The major strategies for designing surfaces that prevent fouling due to proteins, bacteria, and marine organisms are reviewed. Biofouling is of great concern in numerous applications ranging from biosensors to biomedical implants and devices, and from food packaging to industrial and marine equipment. The two major approaches to combat surface fouling are based on either preventing biofoulants from attaching or degrading them. One of the key strategies for imparting adhesion resistance involves the functionalization of surfaces with poly(ethylene glycol) (PEG) or oligo(ethylene glycol). Several alternatives to PEG-based coatings have also been designed over the past decade. While protein-resistant coatings may also resist bacterial attachment and subsequent biofilm formation, in order to overcome the fouling-mediated risk of bacterial infection it is highly desirable to design coatings that are bactericidal. Traditional techniques involve the design of coatings that release biocidal agents, including antibiotics, quaternary ammonium salts (QAS), and silver, into the surrounding aqueous environment. However, the emergence of antibiotic- and silver-resistant pathogenic strains has necessitated the development of alternative strategies. Therefore, other techniques based on the use of polycations, enzymes, nanomaterials, and photoactive agents are being investigated. With regard to marine antifouling coatings, restrictions on the use of biocide-releasing coatings have made the generation of nontoxic antifouling surfaces more important. While considerable progress has been made in the design of antifouling coatings, ongoing research in this area should result in the development of even better antifouling materials in the future.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/adma.201001215

Antifouling coatings: recent developments in the design of surfaces that prevent fouling by proteins, bacteria, and marine organisms.

Polymer surface modification for the attachment of bioactive compounds

Perspectives for chitosan based antimicrobial films in food applications

https://ciptaindomedica.files.wordpress.com/2011/01/antimicrobial-herb-and-spice-compounds-in-food.pdf

Antimicrobial herb and spice compounds in food.

Antioxidant activity has been assessed in many ways. The limitation of many newer methods is the frequent lack of an actual substrate in the procedure. The combination of all approaches with the many test methods available explains the large variety of ways in which results of antioxidant testing are reported. The measurement of antioxidant activities, especially of antioxidants that are mixtures, multifunctional or are acting in complex multiphase systems, cannot be evaluated satisfactorily by a simple antioxidant test without due regard to the many variables influencing the results. Several test procedures may be required to evaluate such antioxidant activities. A general method of reporting antioxidant activity independent of the test procedure is proposed.

http://ucce.ucdavis.edu/files/datastore/608-46.pdf

Methods for testing antioxidant activity

In this study, several nonlinear models (Gompertz, Baranyi, Logistic 1 and Logistic 2) were compared to describe the antimicrobial activity of different concentrations (5 ppm, 6 ppm, 7 ppm) of monolaurin against Alicyclobacillus acidoterrestris vegetative cells. For all models and each concentration, the growth index was calculated by using absorbance data. By the evaluation of the goodness of fitting through some indices, such as MARE, MRE, minimum and maximum of relative error, bias and accuracy factor, RSS and RMS, the Gompertz and Baranyi models were decided to be sufficient models to describe the effect of monolaurin on microbial growth of Alicyclobacillus acidoterrestris.

Modeling Alicyclobacillus acidoterrestris growth under monolaurin action

Enzymes and Enzymatic Systems as Natural Antimicrobials

Gluten Friendly™ (GF) is a new gluten achieved through a physicochemical process applied to wheat kernels. The goal of this research was to assess the in vivo effects of Gluten Friendly™ bread on celiac gut mucosa and microbiota. In a double-blind placebo-controlled intervention study, 48 celiac disease (CD) patients were randomized into 3 groups to eat 100 g of bread daily, containing different doses (0; 3 g; 6 g) of GF for 12 weeks. The small-bowel morphology (VH/CrD), intraepithelial densities of CD3+, celiac serology, MUC2, CB1, gut permeability, proinflammatory cytokines, gluten in stools, symptoms, and gut microbial composition were assessed. All 48 CD subjects experienced no symptoms. K-means analysis evidenced celiac subjects clustering around unknown parameters independent of GF dosage: K1 35%; K2 30%; K3 35%. VH/CrD significantly decreased in K1 and K2. VH/CrD did not correlate with IEL increase in K2. 33-mer was not detected in 47% and 73% of patients in both K1 and K2, respectively. VH/CrD and IEL did not change significantly and strongly correlated with the absence of 33-mer in K3. Inflammation and VH/CrD decrease are strongly related with the presence of proinflammatory species at the baseline. A boost in probiotic, butyrate-producing genera, is strongly related with GF tolerance at the end of the trial. Our research suggests that a healthy and proinflammatory ecology could play a crucial role in the digestion and tolerance of the new gluten molecule in celiac subjects. However, GF can be completely digested by gut microbiota of CD subjects and shapes it toward gut homeostasis by boosting healthy butyrate-producing populations. The clinical trial registry number is NCT03137862 (https://clinicaltrials.gov).

/pdf/healthy-and-pro-inflammatory-gut-ecology-plays-a-crucial-3buwwx58.pdf

Healthy and pro-inflammatory gut ecology plays a crucial role in the digestion and tolerance of a novel Gluten Friendly™ bread in celiac subjects: a randomized, double blind, placebo control in vivo study.

This paper focuses on the use of statistical Design of Experiments (DoE) to investigate the effects of two anti-lactic acid bacteria compounds on growth and metabolism of lactobacilli isolated from Italian table olives. p-Coumaric and vanillic acids (0.0–0.4%) were used as phenolic compounds, which were combined with salt (0.0–6.0%) and glucose (0.0–4.0%) through a Central Composite Design. Three strains of Lactobacillus plantarum (5 log cfu/ml) were used as test organisms, samples were stored at 37 °C, and cell counts and pH were evaluated periodically. The growth of lactobacilli was affected in a significant way by salt, p-coumaric and vanillic acids, being the salt the most significant factor after 24 h (short storage time), then replaced by p-coumaric acid. p-Coumaric acid also played a significant role on the acidifying ability, expressed as decrease of pH of the medium: microbial metabolism, in fact, appeared as completely inhibited at 0.2% of p-coumaric acid.

Use of central composite design in food microbiology: a case study on the effects of secondary phenols on lactic acid bacteria from olives.

Summary
The main topic of this study was to study how cell surface hydrophobicity (CSH) could change in response to pH, temperature and inulin; Lactobacillus acidophilus La-5 was used as a model microorganism. pH, temperature, inulin and incubation time (exposure to prebiotic or incubation at pH 4.0 and 9.0) were combined through a full factorial design and a Central Composite Design; the results were analysed using a multifactorial anova (first step) and a stepwise regression (second step). Temperature and pH significantly affected CSH: an increase in the temperature determined a significant increase in CSH, whereas the correlation pH vs. CSH was negative, as an increase in pH caused a significant decrease in CSH. Inulin played a significant role, but its effect could be influenced by temperature, pH and exposure time. This study is the first approach on the effects of some environmental factors on CSH and suggests that the culturing conditions and/or the exposure to some prebiotics could modify it with positive or negative effects.

Milena Sinigaglia

Papers

Modeling Alicyclobacillus acidoterrestris growth under monolaurin action

Enzymes and Enzymatic Systems as Natural Antimicrobials

Healthy and pro-inflammatory gut ecology plays a crucial role in the digestion and tolerance of a novel Gluten Friendly™ bread in celiac subjects: a randomized, double blind, placebo control in vivo study.

Use of central composite design in food microbiology: a case study on the effects of secondary phenols on lactic acid bacteria from olives.

Changes of the cell surface hydrophobicity of Lactobacillus acidophilus La-5 in response to pH, temperature and inulin