Optimization of Conditions for Xylanase Production Using Aspergillus tubingensis Under Different Carbon Sources

Xylanases are hydrolytic enzymes with wide range of applications in food processing, bleaching of pulp in paper manufacturing industry, bio-conversion of biomass wastes to fermentable sugars and enhancing nutrient digestibility in animal feeds. The optimization of growth conditions and evaluation of an appropriate substrate as carbon source among cassava peels, corn cobs, wheat bran and rice husk on xylanase production by novel strain of Aspergillus tubingensis under Solid State Fermentation (SSF) was investigated. The fungal isolate was identified based on ribosomal RNA gene and ITS gene sequencing analysis as Aspergillus tubingensis. Results showed that Corn cobs had the highest xylanase production among the four substrates. Corn cobs recorded the highest value of xylanase production at pH of 6.0 (107.97 U/g), after incubation period of 72 hour (111.23 U/g), at temperature of 30oC (44.26 U/g) and at ratio 1:3 (45.68 U/g). The optimum growth conditions for xylanase production by Aspergillus tubingensis were: pH 6.0, incubation period of 72 hours, temperature of 30oC and substrate concentration of 1:3 (4g of substrate per 12ml of fermentation medium). Corn cobs showed the highest yield of xylanase activity (111.23±0.31 U/g), followed by Rice husk (101.91±0.72 U/g), Wheat bran (89.30±1.16 U/g) and Cassava peel (87.03±0.57 U/g). In conclusion, among the various agro residues that were used as carbon sources, Corn cobs had maximum xylanase activity. Various culture conditions were optimized by using one factor at a time method and the maximum xylanase production was obtained at pH of 6.0, incubation period of 72 hour, temperature of 30oC and substrate concentration of 1:3 under solid state fermentation. It is therefore suggested that some other notable environmental and fermentation factors that influence metabolism-mediated production yields of xylanase like aeration, agitation, carbon and nitrogen sources, metal ion requirement, inoculum size etc. should be optimized for maximum production of enzyme. Keywords: Solid State Fermentation, Cassava peels, Corn cobs, Wheat bran, Rice husk

Birth Preparedness Practice: Profiling Determining Factors for Male Involvement in Southern Nigeria

Maternal mortality remains high in most African countries including Nigeria. Delays in seeking care for normal delivery and obstetric emergencies are the major determinants of maternal mortality. Birth Preparedness (BP) has been found to be very effective in reducing these delays. Females have always been focused on birth preparedness studies. This study was however designed to investigate male involvement in the practice of birth preparedness in Southern, Nigeria. This was a descriptive study design using a validated structured interviewer-administered questionnaire. A multistage sampling technique was used to select 302 married men in the community. Knowledge on BP was measured on a 48-point knowledge scale and a 30-point practice scale was used to determine male involvement in BP. Data were analysed using descriptive and inferential statistics at p<0.05. The mean age of the respondents was 38.0 ± 8.6 years. Majority (59.9 %) of the respondents had good knowledge on birth preparedness. Mean score for level of involvement was 21.52±5.4 and 43.0% of the respondents had good score. Identified factors militating against male involvement in birth preparedness include low socioeconomic status, busy work schedule, cultural belief, and poor attitude of health workers. There was significant association between knowledge of birth preparedness and religion as well as level of male involvement in BP (p=0.018; 0.001 respectively). This study showed low level of male involvement in birth preparedness. Several factors were identified to be responsible for this. There is therefore the need for sustainable community health education programmes to motivate and encourage male involvement in birth preparedness. Keywords: Birth preparedness, Knowledge, Male involvement, Practices

Antibacterial Efficacies of Extracts of Lemon Grass (Cymbopogon citratus) on Some Clinical Microbial Isolates

