Caractérisation partielle et distribution des activités osidasiques de l\'extrait brut enzymatique de la blatte Periplaneta americana

L\'objectif de ce travail était d\'utiliser la blatte Periplaneta americana comme source de glycosidases à activités originales pouvant intervenir dans la valorisation des molécules alimentaires et non alimentaires des ressources agricoles et comprendre la dégradation des macromolécules alimentaires chez cette espèce de blatte. Cette étude a été réalisée à l\'aide de l\'extrait brut enzymatique total et des différentes portions du tube digestif de la blatte Periplaneta americana. Il ressort de ce travail que l\'extrait brut enzymatique total de la blatte Periplaneta americana possède un équipement glycosidasique dont l\'action s\'exerce aussi bien sur les polyholosides, les hétérosides que sur les oligosides. De façon générale, ces activités osidasiques obtenues à des pH optimums acides sont mésophiles avec des températures optimales comprises entre 45 et 60 °C dans le tampon acétate. Cependant, les activités &#945-galactosidasique, &#945-mannosidasique, &#945-glucosaminidasique et &#945- xylosidasique sont thermophiles. L\'étude de l\'inactivation thermique montre que certaines de ces activités sont stables (activités xylanasique, lichnanasique, amylasique, &#945-glucosidasique et invertasique). La comparaison des activités enzymatiques obtenues dans les différentes parties du tube digestif de la blatte Periplaneta americana montre que la majorité des enzymes étudiées sont surtout distribuées au niveau des intestins moyen (mésenteron) et antérieur et dans une moindre mesure au niveau de la panse. Ce qui nous fait penser que la dégradation des macromolécules en sucres simples chez cette blatte a lieu principalement dans ces portions. Ces résultats montrent que la blatte Periplaneta americana possède une richesse en diverses glycosidases qui pourraient constituer après purification des outils enzymatiques indispensables dans les industries agroalimentaire, pharmaceutique et du textile. Keywords: Blatte, Periplaneta americana, activités osidasiques, distribution, tube digestif. International Journal of Biological and Chemical Sciences Vol. 2 (2) 2008: pp. 128-13

Niveaux de résidus de pesticides organochlorés dans les produits du cacao en Côte d’Ivoire

L’objectif de cette étude est de déterminer le contenu en résidus de quelques pesticides organochlorés du cacao masse, des tourteaux et du beurre de cacao. Pour se faire, 75 échantillons de fèves de cacao ont étéprélevés auprès des planteurs et coopératives du département d’Agboville et des exportateurs des ports de San Pedro et d’Abidjan. Les concentrations en 18 pesticides organochlorés ont été déterminées au chromatographe en phase gazeuse de marque Agilent Technologies 6980N munie de deux détecteurs à capture d’électrons (μECD), deux colonnes capillaires (30 m X 0,25 mm X 0,25 μm) et d’un injecteur automatique. Il ressort de cette étude que 15 des 18 pesticides recherchés sont présents à des concentrations variant de 2 μg/kg à 59,6 μg/kg dans les différents produits analysés. Les fèves de cacao issues du département d’Agboville se sont révélées plus contaminées en pesticides organochlorés (aldrine, alpha BHC, bêta BHC, delta BHC, lindane, dieldrine, endosulfane I, endosulfane II, endosulfane sulfate, endrine, endrine aldéhyde, endrine ketone, heptachlore, heptachlore epoxyde, 4,4'-DDD, 4,4'-DDE, 4,4'-DDTet metoxychlore), en nombre et en quantité. Il convient d’informer les différents acteurs du domaine d’activité sur les dangers encourus, d’éduquer les vendeurs et les planteurs et de contrôler leur activité par la mise en place de bonnes pratiques agricoles et le respect des normes sur les pesticides

Purification and physicochemical properties of - amylase from cockroach, Periplaneta americana (LINNAEUS), for starches saccharification

