Lysinibacillus macroides 38352 Isolated from Traditional Chinese Fermented Foods: A Dual Effect on Ochratoxin A Detoxification and Immune Suppression Alleviation

Ochratoxin A (OTA), a nephrotoxic, immunosuppressive, and potentially carcinogenic mycotoxin produced by Aspergillus and Penicillium species, poses a persistent threat to global food safety and livestock health. In this study, we isolated three OTA-degrading bacterial strains from 28 types of traditional Chinese fermented foods. Among them, Lysinibacillus macroides 38352 exhibited the highest degradation efficiency, removing 51.4% of 2.5 μg/mL OTA within 72 hours at 37 °C, with further increases observed over time. Mechanistic analysis revealed that the degradation was mediated not by cell surface adsorption but by secreted metabolites generated through active cellular metabolism. The strain also demonstrated excellent probiotic properties, including tolerance to pH 2–12 and 0.2% bile salts, sensitivity to 15 antibiotics (indicating no resistance), and no pathogenicity in mice. Notably, oral administration of L. macroides 38352 significantly reversed OTA-induced immunosuppression, enhancing vaccine-induced specific IgG, neutralizing antibody titers, and cytokine levels (IL-1β, IL-4, IL-12, IL-17, and IFN-γ), while also reducing inflammatory damage and improving growth performance in OTA-exposed broilers.
Figure 1. Isolation of the OTA-degrading strains. (A) Colony and cell morphology of 38351, 38352 and 38362. (B) Removal ratio of OTA by strains.
Figure 2. Phylogenetic tree of the isolated 38351, 38352 and 38362 and related taxa. (A) Phylogenetic Tree Analysis of Isolates Based on Partial 16S rRNA Gene Sequences. (B) Phylogenetic Tree Analysis of Isolates Based on Partial gyrB Gene Sequences.
Figure 3. Degradation properties of OTA by isolated strains. (A) Growth Curve of Isolated Strain 38352 (B) Degradation rate of OTA by different cell components. OTA Degradation Ability of Strain 38352: Effect of Culture Temperature (C), Effect of Different Cell Concentrations (D), and Effect of Culture Time (E).
Figure 4. Results of body weight change monitoring. (A) Line chart of body weight change before poison attack. (B) Histogram of Body Weight Change after Poisoning.
Figure 5. The level of the specific IgG antibody. (A) Specific IgG antibody level in chicken serum before virus attack. (B) Specific IgG antibody level in serum of broilers after 7 days of virus attack.
Figure 6. Gene transcription of immune related cytokines in jejunum (A) and cecal tonsil (B). Data were presented as means ± SD (*P < 0.05, and **P < 0.01).
Table 1. Drug abbreviations: FFC Florfenicol (30 µg), CZO Cefazoline (30 µg), SH Spectinomycin (100 µg), MNO Minocycline (30 µg), TGC Tigecycline (15 µg), MID Midecamycin (30 µg), LZD Linezolid (30 µg), DOX Doxycycline (30 µg), SM streptomycin (10 µg), DA clindamycin (2 µg), AMP Ampicillin (10 µg), VAN Vancomycin (30 µg), AMX Amoxicillin (20 µg), TOB Tobramycin (10 µg), CIP Ciprofloxacin (5 µg), RFP Rifampicin (5 µg), OX Oxacillin (5 µg), NAL Nalidixic acid (30 µg), FOT Fosfomycin (30 µg), TLC ticarcillin (85 µg)