Biochar and beneficial microorganisms have gained increasing attention as alternatives for improving soil properties and crop performance under sustainable agricultural systems. Wheat (Triticum aestivum L.), one of the major crops in the Andean region, requires management strategies that enhance productivity while improving soil quality. This study evaluated the effects of biochar from the native high-Andean grass Festuca glyceriantha Pilger, Trichoderma harzianum, and their combination (Trichoderma harzianum immobilized on biochar) on the growth, yield, grain protein, and soil organic carbon (SOC) storage of wheat (Triticum aestivum L.) in Ayacucho, Peru. A 2 × 2 factorial randomized complete block design with four replicates was used (biochar rate: 0.96 t ha−1). Colonization of biochar by Trichoderma harzianum yielded 5 × 108 spores mL−1 in the recovered suspension, supporting its use as a microbial carrier. Both inputs improved root length, plant height, and biomass accumulation, with responses varying across phenological stages. Grain yield exceeded the control (1.86 t ha−1) by 32.26% with biochar (2.46 t ha−1), 17.74% with Trichoderma harzianum (2.19 t ha−1), and 30.11% with both (2.42 t ha−1). The combination did not outperform biochar alone. The significant biochar × Trichoderma harzianum interaction (yield, p = 0.03; grains per spike, p = 0.02) cannot be interpreted as biological antagonism because inoculum dose and delivery method were not equivalent between treatments (two drench applications in T03 vs. a single application of colonized biochar in the sowing furrow in T04), and the significant biochar × Trichoderma harzianum interaction (yield, p = 0.03; grains per spike, p = 0.02) reflected a less-than-additive response. Trichoderma harzianum increased grain protein content (p < 0.01), whereas biochar did not (p = 0.90); thousand-grain weight and chlorophyll content were unaffected. SOC storage did not differ among treatments (p = 0.101; 156.5–228.4 Mg C ha−1), so no carbon sequestration benefit can be concluded after one growing season. Biochar mainly enhanced grain yield, whereas Trichoderma harzianum mainly improved grain protein. These results support applying each input independently according to the agronomic objective, pending multi-season and multi-site validation with equivalent inoculum doses and complete control treatments.
Probiotic bacteria are increasingly being explored as engineering platforms for local production of bioactive proteins, but the outcome may depend on both the recombinant protein and the bacterial strain. Azurin-producing derivatives of Escherichia coli Nissle 1917 (EcN) and E. coli M17 were generated using the same lacUV5-pelB-azu cassette and evaluated in HCT116 colorectal carcinoma cells. Western blotting confirmed azurin production in both strains, predominantly in cell-associated fractions and at lower levels in concentrated culture supernatants. A separately produced recombinant azurin preparation obtained from E. coli NiCo21(DE3) reduced HCT116 cell biomass after 48 h, with an estimated IC50 of 320 µg/mL. In bacterial co-culture, the azurin-producing derivatives showed lower mean SRB-assessed HCT116 biomass than their corresponding wild-type strains, but these differences did not reach statistical significance. In contrast, YO-PRO-1/PI analysis at a bacteria-to-cell ratio of 500 identified a significant overall increase in the total apoptosis-associated fraction in the azurin-producing groups, whereas the necrosis-associated fraction remained low. The overall response was strain-dependent: EcN showed strong baseline inhibitory activity, whereas the lower baseline effect of M17 allowed the azurin-associated contribution to be distinguished more clearly. Thus, both strains supported recombinant azurin production, but the host–cell response was strongly influenced by the bacterial background. These findings highlight strain selection as an important factor in the development and evaluation of engineered probiotic systems for bioactive protein production.
