Présence et devenir des hormones stéroïdiennes dans les stations de traitement des eaux usées.

Différents produits chimiques naturels et d’origine industrielle présentent une activité endocrinienne. Ces composés sont susceptibles d’agir sur le système endocrinien des animaux et des êtres humains (altération ou déficiences des fonctions reproductrices, occurrence de tumeurs malignes, etc.). De nos jours, il reste de nombreuses questions en suspens (ampleur de la contamination, devenir dans l’environnement, etc.) et le caractère persistant de ces substances en fait un problème majeur pour les générations futures. De plus, plusieurs études ont montré que les estrogènes naturels (tels que l’estrone, le 17β‑estradiol et l’estriol) et l’estrogène synthétique (17α‑éthinylestradiol) sont les composés les plus oestrogéniques présents dans les effluents de stations de traitement des eaux usées. En conséquence, ces estrogènes peuvent rejoindre les eaux de surfaces et les contaminer. En effet, des concentrations aussi faibles que 0,1 ng/L peuvent provoquer des effets oestrogéniques chez les organismes aquatiques exposés. Cette revue s’est donc concentrée sur la présence de ces types de composé dans les eaux de surface et usées, et plusieurs procédés de traitement sont discutés par rapport à leur capacité d’enlèvement des estrogènes. Ainsi, le traitement primaire seul ne permet pas l’enlèvement des estrogènes des eaux usées, alors qu’un traitement secondaire à boue activée réduit généralement les quantités d’estrogènes. Les procédés dits avancés montrent un potentiel élevé pour l’enlèvement des estrogènes, bien qu’ils peuvent former des sous-produits oestrogéniques et/ou cancérigènes. Finalement, les systèmes enzymatiques pourraient être des procédés innovateurs pour le traitement des estrogènes, puisqu’ils montrent un potentiel élevé pour l’enlèvement des composés aromatiques dans les eaux usées.Various natural chemicals and certain contaminants from industries present an endocrine activity. These substances are likely to act on animal and human endocrine system (deterioration or reproductive functions deficiencies, malignant tumor occurrences, etc). Nowadays, many questions related to these compounds are not resolved and the persistent character of these compounds makes it a major problem for future generations. Furthermore, diverse studies determined that natural estrogens (e.g., estrone, 17β-estradiol and estriol) and synthetic estrogen (17α-ethinylestradiol) are the most estrogenic compounds in wastewater treatment plant effluents. Thus, these estrogens can reach surface water and contaminate it. Indeed, concentrations as low as 0.1 ng/L can induce estrogenic effects in exposed aquatic organisms. This review concentrated on this type of compounds in surface water and wastewater, and a number of treatment processes are discussed with regard to their potential on endocrine disrupting chemicals removal. In the primary treatment effluent, limited removal of estrogens has been observed, while secondary treatment involving activated sludge generally reduces all estrogens effluents concentrations. The advanced processes display a high potential for removing estrogens, although they may produce estrogenic and/or carcinogenic by-products. Enzymatic processes could be an innovative strategy for estrogens removal since they show a high potential to remove aromatic compounds from wastewater

Pre-treatment Technologies to Enhance Anaerobic Digestion

Sustainable energy production is the major priority in the world due to global warming, climate change, and fossil fuels depletion. Anaerobic digestion (AD) of sludge is the sustainable process producing the energy and minimizing the fossil fuel usage. However, conventional AD of sludge is not sustainable since it takes longer time for digestion which increases the energy input and greenhouse emissions. Therefore, pretreatment technologies have emerged to enhance methane production and thus the energy output from the AD process. In this chapter, pre-treatment technologies adopted mainly physical, chemical, thermal, and other advanced processes to enhance methane production in the last decade are elaborated. In addition, energy balance of the process and the feasibility of the pre-treatment technologies and their current status are discussed

IN VITRO ASSESSMENT OF BIOPESTICIDE BACILLUS THURINGIENSIS VAR. KURSTAKI HD- 1 EFFECTIVENESS ON PHYTOPHTHORA PALMIVORA, AGENT OF COCOA BLACK POD ROT IN CÔTE D’IVOIRE

