Eloy Argañaraz-Martínez

Exopolysaccharides (EPSs) produced by lactic acid bacteria have attracted increasing attention as multifunctional biopolymers owing to their structural diversity and technological and biological properties. However, despite the extensive use of Ligilactobacillus salivarius as a probiotic species, particularly in poultry production, its EPS-producing capacity remains poorly characterised. Here, we demonstrate that EPS production constitutes an additional value-added trait of the poultry probiotic strain L. salivarius CRL 2217. Response surface methodology identified 5% sucrose, initial pH 6.5, and 37 °C as optimal conditions, with a maximum crude EPS concentration of 1.40 mg/mL (glucose equivalents). EPS synthesis resulted in extracellular polymer accumulation without affecting wheat germ agglutinin binding. Monosaccharide analysis, GC, GPC-HPLC, FT-IR, Raman spectroscopy, and one- and two-dimensional NMR identified the polymer as a high-molecular-weight dextran (Mw > 1.5 × 10⁶ Da) composed predominantly of α-(1→6)-linked D-glucopyranosyl residues with minor α-(1→3)-associated structural features. The EPS showed high water-holding capacity, water solubility, and stable emulsifying activity, as well as concentration-specific effects on neutral red uptake and nitrite production by RAW 264.7 macrophages, without cytotoxicity. These findings support the notion of dextran production as a distinct functional and biotechnological trait of CRL 2217.

The study provides valuable insights into the sustainable utilization of edible tuber peels from the high mountains of the Argentinian Puna, which constitutes promising reserves of bioactive phenolic compounds with the potential to enhance the biofunctional properties of lactic acid bacteria. Thirty-two extracts derived from peels of different varieties of tubers, such as Oxalis tuberosa Mol., Ullucus tuberosus Caldas, and Solanum tuberosum L. were incorporated into lactobacilli cultures and individually evaluated. These selectively enhance the development of the probiotic strain Lactiplantibacillus plantarum ATCC 10241 and of Lacticaseibacillus paracasei CO1-LVP105 from ovine origin, without promoting the growth of a pathogenic bacteria set (Escherichia coli O157:H12 and ATCC 35218, Salmonella enterica serovar Typhimurium ATCC 14028, and S. corvalis SF2 and S. cerro SF16), in small amounts. To determine the main phenolic group concentrated in the phytoextracts, a bio-guided study was conducted. The most significant results were obtained by O. tuberosa phytochemicals added to the culture medium at 50 µg/mL, yielding promising increases in biofilm formation (78% for Lp. plantarum and 43% for L. paracasei) and biosurfactant activity (112% for CO1-LVP105 strain). These adaptive strategies developed by bacteria possess key biotechnological significance. Furthermore, the bio-detoxification capacity of phenol and o-phenyl phenol, particularly of the novel strain CO1-LVP105, along with its mode of action and genetic identification, is described for the first time to our knowledge. In conclusion, lactobacilli strains have potential as fermentation starters and natural products, recovered from O. tuberosa peels, and added into culture media contribute to multiple bacterial biotechnological applications in both health and the environment.

The study provides valuable insights into the sustainable utilization of edible tuber peels from high-mountain regions, which constitute promising reserves of bioactive phenolic compounds with the potential to enhance the biotechnological properties of lactic acid bacteria. Thirty-two extracts derived from peels of different varieties of tubers, such as Oxalis tuberosa Mol. (Oxalidaceae), Ullucus tuberosus Caldas (Basellaceae) and Solanum tuberosum L. subsp. andigena (Solanaceae) from the Argentinian Puna were incorporated into lactobacilli cultures and individually evaluated. These selectively enhance the development of the probiotic strain Lactiplantibacillus plantarum ATCC 10241 and of Lacticaseibacillus paracasei CO1 from ovine origin, without promoting the growth of pathogenic bacteria when small amounts of each extract are incorporated into the culture media. To determine the main compounds concentrated in the phytoextracts, a bio-guided study was conducted. The most significant results were obtained by O. tuberosa phytochemicals added to the culture medium, yielding promising increases in biofilm formation and biosurfactant activity. These adaptive strategies developed by bacteria possess key biotechnological significance. Furthermore, the bio-detoxification capacity of mutagenic substances, particularly of the novel strain CO1, along with its mode of action and genetic identification are reported for the first time. In conclusion, lactobacilli strains have potential as fermentation starters, and natural product-based culture media contribute to multiple bacterial biotechnological applications in both health and the environment.

The search for sustainable alternatives to antibiotic growth promoters in poultry production has intensified in recent years, driven by global concerns over antimicrobial resistance and consumer demand for safer food systems. Among the probiotic candidates investigated, Bifidobacterium spp. stand out for their well-documented safety, immunomodulatory properties, and ability to enhance gut health. This review provides a comprehensive analysis of the biological roles, delivery strategies, and microencapsulation techniques for Bifidobacterium spp. as probiotics in poultry. Bifidobacteria contribute to poultry health by modulating the gut microbiota, improving intestinal morphology and digestive enzyme activity, and regulating immune responses through cytokine balance and epithelial barrier reinforcement. However, their strict anaerobic metabolism and sensitivity to gastric acid and processing conditions limit their viability during conventional administration. To address these challenges, we examine various administration routes, including oral, in ovo, spray/litter, and cloacal methods, highlighting their practical advantages and constraints. Special attention is given to microencapsulation technologies, such as spray drying, freeze drying, spray chilling, extrusion, and emulsion, which protect bifidobacteria from environmental stress and enhance their delivery to target intestinal sites. By integrating recent advances in biotechnology and delivery systems, this review underscores the potential of Bifidobacterium spp. as functional feed additives in antibiotic-free poultry production. Tailoring encapsulation materials and administration routes to match specific production goals is key to maximizing probiotic efficacy. Continued research on strain performance under commercial conditions will be essential to facilitate their large-scale application in sustainable poultry farming.

