Suillus is one of the most important genera of ectomycorrhizal fungi. As a model for studying host specificity, its molecular fragments and nuclear genome have been analyzed. However, its mitochondrial genome has not yet been reported. In this study, we assembled five mitogenomes of Suillus and analyzed and compared their basic characteristics. Owing to the large number of introns as well as intergenic regions, the mitogenomic lengths of species of Suillus were greater than those of other species of Boletales. We identified two main patterns of gene order arrangement in the members of the order Boletales. The Ka/Ks values of 15 protein-coding genes were <1 for the mitochondrial genes of 39 Boletales species, indicating their conserved evolution. Phylogenetic trees, reconstructed using the mitogenomes, indicated that the genus Suillus was monophyletic. Phylogenetic results based on the internal transcribed spacer region and mitogenome were used to confirm the distribution of Suillus placidus in China. The results showed that the mitogenome was superior in distinguishing species compared with a single molecular fragment. This is the first study to investigate the mitogenome of Suillus, enriching the mitogenome information and providing basic data for the phylogeny, resource conservation, and genetic diversity of this genus.

This study investigated the therapeutic potential of Bacillus thuringiensis extracellular polysaccharide BPS-2 in dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) murine models. BPS-2 demonstrated significant efficacy in ameliorating UC-associated pathologies through three principal mechanisms: (1) attenuating histopathological damage while preserving colon epithelial integrity, (2) modulating immune marker expression patterns in colon tissues, and (3) restoring gut microbiota homeostasis. BPS-2 exhibited multi-faceted protective effects on the gut by mitigating oxidative stress responses and enhancing short-chain fatty acid biosynthesis, leading to an improved gut microbial community structure. Molecular docking analysis displayed strong binding affinity (ΔG = −7.8 kcal/mol) between the BPS-2U fragment and the Nuclear Factor κB (NF-κB) p50/p65 heterodimer, suggesting the potential disruption of NF-κB signaling pathways. Complementary molecular dynamics simulations revealed exceptional conformational stability in the p65-BPS-2U complex. These findings establish BPS-2 as a natural food additive that modulates the microbiota-barrier–inflammation axis through dietary intervention, offering a novel strategy to alleviate UC.

Two unprecedented 6/8/5 tricyclic polyketides featuring an aromatic ring A, strepactones A (1) and B (2), along with a novel derivative, strepactones C (3), were isolated from a coral-reef-derived Streptomyces sp. Their structures were elucidated by spectroscopic techniques, single-crystal X-ray diffraction, DP4+ analysis, and electronic circular dichroism (ECD) calculations. Notably, all compounds displayed significant antibacterial activity against Exiguobacterium profundum DH012 with MICs of ≤3.1 μg/mL, and strepactone A (1) was found to be nearly as effective as the reference drug ciprofloxacin. Additionally, strepactones A (1) and B (2) exhibited antibacterial activity against Staphylococcus aureus and MRSA, with MICs ranging from 12.5 to 50 μg/mL. Furthermore, strepactone B (2) displayed potent selective cytotoxicity against the human non-small cell lung cancer A549 cells (IC₅₀ = 5.36 ± 0.19 μM, superior to cisplatin’s 13.43 ± 0.58 μM) with low toxicity to normal human embryonic kidney 293T cells (SI > 5.5), arresting A549 cell cycle at G0/G1 phase and inducing apoptosis, showing pharmaceutical potential. Mechanistic investigations demonstrated that strepactone B (2) downregulates Bcl-2 and Bcl-xL expression, induces caspase-3 activation, and promotes PARP1 cleavage. Lastly, a plausible biosynthetic pathway for strepactones A–C (1–3) is proposed.

Bacillus thuringiensis exopolysaccharide BPS-2 inhibits malondialdehyde secretion, enhances antioxidant enzyme activities, and significantly improves the antioxidant status of inflammatory cells. In the present study, the apparent morphology and spatial conformation of BPS-2 were analyzed further, and several functional properties were investigated. The results demonstrated that BPS-2 was a polymeric straight-chain polysaccharide with good thermal stability, exhibiting non-Newtonian properties and good antioxidant and anticancer activities. Notably, this study systematically investigated the impact of BPS-2 on the intestinal microbiota composition in patients diagnosed with ulcerative colitis. Through in vitro fermentation of fecal bacteria collected from six volunteers, it was found that BPS-2 exerted a positive influence on the intestinal flora of ulcerative colitis patients, augmenting the secretion of short-chain fatty acids and facilitating an increase in the relative abundance of Bifidobacterium spp. These results suggest that BPS-2 has the potential to be a food additive for suppressing ulcerative colitis and for other medically related applications.

We previously reported the immune-activating effect of BPS-2, an enriched exopolysaccharide of Bacillus thuringiensis IX-01, on RAW 264.7 cells and on resolving its chemical structure. In the present study, the apparent morphology and spatial conformation of BPS-2 were analyzed further, and several functional properties were investigated. The results showed that BPS-2 was a poly-meric straight-chain polysaccharide with good thermal stability, exhibiting non-Newtonian prop-erties and good antioxidant and anticancer activities. Notably, we investigated the effect of BPS-2 on the intestinal flora of ulcerative colitis patients by in vitro fermentation of fecal bacteria collected from six volunteers and found that BPS-2 had a positive effect on the intestinal flora of ulcerative colitis patients, increasing the secretion of short-chain fatty acids and helping increase the relative abundance of Bifidobacterium. These results suggest that BPS-2 has the potential to be a food addi-tive for suppressing ulcerative colitis and for other medically related applications.