Bioaccessibility and In Vitro Intestinal Permeability of a Recombinant Lectin from Tepary Bean (Phaseolus acutifolius) Using the Everted Intestine Assay.

Tepary bean (Phaseolus acutifolius) lectins exhibit differential in vitro and in vivo biological effects, but their gastrointestinal interactions and digestion have not yet been assessed. This work aimed to evaluate the changes of a recombinant Tepary bean lectin (rTBL-1) through an in vitro and ex vivo gastrointestinal process. A polyclonal antibody was developed to selectively detect rTBL-1 by Western blot (WB) and immunohistochemical analysis. Everted gut sac viability was confirmed until 60 min, where protein bioaccessibility, apparent permeability coefficient, and efflux ratio showed rTBL-1 partial digestion and absorption. Immunoblot assays suggested rTBL-1 internalization, since the lectin was detected in the digestible fraction. The immunohistochemical assay detected rTBL-1 presence at the apical side of the small intestine, potentially due to the interaction with the intestinal cell membrane. The in silico interactions between rTBL-1 and some saccharides or derivatives showed high binding affinity to sialic acid (-6.70 kcal/mol) and N-acetylglucosamine (-6.10 kcal/mol). The ultra-high-performance liquid chromatography-electron spray ionization-quantitative time-of-flight coupled to mass spectrometry (UHPLC-ESI-QTOF/MS) analysis showed rTBL-1 presence in the gastric content and the non-digestible fraction after intestinal simulation conditions. The results indicated that rTBL-1 partially resisted the digestive conditions and interacted with the intestinal membrane, whereas its digestion allowed the absorption or internalization of the protein or the derivative peptides. Further purification of digestion samples should be conducted to identify intact rTBL-1 protein and digested peptides to assess their physiological effects.

Study of a light hydrocarbon fraction spill migration that occurred in an area of the Mexican southeast using computational fluid dynamics.

The present work aimed to study, predict and understand benzene migration that occurred during an industrial spill using numerical simulation by computational fluid dynamics. Advection, diffusion and adsorption were the main mechanisms considered that governed the spill incident. The incident occurred due to a fracture under a fuel oil storage tank. The tank was located on a hill 18 m high, and the initial value of benzene concentration (soil saturation) was 60 ppm. When the spill was discovered, samples in the affected zone were taken using an experimental design. Many samples showed a greater concentration of benzene than allowed by Mexican Official Standards (MOSs) (15 ppm). The concentrations found 100 m away from the spill were around 60 to 15 ppm. Due to the spill being under the tank, it was difficult to discover. The numerical simulation provided an estimate that the spill started around 2 years ago. The type of soil in the afflicted zone is rocky, and, consequently, it is difficult to estimate how long it will take to reach the concentration allowed by the MOSs, but the numerical simulation predicts that this concentration will be reached in 14 years. Experimental values of the spill contaminant concentration were statistically similar to the CFD estimated data (p < 0.05).