A study of the effect of the organic loading rate (OLR) on the anaerobic acidogenic fermentation of two-phase olive mill solid residue (OMSR) derived from fruits with a low ripening index was carried out in a laboratory-scale completely stirred tank reactor at mesophilic temperature (35 degrees C). Eight experimental runs were carried out at OLRs of 3.2, 5.6, 7.4, 9.6, 11.0, 12.9, 14.0 and 15.1g T-COD/ld, which were equivalent to hydraulic retention times of 50.0, 28.8, 21.8, 16.9, 14.7, 12.4, 11.5 and 10.7d, respectively. The experimental results obtained demonstrated that the optimum value of OLR for the acidogenic fermentation process was 12.9 g T-COD/ld, for which a maximum production of acetic acid was achieved. It was found that inhibition of the process occurred at OLRs higher than 12.9 g T-COD/ld. This was characterized by a significant decrease in the acetic acid concentration in the effluent and an increase in the concentration of other volatile acids that may affect the methanogenic step. The process inhibition was also characterized by the plateau in the curves of the effluent substrate concentration versus the OLR applied. It was found that a first-order kinetics satisfactorily described the influence of non-acetic acid soluble organic matter concentration (S-COD( *)) on the rate of soluble organic matter conversion to acetic acid (R(S-COD)( *)), and the influence of acetic acid concentration (AcH) on the rate of acetic acid production (R(AcH)), while a potential equation type adequately described the influence of acetic acid concentration on the volumetric hydrogen production (R(ACH) ). The kinetic constant for soluble organic matter removal was 0.145 d(-1), while the constant for acetic acid formation was found to be 0.075 d(-1).
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http://dx.doi.org/10.1016/j.wasman.2007.02.030 | DOI Listing |
J Pept Sci
March 2025
Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense, Denmark.
Fluorescent probes are widely used in cellular imaging and disease diagnosis. Acting as substitute carriers, fluorescent probes can also be used to help transport drugs within cells. In this study, commonly used fluorophores, TAMRA (5-carboxytetramethylrhodamine), PBA (1-pyrenebutyric acid), NBD (nitrobenzoxadiazole), OG (Oregon Green), and CF (5-carboxyfluorescein) were conjugated with the dipeptide β-Ala-Lys, the peptide moiety of the well-established peptide transporter substrate β-Ala-Lys(AMCA) (AMCA: 7-amino-4-methyl-coumarin-3-acetic acid) by modifying it with respect to side-chain length and functional end groups.
View Article and Find Full Text PDFMagn Reson Chem
January 2025
Laboratório de Química Computacional e Modelagem Molecular (LQC-MM), Departamento de Química Inorgânica, Instituto de Química, Universidade Federal Fluminense (UFF), Niterói, Rio de Janeiro, Brazil.
We present a DFT-PCM NMR study of 3-indoleacetic acid (3-IAA), used as a working example, including explicit solvent molecules, named PCM-nCHCl, PCM-nDMSO (n = 0, 2, 4, 8, 14, 20, and 25), to investigate the dimer formation in solution. Apart from well-known cyclic (I) and open (II) acetic acid (AA) dimers, two new structures were located on DFT-PCM potential energy surface (PES) for 3-IAA named quasicyclic A (III) and quasicyclic B (IV), the last one having N-H…O hydrogen bond (instead of O-H…O). In addition, four other structures having π-π type interactions named V, VI, VII, and VIII were also obtained completing the sample on the PES.
View Article and Find Full Text PDFPlant Physiol Biochem
January 2025
College of Life Science, Sichuan Agricultural University, Ya'an, 625014, China. Electronic address:
Tartary buckwheat (Fagopyrum tataricum), a functional grain known for its medicinal and nutritional properties, has garnered significant attention due to its high flavonoid content and unique health benefits. Heat stress during the flowering stage can lead to sterility in Tartary buckwheat, resulting in reduced yields. This study investigates the effects of a treatment (30/27 °C for 7 days) on flower development, fertility, stress physiology, and gene expression in Tartary buckwheat, while also validating the efficacy of hormone treatments in alleviating the negative effects of heat stress.
View Article and Find Full Text PDFJ Environ Manage
January 2025
State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, PR China; School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing, 100049, PR China. Electronic address:
Xylooligosaccharides (XOS), consisting 2-6 xylose residues, are a new type of prebiotic and functional oligosaccharides, and can usually be produced from the xylan-riched lignocellulosic biomass by acetic acid (HAc) hydrolysis, while the waste HAc was a problem to the environment. In this study, the main aim was to recover and reuse the waste HAc in XOS production. First, it was found that a temperature of 190 °C and a hydrolysis time of 60 min were favorable for XOS production by HAc hydrolysis, and the by-products xylose and furfural were the main inhibitors, hindering the reuse of the waste HAc.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China; Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education and Tianjin, Tianjin 300457, China. Electronic address:
Probiotics intervention by Lactobacillus acidophilus has potential effect on alleviating obesity and insulin resistance. However, the limited knowledge of functional substances and potential regulatory mechanisms hinder their widespread application. Herein, L.
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