: Actinomycetes is an abundant resource for discovering a large number of lead compounds, which play an important role in microbial drug discovery. Compared to terrestrial microorganisms, marine actinomycetes have unique metabolic pathways because of their special living environment, which has the potential to produce a variety of bioactive substances. In this paper, secondary metabolites isolated from marine actinomycetes are reviewed (2013-2018), most of which exhibited cytotoxic, antibacterial, and antiviral biological activities.

In this study, computer simulations were performed on ionic solutions containing heavy metal ions Pb(II), Cd(II) and As(III). The situation where these aqueous ions are retained through the sand/graphene oxide column is simulated. The sand/graphene oxide separation column is formed by the aggregation of constructed sand particles and graphene oxide (GO) molecular clusters. The process of ion aqueous solution flowing through the column is investigated and the mobility of each ion is evaluated. The simulation shows that adding GO to the sand can separate the heavy metal ions more effectively. The sequence of the mobility of the simulated heavy metal ions in the column is: As(III)>Cd(II)>Pb(II), which is consistent with the experimental results reported in the literature. We use simulation methods to study the electrostatic interaction between heavy metal ions and GO sheets. It is found that this interaction is an important factor in the separation of sand/GO column.

The development of high-efficiency, stable, and cost-effective adsorbents for fluoride remediation remains a formidable challenge in wastewater treatment. While cerium-based materials are recognized for their strong fluoride affinity, conventional research has predominantly attributed their performance to surface hydroxyl (Ce-OH) ligand exchange or electrostatic attraction, largely overlooking the decisive role of lattice oxygen vacancies (OVs) within the metal oxide framework. In this study, a lattice-induced oxygen vacancy engineering strategy was implemented through controlled Ce doping in magnetite. A series of core–shell Mag-CeFeO composites, featuring a magnetite core and a cerium-iron oxide shell, were synthesized via a facile one-pot hydrothermal route. By incorporating a minimal Ce loading of only 5.27 wt%, significant lattice expansion was triggered, generating abundant OVs as quantitatively verified by XRD Rietveld refinement, EPR, and XPS. The optimized Mag-CeFeO delivered an exceptional fluoride adsorption capacity of 102.57 mg/g - a 4.5-fold enhancement over pristine magnetite (22.8 mg/g) and superior to many reported adsorbents with substantially higher Ce content. Mechanistic investigations reveal a unique synergistic effect: lattice-induced OVs create localized, positively charged defect sites that accelerate electrostatic fluoride capture, while the CeFeO shell facilitates the in-situ mineralization of stable CeF3 nanophases. Furthermore, the robust core-shell architecture ensures outstanding structural durability and reusability, exhibiting minimal Ce leaching (only 8.2%) and over 95% capacity retention after eight NaOH regeneration cycles. This work provides a advance in defect-enhanced water purification and establishes a sustainable, magnetically separable, and rare-earth-efficient strategy for fluoride remediation.