Cross-Over Application of Algerian Dairy Lactic Acid Bacteria for the Design of Plant-Based Products: Characterization of Weissella cibaria and Lactiplantibacillus plantarum for the Formulation of Quinoa-Based Beverage

The food industry constantly seeks new starter cultures with superior characteristics to enhance the sensory and overall quality of final products. Starting from a collection of Algerian dairy (goat and camel) lactic acid bacteria, this work focused on the exploration of the technological and probiotic potential of Weissella cibaria (VR81 and LVT1) and Lactiplantibacillus plantarum R12 strains isolated from raw camel milk and fermented milk, respectively. These bioactive strains were selected for their high performance among ten other LAB strains and were used as starter cultures to develop a novel and nutritionally enhanced dairy-like plant-based yogurt using quinoa (Chenopodium quinoa Willd) as a raw matrix. The strains were evaluated for their antagonistic effects against Listeria innocua, Listeria ivanovii, Staphylococcus aureus, Escherichia coli, Salmonella enterica, and Pseudomonas aeruginosa, resilience to acidic and osmotic challenges, and tolerance to gastrointestinal mimicking conditions (i.e., pepsin and bile salt). Their aggregation and adhesion profiles were also analyzed. Furthermore, L. plantarum and W. cibaria were tested in single and co-culture for the fermentation and biocontrol of quinoa. The strains exhibited probiotic properties, including a high potential for biocontrol applications, specifically against L. innocua and P. aeruginosa (20 mm diameter zone with the neutralized cell-free supernatant), which disappeared after protease treatment, suggesting that bioactive peptides might be responsible for the observed antimicrobial effect. Additionally, they demonstrated resilience to acidic (pH 2) and osmotic challenges (1M sucrose), tolerance to gastro-intestinal conditions, as well as good aggregation and adhesion profile. Furthermore, the strains were able to produce metabolites of interest, such as exopolysaccharide (yielding up to 4.7 mg/mL) and riboflavin, reaching considerable production levels of 2.5 mg/L upon roseoflavin selection. The application of W. cibaria and L. plantarum as primary starters (both in single and co-culture) for fermenting quinoa resulted in effective acidification of the matrix (ΔpH of 2.03 units) and high-quality beverage production. in vivo challenge tests against L. innocua showed the complete inhibition of this pathogen when L. plantarum was included in the starter, either alone or in combination with W. cibaria. Both species also inhibited Staphylococcus and filamentous fungi. Moreover, the co-culture of mutant strains of L. plantarum R12d and W. cibaria VR81d produced riboflavin levels of 175.41 µg/100 g in fermented quinoa, underscoring their potential as starters for the fermentation, biopreservation, and biofortification of quinoa while also displaying promising probiotic characteristics.

Polyphenolic characterization, nutritional and microbiological assessment of newly formulated semolina fresh pasta fortified with grape pomace

The application of an innovative patented technology on grape pomace allowed to obtain a food ingredient no matter the seasonality and with a great shelf-life thanks to its high polyphenolic content. Then, fresh pasta samples fortified with 5 and 10 g/100 g of this innovative ingredient were prepared and their polyphenolic content, nutritional and microbiological assessments were investigated. The two levels of fortification led to an increase of polyphenols content before and after pasta cooking, which resulted in an increased antibacterial activity. Only the fortification with 5 g/100 g of grape pomace powder determined a high level of Slowly Digestible Starch and a low predicted Glycaemic Index, highlighting a possible 'limit effect' for the fortification of semolina fresh pasta. Overall, results confirmed that the use of this concentration obtained with the employment of the new technology allowed the production of fresh pasta with better polyphenolic profile and nutritional value even after cooking.

