CHARACTERISATION OF PARTIALLY PURIFIED CELL WALL-DEGRADING ENZYMES: POLYGALACTURONASE AND CELLULASE FROM TOMATO FRUITS DEGRADED BY ASPERGILLUS NIGER

Aspergillus niger is a soil saprobe and produces a wide array of hydrolytic and oxidative enzymes and cell wall degrading enzymes. An investigation on the various properties of partially purified polygalacturonase and cellulase enzymes extracted from tomato fruits deteriorated by Aspergillus niger was carried out in this study. The results obtained shows that temperature, pH and substrate concentration have a profound effect on enzyme activity. The molecular weights of the enzymes extracted also suggest that it may be species dependen

Characterization of α-Amylase from Soursop (Annona muricata Linn.) Fruits Degraded by Rhizopus stolonifer

Rhizopus stolonifer is a fungus and one of the most common species of the genus Rhizopus. The organism has been a very important microbe used in the field of industrial microbiology. It has been used in the production of many hydrolytic and extracellular enzymes among which is the "-amylase. This enzyme has found various uses in the industry. Fruit juices are important sources of nutrients and they contain several important therapeutic properties that may reduce the risk of various diseases. An investigation on "-amylase extracted from soursop fruits deteriorated by R. stolonifer and the effect of the enzyme on soursop juice clarification was carried out in this study. The results obtained shows that the soursop juice with low concentration of extracted enzyme and less incubation time was more viscous and cloudy compared with the juice with high concentrations of amylase and higher incubation time which was clearer and less viscous. The results of this research will be very useful in soursop juice producing companie

Studies on Staphylococcus aureus Isolated from Pimples

Background and Objective: Pimples (acne) are small skin lesions or inflammations of the skin. The most common factor causing acne is the hormonal changes that occur during adolescent and teenage years. Antibiotics are becoming less effective in the treatment of pimples due to increasing concerns of antibiotic resistance. This study was therefore carried out to characterize the isolates from the pimples of Covenant University Students and to determine their antibiotics sensitivity pattern. Materials and Methods: A total of 20 swab samples were obtained from male and female students with obvious signs of pimples in Covenant University, Ota, Ogun State, Nigeria. The samples obtained were cultured on Mannitol Salt Agar and incubated at 37EC. Pure isolates obtained were subjected to Gram staining and other biochemical tests for identification. The isolates were further subjected to antibiotics sensitivity tests using antibiotic dics. Results: Macroscopic examination indicated that the organisms were convex, smooth and shiny. Microscopic examination revealed that the isolates were positive after employing the Gram Staining technique and they appeared as grape-like clusters. Biochemical tests revealed that the isolates were Coagulase positive, Catalase positive, Urease positive, Citrate positive, Methyl-Red positive, Voges-Proskauer negative and negative upon starch hydrolysis. The sugar fermentation tests revealed that the isolates fermented Glucose, Maltose, Galactose, Sucrose and Lactose, respectively. The antibiotic susceptibility test showed that isolates were resistant to Cotrimazole, Cloxacillin, Erythromycin, Gentamycin, Augmentin, Streptomycin, Tetracycline and Chloramphenicol. Conclusion: The results therefore indicated that the isolates were Staphylococcus aureus and other staphylococci species. Indiscriminate use of antibiotics should be avoided to prevent the development of resistant strains of the Staphylococci genera and other pathogenic organisms

Modification of Cell Wall Degrading Enzymes from Soursop (Annona muricata) Fruit Deterioration for Improved Commercial Development of Clarified Soursop Juice (A Review

The soursop fruit and the entire soursop plant is associated with a lot of health benefits which includes the killing of cancer cells in cancer patients. The treatment of cancer with soursop has been reported to be accompanied with the risk of Parkinson’s disease while soursop juice is considered safe for consumption. The fruit had been associated with preharvest and postharvest deterioration caused by microorganisms and this reduces the total production of soursop fruit. The deterioration process is being accompanied with the production of cell wall degrading enzymes which has the advantage of being used for industrial purposes. One of the important uses of these enzymes is in the clarification of fruit juices. This review proposes the genetic modification of the genes coding for important microbial enzymes for the clarification of soursop juice for improved yield, taste, and colour

CHARACTERIZATION OF CHITINASE FROM THE AFRICAN CATFISH, CLARIAS GARIEPINUS (BURCHELL, 1822)

