Introduction

There is a large and continuing interest in the screening of microbial cultures for the production of biologically active metabolites (e.g. 1-18 ), which can provide structural templates for synthetic programmes using rational methods of drug design. As well as the increasing use of combinatorial chemical libraries 19-25 , methods based on phage display 26-28 , synthetic oligonucleotides 29 30 and DNA shuffling 31-35 can provide further levels of diversity from biological starting points....

Theory Of Htrf

The name Homogeneous Time-Resolved Fluorescence can be used as a starting point to explain how this method works. A homogeneous assay is one in which the biological interactions occur completely in solution without the use of beads or other solid phase attachments. The reagents are simply pipetted, incubated and measured. Because it requires no separation or processing steps, this fast and efficient method saves both time and labor so that more compounds can be tested in less time. Another...

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References

J. & Winstanley, D. J. (1982)Bioactive microbial products search and discovery. Academic, New York. 2. Elander, R. P. (1987) Microbial screening, selection and strain improvement. In Basic Biotechnology (ed. J. Bu'lock and B. Kristiansen), pp. 217-251. Academic Press, London. 3. Vandamme, E. J. (1984) Biotechnology in industrial antibiotics. Marcel Dekker, New 4. Verrall, M. S. (1985) Discovery and isolation of microbial products. Ellis Horwood, 5. Omura, S. (1986)...

Automated techniques in screening for microorganisms with biocatalytic properties

Ariagno and A. Goulard. Rh ne-Poulenc Industrialisation, CRIT-C, 85 Avenue des Fr res-Perret, 69192 St Fons, France. Phone 33.4.72.93.67.29. Fax 33.4.72.93.67.21. E-mail Experts estimate that probably less than 1 of the world's microorganisms have been properly examined. Therefore, there is much potential for finding new biocatalysts. However, the probability of finding the right microorganism among billions is very low. It is,therefore, of great interest for the...

Info

It is difficult to explain, that the division Hymenomycetes from the class Basidiomycotina and only one single Oomycetes strain from the class Mastogomycotina should be usable for this reaction type. Presumably the explanation is based on the sterical structure or the deficient lipophilic-hydrophilic properties of the exclusively tested substrate, which turned out to be unsuitable for the hydroxylases of other strains. Some guidelines generally exist for the selection of a useful strain from...

N3oh

Chemo-Enzymatic Synthesis of d4T & AZT Methyluridine is an important intermediate for the chemical synthesis of D4T and AZT, which are potential anti-HIV agents. In the preparation of methyluridine, guanosine and thymine were used as the substrates for screening and Erwinia carotovora was found to be the best producer of methyluridine. D4T and AZT can be synthesized through chemical reaction, as shown in Fig. 7.13> 6. Synthesis of DDI (Fig. 8) > *> 2',3'-dideoxyinosine (DDI)...

Stereopreference Of Lipases

The enzyme activities observed with the nove lipids depend on the enzyme used, chirality of the substrate, and the form of substrate solubilization (4). In most cases, lipases are more active on detergent micelles or in mixtures of ethanol-water as compared to lipid-albumin complexes. However, the most reproducible results are always obtained with the lipid-albumin system. Figure 3 shows the effect of substrate solubilisation on the stereopreference of a lipase from Candida rugosa. Three...

Ph

Fig.4 Effect of pH on the activity of amylase300. The activity of amylase300 was measured as written in the text. Each symbol indicates the buffer used in the reaction. Symbols O, acetate-sodium acetate , maleic acid monosodium-NaOH A, Phosphate-NaOH MOPS-MOPSNa , Tris-HCl CHES-NaOH buffer. All buffers were used at 0.1 M. The maximum activity pH 6.8 is expressed as 100 . Isolation of a chitosan degrading fungus, Penicillium spinulosum, and chitosanase production by the isolate 0. Ak, U. Bakirb...

Methods

Yeast strains isolation and culture conditions The yeast strains Candida molischiana 35 5 and 35M5N 6 , Candida entomophila 7 , Zygosaccharomyces bailii 8 were isolated in our laboratory. The others strains come from culture collection. The basal culture medium was G medium to which carbon sources were added to a final concentration of 0.5 w v . The cultures were incubated at 28 C in Erlenmeyer flasks filled to one tenth of their volume. Growth was monitored by measuring the absorbance at...

Some Aspects Of Regulation Of Terpenoid Biosynthesis In Plant Cell Cultures

The present knowledge on the enzymes involved in the early steps of terpenoid biosynthesis in plants indicate that plant cells have the same set of enzymes at their disposal as other eukaryotic cells, as yeasts and mammalian cells. For plant terpenoid biosynthesis, it is now of importance to understand the regulatory mechanisms controlling the flux through this pathway. An important aspect of regulation is the subcellular localization of the enzymes involved. In plant cells, three metabolic...

Conclusion

It is obvious that an urgent need exists in the countries of the developing world including India for an early initiation of research and development programmes for exploring their natural microbial biodiversity, conserving them in knowledge-based germplasm banks in conformity with international standards and undertaking investigations to unravel the biotechnology potential of their respective indigenous microflora through a combination of conventional as well as molecular biological...

Results And Discussion

A chitosanase producing fungus was isolated from chitosan which was isolated from Rhizopus cell walls. The strain was isolated by streaking the spores on YPG agar and incubating at 28 C for five days. A creamy-white growth was observed after two days of incubation and later, dark green spores formed. The strain has the ability to grow on a salts medium containing 0.1 K2H04, 0.05 MgS04, 0.05 KCI, 0.001 FeS04, 0.5 NH4NO3 and sole carbon source of 0.1 chitosan. Later the strain was identified as...