バイオフィルムは水環境や環境工学プロセスに広く存在するとともに，医療関連感染症の発症や難治化にも深く関与している。その機能発現には，微生物細胞と菌体外マトリクス（extracellular polymeric substances: EPS）からなる三次元構造が重要であるが，分厚いバイオフィルム内部の可視化は従来困難であった。本稿では，バイオフィルムを数秒以内に透明化し，厚みのある試料でも深部まで観察可能な瞬間バイオフィルム透明化法（instantaneous Clearing of Biofilm: iCBiofilm法）を紹介する。

The subseafloor biosphere hosts vast and diverse microbial communities, yet many of its members remain “invisible” because cells are extremely sparse and buried in a geological matrix. This review summarizes methodological advances that enable life detection in low-biomass subseafloor sediments and rocks. We highlight (i) discriminative cell enumeration (SYBR-DiCE), which mitigates non-specific adsorption of DNA dyes to particles; (ii) density-based cell separation and clean handling that increase analytical sensitivity; (iii) single-cell substrate incorporation probing using incubation coupled to NanoSIMS, which revealed high fractions of active and revivable cells in ultraoligotrophic sediments; and (iv) synchrotron micro-CT approaches to visualize pore networks and potential cell distributions, including iodine-bearing ionic liquids with K-edge differential imaging and osmium staining. By integrating quantitative enumeration, single-cell activity, and 3D microstructure, next-generation life detection will better constrain the limits of life and its biogeochemical significance in the deep biosphere.

In medicinal Basidiomycetes fungi, specifically the rare species Phellinus linteus and Fuscoporia obliqua, as well as Ganoderma lucidum and Sparassis crispa, the effects of extracts obtained from both mycelia and fruiting bodies were investigated with respect to fibrinolytic activity and antioxidant activity. The results indicated that ratio of fibrinolytic velocity tended to be higher in the mycelial extracts than in the fruiting body extracts. In particular, Ganoderma lucidum and S. crispa were confirmed to possess remarkably high fibrinolytic activity. On the other hand, antioxidant activity was generally higher in the fruiting body extracts than in the mycelial extracts, with F. obliqua exhibiting especially strong antioxidant capacity, thereby confirming the usefulness of its pharmacological effects. Furthermore, it was revealed that S. crispa retains potent pharmacological activities in both fibrinolytic and antioxidant properties.

Rhodococcus zopfii Y 50158 is a bacterium that can degrade and transform estrone (E1), 17β-estradiol (E2), estriol (E3) and 17α-ethinyl estradiol (EE2) into substances without estrogenic activity. In this study a duckweed holobiont consisting of Y 50158 and Lemna minor, Y/L system, was created. It was demonstrated that a fifty Y/L system in 50 mL culture degraded 5 ppm E2 in two days at 28°C under light illumination. Moreover, E2 degradation activity of Y/L system was sustained for ten days by transferring the Y/L system to new medium four times every two days. The number of Y 50158 cells colonized on one plant body of L. minor was 1.7×10⁵ on day 0 and 2.0×10⁴ on day 10 in CFU, respectively. On the other hand, it was also found that Y 50158 inhibited the growth of L. minor. A duckweed growth-promoting bacterium, Pelomonas saccharophila MRB3 could not co-exist with Y 50158 in the multiple duckweed holobiont YM/L system. Finally, addition of 10 ppm ascorbic acid successfully cancelled the duckweed growth inhibition by strain Y 50158 in Y/L system. These results suggest that the duckweed holobiont Y/L system enables stable light driven estrogen degradation.