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Biosynthesizing conjugated linoleic acid (CLA) using food processing by-products offers a practical and efficient method for producing this valuable compound, delivering health benefits, promoting sustainability, and providing economic advantages. Here, we optimized the fermentation conditions for in situ biosynthesis of CLA using Bacillus coagulans IBRC-M 10807, with grapeseed oil by-product providing the linoleic acid precursor, focusing on temperature, pH, incubation time, concentrations of grapeseed oil and yeast extract. The total CLA was measured using a UV-Vis spectrophotometer at 233 nm, and the concentration was evaluated using a standard curve of conjugated linoleic acid. To analyze the isomers and identify the functional groups of biosynthesized CLA, gas chromatography (GC) and Fourier-transform infrared spectroscopy (FTIR) were used, respectively. The results indicated that the maximum amount of CLA production was 225.37 ± 0.74 μg/mL, obtained under optimal conditions: an initial pH of 6.8, a temperature of 44.8°C, an incubation time of 48 h, a grapeseed oil concentration of 1,000 μg/mL, and a yeast extract concentration of 3.88%. Characterization of the produced CLA revealed two main isomers--CLA 1: c-9, t-11 C18:2, and CLA 2: t-10, c-12 C18:2 methyl esters. These results suggest that B. coagulans has high potential to produce CLA as a bioactive compound, offering an excellent opportunity for use in various industries, including nutraceuticals, foods, pharmaceuticals, cosmetics, and animal feeds. [ABSTRACT FROM AUTHOR]

Today, the use of waste tires mixed with soil has been expanded in various geotechnical projects to absorb and reduce the vibration caused by seismic and dynamic loads. Therefore, the objective of this work was to evaluate the dynamic properties of such mixtures prior to practical applications. To this reason, 1-g shaking table tests were carried out, and the effects of important parameter like loading frequency on the dynamic behavior of mixtures were investigated. Tire powders were added to the sand with 5%, 10%, 15% and 20% in gravimetric basis and with a relative density of zero were subjected to sinusoidal loading at frequencies of 0.5, 1, 2, 3, 5, 7 and 9 Hz and input acceleration of 0.1 g and 0.3 g. The results showed that in all cases, the increase in frequency in the same cycles increased the shear modulus and the damping ratio. Also, with increasing shear strain, the shear modulus of the mixture decreased, but the damping ratio increased. On the other hand, by increasing the tire powder, the value of the shear modulus is reduced, but the amount of damping ratio is increased. [ABSTRACT FROM AUTHOR]