Lactobacilli Cell-Free Supernatants Modulate Inflammation and Oxidative Stress in Human Microglia via NRF2-SOD1 Signaling

Microglia are macrophage cells residing in the brain, where they exert a key role in neuronal protection. Through the gut-brain axis, metabolites produced by gut commensal microbes can influence brain functions, including microglial activity. The nuclear factor erythroid 2-related factor 2 (NRF2) is a key regulator of the oxidative stress response in microglia, controlling the expression of cytoprotective genes. Lactobacilli-derived cell-free supernatants (CFSs) are postbiotics that have shown antioxidant and immunomodulatory effects in several in vitro and in vivo studies. This study aimed to explore the effects of lactobacilli CFSs on modulating microglial responses against oxidative stress and inflammation. HMC3 microglia were exposed to lipopolysaccaride (LPS), as an inflammatory trigger, before and after administration of CFSs from three human gut probiotic species. The NRF2 nuclear protein activation and the expression of NRF2-controlled antioxidant genes were investigated by immunoassay and quantitative RT-PCR, respectively. Furthermore, the level of pro- and anti-inflammatory cytokines was evaluated by immunoassay. All CFSs induced a significant increase of NRF2 nuclear activity in basal conditions and upon inflammation. The transcription of antioxidant genes, namely heme oxygenase 1, superoxide dismutase (SOD), glutathione-S transferase, glutathione peroxidase, and catalase also increased, especially after inflammatory stimulus. Besides, higher SOD1 activity was detected relative to inflamed microglia. In addition, CFSs pre-treatment of microglia attenuated pro-inflammatory TNF-α levels while increasing anti-inflammatory IL-10 levels. These findings confirmed that gut microorganisms' metabolites can play a relevant role in adjuvating the microglia cellular response against neuroinflammation and oxidative stress, which are known to cause neurodegenerative diseases.

Psychobiotic Properties of Lactiplantibacillus plantarum in Neurodegenerative Diseases

Neurodegenerative disorders are the main cause of cognitive and physical disabilities, affect millions of people worldwide, and their incidence is on the rise. Emerging evidence pinpoints a disturbance of the communication of the gut-brain axis, and in particular to gut microbial dysbiosis, as one of the contributors to the pathogenesis of these diseases. In fact, dysbiosis has been associated with neuro-inflammatory processes, hyperactivation of the neuronal immune system, impaired cognitive functions, aging, depression, sleeping disorders, and anxiety. With the rapid advance in metagenomics, metabolomics, and big data analysis, together with a multidisciplinary approach, a new horizon has just emerged in the fields of translational neurodegenerative disease. In fact, recent studies focusing on taxonomic profiling and leaky gut in the pathogenesis of neurodegenerative disorders are not only shedding light on an overlooked field but are also creating opportunities for biomarker discovery and development of new therapeutic and adjuvant strategies to treat these disorders. Lactiplantibacillus plantarum (LBP) strains are emerging as promising psychobiotics for the treatment of these diseases. In fact, LBP strains are able to promote eubiosis, increase the enrichment of bacteria producing beneficial metabolites such as short-chain fatty acids, boost the production of neurotransmitters, and support the homeostasis of the gut-brain axis. In this review, we summarize the current knowledge on the role of the gut microbiota in the pathogenesis of neurodegenerative disorders with a particular focus on the benefits of LBP strains in Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, autism, anxiety, and depression.

Potential of Non-Saccharomyces Yeasts as Probiotics and Alternatives to Antibiotics in Animal Production

Probiotics are live yeast or bacterial organisms that have beneficial effects on the host. Several microorganisms exhibit probiotic properties, the most common types being lactic acid bacteria, Bifidobacteria, spore-forming bacteria, and some yeast strains. Saccharomyces cerevisiae var. boulardii is the most important probiotic yeast species. However, another group of foodborne microorganisms, the so-called non-Saccharomyces yeasts (NSYs), has recently been re-evaluated and shown to have enormous potential in various fields of application, ranging from food fermentation to human and animal applications. NSYs are able to produce a range of bioactive compounds such as antimicrobials, mannoproteins, enzymes, polyunsaturated fatty acids, essential amino acids, vitamins, and β-glucans, which increases their potential applications as a new class of probiotics and/or alternatives to antibiotics in animal husbandry. In this review, we aim to highlight the potential and benefits of NSYs as probiotics and natural antimicrobials to improve animal health. Furthermore, the use of NSYs as biological alternatives to antibiotics to control foodborne pathogens in animal production is discussed.