The spread of new infections and the emergence of multidrug resistant strains of microorganisms necessitate the search for new antimicrobials with focus on plant extracts. In this study, the antimicrobial activity of the extracts (aqueous and ethanolic) of lemon grass known usually for bioactive essential oil (Cymbopogon citratus) was investigated in-vitro, against selected clinical isolates (Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa and Candida albicans). Antimicrobial efficacy of the extracts was assessed using the agar-well diffusion and broth-dilution techniques. The aqueous extract of C. citratus was more efficacious as it showed higher antimicrobial activity against all the test isolates at all tested concentrations. In contrast, only two of the test isolates; P. aeruginosa and S. aureus were susceptible to the ethanolic extract with minimum inhibitory (MIC) concentrations of 2 mg/ml (against S. aureus) and 12.5 mg/ml (against P. aeruginosa). The MIC of the aqueous extract were (mg/ml): 2, 6.25, 12.5, 25 and 50 against S. aureus, E. faecalis, P. aeruginosa, E. coli and C. albicans respectively. Meanwhile, both the aqueous and ethanolic extracts of C. citratus exerted only a bacteriostatic effect against the five test isolates at all concentrations. Quantitative phytochemical screening of the two extracts revealed the presence of more concentration of active compounds in the aqueous extract than the ethanolic extract which plausibly accounts for its greater antimicrobial activity. This study has shown that, in difference to the use of its conventional essential oil, solvent extraction of Cymbopogon citratus is also a potent source of efficacious antimicrobials. Further works to determine the respective mechanisms of action(s) of the extracts’ active principle is being projected. Keywords: Lemon grass, clinical isolates, antimicrobial efficacies, bioactive compounds

Antimicrobial and Phytochemical Analyses of Sida acuta Leaf Extracts on Selected Wound Isolates

Medicinal plants have been intensively screened for their bioactivity in order to treat various diseases in human. This study was performed to evaluate the antimicrobial and phytochemical properties of Sida acuta leaf extracts against selected wound microbes. The plant extracts were obtained sequentially using n-hexane, aqueous and acetone respectively in order of increasing polarity. The extracts were tested for their antimicrobial activities against Staphylococcus aureus, Candida albicans, Klebsiella pneumoniae, Enterococcus faecium, Acinetobacter baumannii, Salmonella typhi and Pseudomonas aeruginosa using agar-well diffusion method. The sensitivity of the test organisms to the extracts was represented by zones of inhibitions (mm) at different concentrations. There was corresponding increase in the zones of inhibitions (mm) on the test organisms as the concentration of the extracts increased from 64 mg/ml – 512 mg/ml. Among the plant extracts, the aqueous extract of Sida acuta leaf revealed significantly higher zones of inhibitions (mm) from 7.50±2.12 - 25.00±1.40 on all isolates. This was closely followed by the acetone extract while the n-hexane extract produced the lowest zones of inhibitions (mm) on all the test organisms except for Acinetobacter baumannii which has 9.80±0.42 at the concentration of 512 mg/ml. Results obtained on the phytochemical analyses of the aqueous and acetone extracts revealed the presence of tannins, saponins, alkaloids and flavonoids. Hence, the antimicrobial effects of Sida acuta leaf extracts has been revealed in this study, therefore its controlled use should be encouraged in the treatment of wounds and other infections caused by these microorganisms. Keywords: Antimicrobial properties, Isolates, Phytochemical analyses, Sida acuta

Purification of Wickerhamomyces anomalus Keratinase and Its Prospective Application in Poultry Feed Industries

