA techniques, to induce influenza virus-specific secondary cytotoxic T lymphocyte (CTL) responses. A hybrid protein (c13 protein), consisting of the first 81 amino acids of viral nonstructural protein (NS1) and the HA2 subunit of viral hemagglutinin (HA), induced H-2-restricted, influenza virus subtype-specific secondary CTL in vitro, although other peptides did not. Using a recombinant virus, the viral determinant responsible for recognition was mapped to the HA2 portion of c13 protein. Immunization of mice with c13 protein induced the generation of memory CTL in vivo. The CTL precursor frequencies of A/PR/8/34 virus- and c13 protein-immune mice were estimated as one in 8,047 and 50,312, respectively. These results indicate that c13 protein primed recipient mice, even though the level of precursor frequency was below that observed in virus-immune mice.

scholarly journals Molecular biology of baculovirus and its use in biological control in Brazil

1999 ◽  
Vol 34 (10) ◽  
pp. 1733-1761 ◽  
Author(s):  
Maria Elita Batista de Castro ◽  
Marlinda Lobo de Souza ◽  
William Sihler ◽  
Júlio Carlyle Macedo Rodrigues ◽  
Bergmann Morais Ribeiro
Keyword(s):  
Molecular Biology ◽  
Recombinant Dna ◽  
Host Cells ◽  
Virus Propagation ◽  
Viral Particles ◽  
Occlusion Bodies ◽  
Budded Virus ◽  
Recombinant Dna Techniques ◽  
High Level ◽  
Eukaryotic Organisms

Baculoviruses are insect viruses found mainly in Lepidoptera. The family Baculoviridae is taxonomically divided in two genera, Nucleopolyhedrovirus and Granulovirus, which differ by occlusion body morphology. NPVs (Nucleopolyhedroviruses) have polyhedrical inclusion bodies (PIBs) containing multiple viral particles, while GVs (Granuloviruses) appear to be generally single particles occluded in oval shaped occlusion bodies. During the life cycle, two different viral progenies are produced: BV (Budded Virus) and PDV (Polyhedra Derived Virus), which are essential for the infectious process and virus propagation in host cells. Baculoviruses are being used for pest control and they are especially safe due to their specificity and invertebrate-restricted host range. Baculoviruses have been used as vectors for high level protein expression ofheterologous genes from prokaryotic and eukaryotic organisms. Also, recombinant DNA techniques have allowed the production of genetically modified viral insecticides. This study is a review on the taxonomy, structure, replication and molecular biology of baculoviruses, as well as their use as bioinsecticides in Brazil.

The Growing Role of Genetic Professionals in Forensic DNA

2009 ◽  
Vol 6 (5) ◽  
Author(s):  
Cristina Pinto
Keyword(s):  
Forensic Medicine ◽  
Tandem Repeats ◽  
Nuclear Dna ◽  
Recombinant Dna ◽  
Dna Typing ◽  
Individual Identification ◽  
Bar Code ◽  
Genomic Polymorphism ◽  
Recombinant Dna Techniques ◽  
Dna Profiles

AbstractThrough the last decade there was an enormous revolution in the field of forensic genetic.The Author reviews some of the methodologies used in the definitions of DNA profiling tackling the principles of recombinant DNA techniques. The potentiality of polymorphic DNA fragments in vertebrates is focused as well as the revolution implied in forensic medicine. The resource to DNA-DNA hybridization combined to oligonucleotide probes is emphasized leading to the production of an individual bar code with the resource of genomic polymorphism which leads to a pattern known as genetic fingerprinting. Other techniques for individual identification and paternity testing are focused as well as the use of short tandem repeats (STR's). Mitochondrial DNA sequencing use to complement nuclear DNA typing may also be profitable in certain instances. Relevant problems within the context of the use of these techniques in forensic medicine and law suits are discussed. Final considerations viewing the resource to DNA technology within the scope of the last two decades are referred regarding the resource to DNA profiles not only in the US but in Europe in general and in Portugal in special having lead to compensation and uncover of justice errors.

Fluorescent antibody techniques have allowed for the direct identification and enumeration of individual bacteria in environmental samples without requiring prior growth in culture media (Bahlool and Schmidt 1980, Cloete and Steyn 1988, Macario et al. 1989). The technique involves the use of specific antibodies raised against surface markers of defined pure cultures that are either labelled directly with fluorescent dye molecules or via a fluorescent secondary antibody. This approach has yielded important insights into the spatial distribution of microorganisms, but it suffers from a number of disadvantages. For example, expression of the antigen may be influenced by environmental factors; false-positive and false-negative results may be obtained due to cross-reactivity or lack of reaction; non-specific binding of antibodies may result in high levels of background fluorescence; and production of specific antibodies requires a pure culture of the organism of interest (Cloete and de Bruyn Various recombinant DNA techniques have subsequently been developed that are independent of cultivation methods (Fig. 1). These techniques provide ways of detecting and quantifying specific phylogenetic groups of microbes on 16S rDNA sequences, and relevant structural genes provide ways of monitoring microbial populations of environmental and industrial systems. In addition to these tools, a number of emerging technologies such as the use of biomarker genes are being increasingly used to monitor with great precision and accuracy the behaviour of microbes in the environment.

2003 ◽  
pp. 218-219
Keyword(s):  
Recombinant Dna ◽  
Culture Media ◽  
Specific Binding ◽  
Fluorescent Antibody ◽  
False Negative ◽  
Cross Reactivity ◽  
Phylogenetic Groups ◽  
Specific Antibodies ◽  
Negative Results ◽  
Recombinant Dna Techniques
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