Phytophthora Palmivora is responsible for the cocoa black pod rot in Côte d'Ivoire, with production losses varying from 20 to 40% depending on the regions. Effectiveness of the environmentally friendly biopesticide Bacillus thuringiensis var. kurstaki HD-1 was evaluated in vitro on the pathogen. The medium pea supercooled has been incorporated with the bioproduct at different concentrations: C1 = 100%, C2 = 50%, C3 =25%, C4 = 12.5% and C5 = 6.25%. This medium into Petri dishes was inoculated either by spreading, with 0.1 mL of P. palmivora inoculum at103 zoospores /mL, or with a mycelial disc of P. palmivora calibrated at 6 mm diameter in the center of the box. The results showed that the germination of zoospores was inhibited at the rate of 100% in the presence of the concentrations C1 and C2. This rate was 74.82 ± 21.53%, 73.17 ± 20.88% and 59.12 ± 39.05%, respectively, for C3, C4 and C5. The efficacy of the bioproduct is revealed by a significant reduction of mycelia growth ranging between 57.77± 2.4 to 100% in the presence of the concentrations C5 to C1. The IC50 of germination was 3.36% of concentration and the IC90 was 43.22%; while those which inhibit 50% and 90% of mycelial growth were 5.67% and 77.94% respectively. The biopesticide Btk HD-1 has a proven fungistatic effect against P. palmivora. Its effectiveness increases with its concentration. So it can be a valuable component of an integrated cocoa black pod management

IN VITRO ASSESSMENT OF BIOPESTICIDE BACILLUS THURINGIENSIS VAR. KURSTAKI HD- 1 EFFECTIVENESS ON PHYTOPHTHORA PALMIVORA, AGENT OF COCOA BLACK POD ROT IN CÔTE D’IVOIRE

Phytophthora Palmivora is responsible for the cocoa black pod rot in Côte d'Ivoire, with production losses varying from 20 to 40% depending on the regions. Effectiveness of the environmentally friendly biopesticide Bacillus thuringiensis var. kurstaki HD-1 was evaluated in vitro on the pathogen. The medium pea supercooled has been incorporated with the bioproduct at different concentrations: C1 = 100%, C2 = 50%, C3 =25%, C4 = 12.5% and C5 = 6.25%. This medium into Petri dishes was inoculated either by spreading, with 0.1 mL of P. palmivora inoculum at103 zoospores /mL, or with a mycelial disc of P. palmivora calibrated at 6 mm diameter in the center of the box. The results showed that the germination of zoospores was inhibited at the rate of 100% in the presence of the concentrations C1 and C2. This rate was 74.82 ± 21.53%, 73.17 ± 20.88% and 59.12 ± 39.05%, respectively, for C3, C4 and C5. The efficacy of the bioproduct is revealed by a significant reduction of mycelia growth ranging between 57.77± 2.4 to 100% in the presence of the concentrations C5 to C1. The IC50 of germination was 3.36% of concentration and the IC90 was 43.22%; while those which inhibit 50% and 90% of mycelial growth were 5.67% and 77.94% respectively. The biopesticide Btk HD-1 has a proven fungistatic effect against P. palmivora. Its effectiveness increases with its concentration. So it can be a valuable component of an integrated cocoa black pod management

Utilisation du broyat de péricarpes des cabosses de cacao comme milieu de culture alternatif pour la production de Bacillus thuringiensis var. kurstaki HD-1