This study provides a comprehensive investigation of lactic acid bacteria (LAB) isolated from Argentinean Capsicum annum L. This research covers important aspects, including genotypic characterization, bacterial stress tolerance, adhesion ability, safety evaluation, and functional and technological properties. The predominant isolates were identified as Lactilactobacillus curvatus and Lactiplantibacillus plantarum. A Rep-PCR analysis grouped the isolates into 11 clonal groups. Lp. plantarum LVP 40 and LV 46, Levilactobacillus brevis LVP 41, Pediococcus pentosaceus LV P43, and Lt. curvatus LVP44 displayed both safety and resilience against adverse conditions such as a slow pH, bile, and simulated gastric and intestinal juices. Moreover, the LAB strains exhibited high hydrophobicity and auto-aggregation percentages, NaCl tolerance, and a substantial acidifying capacity. LAB supernatants demonstrated promising surfactant and emulsifying properties. Likewise, they differentially inhibited Staphylococcus aureus and Pseudomonas aeruginosa biofilms, showcasing their potential as antipathogenic agents. Noteworthily, some strains displayed considerable co-aggregation with these pathogens, and several isolates showed an effective antimutagenic and detoxifying power, further emphasizing their multifaceted capabilities. Five pepper bacterial strains showcased beneficial properties, suggesting their potential for gut health enhancement. In summary, these LAB strains hold promise as vegetable fermentation starters, contributing to food safety and versatile applications in food science.

This study provides a comprehensive investigation of lactic acid bacteria (LAB) isolated from Argentinean Capsicum annum L. The research covers important aspects, including genotypic characterization, bacterial stress tolerance, adhesion ability, safety evaluation, and functional and technological properties. The predominant isolates were identified as Lactilactobacillus curvatus and Lactiplantibacillus plantarum. Rep-PCR analysis grouped the isolates into 11 clonal groups. Lp. plantarum LVP 40 and LV 46; Levilactobacillus brevis LVP 41, Pediococcus pentosaseus LV P43, and Lt. curvatus LVP44, displayed both safety and resilience against adverse conditions such a slow pH, bile, and simulated gastric and intestinal juices. Moreover, the LAB strains exhibited high hydrophobicity and auto-aggregation percentages, NaCl tolerance, and substantial acidifying capacity. LAB supernatants demonstrated promising surfactant and emulsifying properties. Likewise, they differentially inhibited Staphylococcus aureus and Pseudomonas aeruginosa biofilms, showcasing their potential as antipathogenic agents. Noteworthy some strains displayed considerable co-aggregation with these pathogens, and several isolates showed an effective antimutagenic and detoxifying power, further emphasizing their multifaceted capabilities. Five pepper bacterial strains showcased probiotic properties, suggesting their potential for gut health enhancement. In summary, these LAB strains hold promise as vegetable fermentation starters, contributing to food safety and versatile applications in food science.

The ban on the use of antibiotics as feed additives for animal growth promotion in the European Union and United States and the expectation of this trend to further expand to other countries in the short term have prompted a surge in probiotic research. Multi-species probiotics including safe and compatible strains with the ability to bind different nutritional lectins with detrimental effects on poultry nutrition could replace antibiotics as feed additives. Lactobacillus salivarius LET201, Lactobacillus reuteri LET210, Enterococcus faecium LET301, Propionibacterium acidipropionici LET103 and Bifidobacterium infantis CRL1395 have proved to be compatible as evaluated through three different approaches: the production and excretion of antimicrobial compounds, growth inhibition by competition for essential nutrients and physical contact, and a combination of both. The safety of P. acidipropionici LET103 was confirmed, since no expression of virulence factors or antibiotic resistance was detected. The innocuity of E. faecium LET301 should be further evaluated, since the presence of genes coding for certain virulence factors (gelE, efaAfm and efaAfs) was observed, albeit no expression of gelE was previously detected for this strain and there are no reports of involvement of efaAfm in animal pathogenicity. Finally, a combination of the five strains effectively protected intestinal epithelial cells of broilers from the cytotoxicity of mixtures of soybean agglutinin, wheat germ agglutinin and concanavalin A. To our knowledge, this is the first time that a combination of strains is evaluated for their protection against lectins that might be simultaneously present in poultry feeds.

Poultry fed on wheat-based diets regularly ingest wheat germ agglutinin (WGA) that has toxic effects in vitro on intestinal epithelial cells (IEC) obtained from 14-d-old broilers. Cytotoxicity and ...