Immunomodulatory Activity on Human Macrophages by Cell-Free Supernatants to Explore the Probiotic and Postbiotic Potential of Lactiplantibacillus plantarum Strains of Plant Origin

Upon dietary administration, probiotic microorganisms can reach as live cells the human gut, where they interact with the microbiota and host cells, thereby exerting a beneficial impact on host functions, mainly through immune-modulatory activities. Recently, attention has been drawn by postbiotics, i.e. non-viable probiotic microbes, including their metabolic products, which possess biological activities that benefit the host. Lactiplantibacillus plantarum is a bacterial species that comprises recognised probiotic strains. In this study, we investigated in vitro the probiotic (and postbiotic) potential of seven L. plantarum strains, including five newly isolated from plant-related niches. The strains were shown to possess some basic probiotic attributes, including tolerance to the gastrointestinal environment, adhesion to the intestinal epithelium and safety. Besides, their cell-free culture supernatants modulated cytokine patterns in human macrophages in vitro, promoting TNF-α gene transcription and secretion, while attenuating the transcriptional activation and secretion of both TNF-α and IL-8 in response to a pro-inflammatory signal, and enhancing the production of IL-10. Some strains induced a high IL-10/IL-12 ratio that may correlate to an anti-inflammatory capacity in vivo. Overall, the investigated strains are good probiotic candidates, whose postbiotic fraction exhibits immunomodulatory properties that need further in vivo studies. The main novelty of this work consists in the polyphasic characterisation of candidate beneficial L. plantarum strains obtained from relatively atypical plant-associated niches, by an approach that explores both probiotic and postbiotic potentials, in particular studying the effect of microbial culture-conditioned media on cytokine pattern, analysed at both transcriptional and secretion level in human macrophages.

Biotechnological Potential and Safety Evaluation of Dextran- and Riboflavin-Producing Weisella cibaria Strains for Gluten-Free Baking

Gluten consumption causes several immunological and non-immunological intolerances in susceptible individuals. In this study, the dextran-producing Weissella cibaria BAL3C-5 and its derivative, the riboflavin-overproducing strain BAL3C-5 C120T, together with a commercial bakery yeast, were used to ferment gluten-free (GF)-doughs obtained from corn and rice flours at two different concentrations and supplemented with either quinoa, buckwheat, or chickpea to obtain laboratory-scale GF bread. The levels of dextran, riboflavin, and total flavins were determined in the fermented and breads. Both strains grew in fermented doughs and contributed dextran, especially to those made with corn plus quinoa (~1 g/100 g). The highest riboflavin (350-150 µg/100 g) and total flavin (2.3-1.75 mg/100 g) levels were observed with BAL3C-5 C120T, though some differences were detected between the various doughs or breads, suggesting an impact of the type of flour used. The safety assessment confirmed the lack of pathogenic factors in the bacterial strains, such as hemolysin and gelatinase activity, as well as the genetic determinants for biogenic amine production. Some intrinsic resistance to antibiotics, including vancomycin and kanamycin, was found. These results indicated the microbiological safety of both W. cibaria strains and indicated their potential application in baking to produce GF bread.

