Bacterial cellulose (BC), a biopolymer, is synthesized by BC-producing bacteria. Almost all producing strains are classified in the family Acetobacteraceae. In this study, bacterial strain P285 was isolated from contaminated honey wine in a honey factory in northern Thailand. Based on 16S rRNA gene sequence identification, the strain P285 revealed 99.8% identity with Komagataeibacter maltaceti LMG 1529 ^T. K. maltaceti P285 produced the maximum BC production at 20–30 °C and an initial media pH of 9.0. The highest BC production in modified mineral salt medium (MSM) was exhibited when glucose (16%, w/v) and yeast extract (3.2%, w/v) were applied as carbon and nitrogen sources, respectively. When sugarcane (8–16%, w/v) or honey (ratio of honey to water = 1: 4) supplemented with yeast extract was used, the BC production was greater. The characterization of BC synthesized by K. maltaceti P285 was undertaken using scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectrometry. Meanwhile, X-ray diffraction results confirmed the presence of crystalline cellulose (2θ = 18.330, 21.390 and 22.640°). The maximum temperature of BC degradation was observed at 314 °C. Tensile properties analysis of hydrated and dried BC showed breaking strength of 1.49 and 0.66 MPa, respectively. These results demonstrated that K. maltaceti P285 has a high potential for BC production especially when grown in high initial media pH. Therefore, the strain would be suitable as an agent to make BC, the value-added product in the related factories.

This study systematically evaluated Escherichia coli (E. coli) expression systems for the production of a humanized single-chain variable fragment targeting interleukin-17A (hScFv-IL-17A). A wild-type hScFv (hScFv-IL-17A-WT), derived from Secukinumab, was compared with a C97S mutant (hScFv-IL-17A-C97S) in which the unpaired cysteine residue in the light-chain complementarity-determining region 3 (CDR3) was substituted with serine. The primary objectives were to identify an optimal expression system for soluble protein production and to assess the functional consequences of the C97S mutation. Protein solubility, yield, and antigen-binding properties were evaluated across expression on three E. coli strains: Origami B (DE3), SHuffle, and BL21 (DE3) incorporating the DisCoTune system. Analyses were performed using SDS-PAGE, Western blotting, enzyme-linked immunosorbent assay (ELISA), and biolayer interferometry (BLI). Among the systems tested, BL21 (DE3) with DisCoTune yielded the highest levels of soluble expression for both variants. Although the C97S mutation enhanced soluble protein yield in this system, it significantly impaired functional activity. The hScFv-IL-17A-WT exhibited a strong binding affinity (K_D = 3.64 × 10^-8 M), whereas the hScFv-IL-17A-C97S demonstrated an approximately 10-fold reduction in affinity. Competitive ELISA further confirmed that both variants recognized the same epitope as a neutralizing monoclonal antibody. Structural modeling predicted that the C97S substitution imposed a moderate stability penalty without inducing major conformational alterations, consistent with the observed reduction in binding affinity. Collectively, these findings indicate that while the C97S mutation improves soluble expression, it compromises biological activity. The hScFv-IL-17A-WT produced in BL21 (DE3) using the DisCoTune system represents the most promising candidate for subsequent therapeutic development.