Cashew apple bagasse as new feedstock for the hydrogen production using dark fermentation process.

Cashew apple bagasse (CAB) has been studied as feedstock for the biohydrogen production using Clostridium roseum and the dark fermentation process. Pretreatment with alkaline hydrogen peroxide (CAB-AHP) on raw material and the acid and enzymatic hydrolysis have been taken into account to evaluate the H2 yields. Results show that the acid hydrolysate obtained from CAB produced higher H2 molar yield (HMY) (15 mmolH2/Lhydrolysate) than the acid hydrolysate from CAB-AHP (4.99 mmolH2/Lhydrolysate), These HMY were noticeably higher than values obtained from the enzymatic hydrolysate of CAB-AHP (1.05 mmolH2/Lhydrolysa) and the enzymatic hydrolysate of CAB (0.59 mmolH2/Lhydrolysa). The maximum biohydrogen productivity (12.57 mLH2/L.h) was achieved using the acid hydrolysate from CAB, with a H2 content of about 72% vol, that could be satisfactory in view of an energetic applications of the biogas. Results suggest that CAB could be considered for the hydrogen production process, providing an appropriate destination for this lignocellulosic biomass, and consequently, reducing the environmental impact it can exert

produzione di bioidrogenio da rifiuti della industria alimentare con biomassa sospesa e adesa utizzando batteri thermofili

This work describes hydrogen production by anaerobic digestion of glucose, molasses and milk whey by 4 thermophilic Thermotoga strains. In the attached-cell tests, the biofilm support characterized by the highest specific surface resulted in the best H2 rate. All the Thermotoga strains examined (T. neapolitana, T. maritima, T. naphtophila, T. petrophila) could produce H2 from glucose, molasses and milk whey, both in suspended- and attached-cell tests. With all the three substrates, the best performances were obtained with T. neapolitana. Some tests were conducted out to select the optimal carrier for the attached-cell conditions. 4 types of carrier were tested: 3 sintered glass carriers and a ceramic one; the chosen carrier was Biomax.Questo lavoro descrive la produzione di idrogeno per digestione anaerobica di siero di latte, glucosio e melasso utilizzando 4 ceppi Thermotoga termofili. Tutte i 4 ceppi di Thermotoga testati (T. neapolitana, T. maritima, T. naphtophila, T. petrophila) sono stati in grado di produrre H2 dal siero di latte, glucosio e melasso, sia in prove con biomassa sospese che adesa. Con tutti i tre substrati, le migliori prestazioni sono state ottenute con T. neapolitana. Sono state condotte alcuni test per selezionare il supporto ottimale per le condizioni con biomassa adesa. Sono stati testati 4 tipi di supporti, 3 in vetro sinterizzato e uno in materiale ceramico; il supporto scelto è stato Biomax

Biosurfactant production by Pseudomonas aeruginosa MSIC02 in cashew apple juice using a 24 full factorial experimental design

In this work, the production of biosurfactants from cashew apple juice by P. aeruginosa MSIC02 was investigate by carrying out a 24 full factorial experimental design, using temperature, glucose concentration from cashew apple juice, phosphorous concentration and cultivation time as variables. The response variable was the percentage of reduction in surface tension in the cell-free culture medium, since it indicates the surface-active agent production. Maximum biosurfactant production, equivalent to a 58% reduction in surface tension, was obtained at 37°C, with glucose concentration of 5.0 g/L and no phosphorous supplementation. Surface tension reduction was significant, since low values were observed in the cell-free medium (27.50 dyne/cm), indicating that biosurfactant was produced. The biosurfactant emulsified different hydrophobic sources and showed stability in the face of salinity, exposure to high temperatures and extreme pH conditions. These physiochemical properties demonstrate the potential for using biosurfactants produced by P. aeruginosa MSIC02 in various applications

Biochemical Characterization of Heat-Tolerant Recombinant l-Arabinose Isomerase from Enterococcus faecium DBFIQ E36 Strain with Feasible Applications in d-Tagatose Production

D-Tagatose is a ketohexose, which presents unique properties as a low-calorie functional sweetener possessing a sweet flavor profile similar to D-sucrose and having no aftertaste. Considered a generally recognized as safe (GRAS) substance by FAO/WHO, D-tagatose can be used as an intermediate for the synthesis of other optically active compounds as well as an additive in detergent, cosmetic, and pharmaceutical formulations. This study reports important features for L-arabinose isomerase (EC 5.3.1.4) (L-AI) use in industry. We describe arabinose (araA) gene virulence analysis, gene isolation, sequencing, cloning, and heterologous overexpression of L-AI from the food-grade GRAS bacterium Enterococcus faecium DBFIQ E36 in Escherichia coli and assess biochemical properties of this recombinant enzyme. Recombinant L-AI (rL-AI) was one-step purified to homogeneity by Ni2+-agarose resin affinity chromatography and biochemical characterization revealed low identity with both thermophilic and mesophilic L-AIs but high degree of conservation in residues involved in substrate recognition. Optimal conditions for rL-AI activity were 50 °C, pH 5.5, and 0.3 mM Mn2+, exhibiting a low cofactor concentration requirement and an acidic optimum pH. Half-life at 45 °C and 50 °C were 1427 h and 11 h, respectively, and 21.5 h and 39.5 h at pH 4.5 and 5.6, respectively, showing the high stability of the enzyme in the presence of a metallic cofactor. Bioconversion yield for D-tagatose biosynthesis was 45% at 50 °C after 48 h. These properties highlight the technological potential of E. faecium rL-AI as biocatalyst for D-tagatose production.Fil: Manzo, Ricardo Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Antunes, André Saraiva Leão Marcelo. King's College London;Fil: de Sousa Mendes, Jocélia. Universidade Estadual do Ceará; BrasilFil: Hissa, Denise Cavalcante. Universidade Estadual do Ceará; BrasilFil: Goncalves, Luciana Rocha Barros. Universidade Estadual do Ceará; BrasilFil: Mammarella, Enrique José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentin