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In the present study the biofilm-forming characteristics of 99 serotyped (DMC strains) and 41 genus levelidentified (IS strains) Salmonella strains originating from Turkey were investigated. The strains were selected based on their ability to show the biofilm morphotype on Congo red agar plates. In addition, all strains were evaluated with regard to properties related to forming pellicle structures, physical differences of pellicles, any changes in the media associated with the formation of pellicles, and the presence of cellulose within the formed biofilm matrix as determined using 366 nm UV light. The Salmonella Typhimurium DMC4 strain was the best producer of biofilm grown on polystyrene microtiter plates (optical density at 595 nm: 3.418). In subsequent experiments industrial process conditions were used to investigate different morphotyped Salmonella strains' biofilm-forming capability on stainless steel, a commonly preferred surface for the food industries, and on polystyrene surfaces. The effect of other important industrial conditions, such as temperature (5, 20, 37• C), pH (4.5, 5.5, 6.5, 7.4) and NaCl concentration (0.5, 1.5, 5.5, 10.5%) on the production of biofilm of the different morphotyped Salmonella strains (DMC4; red, dry and rough morphotyped S. Typhimurium, DMC12; brown, dry and rough morphotyped S. Infantis, DMC13; pink, dry and rough morphotyped S. subsp. Roughform) were also assessed. On the other hand, pH values exhibited variable effects on biofilm-forming features for different Salmonella strains on both polystyrene and stainless steel surfaces.

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Over the last decades, several antimicrobial agents have been made available. Due to increasing antimicrobial resistance, bacteriophages were rediscovered for their potential applications against bacterial infections. In the present study, biofilm inhibition and eradication of Salmonella enterica subsp. enterica serovar Typhimurium DMC4 strain (S. Typhimurium) was evaluated with respect to different incubation periods at different P22 phage titrations. The efficacy of P22 phage on biofilm formation and eradication of S. Typhimurium DMC4 strain was screened in vitro on polystyrene and stainless steel surfaces. The biofilm forming capacity of S. Typhimurium was significantly reduced at higher phage titrations (106 pfu/mL ?). All phage titers (104-108 pfu/mL) were found to be effective at the end of the 24 h-incubation period whereas higher phage titrations were found to be effective at the end of the 48 h and 72 h of incubation. P22 phage has less efficacy on already formed, especially mature biofilms (72 h-old biofilm). Notable results of P22 phage treatment on S. Typhimurium biofilm suggest that P22 phage has potential uses in food systems.

Biofilm formations of 25 Salmonella strains belonging to 19 serotypes were monitored with respect to time at a constant temperature. Two (DMC8 and DMC73) out of 25 strains had low biofilm formation ability and were not included in the modeling study. One (SL1344) strain had awkward biofilm formation which could not be described by a mathematical model, whereas biofilm formation of three strains (DMC33, DMC85 and DMC93) could be described by an exponential model. The modified Gompertz equation with high adjusted determination coefficient (R 2 adj) and low mean square error values produced reasonable fits for the biofilm formation of 19 Salmonella strains. It was also possible to predict the biofilm formation of these strains at two different time values by use of the modified Gompertz equation. Although more studies should be carried out to evaluate different mathematical models under both iso-and nonisothermal conditions, this study reveals that describing and predicting the biofilm formation could be possible.

The ability of Aeribacillus pallidus E334 to produce pellicle and form a biofilm was studied. Optimal biofilm formation occurred at 60 °C, pH 7.5 and 1.5% NaCl. Extra polymeric substances (EPS) were composed of proteins and eDNA (21.4 kb). E334 formed biofilm on many surfaces, but mostly preferred polypropylene and glass. Using CLSM analysis, the network-like structure of the EPS was observed. The A. pallidus biofilm had a novel eDNA content. DNaseI susceptibility (86.8% removal) of eDNA revealed its importance in mature biofilms, but the purified eDNA was resistant to DNaseI, probably due to its extended folding outside the matrix. Among 15 cleaning agents, biofilms could be removed with alkaline protease and sodium dodecyl sulphate (SDS). The removal of cells from polypropylene and biomass on glass was achieved with combined SDS/alkaline protease treatment. Strong A. pallidus biofilms could cause risks for industrial processes and abiotic surfaces must be taken into consideration in terms of sanitation procedures.

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It is commonly well-known that biofilms are the predominant mode of bacterial growth, reflected in the clinic observations, where approximately 80% of all bacterial infections are related to biofilms. Bacteria in biofilms are well protected against environmental stresses, antibiotics, disinfectants and the host’s immune system and are usually extremely difficult to eradicate. Due to common problems caused by biofilms, alternative anti-biofilm strategies must be developed. Enterococcus strains are able to form complex surface-associated communities (biofilms), which contribute to its resistance and persistence in both host and non-host environments, and are especially important in food processing and clinical environments. Enterococcus biofilms showed increased antimicrobial resistance to the most of antibiotics as compared to the planktonic bacteria, which make them difficult to combat. There is an increasing evidence that biofilms are often associated with infectious diseases. Novel anti-biofilm strategies must be designed to include natural bio products instead of common antibiotics. Mushrooms are a nutritionally functional foods and a source of pharmaceuticals having functions such as antitumor, immunomodulating, antioxidant, cardiovascular, anti-hypercholesterolemia, antiviral, antibacterial, anti-parasitic, antifungal, detoxification, hepatoprotective, and antidiabetic. In addition, they have a notable activity against biofilms. In this study, the antimicrobial and anti-biofilm activities of some medicinal and edible mushrooms, namely Morchella angusticeps Peck, Ganoderma lucidum (Curtis) P. Karst., Cerioporus squamosus (Huds.) Quél., Trametes versicolor (L.) Lloyd and Lentinula edodes (Berk.) Singer were screened against multi drug resistant Enterococcus strains. As a result, it was observed that these mushrooms have notable potency to develop alternative medicines to struggle infectious diseases and biofilms.