MOSP - Macao Scientific Publishers

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A new manometric method for measuring carbon dioxide production by dairy starter culture: A case of Leuconostoc mesenteroides

Mebrouk KIHAL*, Jamal Eddine HENNI, Hérvé PREVOST and Charles DIVIÈS

Abstract: This paper describe a technique for carbon dioxide (CO2) measurement based on the displacement of acidifying liquid in burette at constant pressure. It was adapted to allow the growth of Leuconostoc sp. on semi-synthetic media and milk. A highly precise measurement was obtained using the chemical reaction of sodium carbonate with hydrochloric acid. This method has been proven to present an excellent linear response from 0 to 0.895 mM of CO2 with a high sensitivity. With cultures in milk medium, kinetics of CO2 evolved by Leuconostoc mesenteroides subsp. dextranicum L4 were higher than L. mesenteroides subsp. mesenteroides 19D and L. mesenteroides subsp. cremoris Ec195 grown on milk.. The use of L. mesenteroides subsp. dextranicum L4 and their variants Lac(-)Cit(+), Lac(+)Cit(-) and Lac(-)Cit(-) showed that the CO2 production correlated to the substrate utilization. The curve of CO2 measured was close to the amount of CO2 calculated from lactose and citrate used. The CO2 production rate was higher with the parental strain (6.5 mM/ h) than with the variants. The amount of CO2 produced was always close to the theoritical value, and was also correlated to the growth rate and substrates utilization by L. mesenteroides. The volume of CO2 produced by Leuconostoc in milk was highly correlated with the D-lactate production (r= 0.995). This method could be used routinely for the evaluation and the selection of bacteria having potential ability for CO2 production.[...] Read More.

Keywords: Leuconostoc sp., CO2 production, lactic acid, milk.

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Is there any phylogenetic relationship between teleosts and the elasmobranchs?

M NE Dosay-Akbulut

Abstract: There is still disagreement with regard to identifying the sister group of the tetrapods? Different hypotheses were suggested for this relationship. The aim of this article was to present and summarize some of these studies, which were based on the possible phylogenetic relationship between Chondrichtyes and land vertebrates (tetrapods).[...] Read More.

Keywords: Phylogenetic, relationship, Chondrichthyes and tetrapods.

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Microbial growth and substrate utilization kinetics

G.C. Okpokwasili* and C.O. Nweke

Abstract: Microbial growth on and utilization of environmental contaminants as substrates have been studied by many researchers. Most times, substrate utilization results in removal of chemical contaminant, increase in microbial biomass and subsequent biodegradation of the contaminant. These are all aimed at detoxification of the environmental pollutants. Several microbial growth and biodegradation kinetic models have been developed, proposed and used in bioremediation schemes. Some of these models include Monod’s, Andrews, Bungay’s weighted model, general substrate inhibition models (GSIM) and sum kinetic models. Most research on microbial potentials to degrade chemical pollutants has been performed on a laboratory scale. There is a need to extend such studies to pilot scale as well as to full-scale field applications.[...] Read More.

Keywords: Microbial growth, substrate utilization, biodegradation, kinetics, detoxification, organic contaminants, models, environmental pollutants.

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Fungal enrichment of cassava peels proteins

Obadina A.O.*, Oyewole O.B. Sanni .L. O, and Abiola S. S.

Abstract: About 60% of the cassava produced all over the world is used for human consumption. These peels waste were found to contain 42.6% carbohydrate, 1.6% protein, 12.1% ether extract, 5.0% total ash and 22.5% crude fibre. With the advent of biotechnology approaches, there are opportunities for economic utilization of agro-industrial residues such as cassava peels waste. The Microorganisms isolated from the fermenting cassava waste were Aspergillus niger, A. flavus, and A. fumigatus. These and Trichoderma sp. from soil were studied for their ability to increase the protein content of cassava peels waste. Keywords: Cassava peels, Aspergillus flavus, Aspergillus niger, Aspergillus fumigatus.[...] Read More.

Keywords: Cassava peels, Aspergillus flavus, Aspergillus niger, Aspergillus fumigatus.

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Coagulants modulate the hypocholesterolemic effect of tofu (coagulated soymilk)

Ganiyu Oboh

Abstract: The recent increase in soymilk and tofu (coagulated soymilk) consumption especially in western countries is due to the recognition of the health benefits of soy foods. The amount and the type of coagulated biomolecules (such as isoflavones) vary with the type of coagulant, and this will inevitable alter their biological activity. This study sought to assess the effect of some coagulants (calcium chloride, alum and steep water from pap production) commonly use in the production of tofu in Nigeria on the serum cholesterol, high-density lipoproteins (HDL) and low-density lipoproteins (LDL) level in albino rats fed tofu for 14 days. The result of the study revealed that there was no significant difference (P>0.05) in the tofu yield (17.6 – 18.3%), however steep water (12.0 g/kg) had a significantly higher (P[...] Read More.

Keywords: Coagulant, soymilk, tofu, phenol, HDL, LDL, cholesterol.

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Purification and biochemical properties of a new thermostable xylanase from symbiotic fungus, Termitomyces sp.