Lactiplantibacillus plantarum from Unexplored Tunisian Ecological Niches: Antimicrobial Potential, Probiotic and Food Applications

The continued exploration of the diversity of lactic acid bacteria in little-studied ecological niches represents a fundamental activity to understand the diffusion and biotechnological significance of this heterogeneous class of prokaryotes. In this study, Lactiplantibacillus plantarum (Lpb. plantarum) strains were isolated from Tunisian vegetable sources, including fermented olive and fermented pepper, and from dead locust intestines, which were subsequently evaluated for their antimicrobial activity against foodborne pathogenic bacteria, including Escherichia coli O157:H7 CECT 4267 and Listeria monocytogenes CECT 4031, as well as against some fungi, including Penicillium expansum, Aspergilus niger, and Botrytis cinerea. In addition, their resistance to oro-gastro-intestinal transit, aggregation capabilities, biofilm production capacity, adhesion to human enterocyte-like cells, and cytotoxicity to colorectal adenocarcinoma cell line were determined. Further, adhesion to tomatoes and the biocontrol potential of this model food matrix were analyzed. It was found that all the strains were able to inhibit the indicator growth, mostly through organic acid production. Furthermore, these strains showed promising probiotic traits, including in vitro tolerance to oro-gastrointestinal conditions, and adhesion to abiotic surfaces and Caco-2 cells. Moreover, all tested Lpb. plantarum strains were able to adhere to tomatoes with similar rates (4.0-6.0 LogCFU/g tomato). The co-culture of LAB strains with pathogens on tomatoes showed that Lpb. plantarum could be a good candidate to control pathogen growth. Nonetheless, further studies are needed to guarantee their use as probiotic strains for biocontrol on food matrices.

Antimicrobial Properties, Functional Characterisation and Application of Fructobacillus fructosus and Lactiplantibacillus plantarum Isolated from Artisanal Honey

Honey is a valuable reservoir of lactic acid bacteria (LAB) and, particularly, of fructophilic LAB (FLAB), a relatively novel subgroup of LAB whose functional potential for human and food application has yet to be explored. In this study, FLAB and LAB strains have been isolated from honeys of different floral origins and selected for their broad antimicrobial activity against typical foodborne pathogenic bacteria and spoilage filamentous fungi. The best candidates, two strains belonging to the species Lactiplantibacillus plantarum and Fructobacillus fructosus, were submitted to partial characterisation of their cell free supernatants (CFS) in order to identify the secreted metabolites with antimicrobial activity. Besides, these strains were examined to assess some major functional features, including in vitro tolerance to the oro-gastrointestinal conditions, potential cytotoxicity against HT-29 cells, adhesion to human enterocyte-like cells and capability to stimulate macrophages. Moreover, when the tested strains were applied on table grapes artificially contaminated with pathogenic bacteria or filamentous fungi, they showed a good ability to antagonise the growth of undesired microbes, as well as to survive on the fruit surface at a concentration that is recommended to develop a probiotic effect. In conclusion, both LAB and FLAB honey-isolated strains characterised in this work exhibit functional properties that validate their potential use as biocontrol agents and for the design of novel functional foods. We reported antimicrobial activity, cytotoxic evaluation, probiotic properties and direct food application of a F. fructosus strain, improving the knowledge of this species, in particular, and on FLAB, more generally.

Molecular chaperone function of three small heat-shock proteins from a model probiotic species

Small heat-shock proteins (sHSP) are ubiquitous ATP-independent chaperones that prevent irreversible aggregation of heat-damaged denaturing proteins. Lactiplantibacillus plantarum is a widespread Gram-positive bacterium with probiotic claims and vast potential for agro-food, biotechnological and biomedical applications. L. plantarum possesses a family of three sHSP, which were previously demonstrated to be involved in its stress tolerance mechanisms. Here, the three L. plantarum sHSP were heterologously expressed, purified and shown to have a chaperone activity in vitro, measuring their capacity to suppress protein aggregation, as assayed spectrophotometrically by light scattering. Their anti-aggregative capacity was found to be differently influenced by pH. Differences were also found relative to their holdase function and their capacity to modulate liposome membrane fluidity, suggesting interplays between them and indicating diversified activities. This is the first study assessing the chaperone action of sHSP from a probiotic model. The different roles of the three sHSP can increase L. plantarum's capabilities to survive the various types of stress characterising the diverse habitats of this highly adaptable species. Reported evidence supports the interest in L. plantarum as one of the model species for bacteria that have three different sHSP-encoding genes in their genomes.