Animal wastes emanating from cow horns, hooves and feathers are keratinous in nature which can only be degraded by keratinolytic microorganisms. Consequently, the pollution resulting from the accumulation of these wastes in response to growing livestock demand is posing a significant threat to human health and the environment. This study was carried out using cow hooves as the substrate for the production of keratinase from fungal identified as Wickerhamomyces anomalus 9 (18S rDNA gene sequencing) was isolated from soil rich hooves using basal salt agar medium and potato dextrose agar. The keratinase of the isolate was assessed using skim milk agar and the enzyme was produced by solid-state fermentation. The crude enzyme was purified using ammonium sulphate precipitation, ion exchange and gel-filtration chromatography. The specific activity of the enzyme was 0.29 U/mg with a yield of 45% and a 7.25 purification fold. The optimal pH and temperature of the enzyme were 8.0 and 60 oC respectively. The enzyme was observed to be thermo-stable at 50oC between for 30 minutes. The kinetics revealed that the Vmax was 0.384U/min with Km 86.95mg/ml. The native molecular weight of the enzyme was found to be 34KDa. There were significant differences at 95% confidence with poultry feed treated with Wickerhamomyces anomalus keratinase in moisture, ash content, crude fibre, crude fat, nitrogen content, crude protein and carbohydrate compare to the untreated feed. These results suggest an environment-friendly approach for biodegradation of cow hooves wastes for the production of keratinases, animal waste management as well as a promising tool for chicken feed additives. Keywords: Biodegradation, Chromatography, Cow hooves, Keratinase, Pollution

Synthesis, Structural Elucidation and Antimicrobial Activity of Metal (II) Polypyridyl Complexes of 2-Amino-4-(Methylthio) Butanoic Acid

The interaction of selected biometals with dinitrogen donor ligand, 1,10-phennathroline (phen) and amino acid, 2-amino-4-(methylthio)butanoic acid (methionine; met) resulted in isolation of three mononuclear complexes. The prepared complexes were characterized by diverse techniques including elemental and spectroscopic analysis. From the analytical and spectral data, octahedral geometry was proposed to the synthesized metal (II) complexes. Bonding of the metal ion through N- and O- donor atoms of the ligands is revealed by infrared studies. The compounds showed moderate solubility in distilled water and in some common organic solvents. In vivo evaluation of the antimicrobial activities of the metal complexes showed improved inhibitory activity against some micro-organisms as compared to the ligands, with Co(II) and Cu(II) complexes showing the highest activities against the fungi.

Analysis of Heavy Metals in Soils around a Scrap Metal Recycling Company in Ile-Ife, Osun State, Southwestern Nigeria

Contamination of soils by heavy metals has severely increased over the last few decades due to industrial wastes and human activities. Contaminated soils can constitute sources of health hazard to humans globally. However, there is paucity of information on the level of heavy metal concentration in the study area. This study therefore made a pioneering effort in investigating the concentration of selected heavy metals (Cd, Cu, Pb, Zn and Fe) in soils around a scrap metal recycling company in Ile-Ife, Osun State, Nigeria. Thirty soil samples and solid wastes were collected from four sides of the scrap metal recycling company. The samples were air-dried, digested using standard method and analyzed for the selected heavy metals using a flame atomic absorption spectrometer. Results of the Atomic Absorption Spectrophotometric (AAS) analysis revealed that for heavy metals, the concentrations in the soils were below the background levels and permissible limits recommended for soils in some countries. The value of the mean concentration of the analyzed heavy metals in the soils around the scrap metal recycling company ranged from 0.0040 – 0.0140 mg/kg for Cd, 0.061 – 0.108 mg/kg for Fe, 0.037 – 0.047 mg/kg for Cu, 0.003 – 0.0064 mg/kg for Pb and 0.019 – 0.121 mg/kg for Zn. The results from the study indicated that the concentrations of heavy metals around the scrap metal recycling company did not appear to be of serious concern. The concentrations of all the heavy metals were below the background level proposed by the World Health Organization (WHO) residential soil standards.

