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Objective: To solve the problems of an uncertain fermentation process, a long fermentation period, and the unstable quality of traditional naturally fermented preserved fish. Methods: The lactic acid bacteria were isolated from low-salt preserved red fish, and the inhibition ability, salt tolerance, and acid production ability of the strains were investigated. The lactic acid bacteria suitable for fermentation were screened out, and the fermentation of preserved red fish was intensified by inoculation. The amount of red rice flour added, the amount of salt added during curing, and the fermentation temperature were optimized in the fermentation process. Results: There were 22 strains of Pediococcus with inhibitory effect on Escherichia coli or Staphylococcus aureus were isolated, among which Pediococcus pentosaceus P-56 had the best inhibitory effect on Escherichia coli and higher tolerance to bile salt and acid; After inoculation fermentation and process optimization. The pH value of the Zhayu decreased to 4.42 at 4 days of fermentation, the TCA-soluble peptide content was 434.99 μmol/g and the sensory score reached 45.7. Conclusion: The optimal process conditions for the fermentation of preserved red fish with lactic acid bacteria were: 4% salt addition for curing, 4% red yeast rice flour addition and fermentation temperature of 32 ℃.

Abstract Background We have previously studied the histone acetylation in primary human leukemia cells. However, histone H3 methylation in these cells has not been characterized. Methods This study examined the methylation status at histone H3 lysine 4 (H3K4) and histone H3 lysine 9 (H3K9) in primary acute leukemia cells obtained from patients and compared with those in the non-leukemia and healthy cells. We further characterized the effect of phenylhexyl isothiocyanate (PHI), Trichostatin A (TSA), and 5-aza-2’-deoxycytidine (5-Aza) on the cells. Results We found that methylation of histone H3K4 was virtually undetectable, while methylation at H3K9 was significantly higher in primary human leukemia cells. The histone H3K9 hypermethylation and histone H3K4 hypomethylation were observed in both myeloid and lymphoid leukemia cells. PHI was found to be able to normalize the methylation level in the primary leukemia cells. We further showed that PHI was able to enhance the methyltransferase activity of H3K4 and decrease the activity of H3K9 methyltransferase. 5-Aza had similar effect on H3K4, but minimal effect on H3K9, whereas TSA had no effect on H3K4 and H3K9 methyltransferases. Conclusions This study revealed opposite methylation level of H3K4 and H3K9 in primary human leukemia cells and demonstrated for the first time that PHI has different effects on the methyltransferases for H3K4 and H3K9.

Abstract Background We have previously demonstrated that phenylhexyl isothiocyanate (PHI), a synthetic isothiocyanate, inhibits histone deacetylases and remodels chromatins to induce growth arrest in HL-60 myeloid leukemia cells in a concentration-dependent manner. Methods To investigate the effect of PHI, a novel histone deacetylases inhibitor (HDACi), on demethylation and activation of transcription of p15 in acute lymphoid leukemia cell line Molt-4, and to further decipher the potential mechanism of demethylation, DNA sequencing and modified methylation specific PCR (MSP) were used to screen p15-M and p15-U mRNA after Molt-4 cells were treated with PHI, 5-Aza and TSA. DNA methyltransferase 1 (DNMT1), 3A (DNMT3A), 3B (DNMT3B) and p15 mRNA were measured by RT-PCR. P15 protein, acetylated histone H3 and histone H4 were detected by Western Blot. Results The gene p15 in Molt-4 cells was hypermethylated and inactive. Hypermethylation of gene p15 was attenuated and p15 gene was activated de novo after 5 days exposure to PHI in a concentration-dependent manner. DNMT1 and DNMT3B were inhibited by PHI (P < 0.05). Alteration of DNMT3A was not significant at those concentrations. Acetylated histone H3 and histone H4 were accumulated markedly after exposure to PHI. Conclusion PHI could induce both DNA demethylation and acetylated H3 and H4 accumulation in Molt-4 cells. Hypermethylation of gene p15 was reversed and p15 transcription could be reactivated de novo by PHI.

BACKGROUND: Nε‐carboxymethyllysine (CML), Nε‐carboxyethyllysine (CEL) and α‐aminoadipic acid (AAA) are important foodborne hazards and their intake can cause a variety of diseases in humans. It is extremely important to investigate the formation mechanism of CML, CEL and AAA, as well as their association with each other when aiming to control their production. RESULTS: A multi‐response kinetic model was developed within the glucose‐lysine Maillard reaction model system. The concentrations of glucose, lysine, glyoxal (GO), methylglyoxal (MGO), CML, CEL and AAA were quantified at different temperature (100–160 °C) and at different intervals (0–60 min). The experimental data were fitted to the proposed model to calculate kinetic parameters for the corresponding steps. The results indicated that the production of CML was primarily relied on the direct oxidative cleavage of the Amadori product, rather than the reaction between GO and Lys, whereas CEL and AAA were generated through the reaction of MGO with Lys. Significantly, the reaction between α‐dicarbonyl compounds and Lys preferentially generated CML and CEL, resulting in the lower concentrations of AAA compared to CML and CEL. CONCLUSION: The multi‐response kinetic model developed in the present study can be applied well to the Maillard reaction. The relationship between the formation mechanisms of CML, CEL and AAA is also explained. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]