Morphological transformations in primitive organisms have long been observed; however, its biomechanical roles are largely unexplored. In this study, we investigate the structural advantages of dimorphism in Arthrospira platensis, a filamentous multicellular cyanobacterium. We report that helical trichomes, the default shape, have a higher persistence length (L_p), indicating a higher resistance to bending or a large value of flexural rigidity (k_f), the product of the local cell stiffness (E) and the moment of inertia of the trichomes’ cross-section (I). Through Atomic Force Microscopy (AFM), we determined that the E of straight and helical trichomes were the same. In contrast, our computational model shows that I is greatly dependent on helical radii, implying that trichome morphology is the major contributor to k_f variation. According to our estimation, increasing the helical radii alone can increase k_f by 2 orders of magnitude. We also observe that straight trichomes have improved gliding ability, due to its structure and lower k_f. Our study shows that dimorphism provides mechanical adjustability to the organism and may allow it to thrive in different environmental conditions. The higher k_f provides helical trichomes a better nutrient uptake through advection in aquatic environments. On the other hand, the lower k_f improves the gliding ability of straight trichomes in aquatic environments, enabling it to chemotactically relocate to more favorable territories when it encounters certain environmental stresses. When more optimal conditions are encountered, straight trichomes can revert to their original helical form. Our study is one of the first to highlight the biomechanical role of an overall-shape transformation in cyanobacteria.

Synthetic culture media, such as Zarrouk’s medium (ZM), are widely used in industrial Arthrospira cultivation but rely heavily on chemical fertilizers, raising concerns over cost and environmental impact. In natural habitats where Arthrospira blooms, the macronutrient concentrations are much lower than those provided by synthetic media. We hypothesized that natural growth may be facilitated by a microbial consortium. To test this, we developed a lab-scale Arthrospira platensis H53 cultivation system using a newly developed organic compost medium (OCM), designed to mimic the natural nutrient composition and microbial interactions. Compared to ZM, A. platensis H53 grown in OCM exhibited elevated growth by day 7. The specific growth rate in OCM was 0.20 day⁻¹, higher than that of 0.17 day⁻¹ in ZM, with optical density values reaching 1.57, compared to 1.13 in ZM. A 1.63-fold increase in biomass was observed in OCM, despite lower initial macronutrient concentrations. Nutrient use efficiency (NUE) in OCM was significantly improved, with nitrate (NO₃⁻) and phosphate (PO₄³⁻) utilization up to 5.8-fold higher. Additionally, A. platensis H53 filaments in OCM were more tightly coiled, indicating a physiological change in response to lowered macronutrient concentrations. Microbial composition analysis using 16S rRNA gene amplicon sequencing revealed the presence of growth-promoting bacteria, including Pontibacter spp., Brevundimonas spp., and Aliihoeflea spp., likely contributing to nutrient cycling and enhanced growth. These findings suggest potential symbiotic interactions between cyanobacteria and non-cyanobacteria in the OCM system, promoting increased growth and productivity. This study is the first to propose such symbiosis in an extremely alkalophilic environment, offering another sustainable alternative to traditional chemical-based Arthrospira cultivation methods.

Arthrospira platensis (Spirulina) has been recognized for its diverse benefits to human health. Currently, stress and sleep disorders are prevalent and increasing annually worldwide. This study aimed to conduct a randomized controlled trial to assess the effects of Spirulina on sleep quality, mental health status, and body mass index (BMI) measurements in adults with mild to moderately severe depression. Sixty‐six participants with mild to moderately severe depression were randomly assigned to receive either 2 g/day of Spirulina (two 1000 mg capsules) (n = 33) or a placebo (n = 33) for 8 weeks. Assessments conducted at baseline, week 4, and the end of the intervention included General Interview Questionnaires (GIQ), BMI, pulse and blood pressure measurements, the Depression Anxiety Stress Scales (DASS‐21), the Pittsburgh Sleep Quality Index (PSQI), and the Sleep Hygiene Index (SHI). Sixty‐three participants completed the trial. Adherence to supplementation was high, with two participants in the Spirulina group reporting missed doses for one day and 3 days, respectively. Out of 66 participants, three from the control group dropped out by the end of the study. Analysis using repeated measures ANOVA revealed a significant difference in PSQI scores in the experimental group from baseline to 8 weeks, with the mean score decreasing from 7.03 ± 3.52 to 4.97 ± 1.98. The control group's mean score decreased from baseline to week 4, followed by a slight increase by week 8. Comparing the experimental and control groups at week 8, the mean PSQI scores differed significantly, with 4.97 ± 1.98 and 6.73 ± 2.69 (95% CI [−2.945, −0.582], p = 0.004). Significant differences were found in sleep quality and sleep latency between the groups, with scores of 0.82 ± 0.58 and 1.33 ± 0.61 (95% CI [−0.815, −0.215], p = 0.001) and 0.79 ± 0.70 and 1.33 ± 0.71 (95% CI [−0.900, −0.191], p = 0.003), respectively. Both groups showed statistically significant decreases in DASS‐21 scores. The experimental group exhibited gradual reductions across all assessments (19.27 ± 13.09, 14.24 ± 10.13, 11.58 ± 8.19) at p < 0.05. Conversely, the control group saw an increase in mean scores by week 8 (15.43 ± 9.18, 12.57 ± 9.83, 12.63 ± 10.50). BMI indices and blood pressure exhibited no statistically significant changes (p > 0.05). Sleep quality, sleep latency, and mental health improved after Arthrospira platensis daily softgel supplementation. Further clinical studies, potentially conducted over extended periods, could provide additional support for the trends observed in this study.

Genetically-modified monoclonal cell lines are currently used for monoclonal antibody (mAbs) production and drug development. The isolation of single transformed cells is the main hindrance in the generation of monoclonal lines. Although the conventional limiting dilution method is time-consuming, laborious, and skill-intensive, high-end approaches such as fluorescence-activated cell sorting (FACS) are less accessible to general laboratories. Here, we report a bench-top approach for isolating single Chinese hamster ovary (CHO) cells using an adapted version of a simple microwell-based microfluidic (MBM) device previously reported by our group. After loading the cell suspension to the device, the electrostatically trapped cells can be viewed under a microscope and transferred using a micropipette for further clone establishment. Compared to the conventional method, the invented approach provided a 4.7-fold increase in the number of single cells isolated per round of cell loading and demonstrated a 1.9-fold decrease in total performing time. Additionally, the percentage of correct single-cell identifications was significantly improved, especially in novice testers, suggesting a reduced skill barrier in performing the task. This novel approach could serve as a simple, affordable, efficient, and less skill-intensive alternative to the conventional single-cell isolation for monoclonal cell line establishment.