Weissella cibaria riboflavin-overproducing and dextran-producing strains useful for the development of functional bread

This work describes a method for deriving riboflavin overproducing strains of Weissella cibaria by exposing three strains (BAL3C-5, BAL3C-7, and BAL3C-22) isolated from dough to increasing concentrations of roseoflavin. By this procedure, we selected one mutant overproducing strain from each parental strain (BAL3C-5 B2, BAL3C-7 B2, and BAL3C-22 B2, respectively). Quantification of dextran and riboflavin produced by the parental and mutant strains in a defined medium lacking riboflavin and polysaccharides confirmed that riboflavin was only overproduced by the mutant strains, whereas dextran production was similar in both mutant and parental strains. The molecular basis of the riboflavin overproduction by the mutants was determined by nucleotide sequencing of their rib operons, which encode the enzymes of the riboflavin biosynthetic pathway. We detected a unique mutation in each of the overproducing strains. These mutations, which map in the sensor domain (aptamer) of a regulatory element (the so-called FMN riboswitch) present in the 5' untranslated region of the rib operon mRNA, appear to be responsible for the riboflavin-overproducing phenotype of the BAL3C-5 B2, BAL3C-7 B2, and BAL3C-22 B2 mutant strains. Furthermore, the molecular basis of dextran production by the six W. cibaria strains has been characterized by (i) the sequencing of their dsr genes encoding dextransucrases, which synthesize dextran using sucrose as substrate, and (ii) the detection of active Dsr proteins by zymograms. Finally, the parental and mutant strains were analyzed for in situ production of riboflavin and dextran during experimental bread making. The results indicate that the mutant strains were able to produce experimental wheat breads biofortified with both riboflavin and dextran and, therefore, may be useful for the manufacture of functional commercial breads.

Functionalization of soy residue (okara) by enzymatic hydrolysis and LAB fermentation for B2 bio-enrichment and improved in vitro digestion

The utilization of major edible soy-waste (okara) remains a challenge due to its poor digestion, nutritional imbalance (lack of B-vitamins), and undesirable off-flavors. Herein, fresh okara was enzymatically hydrolyzed and then fermented using the B2-overproducing Lactiplantibacillus plantarum UFG169 strain. SEM micrographs showed the microporous and honeycombed structures on the surface of okara. The off-flavors were reduced, and the essential amino acids content was significantly increased in fermented okara. The higher β-glucosidase activity, increased aglycone isoflavones, and in situ riboflavin (B2) were associated with the enhanced antioxidant potential of the fermented okara. The in vitro digestion of okara resulted in reduced particle size, higher protein digestibility, improved aggregation, lower protein molecular chains, and increased polyphenols. Overall, our study indicated the improved nutrition and digestibility of B2 bio-enriched okara.

m6A modification regulates early human cardiomyocyte lineage specification

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 813716.

Background

RNA modifications affect gene expression through the regulation of RNA metabolism. N6-methyladenosine (m6A) is the most abundant post-transcriptional modification that occurs in RNAs. Its dynamic expression is regulated by the "writer complex" (methyltransferases) and "erasers" (demethylases) and affects numerous biological functions, including mammalian embryonic stem cell (ESC) fate specification. However, the role of m6A in human cardiomyocyte (CM) lineage specification remains unclear.

Purpose

In this study, we aim to investigate the impact of m6A modification on early human cardiomyocyte differentiation, following the dynamic expression of m6A modification of human induced pluripotent stem cells (hiPSC) into cardiomyocytes (hiPSC-CMs).

Methods

hiPSCs were differentiated into hiPSC-CMs by mesodermal induction, followed by inhibition of WNT-signaling.  We collected hiPSC derivates at different stages of the differentiation protocol: hiPSCs, hiPSC-derived cardiac mesoderm cells, hiPSC-derived cardiomyocyte progenitors (hiPSC-CPCs), and mature hiPSC-CMs. Protein levels of m6A key regulators were analyzed. To systematically profile the expression of m6A modification, we subjected hiPSC derivates to m6A immunoprecipitation combined with deep sequencing (MeRIP-seq) and RNA-seq. Enrichment analyses of gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) pathway analyses were conducted to elucidate the biological significance of differentially expressed and methylated genes.

