470 research outputs found

    Water chemistry of some rivers draining the basement complex in Southwestern Nigeria

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    Nous avons effectué une étude physico-chimique pendant quinze mois, des eaux des fleuves Owena, Ohoo et Orunro, dans le bassin sud-ouest nigérian afin d'en relever le pH, la conductivité, l'alcalinité, O2 dissous, CO2, silicate-SI,PO4-P, NO3N, Fe, Cl-, Ca2+, Mg2+ et la matière dissoute ... Le pH, la conductivité, l'alcalinité et le CO2 total sont en rapport direct avec le mode saisonnier des précipitations et les crues. La composition des eaux reflète la composition chimique et l'altérité des bassins des fleuves (granite-gneiss, les amphiboles et schistes ordinaires

    Effect of some nitrogen sources of growth medium on

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    Penicillium solitum and Aspergillus rubrum isolated from deteriorated yam (Dioscorea alata) using potato dextrose agar grew and sporulated at 25oC. They expresse

    α-Amylases by strains of Candida albicans and Fusarium sp.: Expression and characterization

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    In this investigation, a defined medium was inoculated with Candida albicans and Fusarium sp. Incubation was at 28oC. The composition of the medium was potassium dihydrogen sulphate, magnesium sulphate, calcium sulphate, hydrated iron sulphate, manganese sulphate, copper sulphate, zinc sulphate, thiamine, biotin, sodium nitrate (nitrogen source) and galactose (carbon source). Proteins which exhibite

    STUDIES ON PECTINOLYTIC AND PROTEOLYTIC ENZYMES FROM DETERIORATED GRAPES (Vitis vinifera)

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    The ability of microorganisms to cause grape (Vitis vinifera) fruit deterioration by production of pectinolytic and proteolytic enzymes to degrade the plant cell was carried out in the Microbiology laboratory of the Department of Biological Sciences, Covenant University, Ota, Ogun State, Nigeria. A bunch of grape fruit was purchased from a local market in Ikeja, Lagos, South West, Nigeria. These samples were allowed to rot for five days in a clear packaging bag. The grape samples were disinfected and cultured on nutrient agar and potato dextrose agar for bacterial and fungal isolates respectively. The morphological and microscopic characteristics of the isolates in combination with a series of biochemical tests were used to identify them. The isolates were tested for their ability to produce pectinolytic and proteolytic enzymes. Aspergillus sp, Mucor sp, Rhizopus sp., Micrococcus sp., and Bacillus sp. were the organisms isolated from this study. The results of this investigation revealed appreciable pectinolytic, and proteolytic enzymes by Aspergillus niger and Bacillus sp. These organisms can be utilized as good sources of industrial enzymes

    Partial Purification ofPolygalacturonase from Tomato Fruits Infected by Rhizopus arrhizus Fisher

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    The production of polygalacturonase during the deterioration of tomato (Lycopersicon esculentum Mill.) by Rhizopus arrhizus Fisher was investigated. The enzyme was partially purified by a combination of ammonium sulphate precipitation, gel filtration and ion-exchange chromatography. Two peaks of absorption, with molecular weight estimates of approximately 166 000 Daltons and 60 260 Daltons were obtained

    The Effect of Temperature on the Clarification of Apple (MALUS DOMESTICA) Juice with Pecinase obtained from ASPERGILLUS NIGER

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    Aspergillus niger is a saprophytic fungus existing ubiquitously in the soil and on decaying vegetation. Various researchers have reported Aspergillus niger as frequently responsible for postharvest decay of fresh fruits such as apples, pears, grapes, melons, onions and some vegetables. The fungus has been implicated in the deterioration of apple fruits with the production of Pectinolytic enzymes during the breakdown of the plant cell wall by microbial attack. The three varieties of apple (Malus domestica) fruits used for this work are commonly referred to as Red, Green and Yellow varieties from their physical appearance. The fruits were obtained from a grocery store along Idiroko road, Ota, Ogun State in Nigeria. The fruits were disinfected and inoculated with a 72-h-old culture of A. niger. Control fruits were inoculated with sterile inoculum. The fruits were incubated at room temperature of 27oC for twelve days. Extracts from the inoculated fruits exhibited appreciable polygalacturonase activity while those from the uninoculated fruits possessed only traces of the enzyme activity. The enzyme obtained from the deteriorated fruits and commercially produced pectinase were applied for the clarification of freshly ripe apple fruits under controlled experimental conditions at different temperatures (20oC, 25oC, 30oC, 35oC, 40oC and 45oC) to investigate the role of pectinase in the clarification of apple juice. The temperature of incubation had different effects on the three varieties of apple fruits studied. The volume of juice was more in the cylinders with the enzyme clarification at all temperatures than that with water. The optimum temperature was at 25oC for the three varieties green and red apples. The commercial pectinase produced more juice than the crude pectinase

    Antibiotics resistance of a strain of Escherichia coli isolated from bore hole in Ile Ife, Osun state, Nigeria

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    Abstract:Escherichia coli were isolated from water from two boreholes in Ile Ife, Osun state, Nigeria. This was an indication of faecal contamination. These strains of Escherichia coli were Gram negative short rods, Catalase positive, Methyl red positive, Voges Proskaeur negative. The strains could ferment glucose galactose, sucrose, lactose, mannitol and maltose with the production of acid and gas but could not hydrolyze starch. A particular strain was resistant to sulfamethoxazole, ampicillin, cotrimoxazole, cephaloridine, streptomycin, carbenicillin, sulfafurazole and tetracycline but sensitive to gentamicin, colistin, nalidixic acid, nitrofurantoin and colistin sulphat

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

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    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
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