January 2004
Potential use of rhizobial bacteria as promoters of plant growth for increased yield in landraces of African cereal crops
Rhizobia form root nodules that fix nitrogen (N2) in symbiotic legumes. Extending the ability of these bacteria to fix N2 in non-legumes such as cereals would be a useful technology for increased crop yields among resource-poor farmers. Although some inoculation attempts have resulted in nodule formation in cereal plants, there was no evidence of N2 fixation. However, because rhizobia naturally...
January 2004
Small round structured viruses (SRSVs) and transmission electron microscopy
Key words: Small round structured viruses, Caliciviruses, automated specimen search (ASS) system, transmission electron microscopy.
January 2004
Production of Polyhydroxyalkanoates, a bacterial biodegradable polymer
There has been considerable interest in the development and production of biodegradable polymer to solve the current problem of pollution caused by the continuous use of synthetic polymer of petroleum origin. Polyhydroxyalkanoates (PHAs) are known to be accumulated as intracellular inclusion in some bacteria. The materials properties exhibited by PHAs, ranging from stiff, brittle to rubber-like makes it a close...
January 2004
Pathogenic and genetic characterization of Algerian isolates of Fusarium oxysporum f. sp. lentis by RAPD and AFLP analysis
Thirty-two isolates of Fusarium oxysporum f. sp. lentis were isolated from wilted lentil plants collected from different lentil growing areas in north-west Algeria. A pathogenicity test was performed for all isolates. Results indicated that the Fol isolates represent a single race but differ in their aggressiveness on the susceptible lines. The amount of genetic variation was evaluated by...
January 2004
Patterns of phenotypic variation in endod (Phytolacca dodecandra) from Ethiopia
The extent of morphological variability of endod (Phytolacca dodecandra) sampled from 17 localities in Ethiopia that varied from 1600 to 3000 meters above sea level (m.a.s.l) was investigated using 16 characters. Statistical analyses were performed using leaf hairiness and altitude as categorical variables. Cluster analysis performed using average taxonomic distance matrix revealed the separation of most plants into...
January 2004
Reproductive biology in Balanites aegyptiaca (L.) Del., a semi-arid forest tree
Balanites aegyptiaca (L.) is an important tree in the semi-arid ecosystem with beneficial attributes. However, very little information is available in its reproductive biology. In order to better control the reproduction system of B. aegyptiaca, three experimental approaches are used: floral morpholgy, fluorochromatic procedure and hand pollination. The floral morphology shows that B....
January 2004
Effects of soaking duration on germination and seedling growth of tomato (Lycopersicum esculentum Mill)
The effects of soaking duration on germination and seedling growth of tomato (Lycopersicum esculentum Mill) Roma VF, UC82B and Xina varieties were investigated. The treatments consisted of three soaking durations (12, 24, 36 h) and control replicated four times in a latin square design. Results indicated significant enhancement of germination by all soaking durations except for Xina variety where 36 h treatment...
January 2004
Effect of lemon grass (Cymbopogon citratus Stapf) powder and essential oil on mould deterioration and aflatoxin contamination of melon seeds (Colocynthis citrullus L.)
Experiments were carried out to determine the potential of using the powder and essential oil from dried ground leaves of Cymbopogon citratus (lemon grass) to control storage deterioration and aflatoxin contamination of melon seeds (Colocynthis citrullus L.). Four mould species: Aspergillus flavus, A. niger, A. tamarii and Penicillium citrinum were inoculated in the form of conidia suspension (approx. 106 conidia...
January 2004
Assessment of the toxic potentials of some plants powders on survival and development of Callosobuchus maculatus
Dried leaves powders of Guirea senegalensis, Piliostigma reticulatum and dried fruit powder of Piper guineense, were tested along side a conventional insecticide, Actellic-2-Dust, to compare their efficacies on survival of cowpea weevil (Callosobuchus maculates) during storage. Both the treated and untreated cowpeas (control) were then infested with newly emerged adult bruchids of both...
January 2004
Effect of carbon and nitrogen sources and incubation times on poly-beta-hydroxybutyrate (PHB) synthesis by Bacillus subtilis 25 and Bacillus megaterium 12
In this study, poly-beta-hydroxybutyrate (PHB) production by the Bacillus subtilis 25 and Bacillus megaterium 12 strains was investigated in nutrient broth medium at different incubation times (between 6 h and 48h). The best PHB production and all yields of these strains were determined. The productions were 0.101 g/L, 0.142 g/L and the percentage yields were 18.03%, 14.79% after 45h, respectively....
