The stability of gut microbiota is essential for the host health. Parabacteroides spp., core members of the human gut microbiota, have average abundance of 1.27% in the human of 12 populations. Parabacteroides has been recently reported to have a close relationship with host health (E.g., metabolic syndrome, inflammatory bowel disease and obesity). Parabacteroides have the physiological characteristics of carbohydrate metabolism and secreting SCFAs. However, antimicrobial resistance of Parabacteroides to antibiotic (such as clindamycin, moxifloxacin and cefoxitin) should not be ignored. In this review, we primarily focused on Parabacteroides distasoniss, Parabacteroides goldsteinii, Parabacteroides johnsonii and Parabacteroides merdae and discussed their relationships with host disease, diet and the prevention or induction of diseases. P. distasonis and P. goldsteinii may be viewed as the potential next generation probiotics (NGP) candidate due to their protective effects on inflammation and obesity in mice. We also discussed the potential therapeutic application of Parabacteroides spp. in maintaining host-intestine homeostasis.

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Bacteriocins are generally considered as low‐molecular‐weight ribosomal peptides or proteins synthesized by G+ and G− bacteria that inhibit or kill other related or unrelated microorganisms. However, low yield is an important factor restricting the application of bacteriocins. This paper reviews mining methods, heterologous expression in different systems, the purification technologies applied to bacteriocins, and identification methods, as well as the antibacterial mechanism and applications in three different food systems. Bioinformatics improves the efficiency of bacteriocins mining. Bacteriocins can be heterologously expressed in different expression systems (e.g., Escherichia coli, Lactobacillus, and yeast). Ammonium sulfate precipitation, dialysis membrane, pH‐mediated cell adsorption/desorption, solvent extraction, macroporous resin column, and chromatography are always used as purification methods for bacteriocins. The bacteriocins are identified through electrophoresis and mass spectrum. Cell envelope (e.g., cell permeabilization and pore formation) and inhibition of gene expression are common antibacterial mechanisms of bacteriocins. Bacteriocins can be added to protect meat products (e.g., beef and sausages), dairy products (e.g., cheese, milk, and yogurt), and vegetables and fruits (e.g., salad, apple juice, and soybean sprouts). The future research directions are also prospected.

Lignin valorization can be obtained through cleavage of selected bonds by microbial enzymes, in which lignin is segregated from cellulose and hemicellulose and abundant phenolic compounds can be provided. In this study, Pseudomonas sp. Q18, previously isolated from rotten wood in China, was used to degrade alkali lignin and raw lignocellulosic material. Gel-permeation chromatography, field-emission scanning electron microscope, and GC-MS were combined to investigate the degradation process. The GC-MS results revealed that the quantities of aromatic compounds with phenol ring from lignin increased significantly after incubation with Pseudomonas sp. Q18, which indicated the degradation of lignin. According to the lignin-derived metabolite analysis, it was proposed that a DyP-type peroxidase (PmDyP) might exist in strain Q18. Thereafter, the gene of PmDyP was cloned and expressed, after which the recombinant PmDyP was purified and the enzymatic kinetics of PmDyP were assayed. According to results, PmDyP showed promising characteristics for lignocellulosic biodegradation in biorefinery.