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Inosine could potentially become a novel antibacterial agent against Alicyclobacillus acidoterrestris as low doses of inosine can prevent its contamination. However, until now the antibacterial mechanism of inosine targeting A. acidoterrestris is still unknown. In this study, to unravel the mechanism of inosine against A. acidoterrestris puzzle, the effects of inosine on bacterial surface hydrophobicity, intracellular protein content, cell membrane damage extent, and permeability of the A. acidoterrestris were investigated. The results showed that inosine can effectively inhibit the growth and reproduction of A. acidoterrestris by destroying the integrity of cell membrane and increasing its permeability, causing the leakage of intracellular nutrients. Furthermore, the interaction networks of inosine target proteins were analyzed. The interaction networks further revealed that damage to bacterial cell membranes might be relevant to inosine's effect on bacterial DNA replication and cell energy metabolism through regulating nucleotide synthesis and metabolism and the activity of translation initiation factors. Finally, the antibacterial mechanism of inosine against A. acidoterrestris was proposed. [ABSTRACT FROM AUTHOR]

Background: The present study investigated the effects of fermentation by Lactobacillus rhamnosus zrx01 (LR‐zrx01), Lactobacillus acidophilus zrx02 (LA‐zrx02), and Lactobacillus plantarum zrx03 (LP‐zrx03), as well as dynamic simulated digestion by bionic rats, on the biotransformation and antioxidant potential of apple polyphenols. Polyphenols were determined by ultra‐high‐performance liquid chromatography‐mass spectrometry, the dynamic simulated digestion of fermented apple pulp was determined by bionic rats, and the antibacterial and antioxidant activities were analyzed. Results: The polyphenol content of apple pulp fermented using the three strains was respectively 1.41, 1.38, and 1.36 times that of non‐fermented pulp. The antibacterial activity of apple pulp improved dramatically after fermentation. Moreover, the antioxidant potential of apple pulp increased after fermentation and digestion. After dynamic simulated digestion by bionic rats, the polyphenol content in unfermented and the three fermented groups increased significantly by 1.19, 1.23, 1.20, and 1.19 times compared to that before digestion, respectively. The major polyphenols in each group with obvious changes were epicatechin, rutin, kaempferol, quercetin‐3 galactoside, p‐coumaric acid, and two unknown substances, 1 and 2. Conclusion: Fermented and digested apple polyphenols showed better biotransformation effects and mostly existed in the form of small molecules, which was conducive to the improvement of polyphenol bioavailability and beneficial to the absorption of active substances by the human body. These findings build a foundation for the development of functional food beverages. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND Fusarium head blight (FHB) is one of the disasters that seriously harm wheat and other small grain crops. It causes spoilage and mildew of the grain leading to a significant decline in the yield and quality of the grain. This research aimed to isolate antagonistic bacteria to purify antifungal proteins. A strain was isolated from the rhizosphere of healthy wheat in a wheat field affected by a severe FHB epidemic. This isolated strain was tentatively identified as Paenibacillus polymyxa 7F1, which displayed a strong inhibitory effect against several other pathogens. One novel antifungal protein was purified from the P. polymyxa 7F1 and successfully expressed. RESULTS: A crude culture of P. polymyxa 7F1 demonstrated antifungal activity that was stable at a temperature range of 60–90 °C and a pH range of 2.6–9.0. However, the antifungal activity of the P. polymyxa 7F1 was inhibited with proteinase K, trypsin, and neutral protease treatment. A 36 kDa protein with broad‐spectrum antifungal activity was purified from the P. polymyxa 7F1. A glycosyl hydrolase domain was identified from this protein through liquid chromatography–mass spectrometry (LC–MS) analysis. A recombinant plasmid pET32a(+)/36kd for prokaryotic expression was constructed, and the renatured p36kd protein demonstrated similar antifungal activity to the 36 kDa protein purified from the P. polymyxa 7F1. CONCLUSION: A novel antifungal protein produced by P. polymyxa 7F1 was purified and expressed. The recombinant protein showed good antifungal activity as the novel purified protein. The novel antifungal protein provides an effective way to control the Fusarium head blight. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

To make full use of apple pomace, pretreatment with steam explosion (SE) was investigated to determine its effects on the yield and functionality of soluble dietary fiber (SDF). Response surface methodology (RSM) was used to optimize the effects of SE parameters. According to the quadratic polynomial model, the optimum SE parameters were as follows: steam pressure, 0.51 MPa; residence time, 168 s; and sieving mesh size, 60. Under the optimized conditions, the SDF yield from apple pomace after SE was 29.85%, which is 4.76 times the yield of SDF (6.27%) in untreated apple pomace. The SDF prepared with SE also exhibited higher functionality values. Scanning electron micrographs (SEM) indicated that the SDF surface from apple pomace was poriferous, rough and lax after SE treatment; therefore, it can be concluded that the SDF morphology was altered by the steam explosion. [ABSTRACT FROM AUTHOR]