In food processing environments, various microorganisms can adhere and aggregate on the surface of equipment, resulting in the formation of multi-species biofilms. Complex interactions among microorganisms may affect the formation of multi-species biofilms and their resistance to disinfectants, which are food safety and quality concerns. This paper reviews the various interactions among microorganisms in multi-species biofilms, including competitive, cooperative and neutral interactions. Then, the preliminary mechanisms underlying the formation of multi-species biofilms are discussed in relation to factors, such as quorum sensing (QS) signal molecules, extracellular polymeric substances (EPS) and biofilm-regulated genes. Finally, the resistance mechanisms of common contaminating microorganisms to disinfectants in food processing environments are also summarized. This review is expected to facilitate a better understanding of inter-species interactions, and provide some implications for the control of multi-species biofilms in food processing.

Immunochromatography test strips have been widely used to detect foodborne pathogens due to their high sensitivity, stability and specificity, and the selection of the label is an important factor. In this study, CdTe/CdS quantum dots with a high fluorescence were synthesized as a fluorescence label to conjugate with antibodies to prepare an immunochromatography test strip for the detection of Escherichia coli O157:H7 (E. coli O157:H7). Antibody-quantum dot conjugation was coated onto a glass fiber membrane, which played the role of the conjugate pad. E. coli O157:H7 polyclonal antibodies and goat anti-rabbit immunoglobulin G (Ig G) were used to create the test line and the control line, respectively. The detection limit was determined as 10⁴ CFU mL⁻¹ and no cross-reactions were discovered with other Escherichia coli and other strains. In addition, the strips detected effectively after storing at room temperature in the dark for 35 d. The detection was easy to perform, rapidly and sensitively, and the total detection time was less than 12 min to obtain accurate results, and this method has the potential to be a powerful tool to detect bacteria quantitatively.

Following a ban on antibiotic use in the feed industry, trials on the effects of various immunostimulants (prebiotics, probiotics, antimicrobial peptides [AMPs], and herbs) on the survival, growth, immunity, and disease control of farmed fish in aquaculture are being rapidly conducted. The wide variety of microbes with roles in nutrition, metabolism, and immunity in the fish intestine is the primary factor affecting the fermentability and functionality of dietary immunostimulants. For this reason, the dynamic interactions between immunostimulants and the intestinal microbiome may influence fish health. In this study, the effects of two agriculturally important AMPs (nisin and cecropin) and one herb (Penthorum chinense) on the gut microbiome of common carp were investigated, using 16S rDNA high-throughput sequencing. The results suggest that all three substances can alter the richness, diversity, and composition of the intestinal microbiota of common carp. P. chinense had a similar effect on the gut microbiota of common carp to that of nisin, and both promoted more striking changes in the gut microbiota community than did cecropin. The relative abundance of Proteobacteria was lower in the nisin and P. chinense groups than in the control and cecropin groups. The relative abundance of Bacteroidetes in the nisin, cecropin, and P. chinense groups was markedly increased, compared with that of the control group. Additionally, nisin, cecropin, and P. chinense showed obvious anti-inflammatory effects on the fish intestine, which was reflected by significantly increasing the expression levels of two anti-inflammatory cytokines IL-10 and TGF-β. Some digestive enzyme activities in the fish intestine were also significantly enhanced by supplementing these three substances in feeds.

The aim of this work is to develop a green route for platinum nanoparticles (PtNPs) biosynthesized using Cordyceps flower extract and to evaluate their antioxidant activity and antibacterial activity. Different characterization techniques were utilized to characterize the biosynthetic PtNPs. The results showed that PtNPs were spherical particles covered with Cordyceps flower extract. The average particle size of PtNPs in Dynamic Light Scattering was 84.67 ± 5.28 nm, while that of PtNPs in Transmission Electron Microscope was 13.34 ± 4.06 nm. Antioxidant activity of PtNPs was evaluated by DPPH free radical scavenging ability test. The results showed that the antioxidant activity was positively correlated with the concentration of PtNPs, the DPPH scavenging efficiency of PtNPs (0.50–125.00 μg/mL) was 27.77–44.00%. In addition, the morphological changes of four kinds of bacteria (Escherichia coli, Salmonella typhimurium, Bacillus subtilis, Staphylococcus aureus) exposed to PtNPs were observed by scanning electron microscope. The results showed that the antibacterial activity of PtNPs against Gram-negative bacteria was stronger than that of Gram-positive bacteria.

In order to produce fermented bamboo shoots with functional properties, two strains of lactic acid bacteria were selected for inoculation and fermentation. One strain, Lactiplantibacillus plantarum R1, exhibited prominent potential probiotic properties (including gastrointestinal condition tolerance, adhesion ability, antimicrobial ability, and antibiotic resistance), while the other, Levilactobacillus brevis R2, demonstrated the capability of high γ-aminobutyric acid (GABA) production (913.99 ± 14.2 mg/L). The synergistic inoculation of both strains during bamboo shoot fermentation led to a remarkable increase in GABA content (382.31 ± 12.17 mg/kg), surpassing that of naturally fermented bamboo shoots by more than 4.5 times and outperforming mono-inoculated fermentation. Simultaneously, the nitrite content was maintained at a safe level (5.96 ± 1.81 mg/kg). Besides, inoculated fermented bamboo shoots exhibited an increased crude fiber content (16.58 ± 0.04 g/100 g) and reduced fat content (0.39 ± 0.02 g/100 g). Sensory evaluation results indicated a high overall acceptability for the synergistically inoculated fermented bamboo shoots. This study may provide a strategy for the safe and rapid fermentation of bamboo shoots and lay the groundwork for the development of functional vegetable products enriched with GABA.

Salmonella enterica is a prominent foodborne pathogen, including diverse serotypes that are prolific biofilm formers. Its ability to form biofilm can be affected by multiple environmental ... HIGHLIGHTS Salinity differentially affects biofilm formation in Salmonella Enteritidis and Newport. NaCl at 0.5% abolishes biofilm formation of Salmonella Newport but not Salmonella Enteritidis. Th...