Results

m6A distribution analysis on hiPSC derivates revealed a conserved pattern on a transcriptome-wide level: methylation sites are mainly located nearby the stop coding regions. However, we observed upregulated levels of writer proteins during the transition of hiPSC-derived cardiac mesoderm cells into hiPSC-CPCs. Interestingly, the dynamic changes in writer protein levels toward hiPSC-CPC transition were accompanied by a higher number of significantly upregulated and hyper-methylated mRNA transcripts. GO and KEGG analyses indicated hyper-methylated upregulated transcripts are enriched in muscle cell differentiation, cardiac physiology and calcium and MAPK signaling pathways regulating heart contraction.

Conclusion

For the first time, our study provides evidence that m6A modification is a mediator of early human cardiomyocyte differentiation. The role of specific writer regulators and individual m6A transcripts will be further investigated.

A single change in the aptamer of the Lactiplantibacillus plantarum rib operon riboswitch severely impairs its regulatory activity and leads to a vitamin B2 - overproducing phenotype

Manufacturing of probiotics and functional foods using lactic acid bacteria (LAB) that overproduce vitamin B2 has gained growing interest due to ariboflavinosis problems affecting populations of both developing and affluent countries. Two isogenic Lactiplantibacillus plantarum strains, namely a riboflavin-producing parental strain (UFG9) and a roseoflavin-resistant strain (B2) that carries a mutation in the FMN-aptamer of the potential rib operon riboswitch, were analysed for production and intra- and extracellular accumulation of flavins, as well as for regulation of the rib operon expression. Strain B2 accumulated in the medium one of the highest levels of riboflavin+FMN ever reported for LAB, exceeding by ~ 25 times those accumulated by UFG9. Inside the cells, concentration of FAD was similar in both strains, while that of riboflavin+FMN was ~ 8-fold higher in B2. Mutation B2 could decrease the stability of the aptamer's regulatory P1 helix even in the presence of the effector, thus promoting the antiterminator structure of the riboswitch ON state. Although the B2-mutant riboswitch showed an impaired regulatory activity, it retained partial functionality being still sensitive to the effector. The extraordinary capacity of strain B2 to produce riboflavin, together with its metabolic versatility and probiotic properties, can be exploited for manufacturing multifunctional foods.

Recurrent aphthous stomatitis (RAS): guideline for differential diagnosis and management

AIM

Recurrent aphthous stomatitis (RAS) is a painful and common ulcerative form that can pose a diagnostic challenge. In fact, similar oral ulcers can appear secondary to a variety of well-defined pathological conditions. Thus, the purpose of this work was to update the current knowledge about RAS METHODS: A narrative review is presented aiming to clarify the extensive differential diagnosis of RAS and its management.

CONCLUSION

As a first aid in relieving the pain, topical applications of corticosteroids, antibiotics, and analgesics are highly recommended, while systemic therapy of RAS should be used in the case of multiple painful ulcerations compromising the quality of life of the patient. Also, natural anti-inflammatory substances from medicinal herbs, in the form of essential oils and extracts are promising agents in the management of RAS.

