Search

Aims The aim of this study was to determine the biofilm-forming ability of a strain belonging to the Pseudomonas fluorescens group isolated from the dairy environment under food-relevant conditions. Moreover, the effects of commercial sanitizers against preformed biofilms were assessed both in terms of viability and structure. Methods and results The biofilms were formed on polystyrene, stainless steel (SS), and polytetrafluoroethylene (PTFE) in a wide range of temperatures (4–25°C) and were subjected to the action of 10 different sanitizers. The strain under study showed to be a strong biofilm-former regardless of temperature, particularly on polystyrene. The biofilms were mostly sensitive to chlorine and peracetic acid-based sanitizers. For some sanitizers (e.g. amphoteric), a relationship was observed between the material and the tolerance, while the temperature was not statistically significant. The formation of long-term biofilms on SS was also structurally affected by the temperature, showing microcolonies more irregular in shape and with lower cellularity at 4°C compared to 15°C, where the biofilm was more compact and with a high presence of EPS. Conclusions The strain belonging to the P. fluorescens group was shown to quickly adhere and form mature biofilm at temperatures and on materials relevant to the food sector; however, biofilms formed under different conditions were differently tolerant to disinfectants.     Significance and impact of the study Findings from this study could provide a basis for developing targeted sanitation protocols in food plants. [ABSTRACT FROM AUTHOR]

Biofilms pose a serious public health hazard with a significant economic impact on the food industry. The present scoping review is designed to analyse the literature published during 2001–2020 on biofilm formation of microbes, their detection methods, and association with antimicrobial resistance (if any). The peer‐reviewed articles retrieved from 04 electronic databases were assessed using PRISMA‐ScR guidelines. From the 978 preliminary search results, a total of 88 publications were included in the study. On analysis, the commonly isolated pathogens were Listeria monocytogenes, Staphylococcus aureus, Salmonella spp., Escherichia coli, Bacillus spp., Vibrio spp., Campylobacter jejuni and Clostridium perfringens. The biofilm‐forming ability of microbes was found to be influenced by various factors such as attachment surfaces, temperature, presence of other species, nutrient availability etc. A total of 18 studies characterized the biofilm‐forming genes, particularly for S. aureus, Salmonella spp., and E. coli. In most studies, polystyrene plate and/or stainless‐steel coupons were used for biofilm formation, and the detection was carried out by crystal violet assays and/or by plate counting method. The strain‐specific significant differences in biofilm formation were observed in many studies, and few studies carried out analysis of multi‐species biofilms. The association between biofilm formation and antimicrobial resistance was not clearly defined. Further, viable but non‐culturable form of the foodborne pathogens is posing an unseen (by conventional cultivation techniques) but potent threat to the food safety. The present review recommends the need for carrying out systematic surveys and risk analysis of biofilms in food chain to highlight the evidence‐based public health concerns, especially in regions where microbiological food hazards are quite prevalent. [ABSTRACT FROM AUTHOR]

Mixed‐species biofilms represent the most frequent actual lifestyles of microorganisms in food processing environments, and they are usually more resistant to control methods than single‐species biofilms. The persistence of biofilms formed by foodborne pathogens is believed to cause serious human diseases. These challenges have encouraged researchers to search for novel, natural methods that are more effective towards mixed‐species biofilms. Recently, the use of bacteriophages to control mixed‐species biofilms have grown significantly in the food industry as an alternative to conventional methods. This review highlights a comprehensive introduction of mixed‐species biofilms formed by foodborne pathogens and their enhanced resistance to anti‐biofilm removal strategies. Additionally, several methods for controlling mixed‐species biofilms briefly focused on applying bacteriophages in the food industry have also been discussed. This article concludes by suggesting that using bacteriophage, combined with other 'green' methods, could effectively control mixed‐species biofilms in the food industry. [ABSTRACT FROM AUTHOR]

Objective: The present review highlights the advantages of using natural colorant over the synthetic one. We have discussed the fermentation parameters that can enhance the productivity of Monascus pigment on agricultural wastes. Background: Food industry is looking for natural colours because these can enhance the esthetic value, attractiveness, and acceptability of food while remaining nontoxic. Many synthetic food colours (Azorubine Carmoisine, quinoline) have been prohibited due to their toxicity and carcinogenicity. Increasing consumer awareness towards the food safety has forced the manufacturing industries to look for suitable alternatives. In addition to safety, natural colorants have been found to have nutritional and therapeutic significance. Among the natural colorants, microbial pigments can be considered as a viable option because of scalability, easier production, no seasonal dependence, cheaper raw materials and easier extraction. Fungi such as Monascus have a long history of safety and therefore can be used for production of biopigments. Method: The present review summarizes the predicted biosynthetic pathways and pigment gene clusters in Monascus purpureus. Results: The challenges faced during the pilot‐scale production of Monascus biopigment and taming it by us of low‐cost agro‐industrial substrates for solid state fermentation has been suggested. Conclusion: Keeping in mind, therapeutic properties of Monascus pigments and their derivatives, they have huge potential for industrial and pharmaceutical application. Application: Though the natural pigments have wide scope in the food industry. However, stabilization of pigment is the greatest challenge and attempts are being made to overcome this by complexion with hydrocolloids or metals and by microencapsulation. [ABSTRACT FROM AUTHOR]

Aims: Listeria species may colonize and persist in food processing facilities for prolonged periods of time, despite hygiene interventions in place. To understand the genetic factors contributing to persistence of Listeria strains, this study undertook a comparative analysis of seven persistent and six presumed non‐persistent strains, isolated from a single food processing environment, to identify genetic markers correlating to promoting persistence of Listeria strains, through whole genome sequence analysis. Methods and Results: A diverse pool of genetic markers relevant to hygiene tolerance was identified, including disinfectant resistance markers qacH, emrC and the efflux cassette bcrABC. Both persistent and presumed non‐persistent cohorts encoded a range of stress resistance markers, including heavy metal resistance, oxidative and pH stress, although trends were associated with each cohort (e.g., qacH and cadA1C resistance was more frequently found in persistent isolates). Persistent isolates were more likely to contain mutations associated with attenuated virulence, including a truncated InlA. Plasmids and transposons were widespread between cohorts. Conclusions: Results suggest that no single genetic marker identified was universally responsible for a strain's ability to persist. Persistent strains were more likely to harbour mutation associated with hypovirulence. Significance and Impact of the Study: This study provides additional insights into the distribution of genetic elements relevant to persistence across Listeria species, as well as strain virulence potential. [ABSTRACT FROM AUTHOR]