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Staphylococcus aureus is a facultative anaerobic Gram-positive coccal bacterium whose incidence ranges from skin, soft tissue, respiratory, bone, joint, endovascular to wound infections. The purpose of this study was to identify Staphylococcus aureus from clinical specimens using routine conventional and rapid tests. Gram staining, catalase test, coagulase test, DNase test, haemolysis on blood agar and Microgen™ STAPH-ID kit tests were carried out. A total of 125 Gram positive cocci were tested. The Gram staining technique yielded 100 (80.00%) Staphylococcus spp (Gram positive cocci in clusters). 89(71.20%) isolates were positive to haemolysis on blood agar. Mannitol Salt Agar, DNase agar and Catalase test correctly identified 69 (55.2%) of the Gram positive cocci to be S. aureus as was confirmed by the Microgen™ STAPH-ID kit test. Coagulase test yielded 66 (52.8%) positive results. The Microgen™ STAPH-ID kit test identified three non-coagulase Staphylococcus aureus isolates. The Microgen™ STAPH-ID kit test was the most reliable of the tests, with accuracy comparable to any other rapid test. However, it is the most expensive of the tests. This study established that conventional tests can be used for direct identification of S. aureus to species level if the battery of tests is increased.

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Background Biosurfactants are amphipathic biological compounds with surface active potential and are produced by many microorganisms. Biosurfactant production by Lysinibacillus fusiformis MK559526 isolated from automobile-mechanic-shop soil was investigated with a view to assessing its potential for production and potential for optimization. Materials and methods Effects of carbon and nitrogen sources, pH, temperature and incubation periods on biosurfactant production were evaluated with a view to optimizing the processes. Fourier Transform Infra-Red absorption peaks and Gas chromatography mass spectrometry were used to determine the functional groups of the chemical make-up and the chemical profile of the biosurfactant respectively. Results Lysinibacillus fusiformis surfactant had emulsification index of 65.15 ± 0.35 %, oil displacement of 2.7 ± 0.26 mm, zone of haemolysis of 7.3 ± 0.16 mm and a positive drop collapse test. Optimized culture conditions for biosurfactant production: temperature, 35 ºC; pH, 7.0; starch solution, 40 g/L and urea, 1.5 g/L showed a reduction in surface tension to 28.46 ± 1.11 mN/m and increased emulsification index to 93.80 ± 0.41 %. Maximum biosurfactant production of 2.92 ± 0.04 g/L was obtained after 72 h. The biosurfactant contained peptides and fatty acids. The predominant fatty acid was 9-Octadecenoic acid (80.80%). Conclusions The above results showing high emulsification potential and remarkable reduction in the surface tension are good biosurfactant attributes. Consequently, Lysinibacillus fusiformis MK559526 is a good candidate for biosurfactant production.

Biosurfactants synthesized by microorganisms are chemically diverse and have gained interest industrially due to their surface and interfacial tensions-reducing activities. In this study Bacillus species from contaminated soils were screened and characterized for biosurfactant production. The study was carried out at the Microbiology Laboratory, Federal University of Agriculture Makurdi, Nigeria. The Bacillus species were isolated from kerosene shops, palm oil shops, nearby restaurants, mechanic workshops and abattoir effluents- contaminated soil samples collected from Makurdi metropolis. The Bacillus spp. were screened for biosurfactants production potentials using various screening methods (oil spreading, beta haemolysis, drop collapse and emulsification index). Specific primers were used to amplify the srfAA (surfactin gene) gene in the Bacillus isolates and the nucleotide sequences were determined at Inqaba Biotec, South Africa. The screening results were statistically analysed using analysis of variance (ANOVA) at 95 % confidence level. Isolate RT7(4)B exhibited the ability to produce biosurfactant, as well as the highest emulsification index (E24) of 73.25 % while isolate PO7(3)C gave the highest oil displacement of 6.77 mm. The supernatant obtained from isolate RT7(4)B showed reduction in surface tension of up to 30.26 mN/m. The isolates gave positive results for biosurfactant production when subjected to drop collapse and Beta haemolytic tests. The Polymerase chain reaction (PCR) results revealed amplifications of srfAA gene from 7 isolates. Based on these findings, the isolates used in this study can be utilized for biosurfactant production, and can also be useful for bioremediation and industrial biotechnology applications. Keywords: Biosurfactants; emulsification index; Bacillus; surface tension; Drop collapse

This study evaluated insecticidal activity of different doses of Adansonia digitata stem bark and leaf powders on yam beetles dinoderus porcellus. Obtained plant parts from Federal colloge of Forestry, Jos were pulverized into powders. Phytochemical constituents of the plant were extracted by Soxhlet extraction and identified using standard procedure. Mortality testing was done by exposing dinoderus porcellus to yam chips mixed with various doses of Adansonia digitata stem bark and leaf powders. Yam chips without treatment served as the control. The experiments were laid out in randomized complete design with three replications. Data obtained were analysed using analysis of variance (P≤ 0.05). The result of the phytochemical examination of ethanolic extract of A. digitata revealed the presence of saponins, phenols, tannins and alkaloids flavonoids. The finding revealed the superiority of yam chips mixed stem bark and leaf powders over the untreated. The effect of plant extracts on percentage mortality showed significant difference (p<0.05) among the treated and control. The sample treated with 15g of A. digitata stem-bark powder gave the highest mortality. The research hence recommends the use of 15 g of A. digitata stem-bark powder in elimination of Dinoderus porcellus infecting yam chips. Keywords: A. digitata, Insecticida, Mortality, flavonoid, Dinoderus porcellus

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This study assessed the reproduction inhibition effects of Adansonai digitata plant part powders against D. porcellus affecting yam chips. Reproduction of adults D. porcellus were monitored with various doses of Adansonai digitata plant part powders and untreated yam chips as negative control (0 g). The finding of the research indicated that all treatments exhibited anti-reproduction potential and strong inhibition of D. porcellus emergence. The result of analysis of variance showed significant difference between the treated samples and the control (untreated) after 37 days. Adansonai digitata stem bark powders (10 g) was able to achieve no reproduction(0.00) after 37 days exposure. Based on this results, combining yam chips with 10 g of Adansonai digitata stem bark powders could ensure adequate management of D. porcellus destroying yam chips and yam tubers as a whole. Keywords: Adansonai digitata, D. porcellus, yam chips, Stem bark powder, Leaf powder