Antioxidant Parameters, Lipid Profiles and Performance Studies of Broiler Birds Fed Graded Level Taurine-Supplemented Diets

The research was targeted towards monitoring the activities of antioxidant enzymes, levels of non-enzymic antioxidants, lipid profiles and performance activities of broiler birds fed taurine-supplemented diets. One hundred and eighty 1-day-old unsexed arbor acre strain broiler birds were randomly distributed into five dietary treatments, six replicates per treatment and six birds per replicate. Treatments 1 to 5 contained 0%, 0.002%, 0.004%, 0.006% and 0.008% taurine supplements respectively as add-over. Treatment 1 served as the control diet. The birds were grouped and brooded for a week and the experiment lasted for six weeks. The birds were sacrificed and the liver, kidneys and serum were collected. The activities of catalase and myeloperoxidase, concentrations of reduced glutathione and nitric oxide as well as the serum lipid profiles were monitored. Liver catalase activities was highest for birds placed on 0.006 and 0.008% taurine-supplemented diets as compared with those on 0% taurine-supplemented diet. The trend was similar for the kidney reduced glutathione concentration. Liver nitric oxide concentrations and kidney myeloperoxidase activities were significantly higher (p<0.05) for birds placed on 0.004%, 0.006% and 0.008% taurine-supplemented diets as compared to birds placed on the control diets. High density lipoprotein was highest for birds on a 0.008% diet and lowest for birds on the control diet. The best feed conversion ratio was obtained for birds placed on 0.008% taurine-supplemented diet. Taurine-supplemented diets at between 0.002 and 0.008% favoured birds’ antioxidant defense mechanisms, had no deleterious effect on lipid profile, and equally improved the performance characteristics of broiler birds.

Comparison of Solid and Solvent - Based Syntheses, Characterization and Antioxidant Property of Metal Complexes of Sodium Diclofenac

Mechanosynthesis and solvent – based syntheses of transition metals (Ni, Co and Zn) complexes of Sodium diclofenac has been carried out by 1:1 molar ratio of the ligand to metal salts respectively. The synthesis of the metal complexes were confirmed by melting point determination, FT-IR (Fourier Transform Infra-red) and UV-visible spectroscopies. The ligand showed bidentate coordination to the metal ions through carboxylate moiety. Octahedral geometry was proposed for all the metal complexes. The antioxidant property of metal complexes was determined using DPPH (1,1-diphenyl-2-picrylhydrazyl) assay with Ascorbic acid as control. The antioxidant evaluation results revealed that the synthesized metal complexes are promising antioxidant agents.

Anti-Hyperlipidemic Activity of Polyphenol-Rich Extract of Cochlospermum Planchonii Roots in Triton x-100 Induced Rats

Cochlospermum planchonii is used for treatment of cardiovascular diseases in Nigeria and in some other African countries. This study investigated the anti-hyperlipidemic activity of polyphenol-rich extract of C. planchonii root in triton X-induced hyperlipidemic rats. Polyphenols were extracted from roots of C. planchonii with 80% aqueous methanol and acetone. Thirty female albino rats were randomized into six groups of five (5) rats each, Group I the non-hyperlipidemic control received saline only, group II the hyperlipidemic group received only saline, group III served as hyperlipidemic rats treated with 10 mg/kg b.w. atorvastatin while group(s) V-VII were hyperlipidemic rats treated with 25, 50 and 100 mg/kg b.w polyphenol-rich extract of C. Planchonii respectively. The effect of the administration of the extract on the serum lipid profile and hematological parameters was investigated. C. planchonii roots contained 47.7 ± 0.23 mg gallic acid equivalent / g dry extract and 49.14 ± 0.23 mg quercetin acid equivalent / g dry extract. Significant (p < 0.05) increase observed in serum total cholesterol, triacylglycerol and low-density lipoprotein with concomitant reduction in high-density lipoprotein concentration were mitigated by the polyphenol-rich extract. No significant changes were observed in the hematological indices of the hyperlipidemic rats at the doses investigated when compared to the control. The results indicated that polyphenol-rich extract of C. planchonii root exhibited anti-hyperlipidemic activity. Thus, it could be promoted as a recipe for protection against hyperlipidemia.