African Journals On-line
African Journal of Biotechnology

Volume 2, Number 4 April 2003
ABSTRACTS

Acinetobacter: environmental and biotechnological applications

Desouky Abdel-El-Haleem

Abstract: Environmental Biotechnology Department, Genetic Engineering and Biotechnology Research Institute, Mubarak City for Scientific Research and Technology Applications, New Burg-Elarab City, Alexandria, Egypt. Phone: (00203) 459-3421, fax: (00203) 459-3423, e-mail: [email protected]

Among microbial communities involved in different ecosystems such as soil, freshwater, wastewater and solid wastes, several strains belonging to the genus of Acinetobacter have been attracting growing interest from medical, environmental and a biotechnological point of view. Bacteria of this genus are known to be involved in biodegradation, leaching and removal of several organic and inorganic man-made hazardous wastes. It is also well known that some of Acinetobacter strains produce important bioproducts. This review summarizes the usefulness and environmental applications of Acinetobacter strains.

Key words: Acinetobacter, biodegradation, xenobiotic, oil, heavy metals, bioproducts, lipases, polysaccharides.

Functional and comparative analysis of expressed sequences from Diuraphis noxia infested wheat obtained utilizing the conserved Nucleotide Binding Site

Lynelle Lacock, Chantal van Niekerk, Shilo Loots, Franco du Preez and Anna-Maria Botha*

Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, ZA0002 South Africa

*Corresponding Author; E-mail: [email protected], tel: +27 12 420 3945, fax: +27 12 420 3947

Accepted 10 March 2003

Abstract: Russian wheat aphid (Diuraphis noxia, Morvilko; RWA) is a major pest on wheat, barley and other triticale in South Africa. Infestation by the RWA results in altered protein expression patterns, which is manifested as differential expression of gene sequences. In the present study, Russian wheat aphid resistant (Tugela DN, Tugela*5/SA2199, Tugela*5/SA463, PI 137739, PI 262660, and PI 294994) and susceptible triticale (Tugela) were infested and cDNA synthesized. A PCR based approach was utilized to amplify the nucleotide binding site conserved region to obtain expressed sequence tags (ESTs) with homology to resistance gene analogs (RGAs). The approach proved highly feasible when the isolation of RGAs is the main objective, since 18% of all obtained ESTs showed significant hits with known RGAs, when translated into their corresponding amino acid sequences and searched against the nonredundant GenBank protein database using the BLASTX algorithm.

Key words: Resistance gene analogs, degenerate PCR, nucleotide-binding site-leucine rich repeat resistance genes, Aegilops tauschii.

PCR identification of Fusarium genus based on nuclear ribosomal-DNA sequence data

Kamel A. Abd-Elsalam ^{1, 3*}, Ibrahim N. Aly², Mohmed A. Abdel-Satar²,

Mohmed S. Khalil¹ and Joseph A. Verreet³

¹ Agricultural Research Center, Plant Pathology Research Institute, Giza, Egypt.

² Suez Canal University, Faculty of Agriculture, Ismailia, Egypt.

³ Christian Albrechts Universität zu Kiel, Institut für Phytopathologie, Kiel, Germany.

*Corresponding author; phone: (49 431) 880 2993, fax: (49 431) 880 1583, e-mail: [email protected]

Accepted 25 March 2003

Abstract: We have developed two taxon-selective primers for quick identification of the Fusarium genus. These primers, ITS-Fu-f and ITS-Fu-r were designed by comparing the aligned sequences of internal transcribed spacer regions (ITS) of a range of Fusarium species. The primers showed good specificity for the genus Fusarium, and the approximately 389-bp product was amplified exclusively. PCR sensitivity ranged from 100 fg to 10 ng for DNA extracted from Fusarium oxysporum mycelium. No amplification products were detected with PCR of DNA from Rhizoctonia solani and Macrophomina phaseolina isolates using these primers. The assay is useful for rapid identification of Fusarium spp. cultures. The application of these PCR methods for early diagnosis of the seedling and wilt disease of cotton needs to be studied further.

Key words: rDNA, taxon-specific primer, Fusarium genus, Gossypium barbadense.

Genetic comparisons of Egyptian date palm cultivars (Phoenix dactylifera L.) by RAPD-PCR

Said Saad Soliman¹, Bahy Ahmed Ali^2*, Mohamed Morsy Mohamed Ahmed²

¹National Research Center (NRC) Dokki, Cairo, Egypt.

²Nucleic Acid Research Dept., Genetic Engineering & Biotechnology Research Institute (GEBRI), Mubarak City For Scientific Research & technology Applications, Alexandria, Egypt.

*Corresponding author; E-mail: [email protected]

Accepted 25 March 2003

Abstract: Random amplified polymorphic DNA technique was used to compare genetic material from four females date palm and four unknown male trees of Egyptian date palm. The genetic similarity between the four females date palm (Zaghloul, Amhat, Samany and Siwi) ranged from 87.5 to 98.9%. The banding profiles obtained suggested that both males 3 and 4 are genetically related to the four female cultivars.

Key words: Date palm, cultivars, RAPD-PCR, genetic similarity.

A home made kit for plasmid DNA mini-preparation

Simeon Oloni KOTCHONI^1*, Emma Wanjiru GACHOMO², Eriola BETIKU^3,Y and Olusola Olusoji SHONUKAN⁴

¹Department of Plant Molecular Biology, Institute of Botany, Kirschallee 1, University of Bonn, D-53115 Germany.

²Institute for Plant Diseases, Nussallee 9, University of Bonn, D-53115 Germany.

³Chemical Engineering Department, Faculty of Technology, Obafemi Awolowo University, Ile-Ife, Nigeria.

⁴Department of Microbiology, Faculty of Science, Obafemi Awolowo University, Ile-Ife, Nigeria.

^YCurrent Address: German Research Centre for Biotechnology (GBF), Mascheroder Weg 1, Braunschweig, D-38124 Germany.

* Corresponding author; Tel: +49-228739580, fax: +49-228-732689, e-mail: [email protected]

Accepted 26 March 2003

Abstract: Many methods have been used to isolate plasmid DNA, but some of them are time consuming especially when extracting a large number of samples. Here, we developed a rapid protocol for plasmid DNA extraction based on the alkaline lysis method of plasmid preparation (extraction at pH 8.0). Using this new method, a good plasmid preparation can be made in approximately one hour. The plasmids are suitable for any subsequent molecular applications in the laboratory. By applying the recommendations to avoid contaminations and to maximize the plasmid yield and quality during extraction, this protocol could be a valuable reference especially when analyzing a large number of samples.

Key words: Plasmid extraction, PCR, restriction enzymes, sequencing, contamination.