An -amylase was purified from the American cockroach Periplaneta americana (Linnaeus) to homogeneity by four steps purification via ammonium sulphate crude extract precipitation, SephacrylS-100 HR gel permeation chromatography, anion exchange chromatography on DEAE-Sepharose CL-6B and hydrophobic interaction chromatography on phenyl Sepharose CL-4B. The purification was approximatively 38.42 fold with a 24.31% yield. Optimums pH and temperature of the purified -amylase were found to be 5.6 and 55°C, respectively. The enzyme was stable up to 55°C and its pH stability was in range of 5.6 - 6.6. The KM and Vmax of the enzyme with soluble starch as substrate were 5 mg/ml and100 ìmol/min/mg, respectively, and the energy of activation (Ea), was 50.32 Kj/mol. The -amylase was inhibited by Tris, Fe3+, Ba2+, Mo+ and EDTA. While Ca2+, K+, Cu2+, Mg2+ and  para-hydroxymercuribenzoate (pHMB) activated the enzyme. Analysis of the amylolytic reaction products by HPLC showed thepresence of maltose and maltodextrin but not glucose in the starch hydrolysate (2 h of reaction). This result indicated that the amylolytic enzyme of P. americana is an -amylase (an endoamylase). Thepurified -amylase hydrolysed maltopentose, maltohexose and maltoheptose. Maltose, maltotriose and maltotetrose were not hydrolysed by this enzyme. Therefore, the purified -amylase is active only on substrates with more than four residues of glucose

Assessment of organochlorine pesticides residues in fish sold in Abidjan markets and fishing sites.

This study aimed to investigate the organochlorine pesticide residues in fish sold in markets and fishing sites in Abidjan, Côte d’Ivoire. Pesticides are not only used in agriculture but also in public health for the prevention of malaria. However, pesticide residues may be found in foodstuffs. Contamination of foods by pesticides can give rise to carcinogenic, mutagenic and teratogenic effects. Pesticides are also accountable for toxic effects on the nervous, immune, reproductive, renal, hepatic and hematopoietic systems. For the present study, one hundred fish specimens representing five fish species collected from markets and fishing sites were analyzed. Analyses were performed with the help of a Gas Chromatograph (GC), brand Agilent Instruments 6890N equipped with two micro-electrons capture detectors (μECD), two Zebron capillary columns (ZB-5MS and ZB-1701P; 30 m x 0.25 mm x 0.25 μm), an automatic injector and monitored by a microcomputer equipped with the ChemStationplus software version 2002. The injection was done in Splitless mode and Nitrogen N50 was used as vector gas. Of the 16 organochlorine pesticides considered in this study, 11 were present in the samples analyzed, at various concentrations ranging from 0.4 to 14.4 μg.kg-1 of fresh product. Samples were mostly contaminated by Dichloro Diphenyl Dichloroethane (DDD). The catfish, with a total average concentration (27.2 μg.kg-1 of fresh product) was the most contaminated species. Heads (27.8 μg.kg-1 of fresh product) and viscera (17.5 μg.kg-1 of fresh product) were, respectively the most contaminated parts of the fish species analyzed. The fishing port of Vridi was the most contaminated site. The species collected on this site presented a total average concentration of 24.4 μg.kg-1 of fresh product. The comparison of total concentration mean of organochlorine pesticides in species collected, with the maximum residue limits (MRL) set for the fishery products, suggests that health risks faced by populations in Abidjan through fish consumption are currently low.Key words: Organochlorine pesticides, GC, Fish, Consumptio

Characterisation of purple acid phosphatase from breadfruit (Artocarpus communis) seeds