Validation of a Standard Protocol to Assess the Fermentative and Chemical Properties of Saccharomyces cerevisiae Wine Strains

This paper reports on a common experiment performed by 17 Research Units of the Italian Group of Microbiology of Vine and Wine (GMVV), which belongs to the Scientific Society SIMTREA, with the aim to validate a protocol for the characterization of wine strains of Saccharomyces cerevisiae. For this purpose, two commercial S. cerevisiae strains (EC 1118 and AWRI796) were used to carry out inter-laboratory-scale comparative fermentations using both synthetic medium and grape musts and applying the same protocol to obtain reproducible, replicable, and statistically valid results. Ethanol yield, production of acetic acid, glycerol, higher alcohols, and other volatile compounds were assessed. Moreover, the Fourier transform infrared spectroscopy was also applied to define the metabolomic fingerprint of yeast cells from each experimental trial. Data were standardized as unit of compounds or yield per gram of sugar (glucose and fructose) consumed throughout fermentation, and analyzed through parametric and non-parametric tests, and multivariate approaches (cluster analysis, two-way joining, and principal component analysis). The results of experiments carried out by using synthetic must showed that it was possible to gain comparable results from three different laboratories by using the same strains. Then, the use of the standardized protocol on different grape musts allowed pointing out the goodness and the reproducibility of the method; it showed the main traits of the two yeast strains and allowed reducing variability amongst independent batches (biological replicates) to acceptable levels. In conclusion, the findings of this collaborative study contributed to the validation of a protocol in a specific synthetic medium and in grape must and showed how data should be treated to gain reproducible and robust results, which could allow direct comparison of the experimental data obtained during the characterization of wine yeasts carried out by different research laboratories.

Comprehensive non-invasive and invasive functional assessment of anomalous coronary arteries with anatomical high-risk features

Background

Anomalous aortic origin of a coronary artery (AAOCA) is a rare congenital disease associated with an increased risk of myocardial ischemia. In AAOCA, the occurrence of ischemia is based on the extent of a fixed and a dynamic component, each attributed to different anatomical high-risk features (i.e., acute take-off angle, slit-like ostium, proximal narrowing, elliptic vessel shape and intramural course). Coronary computed tomography angiography (CCTA) is the primary non-invasive imaging method to depict the presence and quantitatively assess anatomical high-risk features while invasive physiologic evaluation under maximal dobutamine-volume challenge is the gold standard to unravel the hemodynamic relevance of AAOCA.

Methods

We included all consecutive AAOCA patients with anatomical high-risk features from our prospective, open-label registry. The objective is to quantify anatomical high-risk features in the CCTA and to measure hemodynamic relevance using invasive fractional flow reserve with maximal dobutamine-volume challenge (gradually increasing dose of dobutamine max. 40 μg/kg per body weight/min, max. 3000 mL ringer lactate and max. 1mg atropine). Pathological invasive FFR was defined as FFR Dobutamine<0.80. Additionally, CCTA-data were processed to assess computational fluid dynamics (CT FFR) and intravascular ultrasound (IVUS) was used to determine minimal lumen area (MLA) during baseline and maximal stress conditions.

Results

A total of 11 patients were included between 05/19 and 11/2020. Mean age was 59±13 years (range: 40–79), 10 patients showed a right-AAOCA and one patient showed a single right coronary artery. All patients had either one (i.e., in 1 patient) or more than one anatomical-high risk features (i.e., in 10 patients). Mean invasive FFR Dobutamine was 0.88±0.07 with n=2 (18%) being pathological. Mean non-invasive CT FFR was 0.89±0.04 (FFR<0.80; n=0), mean invasive FFR Adenosine was 0.92±0.06 (FFR<0.80; n=1; 9%). There was a significant decrease in IVUS MLA between rest (7.93±2.79mm2) and under dobutamine-volume challenge (6.57±3.20mm2, p=0.008). Mean percentage of MLA reduction was 19±18%.

Conclusion

Our preliminary results provide evidence that relevant myocardial ischemia seems to be often absent in a middle-aged population with AAOCA and anatomical high-risk features. However, in a minority of cases hemodynamic relevance could be depicted, especially when stressing with dobutamine-volume challenge. The presence of a dynamic component in AAOCA is represented by the reduced minimal lumen area under stress conditions. Comprehensive diagnostic evaluation should be performed to prevent unnecessary guideline recommended open-heart surgery in a middle-aged population with AAOCA.

Funding Acknowledgement

Type of funding sources: None.

