The biochemical methane potential (BMP) test was used to evaluate the anaerobic biodegradabilities of food waste (FW), waste activated sludge (WAS), and the mixtures having the ratios of 10:90, 30:70, 50:50, 70:30, and 90:10 (FW:WAS) on a volatile solid (VS) basis. The carbon/nitrogen (C/N) ratio and the biodegradability of the mixtures improved from 6.16 to 14.14 and increased from 36.6 to 82.6% as the FW proportion of the mixture increased from 10 to 90%, respectively. The stability and performance of the single-stage anaerobic digester (SSAD) for the co-digestion of FW and WAS were investigated, operated at the hydraulic retention times (HRTs) of 10, 13, 16, and 20 days with five mixtures at 35 degrees C, respectively. During all the experiments, there were no indication of failure such as low pH, insufficient alkalinity, ammonia inhibition, and the accumulation of volatile fatty acids (VFAs) in any of the digesters, and the buffer capacity was the highest in the digester fed with a feed mixture of 50:50. The optimum operating conditions of the SSAD were found to be an HRT of 13 days and a mixture of 50:50 in terms of the buffer capacity of the digester and the effluent VS concentration, the methane content of the biogas produced and the specific methane production (SMP). The VS removal efficiency, biogas production rate (GPR), and SMP in this condition achieved 56.8%, 1.24 m3 m(-3) d(-1) and 0.321 m3 CH4 kg(-1) VS(fed)(-1) with an organic loading rate (OLR) of 2.43 kg VS m(-3) d(-1).

Efficient epigenetic reprogramming is crucial for the in vitro development of mammalian somatic cell nuclear transfer (SCNT) embryos. The aberrant levels of histone H3 lysine 9 trimethylation (H3K9me3) is an epigenetic barrier. In this study, we evaluated the effects of chaetocin, an H3K9me3-specific methyltransferase inhibitor, on the epigenetic reprogramming and developmental competence of porcine SCNT embryos. The SCNT embryos showed abnormal levels of H3K9me3 at the pronuclear, two-cell, and four-cell stages compared to in vitro fertilized embryos. Moreover, the expression levels of H3K9me3-specific methyltransferases (suv39h1 and suv39h2) and DNA methyltransferases (DNMT1, DNMT3a, and DNMT3b) were higher in SCNT embryos. Treatment with 0.5 nM chaetocin for 24 h after activation significantly increased the developmental competence of SCNT embryos in terms of the cleavage rate, blastocyst formation rate, hatching rate, cell number, expression of pluripotency-related genes, and cell survival rate. In particular, chaetocin enhanced epigenetic reprogramming by reducing the H3K9me3 and 5-methylcytosine levels and restoring the abnormal expression of H3K9me3-specific methyltransferases and DNA methyltransferases. Chaetocin induced autophagic activity, leading to a significant reduction in maternal mRNA levels in embryos at the pronuclear and two-cell stages. These findings revealed that chaetocin enhanced the developmental competence of porcine SCNT embryos by regulating epigenetic reprogramming and autophagic activity and so could be used to enhance the production of transgenic pigs for biomedical research.

Parabens are widely used in personal care products due to their antimicrobial effects. Although the toxicity of parabens has been reported, little information is available on the toxicity of butylparaben (BP) on oocyte maturation. Therefore, we investigated the effects of various concentrations of BP (0 μM, 100 μM, 200 μM, 300 μM, 400 μM, and 500 μM) on the in vitro maturation of porcine oocytes. BP supplementation at a concentration greater than 300 μM significantly reduced the proportion of complete cumulus cell expansion and metaphase II oocytes compared to the control. The 300 μM BP significantly decreased fertilization, cleavage, and blastocyst formation rates with lower total cell numbers and a higher rate of apoptosis in blastocysts compared to the control. The BP-treated oocytes showed significantly higher reactive oxygen species (ROS) levels, and lower glutathione (GSH) levels than the control. BP significantly increased the aberrant mitochondrial distribution and decreased mitochondrial function compared to the control. BP-treated oocytes exhibited significantly higher percentage of γ-H2AX, annexin V-positive oocytes and expression of LC3 than the control. In conclusion, we demonstrated that BP impaired oocyte maturation and subsequent embryonic development, by inducing ROS generation and reducing GSH levels. Furthermore, BP disrupted mitochondrial function and triggered DNA damage, early apoptosis, and autophagy in oocytes.

Biochemical methane potential (BMP) tests have been carried out to determine the anaerobic digestibility of the waste activated sludge (WAS) and the sludge pretreated by NaOH (PWAS). The optimal NaOH dosage was determined to be 45 meq NaOH/L. The maximum SCOD solubilization was 27.7, 31.4 and 38.3% at the temperatures of 25, 35 and 55 degrees C respectively after 4 hours reaction. The final methane yield of simulated food waste (SFW) was 430 ml CH4/g VS(added), and those of PWAS (25 degrees C), PWAS (35 degrees C) and PWAS (55 degrees C) was 274, 286 and 310 ml CH4/g VS(added) respectively after 20 days. The figures were 66%, 73% and 88% higher than that of WAS. The methane production in anaerobic co-digestion is considerably affected by the fraction of SFW and PWAS in the feed. The anaerobic digestibility of the feed mixture (SFW with PWAS) is higher than that of the feed mixture (SFW with WAS). Anaerobic co-digestion of food waste with the PWAS is found to be an attractive option to reduce the solid waste volume with improved methane recovery.

A concerted computational and experimental study has been undertaken to probe the conformational structure and excited-state dynamics of bis(9-fluorenyl)methane (BFM). We have observed that the relative intensity of the delayed excimer fluorescence of BFM is greatly enhanced in comparison with that of the normal fluorescence. This is presumably because the relative concentration of the triplet excimer is enhanced in comparison with the singlet excimer. B3LYP DFT/6-31G(d) calculations indicate that the sandwich conformer of BFM in the singlet ground state is unstable, whereas that in the triplet excited state has a bound state, being very slightly higher in internal and Gibbs free energies than that of the lowest state of the near-orthogonal conformer.

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Korean food waste was treated with a single-stage anaerobic codigester (SSAD) using waste activated sludge (WAS) generated from a municipal wastewater treatment plant. The stability and performance of the system was analyzed. The C/N ratio was improved with increasing food waste fraction of feed mixture. The pH, alkalinity, and free ammonia nitrogen concentration were the parameters used to evaluate the digester's stability. The experimentally determined values of the parameters indicated that there were no methane inhibitions in the digester. Digester performance was determined by measuring the total chemical oxygen demand TCOD), volate solids (VS) removal, methane content in biogas, methane production rate (MPR), and specific methane productivity. Methane content in biogas and MPR were significantly dependent on hydraulic retention time (HRT) and ratio of food waste to WAS. The methane content in biogas decreased at shorter HRT or higher organic loading rate (OLR) with increased food waste fraction. Concerning the performance of the codigester, the optimum operating condition of the SSAD was found to be at an HRT of 10 d with a feed mixture ratio of 50% food waste and 50% WAS. A TCOD removal efficiency of 53.6% and a VS removal efficiency of 53.7% were obtained at an OLR of 5.96 kg of TCOD/(m3 d) and 3.14 kg of VS/(m3 d), respectively. A maximum MPR of 1.15 m3 CH4/(m3 d) and an SMP of 0.37 m3 CH4/kg of VSfeed were obtained at an HRT of 10 d with a methane content of 63%.

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