In this work, the harvesting of Nannochloropsis oculata microalgae through the use of nanosized Fe₃O₄ immobilized in polyvinyl alcohol (PVA)/sodium alginate (SA) as a flocculant (Fe₃O₄/PS) is investigated. Using the Fe₃O₄/PS immobilized beads could reduce the amount of soluble ferrous ions (Fe²⁺) released from naked Fe₃O₄ in acid treatment, leading to easy recovery. The characterization was performed under different dosages and pH values of Fe₃O₄/PS. The results show that the Fe₃O₄/PS, when applied to the algae culture (500 mg dry cell weight/L), achieves a 96% harvesting efficiency under conditions of a pH of 4 with 200 mT magnetic field intensity. Fe₃O₄/PS can be directly reused without adjusting the pH value. The recycled Fe₃O₄/PS shows stability in terms of its surface properties, maintaining more than 80% harvesting efficiency after five recycles. Magnetophoretic harvesting, using immobilized magnetic iron oxide as a particle-based flocculant, is a potential method to reduce challenges related to the cost-effective microalgae-harvesting method.

The usage time of air-cathode microbial fuel cells (MFCs) is significantly influenced by the moisture content within the proton exchange membrane (PEM). Therefore, enhancing the water retention capability of the PEM by applying a hydrophobic polymer coating to its surface has extended the PEM’s usage time by three times and increased MFCs’ operational duration by 66%. Moreover, the hydrophobic nature of the polymer coating reduces contamination on the PEM and prevents anode liquid from permeating into the air cathode. Towards the end of MFC operation, the internal resistance of the MFC is reduced by 45%. The polymer coating effectively maintained the oxygen reduction reaction activity in the cathode. The polymer coating’s ability to restrict oxygen transmembrane diffusion is demonstrated by experimental data showing a significant decrease in oxygen diffusion coefficient due to its presence. The degradation efficiency of the chemical oxygen demand from 16% to 35% increased by a factor of one.

A novel mesophilic, hydrogenotrophic methanogen, strain CWC-01^T, was isolated from the sediment sample of the piston core collected at station 3 at Good Weather Ridge area offshore southwestern Taiwan from ORI-902A cruise in 2009. Cells of strain CWC-01^T are rod-shaped, measuring 0.4–0.5 µm in width and 1.0–2.0 µm in length. Strain CWC-01^T utilizes formate and H₂/CO₂ to produce methane, but not secondary alcohol, methanol, ethanol, methylamines or acetate as catabolic substrates. The optimal growth conditions are 37 °C, 0.043 M NaCl and pH 6.3. Growth effectors tests indicate tryptone, but not acetate and yeast extract, could stimulate the growth of strain CWC-01. Phylogenetic analysis of 16S rRNA gene reveals that strain CWC-01^T is most closely related to Methanobacterium petrolearium Mic5c12^T, with 96.63% identity. Genome size of strain CWC-01^T is 1.98 Mb and it is the smallest genome size of genus. The genomic DNA G+C content obtained from the genome sequence of strain CWC-01^T is 44.15 mol%. Based on these phenotypic, phylogenetic and genomic analyses, we propose that strain CWC-01^T represents a novel species in genus Methanobacterium, for which the name Methanobacterium aridiramus sp. nov. is proposed. The type strain is CWC-01^T (=BCRC AR10053^T=NBRC 113991^T).

To date, only a few microbial community studies of cold seeps at the South China Sea (SCS) have been reported. The cold seep dominated by tubeworms was discovered at South Yungan East Ridge (SYER) offshore southwestern Taiwan by miniROV. The tubeworms were identified and proposed as Paraescarpia formosa sp. nov. through morphological and phylogenetic analyses. The endosymbionts in the trunk of P. formosa analyzed by a 16S rRNA gene clone library represented only one phylotype, which belonged to the family Sedimenticolaceae in Gammaproteobacteria. In addition, the archaeal and bacterial communities in the habitat of tubeworm P. formosa were investigated by using high-phylogenetic-resolution full-length 16S rRNA gene amplicon sequencing. The results showed that anerobic methane-oxidizing archaea (ANME)-1b was most abundant and ANME-2ab was minor in a consortia of the anerobic oxidation of methane (AOM). The known sulfate-reducing bacteria (SRB) partners in AOM consortia, such as SEEP-SRB1, -SRB2, and -SRB4, Desulfococcus and Desulfobulbus, occurred in a small population (0–5.7%) at the SYER cold seep, and it was suggested that ANME-1b and ANME-2ab might be coupled with multiple SRB in AOM consortia. Besides AOM consortia, various methanogenic archaea, including Bathyarchaeota (Subgroup-8), Methanocellales, Methanomicrobiales, Methanosarcinales, Methanofastidiosales and Methanomassiliicoccales, were identified, and sulfur-oxidizing bacteria Sulfurovum and Sulfurimonas in phylum Epsilonbacteraeota were dominant. This study revealed the first investigation of microbiota in and around tubeworm P. formosa discovered at the SYER cold seep offshore southwestern Taiwan. We could gain insights into the chemosynthetic communities in the deep sea, especially regarding the cold seep ecosystems at the SCS.

We report the complete genome sequence of Anaerotignum sp. strain MB30-C6, which was isolated from the dehydrated sludge collected at the wastewater treatment plant of Sanming Steel Co. Ltd. in Fujian, China. The resulting genome of strain MB30-C6 is a single contig of 3,104,838 bp with 39.49% GC content.