The green alga Pleodorina japonica is an interesting volvocine species that harbors abundant rickettsial endosymbionts ("MIDORIKO") within its cytoplasm. However, the diversity and transmission of these endosymbionts within the species remain unclear. In this study, we examined the presence or absence of "MIDORIKO" and the genetic diversity in 21 culture strains of the host P. japonica population from various localities in Japan. Genomic polymerase chain reactions using "MIDORIKO"-specific primers and 4',6-diamidino-2-phenylindole-staining demonstrated that only five of the 21 strains harbored "MIDORIKO." The 16S ribosomal DNA sequences of "MIDORIKO" from these five strains (1148 bp) were identical to each other and distinct from the sequences of the rickettsial endosymbionts harbored by other algal species and protists, suggesting that "MIDORIKO" from P. japonica is specific to P. japonica. The phylogenetic results for the 21 host strains, which were resolved based on three nuclear genes encoding oxygen-evolving enhancer protein 1, F1F0 ATP synthase subunit beta and actin disagreed significantly. None of the three gene phylogenies supported the close relationship of the five "MIDORIKO"-harboring strains. A recombination test using the three concatenated genes provided strong evidence of recombination. Therefore, gene flow by sexual reproduction has likely occurred in the natural habitats of P. japonica. The transmission of "MIDORIKO" among different P. japonica genotypes could also be considered to occur via sexual reproduction, although it is likely infrequent via that method given the sporadic nature of "MIDORIKO" within the P. japonica population. Although P. japonica exhibits homothallic sexual reproduction, the present genetic data demonstrate that it is undoubtedly a biological species.

An oil palm empty fruit bunch (EFB) sample was sequentially treated with ozone, 5 % NaOH, and ozone again under environmentally friendly and mild conditions to prepare cellulose-rich materials from agricultural EFB wastes. The ozonated, 5 % NaOH-treated, and re-ozonated products (O 3 -EFB, Ex-O 3 -EFB, and O 3 -Ex-O 3 -EFB, respectively) were obtained at mass recovery ratios of 83 %, 65 %, and 50 %, respectively, based on the dry mass of the raw EFB. The O 3 -EFB and Ex-O 3 -EFB samples maintained their original stick-like fiber bundle morphologies. In contrast, the O 3 -Ex-O 3 -EFB sample exhibited mostly individualized fibers. The relative glucose unit content increased from 39 % EFB to 79 % in O 3 -Ex-O 3 -EFB after removal of non-cellulosic components. The O 3 -Ex-O 3 -EFB contained a carboxy-group content of 0.37 mmol/g, which could be used as electrostatic adsorption sites of cationic compounds, nanoparticles, and metals by ion-exchange in aqueous systems. Ozonation remarkably depolymerized the cellulose molecules. However, this sample exhibited a broad molar-mass-distribution characteristic of the EFB sample, which are advantageous for better mechanical properties. The solid-state 13 C NMR spectra of the EFB samples showed the removal of acetyl ester groups in hemicelluloses and lignin during sequential treatment. Based on the results obtained in this study, suitable and unique application fields of EFB samples, different from wood chemical pulps, are provided. • Sequential O 3 -5 % NaOH-O 3 treatment increases cellulose content of EFB from 39 to 79 %. • O 3 -Ex-O 3 -treated EFB exhibits mostly individualized fibers by delignification. • O 3 -Ex-O 3 -treated EFB contains a high weak acid-group content of 0.37 mmol/g. • Degree of polymerization drops from ∼2000 for EFB to ∼330 for O 3 -Ex-O 3 -treated EFB. • 13 C NMR spectra show efficient removal of acetyl groups and lignin during treatment.

Membrane distillation crystallization (MDCr) has emerged as a promising technology to produce inorganic crystals from various feed solutions. MDCr leverages the benefits of membrane distillation (MD), including reduced membrane fouling, operation under waste heat or solar energy while facilitating high-purity crystal formation. This study provides a comprehensive operational assessment of MDCr and the governing mechanisms. The investigation emphasized the influence of temperature gradient, membrane characteristics and feed composition on the processes of supersaturation, nucleation and crystal growth. Attention was focused on the formation of the crystals, and the polymorphs' selectivity influenced by process configuration. Practical applications are discussed across inorganic materials, food and pharmaceutical industries, where MDCr shows potential for recovery of functional crystals. Despite promising application, MDCr remains affected by membrane fouling, wetting, and energy demand, which impact fouling, supersaturation and crystal growth dynamics. The role of in-situ monitoring, modelling and process control is identified to ensure reproducibility and scale-up. The findings show that process optimization and coupling of heat and mass transfer promote the formation of tailored crystalline materials from complex feed solutions. However, this process requires standardized methods, real-time analysis and techno-economic assessment to accelerate the MDCr deployment in the current industrial operations. • Mechanistic understanding of supersaturation, nucleation and crystal grow in MDCr. • Systematic evaluation of fouling, wetting and membrane material limiting MDCr's sustainability. • Risk identification of MDCr application linked to fluorinated membrane materials. • Defining the MDCr future research directions including AI-assisted process and smart membranes