The review presents physical, chemical, and biochemical properties of pullulan. Moreover, recent results of studies on biosynthesis of this microbial polysaccharide are discussed. Already existing real and potential applications in many fields are listed.
Introduction: Bacteria of the genus Proteus are a common cause of urinary tract infections. The O-polysaccharide (OPS) chain of their lipopolysaccharide (LPS) defines the serological specificity of strains. Based on the OPS structures and the immunospecificity of the LPS, Proteus strains have been classified into 74 O-serogroups. Materials and Methods: The OPS of P. mirabilis TG 115 was obtained by mild acid degradation of the LPS and studied by 1H and 13C nuclear magnetic resonance spectroscopy. Antisera were raised by immunization of rabbits with heat-killed bacteria. Serological studies were performed using enzyme immunosorbent assay, passive immunohemolysis, inhibition experiments, absorption of O-antisera, and Western blot.Results: The following structure of the P. mirabilis TG 115 OPS was established: 2)--D-GalpA-(13)--D-GalpNAc-(14)--D-GalpA-(13)--D-GlcpNAc-(1 The same structure has been reported previously for the O-polysaccharides of P. mirabilis CCUG 10701 (O74) and P. mirabilis 41/57 (O23), except that they contain O-acetyl groups in non-stoichiometric quantities. Serological studies showed the antigenic identity of the three strains and their close serological relatedness to P. vulgaris 44/57. Conclusions: Based on the OPS structures and serological data, it is suggested to classify P. mirabilis 41/57, TG 115, and CCUG 10701 into one subgroup and P. mirabilis 42/57 and P. vulgaris 43/57 and 44/57 into another subgroup of the Proteus O23 serogroup.
Molecular mimicry is one of the most important pathogenic factor of microorganism and is defined as a structural similarity of microbial molecules to host tissue contributing to the pathogenicity. Mimicry can be observed at the molecular, serological and functional level. In the review the infectious diseases have been discussed where the mimicry phenomenon may occurr, and also autoimmune disease where due to the molecular mimicry bacterial structures are potent to induce adverse immune reactions. The cross-reacting molecules mimicking the host structures comprise colominic acid, sialic acid containing capsular polysaccharides of Streptococcus group B, phosphocholine containing antigen, lipopolysaccharides of Campylobacter jejuni contributing in induction of Guillain-Barre syndrome or Lewis antigen containing lipopolysaccharides of Helicobacter pylori inducing gut carcinoma. Knowledge on the phenomenon of molecular mimicry is important when new conjugate vaccine has to be constructed, because great care should be paid not to induce autoantibodies with synthetic immunogen. Investigation of microbial factors reveal that many autoimmune diseases are of infection etiology.
In recent years mushroom polysaccharides have been extensively investigated according to their unique biological activity. Among them polysaccharides from Hericium erinaceum (Hydnaceae) are well known as anti-tumor and cholesterol reducing agents as well as growth and differentiation of adrenal nerve cells stimulators. In Poland, H. erinaceum is restricted only to several areas and is considered endangered species. Thus mycelium and culture broth obtained from submerged in vitro culture could be an excellent source of polysaccharides. The review describes methods of isolation, purification and analysis of mushroom polysaccharides and summarizes data about biological activities of Hericium erinaceum polysaccharides.
Polymerase chain reaction has found wide applications in modern research involving transformations and other genomic studies. For reproducible PCR results, however, the quantity and quality of template DNA is of considerable importance. A simple and efficient plant DNA extraction procedure for isolation of high-quality DNA from plant tissues is presented here. It requires maceration of plant tissue of about 1.0/ cm2 (e.g. of a leaf blade) in DNA extraction buffer (100 mM Tris-HCl, 100 mM EDTA, 250 mM NaCl) using 1.5-mL microfuge tubes, followed by cell lysis with 20% SDS, and DNA extraction with phenol: chloroform: iso-amyl alcohol (25:24:1). Hydrated ether is then used to remove polysaccharides and other contaminants from the DNA preparation. Average DNA yield is 20-30 mug/ cm2 for fresh tissues, and ratio of absorbance at 260 nm to absorbance at 280 nm is 1.5-1.8. The DNA is quite suitable for PCR using microsatellites, RAPD and specific markers for recombinant selection. Amplifications have been obtained for these markers by using template DNA extracted from fresh as well as frozen leaf tissues of various plants, including barley, oat, potato and tomato. DNA stored for more than 2 years has been successfully amplified with microsatellite markers, which shows suitability of this method after long-term storage of DNA. Besides, the ease of use and cost-effectiveness make the procedure attractive.
This paper reviews information from last decade world literature on the occurence in tissue cultures of some Lamiaceae species of secondary metabolites.The introductory part of paper gives information on the occurence of the biological active secondary metabolites in the native plant species from Lamiaceae family.
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