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.

Micro-organisms have showed the ability to produce biologically active compounds associated with neurotransmission in higher organisms. In particular, serotonin- and melatonin-producing microbes are valuable sources for the development of eco-friendly bioproducts. Serotonin and melatonin are indoleamines that have received special attention due to their positive effects on human health. These biomolecules exert a critical role in several physiological or pathological processes, including some mental and neurological disorders. This article includes a review of the microbial production of serotonin and melatonin, their functions in micro-organisms and their potential uses as therapeutic and/or preventive agents to improve human health. A description of the quantification methods employed to detect indoleamines and the evidence found concerning their microbial production at laboratory and industrial scale-for application in biotechnological products-is also provided. The microbial ability to synthesize beneficial indoleamines should be further studied and harnessed, to allow the development of sustainable bioprocesses to produce foods and pharmaceuticals for human health.

In this work, we report the entomopathogenic potential ofAkanthomyces muscariusLY72.14, a fungus isolated from a soil sample collected in the Southernmost sector of Las Yungas (Tucuman, Argentina) subtropical rainforest. The isolated fungus exhibited both pathogenicity and virulence in larvae, pupae and adults of the pestiferous fruit flyAnastrepha fraterculus, ability that could then be applicable for fruit pest biocontrol. Groups of 120 late-third-instar larvae were inoculated by immersion with four different conidial concentrations ofA. muscariusLY 72.14 ranging from 10(5)to 10(8)conidia mL(-1). Mycosis was subsequently verified through different time lapses for larva (1-2 days), pupa (14 days) and adults (13 days). Results revealed adult stage as the most susceptible to fungal infection, with a mortality percentage of 29.4 +/- 3.2%, whilst pupal mortality reached 7.8 +/- 1.2%. On the other hand, larval mortality was similar to the non-infected control (5.9 +/- 1.4%). When 10(8)conidia mL(-1)fungal inocula were used, the total host mortality (involving the three fly developmental stages) reached 53%. Virulence against fly adults was significantly dependent on high conidial concentrations, achieving a LC(50)value of 8.4 x 10(7)conidia mL(-1), with a similar killing effectiveness pattern (43-45%) among 10(7)and 10(8)conidial concentrations. The promising herein demonstrated biocontrol potential ofA. muscariusLY 72.14 to effectively infect and killA. fraterculusunder lab-condition assays, makes relevant to evaluate this native fungal isolate under field-cage and open-field conditions to weight the possibilities for biocontrol massive usage and its tentative application for integrated plague management.

Intensive efforts are being made to find new compounds with antimicrobial activity. The search for these novel bio-products in sparsely explored environments may be the key to providing solutions for many emerging problems. Antarctic environments are valuable locations for bioprospecting. In this study, 63 cold-adapted bacterial strains of 6100 different colony morphotypes were isolated from Antarctic seawater samples around South Shetland and Deception islands. Strains were selected based on cold-active antimicrobial production and were grouped into 11 operational taxonomic units by internal spacer region-PCR and amplified ribosomal DNA restriction analysis. Isolates arbitrarily named 2D, 5D, and 6D were closely related to Halomonas titanicae, with 99.8, 98.9, and 96.7% identity according to 16S rDNA sequencing, and 99.7, 99.3, and 98.3% according to gyrB region sequence analysis, respectively. The isolate 18SH was closely related to Candida sake (99.2%) based on sequence analysis of the ITS1–5.8S rDNA–ITS2 and D1/D2 domain of 26S rDNA. Antimicrobials produced by isolates 2D, 5D, and 6D exhibited a low-molecular weight (< 6000 Da) and stability in wide pH and temperature ranges. When tested against foodborne and phytopathogenic bacteria, selected isolates exhibited a wide spectrum of activity. This work reports the isolation and identification of cold-adapted microorganisms with the ability to produce antimicrobial compounds with potential application in the pharmaceutical or in cold-chain management in the food industry. The current results highlight the potential of the Antarctic environment as a valuable and underexploited source of new antimicrobial molecules with exceptional properties for different biotechnological applications.