Bacillus subtilis is a common group of probiotics that have been widely used in the feed industry as they can increase host resistance to pathogens and balance the immune response. However, the regulatory mechanism of Bacillus subtilis on the host immune system remains unclear in teleosts. In this study, we isolated and enriched dendritic cells from white blood cells (WBCs), and then stimulated them with Bacillus subtilis. Morphological features, specific biological functions, and authorized functional molecular markers were used in the identification of dendritic cells. Subsequently, we collected stimulated cells at 0, 4, and 18 h, and then constructed and sequenced the transcriptomic libraries. A transcriptome analysis showed that 2557 genes were up-regulated and 1708 were down-regulated at 4 h compared with the control group (|Fold Change| ≥ 4), and 1131 genes were up-regulated and 1769 were down-regulated between the cells collected at 18 h and 4 h (|Fold Change| ≥ 4). Gene Ontology (GO) annotations suggested many differentially expressed genes (DEGs) (p < 0.05 and |Fold Change| ≥ 4) were involved in immune-related biological functions including immune system progress, cytokine receptor binding, and cytokine binding. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that the cytokine–cytokine receptor interaction pathways were significantly enriched at both time points (p < 0.05), which may play a key role in the response to stimulation. Furthermore, mRNA expression level examination of several pro-inflammatory cytokines and anti-inflammatory cytokines genes by quantitative real-time polymerase chain reaction (qRT-PCR) indicated that their expressions can be significantly increased in Bacillus subtili, which suggest that Bacillus subtilis can balance immune response and tolerance. This study provides dendritic cell (DC)-specific transcriptome data in grass carp by Bacillus subtilis stimulation, allowing us to illustrate the molecular mechanism of the DC-mediated immune response triggered by probiotics in grass carp.

In this paper, a series of Fe3O4/MoS2/NiS composite electrodes were synthesized by a simple coprecipitation method. The influence of different ratio additives (MoS2 and NiS) on the performance of iron anodes for Ni-Fe batteries was systematically investigated. In this paper, the mixed alkaline solution of 6 mol/L NaOH and 0.6 mol/L LiOH was used as electrolyte, and sintered Ni(OH)2 was used as counterelectrode. The experimental results show that the MoS2 and NiS additives can effectively eliminate the passivation phenomena in iron electrodes, reduce the electrode polarization, and increase the reversibility capacity. As a result, the Fe3O4/MoS2/NiS composite electrodes exhibit a high specific capacity, good rate performance, and long cycling stability. Especially, the Fe3O4/MoS2 (5%)/NiS (5%) electrode with a suitable ratio of additives can provide excellent electrochemical performance, with high discharge capacities of 657.9 mAh g−1, 639.8 mAh g−1, and 442.1 mAh g−1 at 600 mA g−1, 1200 mA g−1, and 2400 mA g−1, respectively. This electrode also exhibits good cycling stability.

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In order to study the composition, structure and physicochemical properties of Tremella fuciformis polysaccharide (TFPS), four new polysaccharide fractions (TFPS1, TFPS2, TFPS3 and TFPS4) were successfully isolated from the hot-water extracted crude polysaccharides by DEAE-52 cellulose column. Their structures were analyzed by FT-IR, SEM, HPGPC, monosaccharide composition, Congo red and I2-KI experiments. TFPS1 was a heteropolysaccharide with a molecular weight of 742 Da for the major polysaccharide fragment. TFPS2, TFPS3 and TFPS4 were single component homogeneous polysaccharides with 350774 Da, 622675 Da and 624724 Da, respectively. Glucose was the major monosaccharide of TFPS1 and TFPS2, while Mannose was the major monosaccharide of TFPS3 and TFPS4. TFPS1 and TFPS2 displayed a stable triple helix structure at aqueous solution, while TFPS3 and TFPS4 presented longer side chains and more branched chains. TFPS1, TFPS2, TFPS3 and TFPS4 all possessed in vitro antioxidant activities. Moreover, the four polysaccharide fractions all demonstrated significant cholesterol binding ability, as well as obvious sodium taurocholate binding ability. The results of this study may provide some guidance on the medicinal value of TFPS.

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