Nanobiotechnology: a solution to food insecurity, safety and sustainability

The problems of food insecurity, safety and sustainability occur mostly through the activities of pest and pathogens. The resistance of the causative agents on agricultural production coupled with potential health hazards posed on the environment by synthetic pesticides led to the search for an alternative to synthetic chemicals. Nanotechnology is currently the best candidate for ensuring food security, safety and water quality. National governments especially in developing countries are advised to mount regulating agencies that will be responsible for achieving food security and safety as already done in countries like USA, India and Indonesia among others. Considering the fact that we are now in a period when global population is steadily increasing and there is a very high demand for health food but high cost of production and need for sustainable agriculture has limited the profit margin made by farmers. The cause of naturally-occurring products with interesting antimicrobial eliciting properties and their derivatives has been getting more attention in recent years. Nanotechnology may have concrete solutions against many agriculture-related problems like insect pest management using traditional methods, adverse effects of chemical pesticides; development of improved crop varieties. As with any other technology, controversy surrounding nanotechnology is no exception in a heterogeneous society. Several concerns need to be addressed on different issues like food safety and beneficiaries of the technology.Keywords: Food-insecurity, pathogen, pest, safety, chemicals, materials, benefits, nanoparticles, biotechnolog

Geoelectrical Assessment of a Proposed Dam Site around Ehuhe area of Oji River, Southeastern Nigeria.

The current study involves applying the Vertical Electrical Sounding (VES) by using the symmetrical Schlumberger configuration to evaluate the suitability of the soil underlying Ehuhe area of Oji River Southeastern Nigeria for dam construction. The survey was conducted along the proposed dam axis (about 477 m long) and its vicinity with the view to determining the presence or otherwise of deleterious matter along the dam axis down to a depth of 35m below the surface, evaluate the geo-structural setting of the concealed bedrock, the fracture pattern and possible dam seepage along the dam axis and its banks as well as give suggestions on any other measures/studies that may be needed for a proper engineering design. Twelve (VES) sounding stations at between 40m (VES 1 – VES 10) and 60m (VES 10 – VES 12 and VES 2 – VES 11) were located and fully occupied along the dam axis. The data obtained were subjected to 1-D inversion algorithm to determine the layer parameters. The results show that the subsurface is remarkably inhomogeneous in geological composition. The geoelectric section revealed three (3) lithologic units defined by top loose dry sandstone, hard but jointed iron oxide-cemented sandstone and porous sandstone, with shales being totally absent. Resistivity values range from 9200-66100, 1440-161000 and 555-21300 ohm-m in the topsoil, ironstone and porous sandstone respectively. Depth to each layer varies from 0.5-12.0 m in the topsoil, 3.6-22.1m in the ironstone rich zone and greater than 40m in the porous sandstone region. No structures that will be of deleterious effect were observed in all the VES points down to about 40m. From the results and field observations it is concluded that the proposed dam axis is underlain by high sandy/ arenaceous matter usually brought in from both Ehuhe and Udi areas with high porosity and potentially rife for great infiltration. It is expected that high bearing capacity shall characterize the rock units. However the absence of shales means high infiltration in a sandy environment. Efforts should be made to provide some suitable blanket materials for the dam and mechanism for desilting when the dam is put in place. Keywords: Geoelectric Section, Geometric factor, Lithology, Oji River, Seepage

Studies on effects of mineral fertilizer, organic manure and cultivar on the yield and storability of yam (Dioscorea rotundata Poir)

