A naturally modified cellulose: Cellulose is the most abundant biopolymer on Earth and an important component of bacterial biofilms. Thongsomboon et al. used solid-state nuclear magnetic resonance spectroscopy to identify a naturally derived, chemically modified cellulose, phosphoethanolamine cellulose (see the Perspective by Galperin and Shalaeva). They went on to identify the genetic basis and molecular signaling involved in introducing this modification in bacteria, which regulates biofilm matrix architecture and function. This discovery has implications for understanding bacterial biofilms and for the generation of new cellulosic materials. Science , this issue p. 334 ; see also p. 276

Sugarcane bagasse and rice straw are major agricultural byproducts often discarded or burned as waste after cultivation, leaving their untapped potential for utilization. In this work, cellulose fibers were extracted from sugarcane bagasse and rice straw using a simple procedure: alkaline treatment with sodium hydroxide, bleaching with sodium hypochlorite, and acid hydrolysis. The obtained cellulosic materials were successfully prepared into milky white and transparent films, of which the transparency slightly decreased with the addition of glycerol. The surface of all the films appeared homogeneous with a random orientation of fibers. The rice-straw (RS) film had a more fragile texture than the sugarcane-bagasse (SBG) film. The FTIR analysis clearly indicated the functional groups of cellulose, as well as glycerol for the films mixed with glycerol. Thermal analysis showed that the native SBG film decomposed at 346 °C, higher than the native RS film (339 °C). The presence of glycerol in the films resulted in slightly lower maximum decomposition temperature (T_d,max) values as well as mechanical properties. Regarding water susceptibility, the RS film had a higher percentage than the native SBG and glycerol-mixed SBG films. The extracted cellulose from both sources could form almost spherical-shaped cellulose particles. Thus, through the simple extraction method, sugarcane bagasse and rice straw could serve as excellent sources of cellulose materials for preparing cellulose films and particles, which would be advantageous to the development of cellulose-based materials.

Poly(L-lactide) (PLLA) is a promising candidate as a bioplastic because of its non-toxicity and biodegradability. However, the low flexibility of PLLA limits its use in many applications. Poly(L-lactide)-b-poly(ethylene glycol)-b-poly(L-lactide) (PLLA-b-PEG-b-PLLA) block copolymer is of interest for bioplastic applications due to its superior flexibility compared to PLLA. The aim of this work is to modify PLLA-b-PEG-b-PLLA using a low-cost calcium carbonate (CaCO₃) filler to improve material properties compared to PLLA/CaCO₃ composites. The addition of CaCO₃ enhanced the crystallinity and thermal stability for the PLLA-b-PEG-b-PLLA matrix but not for the PLLA matrix, as determined by differential scanning calorimetry (DSC), X-ray diffractometry (XRD), and thermogravimetric analysis (TGA). Phase morphology investigation using scanning electron microscopy (SEM) revealed that the interfacial adhesion between PLLA-b-PEG-b-PLLA and CaCO₃ was stronger than between PLLA and CaCO₃. Additionally, tensile testing was carried out to determine the mechanical properties of the composites. With the addition of CaCO₃, the tensile stress and Young’s modulus of the PLLA-b-PEG-b-PLLA matrix were increased, whereas these properties of the PLLA matrix were significantly decreased. Thus, CaCO₃ shows great promise as an inexpensive filler that can induce nucleation and reinforcing effects for PLLA-b-PEG-b-PLLA bioplastics.

Oil contamination in aquatic environments remains a persistent challenge, motivating the development of oil–water separation materials that are efficient, low-cost, and environmentally friendly. In this study, manganese dioxide-modified bacterial cellulose (MBC) was developed and evaluated as a bio-based coating for oil–water separation. Bacterial cellulose (BC) was biosynthesized byKomagataeibacter xylinususing either the conventional Hestrin-Schramm (HS) medium or a cost-effective sucrose-rice flour (SRF) medium, followed by in situ MnO₂ functionalization to produce MBC-HS and MBC-SRF, respectively. Both materials were applied as thin coatings on standard filter papers to minimize BC usage. At a low coating density of 0.14 mg·cm^–2, the MBC-coated filter papers achieved separation efficiencies exceeding 98% for palm olein, diesel oil, and motor oil–water mixtures. Surface wettability and interfacial analysis indicate that MBC coatings promote hydrophilic and underwater oleophobic surface characteristics, which favor water permeation while repelling oil droplets. Importantly, MBC derived from SRF-produced BC exhibited separation performance comparable to that of MBC-HS, demonstrating that reduced-cost BC production does not compromise coating functionality. These results highlight the feasibility of combining low-cost BC production with MnO₂ functionalization to fabricate material-efficient bio-based coatings for oil–water separation.