Screening of Lactic Acid Bacteria for the Bio-Control of Botrytis cinerea and the Potential of Lactiplantibacillus plantarum for Eco-Friendly Preservation of Fresh-Cut Kiwifruit

Botrytis cinerea, responsible for grey mold, represents the first biological cause of fruit and vegetable spoilage phenomena in post-harvest. Kiwifruit is a climacteric fruit particularly prone to this mold infestation during storage. Lactic acid bacteria (LAB) are food-grade bacteria that can synthesize several metabolites with antimicrobial activity and are, therefore, suggested as promising and eco-friendly resources for the bio-control of molds on fruits and vegetables. In this work, we propose the screening of a collection of 300 LAB previously isolated from traditional sourdoughs for their ability to counteract in vitro the growth of Botrytis cinerea CECT 20973. Only 2% of tested LAB strains belonging to Lactiplantibacillus plantarum species, exerted a strong antagonism against B. cinerea. The cell-free supernatants were partially characterized and results clearly indicated that high levels of lactic acid contributed to the antagonistic activity. PAN01 and UFG 121 cell-free supernatants were investigated as potential bio-control agents in a preliminary in vivo assay using freshly cut kiwifruits as a food model. The application of cell-free supernatants allowed to delay the growth of B. cinerea on artificially contaminated kiwifruits until two weeks. The antagonistic activity was greatly affected by the storage temperature (25 °C and 4 °C) selected for the processed fruits, suggesting the importance to include microbial-based solution in a broader framework of hurdle technologies.

Non-Saccharomyces Commercial Starter Cultures: Scientific Trends, Recent Patents and Innovation in the Wine Sector

For 15 years, non-Saccharomyces starter cultures represent a new interesting segment in the dynamic field of multinationals and national companies that develop and sell microbial-based biotechnological solutions for the wine sector. Although the diversity and the properties of non- Saccharomyces species/strains have been recently fully reviewed, less attention has been deserved to the commercial starter cultures in term of scientific findings, patents, and their innovative applications. Considering the potential reservoir of biotechnological innovation, these issues represent an underestimated possible driver of coordination and harmonization of research and development activities in the field of wine microbiology. After a wide survey, we encompassed 26 different commercial yeasts starter cultures formulated in combination with at least one non-Saccharomyces strain. The most recent scientific advances have been explored delving into the oenological significance of these commercial starter cultures. Finally, we propose an examination of patent literature for the main yeasts species commercialised in non-Saccharomyces based products. We highlight the presence of asymmetries among scientific findings and the number of patents concerning non-Saccharomyces-based commercial products for oenological purposes. Further investigations on these microbial resources might open new perspectives and stimulate attractive innovations in the field of wine-making biotechnologies.

Microbial-based Biocontrol Solutions for Fruits and Vegetables: Recent Insight, Patents, and Innovative Trends

BACKGROUND

Fruits and vegetables are susceptible to colonisation by undesired microflora, which, in pre- and post-harvest conditions, negatively impact the quality of these products, leading to a reduction of yield, shelf-life, and marketability. In the few last years, the use of microbial Biological Control Agents (BCAs) has assumed international relevance in order to control harmful microorganisms, as a promising alternative to chemical interventions.

OBJECTIVE

The purpose of this review is to discuss the microbial-based solutions applicable for the biocontrol of the main microbial spoilers, phytopathogens, and human food-borne pathogens affecting fruits and vegetables during their production and storage.

RESULTS

A comprehensive overview of the scientific literature investigating the effectiveness of BCA-based products available on the market is provided, as well as of the most recent patents protecting biotechnological applications in this field. Innovative trends are discussed, with a particular focus on the integration of BCAs to minimise spoilage phenomena and microbiological risks adopting combined approaches.

CONCLUSION

This study underlines the growing interest about biocontrol strategies to counteract the growth of spoilage and/or pathogenic microorganisms indicating that in the next years a considerable increase of commercial products and patents will be developed worldwide to exploit innovative biotechnological solutions in the sector.