Yam is an important staple food crop in the humid and sub-humid tropics. Despite inadequacies in supply and availability of fertilizer to boost yam production in Nigeria, there have been reports and arguments that yams grown with chemical fertilizer are susceptible to pathological deterioration in storage while those grown with organic manure store better and have longer shelf life. Therefore, two experiments were conducted to investigate this controversy. The first field experiments tested the responses of five yam cultivars; Amula, Nwaopoko, Ezakwukpolo Danacha and Pepa to fertilizer and organic manure treatments. Statistical differences were not detected in all cases of manuring treatment although tuber yield appeared less where no fertilizer or organic manure was applied. While organic manure appeared to have a better effect on tuber yield with Danacha, NPK fertilizer had better yield effect with Ezakwukpolo, Amula and Pepa. The second experiment tested the effect of manuring treatments on the storage life of the five yam cultivars. Dormancy period was extended in Nwaopoko cultivar when organic manure was used than when no manuring or NPK fertilizer was applied. Tuber weight loss varied significantly among cultivars with different treatments. Rotting was significantly higher in Amula with the application of NPK fertilizer compared with Danacha, Nwaopoko, Ezakwukpolo and Pepa. The combined effects of cultivar and manuring treatments on rotting incidence varied with cultivar type. For example, Amula cultivar had the highest rotting incidence with or without manuring treatments, whereas Danacha and Ezakwukpolo had statistically similar rotting incidence with any of the manuring treatments. In conclusion, evidences in this study show that post harvest losses of yam are, in part due to field management but mostly dependent on species and cultivars. Nwaopoko and Danacha cultivars had better keeping qualities than all other cultivars tested with or without manuring treatment. It is recommended that plant breeders should use the traits in these two cultivars to improve others.Key words: Yam, storability, fertilizer, organic manur

Studies on the fungal flora of Garri, processed cassava (Manihot esculentus crantz) in Nsukka area of southeastern Nigeria

In Nsukka area of southeastern Nigeria, garri is usually displayed in the open market for sale which no doubt exposes the food stuff to dust particles from moving vehicles, wind and other sources. Thus, fungal spores from the air and soil environment could serve as major sources of fungal contamination of this product. Two garri types (white and yellow) were therefore sampled from six popular markets in the area which included Ogige, Nkwo-Ibagwa, Orie-Orba, Orie-Igboeze, Eke- Ozzi and Obollo-Afor markets. These samples were investigated for the presence of various species of fungi. Fungal isolates observed were: Aspergillus foetidus Thom and Raper, Aspergillus niger van Tiegh, Aspergillus sp., Penicillium sp., Rhizopus sp. and Candida sp. The fungal isolates occurred at varying frequencies, with A. foetidus being the most frequently isolated in both white and yellow garri while A. niger had the least occurrence in both white and yellow garri. Comparatively, white garri had higher frequency of occurrence of fungal organisms than yellow garri. Food processors are therefore, advised to always clean and sanitize equipment coming in contact with food to reduce microbial contamination and also to avoid other unhygienic handling of locally marketed foods.Key words: Garri, Processed Cassava, Fungal Flora, Marihot esculemt

Extended-spectrum beta-lactamase and plasmid profiling of Uropathogens cultured from HIV seropositive pregnant women and controls in Akure, south-western Nigeria

Objective(s): Urinary tract infection (UTI) is a known bacterial infection faced by clinicians and patients in developing countries. The causative agents differ from region to region. Extended-spectrum beta-lactamase (ESBLs) producing strains have spread rapidly among humans. Design: Mid-stream urine samples were collected from HIV seropositive pregnant women and their controls. Each sample was cultured on appropriate media and subcultured to obtain pure colonies. Antibiotics sensitivity testing was conducted employing the Kirby-Bauer methods and screening for extended beta-lactam strains was done by double-disk synergy test (DDST). Results: A total of 63 uropathogens were studied, 41% of the isolates were S.aureus, 21% E. coli, 38% Pseudomonas aeruginosa isolates. The data showed that 50 (79.4%) of the bacterial isolates recovered showed multi-resistance to 14 antibiotics used. Majority of the isolates were multiple antibiotics resistant with sensitivity to the aminoglycosides. The result also showed that 7.7% of S. aureus and 69.2% E. coli isolates were beta-lactamase producers. However, 75% of the ESBL isolates tested had plasmids. Conclusion: There might be a shift in the predominance of E. coli as the predominant uropathogen as more studies including ours have shown that S. aureus was the dominant uropathogen in HIV seropositive individuals. Antibiogram did not differ between cohorts, but multiple antibiotic resistance was observed. Most of these isolates were positive to plasmid profiling