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Gayosso-Canales M.,CINVESTAV | Gayosso-Canales M.,Institute Ciencias Agropecuarias | Esparza-Garcia F.J.,CINVESTAV | Bermudez-Cruz R.M.,CINVESTAV | And 3 more authors.
Journal of Environmental Science and Health - Part A Toxic/Hazardous Substances and Environmental Engineering | Year: 2011

A 2m 7-3 fractional factorial experimental design was used to establish 16 culture media, with and without PCBs to enhance the activities of laccase (Lac), manganese peroxidase (MnP), and versatile peroxidase (VP) produced by the white rot fungus Pleurotus ostreatus. The culture was added to 10,000 mg L-1 of transformer oil, containing 71% of the identified Arochlor 1242. The culture conditions were established with eight variables at two values (levels); pH (4 and 6), agitation (100 and 200 rpm), CuSO4 (150 and 250 mg L-1), MnSO4 (50 and 200 mg L -1), Tween 80 (13 and 3500 mg L-1), wheat straw (0 and 2.5 g L-1), sugarcane bagasse (0 and 2.5 g L-1),and Arochlor 1242 (0 and 7100 mg L-1) at 4, 8, 12, 16 and 20 days old culture. Laccase activity was enhanced at a high value of pH and low value of agitation (P < 0.001) and correlated positively (R2 = 0.9; a = 0.05) with the removal of polychlorinated biphenyls (PCBs). VP activity was enhanced 27-fold with PCBs, Tween 80 and pH. The MnP activity was increased 1.2-fold with PCBs. The fractional factorial experimental design methodology allowed us to determine the P. ostreatus culture media conditions to enhance Lac and VP activities for efficient removal of Arochlor 1242 (one of the most recalcitrant organochloride pollutants). The factors that shown the greatest effect on Lac activity were: pH, agitation and high concentrations of Arochlor 1242. Copyright © Taylor & Francis Group, LLC.

Nieto R.,Colegio de Mexico | Nieto R.,Polytechnic University of Francisco I. timber | Sanchez-Torres M.T.,Colegio de Mexico | Figueroa J.L.,Colegio de Mexico | And 5 more authors.
Livestock Science | Year: 2015

The addition of n-3 polyunsaturated fatty acids (PUFA) to the diet of ruminants can benefit the reproductive process in the female. The current study was conducted to assess the effect of a short period of feeding a diet that included fish meal and oil on the progesterone (P4) and insulin (INS) profile, and on reproductive variables including estrous onset, pregnancy and prolificacy in virgin ewes artificially inseminated by laparoscopy (AIL). Forty-two Dorset ewes were assigned into two experimental groups: These groups were no supplementation (CON; n=21) and a group supplemented with fish meal and oil (4 and 0.8%; FMO; n=21). Ewes were fed the experimental diets for 15 days, beginning four days before inserting sponges for estrus synchronization and ending the day the vaginal sponges were removed. Each ewe received 0.8kg d-1 feed in individual pens. Ewes were pre-synchronized with prostaglandin F and later synchronized with chronolone sponges for 11 days. When sponges were removed, the ewes received 200 IU of eCG. The AIL began 48h after sponge removal and estrus detection. The time of estrus onset was different among groups (P<0.05; CON: 35.1±2.1; FMO: 41.0±1.8h). No differences were found in P4 (FMO: 3.8±1.2; CON: 3.5±1.4ngmL-1) or INS concentrations in serum (FMO: 0.12±0.02; CON: 0.13±0.03ngmL-1). Adding fish meal and oil to the diet did not affect pregnancy percentage (FMO: 52%; CON: 55%), but it did affect the prolificacy index (FMO: 1.63; CON: 1.25) (P<0.05). It was concluded that the addition of fish meal and oil to the diet of virgin ewes over a short period time delayed onset of estrus and enhanced prolificacy. © 2015 Elsevier B.V..

Chavarria-Hernandez N.,Institute Ciencias Agropecuarias | Ortega-Morales E.,Institute Ciencias Agropecuarias | Vargas-Torres A.,Institute Ciencias Agropecuarias | Chavarria-Hernandez J.-C.,Institute Ciencias Agropecuarias | Rodriguez-Hernandez A.-I.,Institute Ciencias Agropecuarias
Biotechnology and Bioprocess Engineering | Year: 2010

This study is the first to describe the evolution of both hydrodynamic and oxygen transfer conditions during the submerged culture of the entomopathogenic nematode, Steinernema carpocapsae CABA01 (an indigenous strain isolated within the State of Hidalgo, Mexico), and its symbiotic bacterium, Xenorhabdus nematophila, using an internal-loop mechanically agitated bioreactor of 4.5 L of liquid volume. Concentrations up to 217,306 viable nematodes per mL, with 94% in infective juvenile (IJ) stage (i.e., 204,444 IJ/mL), were achieved in 16 days of bioprocess. The Reynolds number (Re) was used as an index of the actual hydrodynamic conditions, and it varied within the interval 5,150 < Re (dimensionless) < 9,440, involving apparent culture broth viscosity changes from 3 to 5.4 mPa s during the processing. The aeration efficiency was expressed on the basis of the volumetric oxygen transfer coefficient, kLa, which varied within the range 0.026 to0. 170 s-1. © The Korean Society for Biotechnology and Bioengineering and Springer 2010.

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