Betty Meuwiah Faulet, Sébastien Niamké,*, Jean Tia Gonnety and Lucien Patrice Kouamé

Abstract: A xylanase was purified from symbotic fungus, Termitomyces sp. by chromatography on columns of DEAE-Sepharose, CM-Sepharose, gel filtration and Phenyl-Sepharose. The preparation was shown to be homogenous by polyacrylamide gel electrophoresis. The purified enzyme displayed two protein bands on SDS-polyacrylamide gel electrophoresis and its molecular mass was estimated to 80-87 kDa. The xylanase exhibited maximum activity at 65-70°C and at pH 5.6, but it retained more than 80% of its activity in the pH range 5.0-6.0. The enzyme was stable for a long time-period up to 50°C and for 1 h at 60°C. Although the xylanase had a lower carboxymethylcellulase activity, it lacked activity towards substituted xylan, xylobiose, inulin, starch, polygalacturonic acid or pNP-glycosides. Kinetic parameters indicated higher efficiency in the hydrolysis of beechwood xylan and birchwood xylan. The xylanase activity was stimulated by K+, Mn2+ and dithiol-reducing agents and was sensitive to Cu2+, Fe2+, Zn2+ and detergent agents. The enzymatic activity was observed in presence of urea up to a 1% (w/v) concentration. The enzyme could also be used in the presence of organic solvents such as acetone or dioxane (5%, v/v) without loss of activity.[...] Read More.

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Esterase and protease activities of Bacillus spp. from afitin, iru and sonru; three African locust bean (Parkia biglobosa) condiments from Benin

Paulin AZOKPOTA, Djidjoho Joseph HOUNHOUIGAN*, Mathurin Coffi NAGO and Mogens JAKOBSEN

Abstract: Fifty strains of Bacillus spp. comprising Bacillus subtilis and Bacillus licheniformis previously isolated from afitin, iru and sonru were examined for esterase and protease activities. The electrophoretic profiles of fermented African locust bean protein (ALBP), using strains presenting the highest protease activities in casein agar, were analyzed by SDS-PAGE to select strains with good ability to be used as starter cultures. All the Bacillus spp. tested showed esterase activity against tributyrin with high variability among strains. Strains showing the highest esterase activities were B. subtilis, primarily isolated from iru, sonru and lastly in afitin. Only 62% (31/50) of the Bacillus strains tested showed perceptible, but highly variable protease activity in casein agar. Bacillus strains showing the highest protease activities comprised strains of B. subtilis isolated from afitin and iru and strains of B. licheniformis isolated from iru and sonru. A B. subtilis strain isolated from afitin showed high esterase as well as high protease activity. The electrophoretic profile by SDS-PAGE of ALBP fermented by the Bacillus spp. having the highest protease activities showed degradation products with a wide range of molecular size between 4 and 250 kDa. Variability of the characteristics of the Bacillus spp. tested give new opportunities for their use as starter culture for products development.[...] Read More.

Keywords: Bacillus subtilis, bacillus licheniformis, fermentation, esterase and protease activity, SDS-PAGE.

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Production potentials of anti-Plesiomonas shigelloides antibody

Oviasogie, F.E. and Ekhaise, F.O.*

Abstract: Out of the one hundred and fifty stool human samples screened for the prevalence of Plesiomonas shigelloides, only 3 (2%) were positive for the organisms. The positive isolates were used to produce P. shigelloides antibody in experimental animals (rabbits). Autopsy revealed marked inflammation of the liver, spleen and the kidney in the experimental animals not protected with the antibodies. This study showed that the trial rabbits were suitable for the production of antibodies against P. shigelloides, and further demonstrated the diagnostic and protective potentials of the antibodies.[...] Read More.

Keywords: Plesiomonas shigelloides, experimental animals, colloidal carbon particles, antibody and antisera.

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Evaluation of acute and subacute toxicities of aqueous ethanolic extract of leaves of Senna alata (L.) Roxb (Ceasalpiniaceae)

C.A. Pieme*, V. N. Penlap, B. Nkegoum, P. C. L. Taziebou, E.M. Tekwu, F. X. Etoa , J. Ngongang

Abstract: We investigated the acute and subacute toxicities of hydro-ethanolic extract of leaves of Senna alata (L.) Roxb. in Swiss mice and Wistar albino rats. The mice were divided into 6 groups of 10 animals and each group received once by intra-gastric gavages 0, 4, 8, 12, 16, 20 times 1000 mg/kg dose of extract. Distilled water served as the control. For the subacute toxicity, three groups of 10 rats (5 males and 5 females) were treated per os with distilled water (control), 500 or 1000 mg/kg of extract every 48 h for 26 days. At the end of treatment blood sample and 20% liver homogenates were collected for biochemical analyses. The results indicated that the medium lethal dose (LD50) was about 18.50 g/kg of body weight. Significant variation (P[...] Read More.

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Influence of intra-row spacing and mulching on weed growth and bulb yield of garlic (ALLIUM SATIVUM l.) in Sokoto, Nigeria

A.K. Karaye and A.I. Yakubu*

Abstract: Two field experiments were conducted during 2000/2001 and 2001/2002 dry seasons under irrigation at Kwalkwalawa Research FADAMA Farm of Usmanu Danfodiyo University, Sokoto to investigate the response of weed growth and bulb yield of garlic to intra-row spacing and mulching. The treatments consisted of three intra-row spacings (10, 15, and 20 cm) and four mulching rate (0, 5, 7 and 9 t/ha). These were laid out in split plot design and replicated three times. Intra-row spacing was assigned to main plots and mulching was allotted to sub plots. Gross and net plot sizes were 3 x 1.5 m and 2.5 x 1 m, respectively. Results indicated that the number of leaves/plant, weed growth and cured bulb yield responded significantly to intra-row spacing and mulching, except in 2000/2001 trial, when the effect of mulching on cured bulb yield was not significant. Based on the results obtained, it could be concluded that for optimum bulb yield in garlic, the intra-row spacing of 10 cm and 9 t/ha mulching rate should be adopted.[...] Read More.

Keywords: Intra-row spacing, mulching, weed, garlic.

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