January 2004
Feather wastes digestion by new isolated strains Bacillus sp. in Morocco
Eight strains of Bacillus were isolated from non treated soil, characterized and used for the digestion of feather wastes in the laboratory. Non-protein nitrogen (NPN) and total protein (TP) were determined during the incubation time and the microbial counts of the different strains during feather hydrolysis were also monitored. Results of the screening test showed that the solid pieces of feather were...
January 2004
Inhibition of growth and mycotoxins formation in moulds by marine algae Cystoseira tamariscifolia
Different extracts from marine algae (Cystoseira tamaricifolia) were tested for their antimicrobial activities. These extracts were examined for their activities on growth of moulds and yeasts and mycotoxines formation by moulds. The Minimal Inhibitory Concentration (MIC) was determined in every case in terms of dilutions. A total inhibition (100%) was obtained with the ethanolic crude extract on all the fungal...
January 2004
Ca2+ and reactive oxygen species are involved in the defense responses of rice callus culture to rice blast disease
The role of Ca2+ and reactive oxygen species in the defense responses of callus cultures of rice (Oryza sativa L., cv. Zenith) to infection with avirulent strain of rice blast fungus (Magnaporthe grisea, strain Ina168) was investigated. It was observed that rice calli, especially after mild blast infection, exude substances (diffusate) that inhibit spore germination of the avirulent blast fungus. This...
January 2004
Laboratory evaluation of the improved tube test detection limits for b-lactam residues in Kenyan milk
In Kenya there is currently no screening of antimicrobial drug residues in milk. This study evaluated the improved tube test as a possible screening method using seven representatives of the b-lactam antibiotics. The group comprises antimicrobials most frequently used to treat bacterial infections in dairy cows. Each antimicrobial was tested at five concentrations based on established codex alimentarius maximum...
January 2004
The effects of aluminium and selenium supplementation on brain and liver antioxidant status in the rat
This in vivo study was designed to investigate the potential of aluminium (Al), in the absence of added iron, to participate in either antioxidant or pro-oxidant events. Some markers of oxidative stress were determined in liver and brain of rats exposed to aluminium lactate, either alone or in the presence of dietary supplements of selenium (se) as selenite. Exposure to aluminium for 21 days resulted in a...
January 2004
Characterization of Trypanosoma brucei gambiense stocks isolated from humans by RAPD fingerprinting in Côte d’Ivoire: another evidence for multiple infections
Trypanosoma brucei gambiense was isolated twice from each of 23 patients in Côte d’Ivoire. Genetic characterization using RAPD (Random Primed Amplified Polymorphic DNA) showed additional variability within a given isoenzyme profile (zymodeme), confirming that this fingerprinting method has a higher discriminative power (faster molecular clock) than isoenzymes. RAPD confirmed also the evidence of...
January 2004
Comparative biochemical and molecular evaluation of swarming of Proteus and effects of anti-swarm agents
In addition to inadequate understanding of swarming motility and virulence of Proteus, there is paucity of information on the relative effectiveness of the various anti-swarm agents. The anti-swarming effects of urea, sodium dodecylsulphate (SDS) and trihydroxymethylglycine (Tris) on 40 clinical isolates of Proteus Spp. were comparatively investigated and plasmids associated with swarming were...
January 2004
Expression of green fluorescent protein (GFPuv) in Escherichia coli DH5-a, under different growth conditions
The recombinant green fluorescent protein (GFPuv) was expressed by transformed cells of Escherichia coli DH5-a grown in LB/amp broth at 37oC, for 8 h and 24 h. To evaluate the effectiveness of different parameters to improve the expression of GFPuv by E. coli, four variable culturing conditions were set up for assays by a fractional factorial (24-1) design at two levels: (i) the effect of storing...
January 2004
Biolistic transformation of Saccharomyces cerevisiae with b-glucosidase gene from Cellulomonas biazotea
A b‑glucosidase genomic DNA from Cellulomonas biazotea NIAB 442 was isolated and coated onto tungsten microprojectiles for direct transformation of the gene intoSaccharomyces cerevisiae. Transformation of b-glucosidase into S. cerevisaeconferred the ability to hydrolyse esculin and cellobiose, indicated that the gene is expressed in the bombarded yeast. Key words: Biolistic...
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