Chitinases are hydrolytic enzymes that break down the glycosidic bonds in chitin. The role of Chitinases in the treatment and prevention of various diseases have been reported. They have been implicated in the human health care for the treatment of fungal infections, in Asthma and in the control of mosquito which causes the deadly malaria disease accounting for about 70% of infant mortality in Africa. Chitinase was obtained from chitinolytic bacteria inhabiting the skin and gut of the African Catfish (Clarias gariepinus). Bacterial population Isolated from catfish was screened on colloidal-chitin agar medium. The ability to produce Chitinase was determined by zones of hydrolysis produced after 96h of incubation at 37oC. Isolation of chitinase was carried out with colloidal chitin as substrate in sodium phosphate buffer. Optimum conditions were therefore ascertained at a temperature of 500C and a substrate concentration of 0.15g for chitinase produced by bacteria spp (isolate code 17 and 36) while pH 5.5 was obtained for isolate code 36 and pH 6.0 for isolate code 17. The Michaelis –Mentens constant (Km) which is also known as the dissociation constant is the substrate concentration at half maximum velocity. Calculated from the Lineweaver-Burk plot, the apparent Km values for the hydrolysis of chitin by chitinolytic bacterial isolate code 36 and isolate code 17 were approximately 0.09mg/ml and 0.007mg/ml respectively. Isolation of DNA and PCR amplification carried out identified the bacteria as a member of the genus Bacillus. This study established that species of Bacillus inhabiting the gut and skin of the African catfish can be used for Chitinase production in appreciable quantity

Extraction of lycopene with cell wall degrading enzymes from tomato (Lycopersicon esculentum Mill) fruits deteriorated by Aspergillus niger

Lycopene is the carotenoid which gives tomatoes and other red fruits their characteristic colour. It is one of the most powerful antioxidants and singlet oxygen quenching agents. It has been found to be of great medical importance with various anticancer effects and its ability to ameliorate several other medical conditions. Freshly ripe tomato fruits of the Roma vf variety and the Ibadan local variety were allowed to deteriorate after infection with a 96-hr-old culture of Aspergillus niger. Extraction of cell wall degrading enzymes produced during the deterioration process was carried out ten days after inoculation of the tomato fruits. The crude enzymes were precipitated using ammonium sulphate precipitation technique and employed in the extraction of lycopene from tomato peels. The yield of lycopene was 45.25mg/kg and 45.86mg/kg for enzymes extracted from the Roma vf and the Ibadan local varieties of tomato fruits respectively. This study established an improvement in lycopene extraction with crude preparation of cell wall degrading enzymes and compared the yield from the two enzymes obtained from the two most commonly available varieties of tomato fruits in Nigerian markets

Assessment of Risks and Uncertainties in Poultry Farming in Kwara State, Nigeria

This study was designed to assess the risks and uncertainties encountered by poultry farmers in Kwara State, Nigeria. Specifically, the study describes the socio-economic characteristics of the farmers, identify the risks and uncertainties encountered by the farmers, determines the level of severity of the risks and uncertainties, and identifies the coping strategies employed by the farmers. Primary data obtained from 99 registered poultry farmers selected through multistage sampling technique were used for the study. These were complemented with data from published and grey literature. Descriptive statistics and 3-point Likert scale were used to analyze the data. The study shows that poultry farming in the study area is practiced mainly by young, small-scale farmers, who are married, with high level of formal education but had little access to extension services. The major sources of risks encountered by the farmers were severe weather fluctuation, lack of veterinary services, disease outbreak, transportation problems, parasites and severe price fluctuation of birds. The study further revealed that the severe risks encountered by the farmers were disease outbreak, poor parent stock, accumulation of dung, severe weather fluctuation, lack of veterinary services and transportation problems. The study therefore calls for improved extension services, good transportation facilities, adequate veterinary services, market information by government and relevant stakeholders as well as formation of cooperative socities by the farmers

CORPORATE SOCIAL RESPONSIBILITY AND FIRM PERFORMANCE: A STUDY OF LISTED FIRMS IN NIGERIA

This study investigated the Corporate Social Responsibility (CSR) disclosure practices of Nigerian quoted companies and their determinants. A checklist of 20 attributes was developed to capture the social and environmental disclosures from the annual reports of 45 companies from 8 sectors quoted on the Nigerian Stock Exchange over a two-year period (2013 to 2014). The determinants of disclosure were proxied by company size, profitability and auditor type. Company size was measured by total assets, profitability was measured by return on equity (ROE), and auditor type was measured by a dummy variable, ‘1‘ for Big 4 and ’0‘ for otherwise. The data obtained were analysed using descriptive statistics, correlation and regression. The findings revealed that, the level of CSR was 44%, made up of social disclosure (68%) and environmental disclosure (6%). Findings also revealed that CSR was influenced by company size and auditor type; but not by profitability. This paper recommends a mandatory CSR reporting framework in line with international best practice for all listed companies in Nigeri

