Biofilms, present as microorganisms and surviving on surfaces, can increase food cross-contamination, leading to changes in the food industry’s cleaning and disinfection dynamics. Biofilm is an association of microorganisms that is irreversibly linked with a surface, contained in an extracellular polymeric substance matrix, which poses a formidable challenge for food industries. To avoid biofilms from forming, and to eliminate them from reversible attachment and irreversible stages, where attached microorganisms improve surface adhesion, a strong disinfectant is required to eliminate bacterial attachments. This review paper tackles biofilm problems from all perspectives, including biofilm-forming pathogens in the food industry, disinfectant resistance of biofilm, and identification methods. As biofilms are largely responsible for food spoilage and outbreaks, they are also considered responsible for damage to food processing equipment. Hence the need to gain good knowledge about all of the factors favouring their development or growth, such as the attachment surface, food matrix components, environmental conditions, the bacterial cells involved, and electrostatic charging of surfaces. Overall, this review study shows the real threat of biofilms in the food industry due to the resistance of disinfectants and the mechanisms developed for their survival, including the intercellular signalling system, the cyclic nucleotide second messenger, and biofilm-associated proteins.

Microbial Biofilms in the Food Industry—A Comprehensive Review

https://opus.lib.uts.edu.au/bitstream/10453/134855/1/AHL-mediated%20quorum%20sensing%20regulates%20the%20variations%20of%20microbial%20community%20and%20sludge%20properties%20of%20aerobic%20granular%20sludge%20under%20low%20organic%20loading.pdf

AHL-mediated quorum sensing regulates the variations of microbial community and sludge properties of aerobic granular sludge under low organic loading

Slippery liquid-infused porous surfaces inspired by the Nepenthes pitcher plant exhibit excellent performances and are known for their extremely low contact angle hysteresis (<5°) and smooth surface. In contrast, superhydrophobic surfaces (SHS) exhibit poor pressure stability, difficulty in self-healing, and difficulty in removing low surface tension liquids or organic solvents, which can affect the stable air layer. Thus, these issues can be avoided through the replacement of SHS with slippery liquid infused porous surfaces (SLIPS). In this review, the theoretical models of SHS and SLIPS are classified initially, and several design standards for the preparation of SLIPS are briefly described. Then, we focus on comparing the differences in the application of SHS and SLIPS, such as pressure stability, transparency, and droplet manipulation. However, there are still some problems that need to be improved during the preparation of SLIPS, such as the evaporation of the lubricant layer, the use of a lubricant layer of toxic perfluoropolyether and other substances, and easily lost nanostructured lubricant layer. Accordingly, several new improved methods are proposed in this review, and finally, the potential applications and development prospects of SLIPS are presented.

A comparison between superhydrophobic surfaces (SHS) and slippery liquid-infused porous surfaces (SLIPS) in application.

AHLs-mediated quorum sensing threshold and its response towards initial adhesion of wastewater biofilms.

The various detrimental effects of wastewater generated from different anthropogenic activities are among the biggest challenges to sustainable development. Among various technologies developed to tackle wastewater, biological treatment methods, such as moving bed biofilm reactor (MBBR) and membrane bioreactor (MBR), have been extensively used in the past few decades due to their cost-effectiveness, wide applications, technical feasibility, etc. However, certain limitations of MBR and MBBR have led to the hybridization of these two technologies. In this context, a thorough bibliometric assay of MBBR, MBR, and hybrid moving bed membrane bioreactor (MBMBR) has been performed to analyze the current trends in publication, contributing authors and countries, major research hotspots, etc. It was observed that for both MBBR and MBR, China had the maximum contribution, i.e., 30.4% and 30.5%, respectively, in terms of the number of publications. The future trend of the selected treatment methods was assessed with the help of S-curve simulation. In both cases, greater than 70% of research articles were published in the last decade, which may be due to the increasingly stringent regulations on effluent quality. Subsequently, this study investigated the performance and responsible mechanisms for these systems. MBMBR was found to be more effective than MBR in terms of pollutant removal, followed by MBBR. The nutrient removal efficiency of MBMBR systems was significantly higher (73.5%) as compared to MBBR (50%) and MBR (62.5%). Life cycle assessment (LCA) has been discussed for the selected treatment methods to evaluate sustainability aspects.

A systematic review of moving bed biofilm reactor, membrane bioreactor, and moving bed membrane bioreactor for wastewater treatment: Comparison of research trends, removal mechanisms, and performance

Qiuju Liu

Papers

AHLs-mediated quorum sensing threshold and its response towards initial adhesion of wastewater biofilms.

In-situ monitoring AHL-mediated quorum-sensing regulation of the initial phase of wastewater biofilm formation.

Quorum sensing signaling distribution during the development of full-scale municipal wastewater treatment biofilms.

Bacterial assembly during the initial adhesion phase in wastewater treatment biofilms.

In-situ monitoring of the unstable bacterial adhesion process during wastewater biofilm formation: A comprehensive study.