ABSTRACT Objectives: To investigate the biochemical properties, physiological role and possible application of a purple acid phosphatase isolated from breadfruit (Artocarpus communis) seeds. Methodology and results: An acid phosphatase was purified 13.7-fold to apparent homogeneity from breadfruit (Artocarpus communis) seeds, using successive chromatographies on DEAE-Sepharose Fast-flow, Sephacryl S-100 HR, and phenyl Sepharose 6 Fast-flow. The enzyme was a purple acid phosphatase (λmax = 510 nm) that appeared to be a monomeric protein with molecular weight of approximately 27.3 kDa by SDS PAGE. The purple acid phosphatase was optimally active at pH 5.5 and 55°C, but strongly inhibited by molybdate, vanadate, phosphate and zinc. Moreover it did not require divalent cations for catalysis. This phosphatase showed wide substrate specificity with high affinity for sodium pyrophosphate, suggesting that pyrophosphate could be its potential physiological substrate. The enzyme also hydrolyzed sodium phytate. Potential application of finding: The purified enzyme could be applied in the mineral fertilizers industry or as a food additive for monogastric animals, e.g. pigs, in farming systems

Etudes de quelques paramètres de croissance et de valeur nutritive des variétés d'escargot Archachatina marginata (Swainson) élevées en milieu naturel

Studies of some Parameters of Growth and Nutritive Values of Snail Varieties Archachatina marginata (Swainson) Bred in Natural Environment. Approximately two months old juvenile snails of from black and white body varieties Archachatina marginata obtained from indoor rearing were introduced in Banco forest of Nangui Abogoua University in order to study some growth and nutritive values parameters after 24 months. The result obtained showed that 12% of black body snails exhibited average shell length of 12.5 cm with 218.19 and 44.57 average live weight respectively. Concerning white body snails, only 3% exhibited average shell length of 12.5 cm with 231.1 and 50.96 g of average live and body weight respectively. Numbers of these white body snails were small with percentage of 22%, and average live and body weight of 128.5 and 30.2 g, respectively. This result suggests that snail A. marginata under breeding in this natural medium showed good performance of growth comparable to those from the original natural medium. Moreover, the study of nutritive value parameters revealed that body of both varieties of A. marginata had the similar ash content of 9.8% with important calcium contents of 17.38±0.37 and 20.34±2.94% for black and white body varieties, respectively. The shell ash content of both snail varieties showed identical value of 95% with calcium contents of 17.38±0.37 and 20.34±2.94% for black and white body varieties, respectively. Their body protein content was estimated at approximately 62%

A Systematic Review and Meta-Analysis of Fecal Contamination and Inadequate Treatment of Packaged Water

<div><p>Background</p><p>Packaged water products provide an increasingly important source of water for consumption. However, recent studies raise concerns over their safety.</p><p>Objectives</p><p>To assess the microbial safety of packaged water, examine differences between regions, country incomes, packaged water types, and compare packaged water with other water sources.</p><p>Methods</p><p>We performed a systematic review and meta-analysis. Articles published in English, French, Portuguese, Spanish and Turkish, with no date restrictions were identified from online databases and two previous reviews. Studies published before April 2014 that assessed packaged water for the presence of <i>Escherichia coli</i>, thermotolerant or total coliforms were included provided they tested at least ten samples or brands.</p><p>Results</p><p>A total of 170 studies were included in the review. The majority of studies did not detect fecal indicator bacteria in packaged water (78/141). Compared to packaged water from upper-middle and high-income countries, packaged water from low and lower-middle-income countries was 4.6 (95% CI: 2.6–8.1) and 13.6 (95% CI: 6.9–26.7) times more likely to contain fecal indicator bacteria and total coliforms, respectively. Compared to all other packaged water types, water from small bottles was less likely to be contaminated with fecal indicator bacteria (OR = 0.32, 95%CI: 0.17–0.58) and total coliforms (OR = 0.10, 95%CI: 0.05, 0.22). Packaged water was less likely to contain fecal indicator bacteria (OR = 0.35, 95%CI: 0.20, 0.62) compared to other water sources used for consumption.</p><p>Conclusions</p><p>Policymakers and regulators should recognize the potential benefits of packaged water in providing safer water for consumption at and away from home, especially for those who are otherwise unlikely to gain access to a reliable, safe water supply in the near future. To improve the quality of packaged water products they should be integrated into regulatory and monitoring frameworks.</p></div