The microbiological safety of eggs has focused largely on screening for pathogenic bacteria and their antimicrobial resistance (AMR). However, with growing awareness of the widespread distribution of antibiotic resistance genes (ARGs) in environmental bacteria, we investigated the presence of ARGs among underexplored non-fastidious culturable bacteria isolated from table eggs. A total of 54 ready-to-use table eggs were purchased from different vendors, and the shell surfaces were sampled for non-fastidious culturable aerobic bacteria. All isolates (n = 66) were identified using a MALDI-TOF MS biotyper. All isolates were tested for phenotypic susceptibility to tetracycline (a low-cost antimicrobial agent known to be used in poultry farms), and whole-genome sequencing was performed only on tetracycline non-susceptible (TNS) isolates (n = 16). The most common egg isolate was Staphylococcus equorum (n = 21), followed by Mammaliicoccus sciuri (n = 7), Psychrobacter pulmonis (n = 4) and Staphylococcus xylosus (n = 4). Within the TNS subset, 81.3% (13/16) carried tet(K), while the remaining isolates carried tet(33), tet(M) or tet(L). Also, in this TNS subset, the next most common co-carried ARGs identified were mph(C) and lnu(A), which encode resistance to macrolides and lincosamides, respectively. Furthermore, seven isolates co-carried qacG, which confers resistance to quaternary ammonium compounds (QACs). Though WGS analysis was restricted only to TNS isolates, the co-occurrence of biocide and antibiotic-resistant determinants highlights the necessity of surveillance of non-pathogenic microorganisms associated with animal food products.
Postbiotic substances produced by beneficial/probiotic strains can modulate host immunity and confer health benefits. This study evaluated immunomodulatory and antiparasitic effects of the postbiotics Enterocin M and Durancin-like, as well as their producing bacteria in mice experimentally infected with Trichinella spiralis. Enterocin M, Durancin-like, Enterococcus faecium CCM8558, and Enterococcus durans ED26E/7 were administered daily to mice, which were challenged with T. spiralis larvae on day 7 of treatment. Enterocin M and E. faecium CCM8558 stimulated splenic T- and B-cell proliferation during 5–11 days post infection (dpi), increased splenic CD3+, CD4+ and CD8+ T cells, reduced CD19+ B cells, and enhanced serum IgG2a antibodies. Enterocin M also modulated IFN-γ production with an increase at 5–11 dpi followed by suppression at 18 and 25 dpi. Durancin-like exerted weaker but measurable immunomodulatory effects than its producing strain, E. durans ED26E/7, which was detected as elevated B-cell proliferation and CD3+ and CD4+ T cells during the intestinal phase, and elevated CD8+ T-cell numbers were accompanied by the suppression of IL-10, TGF-β, and IL-4 during the muscle phase. All treatments exerted significant antiparasitic effects, confirmed by reductions in the intestinal adult worm burden by 16.3–54.5% and muscle larval counts by 22.8–55.8%. E. faecium CCM8558 produced the greatest reductions in both adult (54.5%) and larval (55.8%) counts. Overall, enterocins and their producing strains exhibited combined immunomodulatory and antiparasitic activities, highlighting their potential as complementary biological agents for the control of trichinellosis.
Argan oil production generates large amounts of press cake that remain underexploited despite their potential as a functional ingredient due to their high protein and fiber content. This study aimed to evaluate the effects of solid-state fermentation of argan press cake (APC) for 24 h and 48 h at 30 °C using Pediococcus pentosaceus LUHS183, Pediococcus acidilactici LUHS29, and Lactiplantibacillus plantarum LUHS135. The effects of fermentation were assessed by determining pH, viable counts of lactic acid bacteria (LAB), free amino acid (FAA) profiles, including γ-aminobutyric acid, biogenic amine (BA) concentrations, fatty acid (FA) and volatile compound (VC) profiles. Additionally, antimicrobial activity was evaluated against 15 pathogenic strains. Fermented samples showed LAB growth, lower pH values than the control, and antimicrobial activity against several of the tested strains. FAA profiles varied among the samples. Only two of the eight BA analyzed, namely spermidine and spermine, were detected in all APC samples. Their concentrations in the control were 29.4 ± 2.29 mg/kg and 29.7 ± 3.66 mg/kg, respectively. Unfermented and fermented samples shared the same predominant FA. Overall, the observed biochemical profiles and antimicrobial activity support further investigation of fermented APC as a potential value-added ingredient in food applications.
