Three new tetronate-class polyketides, nomimicins B, C, and D, along with nomimicin, hereafter named nomimicin A, were isolated from the culture extract of Actinomadura sp. AKA43 collected from floating particles in the deep-sea water of Sagami Bay, Japan. The structures of nomimicins B, C, and D were elucidated through the interpretation of NMR and MS analytical data, and the absolute configuration was determined by combination of NOESY/ROESY and ECD analyses. Nomimicins B, C, and D showed antimicrobial activity against Gram-positive bacteria, Kocuria rhizophila and Bacillus subtilis, with MIC values in the range of 6.5 to 12.5 μg/mL. Nomimicins B and C also displayed cytotoxicity against P388 murine leukemia cells with IC₅₀ values of 33 and 89 μM, respectively.

Colon cancer (CC) remains a leading cause of cancer-related mortality worldwide, with multidrug resistance (MDR) presenting a formidable barrier to successful chemotherapy. Ferroptosis—an iron-dependent, lipid peroxidation-driven form of cell death—offers a novel therapeutic avenue to bypass MDR by exploiting metabolic vulnerabilities distinct from traditional apoptosis pathways. Emerging evidence reveals a dynamic interplay between MDR and ferroptosis: MDR cancer cells suppress ferroptosis through NRF2/GPX4-mediated antioxidant upregulation, iron sequestration by ferritin, and lipid metabolism reprogramming, including SREBP1-driven monounsaturated fatty acid accumulation, while ABC transporters actively efflux ferroptosis inducers. On the other hand, ferroptosis inducers such as erastin and RSL3 have the potential to overcome apoptotic resistance and avoid efflux pathways, which recover therapeutic efficacy. This review first describes the primary mechanisms of chemotherapy resistance in colon cancer and then explains the molecular processes that prevent ferroptosis in resistant cells. We also review recent data on the complex interactions between resistance to chemotherapy and ferroptosis, and outline approaches that may stimulate iron accumulation to reverse MDR. By emphasizing novel methods to induce ferroptosis, this review highlights that this approach is a promising strategy to overcome chemotherapy resistance in colon cancer and will facilitate the development of more precise and efficient treatment.

Microorganisms serve as a vital source of natural anticancer agents, with many of their secondary metabolites already employed in clinical oncology. In recent years, salt-adapted microbes, including halophilic and halotolerant species from marine, salt lake, and other high-salinity environments, have gained significant attention. Their unique adaptation mechanisms and diverse secondary metabolites offer promising potential for novel anticancer drug discovery. This review consolidated two decades of research alongside current global cancer statistics to evaluate the therapeutic potential of salt-adapted microorganisms. Halophilic and halotolerant species demonstrate significant promise, with their bioactive metabolites exhibiting potent inhibitory effects against major cancer cell lines, particularly in lung and breast cancer. Evidence reveals structurally unique secondary metabolites displaying enhanced cytotoxicity compared to conventional anticancer drugs. Collectively, salt-adapted microorganisms represent an underexplored yet high-value resource for novel anticancer agents, offering potential solutions to chemotherapy resistance and treatment-related toxicity.

Maize, one of the most widely cultivated crops globally, is highly susceptible to mycotoxin contamination. In this study, an endophytic strain Pseudomonas sp. HP-1, isolated from Peganum harmala L., demonstrated significant biocontrol potential. The culture extract of Pseudomonas sp. HP-1 (PHE) exhibited strong antifungal activity, with inhibition zones of 40.07 ± 0.21 mm against Penicillium italicum, 29.71 ± 0.25 mm against Aspergillus niger, and 23.10 ± 0.44 mm against A. flavus, along with notable antibacterial activity against Staphylococcus aureus (22.43 ± 0.55 mm). At a concentration of 16 mg/mL, PHE almost completely inhibited the mycelial growth of A. flavus. The antifungal mechanism of PHE was investigated through scanning electron microscopy (SEM) and propidium iodide (PI) staining analysis, which demonstrated that antifungal activity is primarily through the disruption of cellular membrane integrity. Furthermore, PHE significantly reduced the incidence of A. flavus contamination in agroecological maize seeds during storage, and treated PHE showed superior antifungal efficacy compared to non-treated PHE, highlighting its potential as an effective antifungal agent for seed protection. Through one- and two-dimensional NMR and MS analyses, the primary active compound of PHE was identified as 1-phenazinecarboxylic acid. These findings indicate that PHE can be utilized as a sustainable antifungal agent for protecting maize seeds against mycotoxin-producing fungi.

Microbial detoxification, as an environmentally friendly strategy, has been widely applied for benzo[a]pyrene (BaP) degradation. Within this approach, food-derived microbial strains offer unique advantages in safety, specificity, and sustainability for detoxifying food-borne BaP. In this study, we aimed to explore the potential of such strains in BaP degradation. Bacillus mojavensis TC-5, a strain that degrades BaP, was isolated from kefir grains. Surprisingly, 12 genes encoding dehydrogenases, synthases, and oxygenases, including betB, fabHB, qdoI, cdoA, and bioI, which are related to BaP degradation, were up-regulated by 2.01-fold to 4.52-fold in TC-5. Two potential degradation pathways were deduced. In pathway I, dioxygenase, betaine aldehyde dehydrogenase, and beta-ketoacyl-ACP synthase III FabHB act sequentially on BaP to form 4H-pyran-4-one,2,3-dihydro-3,5-dihydroxy-6-methyl via the phthalic acid pathway. In the presence of the cytochrome P450 enzyme, BaP progressively mediates ring cleavage via the anthracene pathway, eventually forming 3-methyl-5-propylnonane in pathway II. Notably, TC-5 achieved an impressive BaP removal efficiency of up to 63.94%, with a degradation efficiency of 32.89%. These results suggest that TC-5 has significant potential for application in addressing food-borne BaP contamination. Moreover, our findings expand the application possibilities of Xinjiang fermented milk products and add to the available green strategies for BaP degradation in food systems.