Adhesion Capacity of Weissella cibaria to Bovine Mammary Tissue and the Effect of Bio-Sealant Topical Application on Physicochemical Properties of Milk.

The ability of a probiotic strain (Weissella cibaria) to adhere on tissue and the effect of its topical application in nipples of lactating cows on physicochemical characteristics of milk were evaluated. An ex vivo model was used to demonstrate the adhesion capacity of W. cibaria. Tissue samples were randomly distributed in three different solutions corresponding to three treatments (a nipple bio-sealant formulation, sterile PBS solution and biomass of W. cibaria, sterile PBS solution without microorganism addition). The number of bacteria adhered in tissue was quantified and observed using electron microscopy. Additionally, a bio-sealant prepared with W. cibaria was topically applied to nipples of dairy cows. Milk samples were taken every 7 days for 60 days. Two controls were used. California mastitis test (CMT), somatic cell count, electrical conductivity, pH, density, and acidity were evaluated. The adhesion capacity of W. cibaria strain to epithelial cells of bovine teat tissue samples was demonstrated. When the strain was added as a bio-sealant, the adhesion capacity of W. cibaria was 80.44%. The response variables did not show significant differences among treatments; these results indicate the safety of the topical application of W. cibaria on the bovine mammary gland. In this study, a new safe way of administering probiotic microorganisms in nipples of lactating cows was demonstrated. W. cibaria adheres to the bovine mammary tissue and can be topically applied in nipples of lactating cows without affecting the physicochemical characteristics of milk.

Characterization of Colombian Clay and Its Potential Use as Adsorbent.

This paper presents a mineralogical and physicochemical characterization of a Colombian clay found in an area with the greatest exploitation potential of smectites and possible use as an adsorbent for the removal of chromium. The clay was characterized by using X-ray diffraction (XRD), cation exchange capacity (CEC), X-ray fluorescence (XRF), Fourier transform infrared spectroscopy (FT-IR), thermal analysis (TGA/DSC), and nitrogen adsorption at 77 K. The homoionized clay was used as an adsorbent for the removal of Cr(III) in an aqueous solution. The homoionized clay was modified with hexadecyltrimethylammonium bromide (HDTMA-Br), and the organoclay obtained was evaluated for the adsorption of Cr(VI) in aqueous solution. The XRD analysis showed that the clay from Armero-Guayabal is primarily constituted by smectite (48 wt%) followed by quartz mineral (21 wt%). The chemical analysis of bulk clay showed that the predominant oxides are SiO2 (55.81 wt%), Al2O3 (16.25 wt%), and Fe2O3 (7.51 wt%), and the nitrogen adsorption indicated that the bulk clay has a specific surface area of 45.1 m2/g. Homoionized clay and organoclay achieved Cr(III) and Cr(VI) removals greater than 85.05 ± 2.04% (pH between 3 and 4) and 82.93 ± 1.03% (pH between 3 and 5), respectively, proving the potential of these materials for the removal of heavy metals in an aqueous solution.