Effect of Lactic Acid Bacteria on the Fermentation Quality and Mycotoxins Concentrations of Corn Silage Infested with Mycotoxigenic Fungi.

This study was conducted to evaluate the effect of lactic acid bacteria (LAB) on fermentation quality, mycotoxin concentrations, and microbial communities of whole-crop corn silages infested with mycotoxigenic fungi. Cultured spores (106 cfu/mL) of mycotoxigenic Aspergillus flavus and Fusarium graminearum were sprayed (5 mL) on corn forage on 27 July and 10 August 2018. On 21 August 2018, sprayed (FI; 3 plots) and unsprayed (NFI; 3 plots) corn forage were harvested at the 1/2 kernel milk line stage, followed by chopping and ensiling without inoculants (CON), or with Lactobacillus buchneri (LB, 1 × 106 cfu/g FW), Lactobacillus plantarum (LT, 1 × 106 cfu/g FW), or L. buchneri + L. plantarum (BT: both L. buchneri and L. plantarum applied at 0.5 × 106 cfu/g FW). After 90 d of ensiling, FI silages had a higher (p < 0.05) pH value and higher acetic acid (ACA), ethanol, and ammonia nitrogen (ammonia N) concentrations, but lower (p < 0.05) lactic acid (LA) concentrations than NFI silage. The inoculants decreased pH and increased LA concentration and LA/ACA compared with CON. The aflatoxin B1 (AFB1) was only detected in FI fresh corn and silages; ensiling decreased (p < 0.05) AFB1 concentration compared with fresh corn, and LB and BT decreased AFB1 concentration compared with CON. The zearalenone (ZEN), deoxynivalenol (DON), and fumonisin B1 (FB1) concentrations were similar (p < 0.05) for NFI silages, while ZEN concentration in BT was the lowest (p < 0.05) among all FI silages; DON and FB1 concentrations in LB, LT, and BT silages were significantly lower (p < 0.05) than those of CON in FI silages. The fungal infestation increased the bacterial and fungal diversity of silages compared with NFI silages. The FI silages had a higher relative abundance (RA) of Lactobacillus, Weissella, Wickerhamomyces, Pichia, and Epicoccum than the corresponding NFI silages. The RA of Aspergillus and Fusarium markedly decreased after 90 d of ensiling, and the inoculation expanded this trend irrespective of fungal infestation. The Penicillium in FI silages survived after 90 d of ensiling, while the inoculants decreased the RA of Penicillium. Inoculants mitigate the adverse effects of fungal infestation on corn silage quality by changing the bacterial and fungal communities.

Enhancement of biomass conservation and enzymatic hydrolysis of rice straw by dilute acid-assisted ensiling pretreatment.

To reduce the cost of lignocellulosic pretreatment, rice straw was ensiled with dilute formic acid (FA, 0, 0.2, 0.4, and 0.6%) for 3, 6, 9, 15 and 30 days, and evaluated its effects on fermentation dynamics, lignocellulosic degradation and enzymatic hydrolysis. The results showed that the application of FA, especially at 0.6% level, reduced total fermentation losses of the resulting silages, as evidenced by low dry matter loss, ammonia nitrogen and ethanol content. Meanwhile, the 0.6% FA application promoted hemicellulose removal (232.41 vs 187.52 g/kg DM) and xylose production (0.35 vs 2.80 g/kg DM). The glucose yield and cellulose convertibility of rice straw increased after 30 days of ensiling, and further enhanced by the 0.6% FA application. In conclusion, the 0.6% FA-assisted ensiling pretreatment improved both biomass preservation, hemicellulose removal and enzymatic hydrolysis of rice straw, which is beneficial to the subsequent biofuel production chain.

Effects of different additives on fermentation quality and aerobic stability of a total mixed ration prepared with local feed resources on Tibetan plateau.

To improve the utilization efficiency of total mixed ration (TMR) on Tibetan plateau, the effects of different additives on fermentation quality and aerobic stability of the ensiled TMR prepared with local feed resources were studied. A total of 150 experimental silos were prepared in a completely randomized design to evaluate the following treatments: (a) control; (b) Lactobacillus buchneri; (c) acetic acid; (d) propionic acid; (e) 1,2-propanediol; and (f) 1-propanol. After 90 days of ensiling, silos were opened for fermentation quality and in vitro parameters analysis, and then subjected to an aerobic stability test for 14 days. The acetic acid, 1,2-propanediol and 1-propanol treatments increased (p < .05) pH and acetic acid content, and lowered (p < .05) the lactic acid production in comparison to control. There were no statistically significant differences in in vitro digestibility parameters among the treatments. Treatments of acetic acid, 1,2-propanediol and 1-propanol substantially improved the aerobic stability of the ensiled TMR, as indicated by almost unchanged pH and lactic acid contents throughout the aerobic exposure test. These results indicated that acetic acid, 1,2-propanediol and 1-propanol had no adverse effect on in vitro digestibility and could be effective additives for enhancing the aerobic stability of ensiled TMR prepared on Tibetan plateau.

Mitofusin-2 (Mfn-2) Might Have Anti-Cancer Effect through Interaction with Transcriptional Factor SP1 and Consequent Regulation on Phosphatidylinositol Transfer Protein 3 (PITPNM3) Expression.

BACKGROUND The aim of this study was to explore the influence of mitofusin-2 (Mfn-2) on phosphatidylinositol transfer protein 3 (PITPNM3) and tumor growth and the potential mechanism behind the regulation of Mfn-2 on PITPNM3 in hepatic carcinoma cell line SMMC-7721. MATERIAL AND METHODS We obtained promoter sequence of PITPNM3 gene from University of Santa Cruz (UCSC) genomic database, and we predict transcriptional factor of PITPNM3 genes by JASPAR database. Target transcription factor was determined by comparison of binding sites number for promoter. SMMC-7721 cells were transfected with expression plasmid containing Mfn-2, transcription factor gene and PITPNM3. The cells transfected with empty vector were used as control. Real-time polymerase chain reaction was used to determine the mRNA level of target genes. Co-immunoprecipitation (Co-IP) assay was used to determine the interaction between Mfn-2 and target transcription factor. Chromatin immunoprecipitation assay (ChIP) assay was used to determine the binding of transcription factor with PITPNM3 promoter. Tumorigenicity assay was used to compare the effect of Mfn-2, SP1, and PITPNM3 on tumor development. RESULTS SP1 was selected as the target transcriptional factor. In the Co-IP assay, Mfn-2 was shown to interact with SP1. In the ChIP assay Mfn-2 transfection resulted in decreased binding number of SP1 with PITPNM3 promoter. Furthermore, PITPNM3 mRNA levels were significantly increased in SMMC-7721 cells transfected with SP1 but were decreased after transfection with Mfn-2. In nude mice, PITPNM3 and SP1 upregulation lead to larger tumor lump and conversely Mfn-2 upregulation lead to smaller tumor lump. CONCLUSIONS Mfn-2 could suppress expression of PITPNM3 through interaction with transcription factor SP1; Mfn-2 may have anti-tumor activity; SP1 and PITPNM3 may promote tumor development.