La recherche de matières premières alternatives pour la production de biopesticides microbiens suscite beaucoup d’intérêts. La présente étude s’est proposée d’utiliser le broyat de péricarpes des cabosses de cacao comme substrat de fermentation pour produire Bacillus thuringiensis var. kurstaki HD-1 (Btk HD-1). Les échantillons de péricarpes des cabosses ont été collectés dans une plantation cacaoyère de Toumokro à Yamoussoukro en Côte d’Ivoire. Les paramètres physico-chimiques ont été déterminés selon les méthodes standards. Le substrat de fermentation a été autoclavé, 2 fois successivement, à 121 °C pendant 30 min et ensemencé avec 4% de l’inoculum de Btk HD-1. Il ressort de cette étude que les teneurs en carbone et en azote total ont été respectivement de 79.7% et 1.4%. Les concentrations en minéraux du substrat ont été plus élevées en calcium (8406.5 mg/kg) et en potassium (8248.8 mg/kg) qu’en magnésium (632.6 mg/kg), sodium (471.5 mg/kg), fer (57 mg/kg), cuivre (52.8 mg/kg), zinc (51.8 mg/kg) et manganèse (44.3 mg/kg). Le dénombrement des cellules et des spores viables a donné respectivement 3.2.1011 et 3.02.1011 UFC/ml, pour le surnageant, et 6.5.1013 et 5.02.1013 UFC/ml, pour le culot. Ce substrat végétal offre une bonne perspective pour la production d’un biopesticide à base de Btk HD-1.© 2016 International Formulae Group. All rights reserved.Mots-clés: Péricarpes des cabosses de cacao, biopesticide, Bacillus thuringiensis var. kurstaki HD-1, fermentation en milieu solide, Côte d’IvoireEnglish Title:  Use of crushed cocoa hulls as an alternative culture medium for Bacillus thuringiensis var. kurstaki HD-1 productionEnglish AbstractResearch for alternative raw material for microbial biopesticides production raises outstanding interests.This study is proposed to use the crushed pericarps cocoa pods as fermentation substrate to produce Bacillus thuringiensis var. kurstaki HD-1 (Btk HD-1). The samples pericarps pods were collected in a cocoa plantation of Toumokro in Yamoussoukro area, Côte d'Ivoire. The physico-chemical parameters were determined using standard methods. The fermentation substrate was autoclaved 2 times successively at 121 °C for 30 minutes and inoculated with 4% of Btk HD-1 inoculum. It appears from this study that the carbon and total nitrogen were 79.7% and 1.4% respectively. Mineral concentrations in substrate were higher in calcium (8406.5 mg/kg) and potassium (8248.8 mg/kg) than magnesium (632.6 mg/kg), sodium (471.5 mg/kg), iron (57 mg/kg), copper (52.8 mg/kg), zinc (51.8 mg/kg) and manganese (44.3 mg/kg). Cell counts and viable spores gave respectively 3.2.1011 and 3.02.1011 CFU/ml, to the supernatant, and 6.5.1013 and 5.02.1013 CFU/ml, for the pellet. This vegetal substrate offers a good prospect for Btk HD-1 based biopesticide production.© 2016 International Formulae Group. All rights reserved.Keywords: Cocoa hulls pod, biopesticide, Bacillus thuringiensis var. kurstaki HD-1, solid medium fermentation, Côte d’Ivoir

Biopesticide Production From Solid Wastes

International audienceAn enormous amount of solid waste is produced all over the world (billions of tonnes/year). Among these the biodegradable and nonhazardous solid wastes could be recycled and utilized in an eco-friendly manner to produce many bio-products (including biopesticides) using microbial strains by a solid-state fermentation process. In general, microbial biopesticides are produced using commercial media, which incurs a high production cost. To suitably address this issue, nonhazardous solid (biodegradable) waste can be used as the raw material, which reduces 35-59% of the cost involved in the use of synthetic media for biopesticide production. The biopesticides market represents $2.5. billion of global pesticide use. In this chapter, the production of microbial biopesticides from bacteria, fungi, and viruses is briefly presented and discussed. Also, the impact of using biopesticides to augment crop production and its vital role in improving human health are concisely highlighted

Value-Added Bio-products From Sewage Sludge

International audienceThe wastewater treatment plant (WWTP) treats wastewater and produces healthy water for water recycling and also produces a huge quantity of solid waste (sludge or biosolids). The municipal solid waste totals nearly 1.9. billion tons produced each year around the world. Disposal and transportation of solid wastes incur costs of around 50% of the total WWTP operation cost. The rich organic-nutrient-possessing sludge can be used as a raw material to produce value-added bio-products (VAPs) using green biotechnology approaches. The production of VAPs from biosolids could greatly reduce the sludge volume and yield beneficial products for industrial applications in an economic and eco-friendly way. In this chapter, the use of solid waste as raw material to produce VAPs like enzymes (laccases, degradative enzymes, and proteases), bioethanol and biodiesel, bio-fertilizer and bio-composting, bio-flocculants/biopolymers, biopesticides, and bioplastics were summarized

Effect of Sludge Concentration and Crude Glycerol Matrix as a Substrate on the Production of Single-Cell Oil by Oleaginous Yeast Yarrowia lipolytica SKY7

The disposal of excess crude glycerol produced by the booming biodiesel industry and wastewater sludge solid waste has become a severe problem, and alternate routes of use and valorization of these waste byproducts are needed. The use of cheaply available wastewater sludge solids in fermentation media is very much desirable to reduce the cost of production. The strains of Yarrowia lipolytica can assimilate a wide array of waste substrates, such as crude glycerol, waste cooking oil, starch wastewater, and cellulosic. This study optimized the concentration of wastewater sludge solids (5–35 g/L) to be used with crude glycerol in fermentation media to produce microbial oil as feedstock for biodiesel production. The results indicated that 20 g/L of sludge solids with 40 g/L of crude glycerol resulted in highest lipid content of 29.35% in 96 h. Further, assuming wet extraction of lipids, it was found that at least 11.2% or higher lipid content is required for this process to have an overall positive net solid waste reduction. Insignificant inhibition was observed by the crude glycerol used in this study as compared to pure glycerol, which proves it to be an adequate source of carbon substrate for lipid production