A multi-site assessment of knowledge of Ebola virus disease among health workers in south-west Nigeria

Objective: Nigeria may have been certified free from Ebola Virus Disease (EVD) by the World Health Organization, but not without its aftermath on many, especially among health workers who came in contact with the infected during the West African outbreak in 2014.This study was conducted among health workers in three tertiary hospitals in South-West Nigeria. It aimed at assessing their knowledge of EVD in a bid to forestall future contagion from patients.Method: 600 consenting participants selected through two-stage sampling method were involved in the study. Primary data was retrieved through self-administered questionnaire.Results: Majority (84.0%) of the participants knew that EVD can be contacted through blood and bodily fluid of an infected person, (78.0%) knew that EVD can be prevented by avoiding contact with an infected person, while (76.0%) identified bleeding from orifices as one of the signs of EVD. However, (6.0%) of the participants did not know how EVD can be prevented.Conclusion: Result showed that participants have average knowledge of EVD and therefore, are not adequately informed of EVD. The study recommended wider dissemination of adequate information on EVD among health workers in tertiary hospitals to forestall future contagion of the infection from patients.Keywords: Knowledge, EVD, Contagion, Outbreak, Prevention, Bleedin

Screening and partial purification of amylase from Aspergillus Niger isolated from deteriorated tomato (Lycopersicon Esculentum mill.) fruits

Amylases (EC 3.2.1.1) are cellwall degrading enzymes associated with the pathogenicity of microorganisms in the spoilage of tomato fruits. The use of amylase in many industries has made it very important to optimize production process to achieve maximum yields. Screening and partial purification of Amylase from Aspergillus niger isolated from tomato (Lycopersicon esculentum Mill.) fruits was studied. Amylase producing fungi were isolated from fresh tomatoes kept at ambient temperature (28±1˚C). Isolates were characterized on the basis of their morphological and cultural techniques. Partial purification of amylase was carried out by ammonium sulphate precipitation. The enzyme activity was determined and optimum conditions were obtained. The molecular weights of the crude and partially purified Amylase were determined by SDS PAGE method. A total of five isolates were obtained using basic screening technique for amylase activity, one of the isolates (Isolate code F2) exhibited maximum amylase activity. The fungi isolate code F2 was identified as Aspergillus niger. Optimum conditions for Amylase AMY F2 were ascertained at pH 6.0; temperature 30°C; substrate concentration of 0.3mg/ml, and time of heating of less than 10min. The molecular weights  f the crude and partially purified Amylase AMY F2 were found to be 55kDa and 35kDa respectively by SDS PAGE method. Microorganisms had been an encouraging means of economical production of enzymes in large scale for the food and drug industry. Keywords: Amylase, Partial Purification, Enzyme, Tomato Fruits Rendement et purification partielle de l'amylase de Aspergillus Niger isolé à partir de tomate déterioré (Lycopersicon Esculentum mill.) fruitsLes amylases (EC 3.2.1.1) sont des enzymes dégradant les parois cellulaires associées à la pathogénicité des microorganismes dans la détérioration des fruits à la tomate. L'utilisation de l'amylase dans de nombreuses industries a rendu très important d'optimiser le processus de production pour obtenir des rendements maximaux. Le dépistage et la purification partielle de l'amylase d'Aspergillus niger isolés à partir des fruits à la tomate (Lycopersicon esculentum Mill.) Ont été étudiés. Les champignons producteurs d'amylase ont été isolés à partir de tomates fraîches conservées à température ambiante (28 ± 1 ° C). Les isolats ont été caractérisés en fonction de leurs techniques morphologiques et culturelles. La purification partielle de l'amylase a été réalisée par précipitation au sulfate d'ammonium. L'activité enzymatique a été déterminée et des conditions optimales ont été obtenues. Les poids moléculaires de l'Amylase brut et partiellement purifiée ont été déterminés par un procédé SDS PAGE. Au total, cinq isolats ont été obtenus en utilisant une technique de dépistage basique pour l'activité amylase, l'un des isolats (code isolé F2) présentait une activité amylase maximale. Le code isolant F2 des Fusions a été identifié comme Aspergillus niger. Les conditions optimales pour Amylase AMY F2 ont été déterminées à pH 6,0; température 30 ° C; concentration de substrat de 0,3 mg / ml et temps de chauffage de moins de 10 min. On a trouvé que les poids moléculaires de l'amylase brute et partiellement purifiée étaient respectivement de 55 kDa et 35 kDa par le procédé SDS PAGE. Les microorganismes ont été un moyen encourageant de production économique d'enzymes à grande échelle pour l'industrie alimentaire et pharmaceutique.Mots-clés: Amylase, Purification partielle, Enzyme, Fruits tomate