Biotechnology Journal最新文献

Skeletal muscle satellite cells (SCs) are essential for muscle regeneration. Their proliferation and differentiation are influenced by fibroblast growth factor (FGF)-2. In this study, we screened for FGF-2-derived peptides that promote SC proliferation. Utilizing photocleavable peptide array technology, a library of 7-residue peptides was synthesized, and its effect on SC proliferation was examined using a mixture of five peptides. The results showed that peptides 1–5 (136%), 21–25 (136%), 26–30 (141%), 31–35 (159%), 71–75 (135%), 76–80 (144%), and 126–130 (137%) significantly increased SC proliferation. Further experiments revealed that peptide 33, CKNGGFF, enhanced SC proliferation. Furthermore, its extended form, peptide 33-13, CKNGGFFLRIHPD, promoted SC proliferation and increased the percentage of Pax7-positive cells, indicating that SCs were maintained in an undifferentiated state. The addition of FGF-2 and peptide 33-13 further induced cell proliferation but did not increase the percentage of Pax7-positive cells. A proliferation assay using an FGF receptor (FGFR) inhibitor suggested that peptide 33-13 acts through the FGFR-mediated and other pathways. Although further research is necessary to explore the mechanisms of action of these peptides and their potential for in vivo and in vitro use, the high sequence conservation of peptides 33 and 33-13 in FGF-2 across multiple species suggests their broad application prospects in biomedical engineering and biotechnology.

The demand for the essential commodity chemical 1,2-propanediol (1,2-PDO) is on the rise, as its microbial production has emerged as a promising method for a sustainable chemical supply. However, the reliance of 1,2-PDO production in Escherichia coli on anaerobic conditions, as enhancing cell growth to augment precursor availability remains a substantial challenge. This study presents glucose-based aerobic production of 1,2-PDO, with xylose utilization facilitating cell growth. An engineered strain was constructed capable of exclusively producing 1,2-PDO from glucose while utilizing xylose to support cell growth. This was accomplished by deleting the gloA, eno, eda, sdaA, sdaB, and tdcG genes for 1,2-PDO production from glucose and introducing the Weimberg pathway for cell growth using xylose. Enhanced 1,2-PDO production was achieved via yagF overexpression and disruption of the ghrA gene involved in the 1,2-PDO-competing pathway. The resultant strain, PD72, produced 2.48 ± 0.15 g L⁻¹ 1,2-PDO with a 0.27 ± 0.02 g g⁻¹-glucose yield after 72 h cultivation. Overall, this study demonstrates aerobic 1,2-PDO synthesis through the isolation of the 1,2-PDO synthetic pathway from the tricarboxylic acid cycle.

Microalgae are a group of microorganisms containing chlorophyll A, which are highly photosynthetic and rich in nutrients. And they can produce multiple bioactive substances (peptides, proteins, polysaccharides, and fatty acids) for biomedical applications. Despite the unique advantages of microalgae-based biotherapy, the insufficient treatment efficiency limits its further application. With the development of nanotechnology, the combination of microalgae and biomaterials can improve therapeutic efficacies, which has attracted increasing attention. In this microalgal-biomaterials hybrid system, biomaterials with excellent optical and magnetic properties play an important role in biological therapy. Microalgae, as a natural vehicle, can increase oxygen content and alleviate hypoxia in diseased areas, further enhancing therapeutic effects. In this review, the synergistic therapeutic effects of microalgal-biomaterials hybrid system in different diseases (cancer, myocardial infarction, ischemia stroke, chronic infection, and intestinal diseases) are comprehensively summarized.

Scalable single-use adherent cell-based biomanufacturing platforms are essential for unlocking the full potential of cell and gene therapies. The primary objective of this study is to design and develop a novel fixed bed bioreactor platform tailored specifically for scaling up adherent cell culture. The bioreactor comprises a packed bed of vertically stacked woven polyethylene terephthalate mesh discs, sandwiched between two-fluid guide plates. Leveraging computational fluid dynamics modeling, we optimized bioreactor design to achieve uniform flow with minimal shear stress. Residence time distribution measurements demonstrated excellent flow uniformity with plug flow characteristics. Periodic media sampling coupled with offline analysis revealed minimal gradients of crucial metabolites (glucose, glutamine, lactate, and ammonia) across the bioreactor during cell growth. Furthermore, the bioreactor platform demonstrated high performance in automated cell harvesting, with ≈96% efficiency and ≈98% viability. It also exhibited linear scalability in both operational parameters and performance for cell culture and adeno-associated virus vector production. We developed mathematical models based on oxygen uptake rates to accurately predict cell growth curves and estimate biomass in real-time. This study demonstrates the effectiveness of the developed fixed-bed bioreactor platform in enabling scalable adherent cell-based biomanufacturing with high productivity and process control.

In the previous study, the culture medium was treated with nicotinamide adenine dinucleotide (NAD⁺) under the hypothesis that NAD⁺ regeneration is a major factor causing excessive lactate accumulation in Chinese hamster ovary (CHO) cells. The NAD⁺ treatment improved metabolism by not only reducing the Warburg effect but also enhancing oxidative phosphorylation, leading to enhanced antibody production. Building on this, four NAD⁺ precursors – nicotinamide mononucleotide (NMN), nicotinic acid (NA), nicotinamide riboside (NR), and nicotinamide (NAM) – were tested to elevate intracellular NAD+ levels more economically. First, the ability of CHO cells to utilize both the salvage and Preiss-Handler pathways for NAD⁺ biosynthesis was verified, and then the effect of NAD⁺ precursors on CHO cell cultures was evaluated. These precursors increased intracellular NAD⁺ levels by up to 70.6% compared to the non-treated group. Culture analysis confirmed that all the precursors induced metabolic changes and that NMN, NA, and NR improved productivity akin to NAD⁺ treatment, with comparable integral viable cell density. Despite the positive effects such as the increase in the specific productivity and changes in cellular glucose metabolism, none of the precursors surpassed direct NAD⁺ treatment in antibody titer, presumably due to the reduction in nucleoside availability, as evidenced by the decrease in ATP levels in the NAD⁺ precursor-treated groups. These results underscore the complexity of cellular metabolism as well as the necessity for further investigation to optimize NAD⁺ precursor treatment strategies, potentially with the supplementation of nucleoside precursors. Our findings suggest a feasible approach for improving CHO cell culture performances by using NAD⁺ precursors as medium and feed components for the biopharmaceutical production.

Plant-derived β-glucosidases hold promise for glycoside biosynthesis via reverse hydrolysis because of their excellent glucose tolerance and robust stability. However, their poor heterologous expression hinders the development of large-scale production and applications. In this study, we overexpressed apple seed β-glucosidase (ASG II) in Komagataella phaffii and enhanced its production from 289 to 4322 U L⁻¹ through expression cassette engineering and protein engineering. Upon scaling up to a 5-L high cell-density fermentation, the resultant mutant ASG II_V80A achieved a maximum protein concentration and activity in the secreted supernatant of 2.3 g L⁻¹ and 41.4 kU L⁻¹, respectively. The preparative biosynthesis of salidroside by ASG II_V80A exhibited a high space-time yield of 33.1 g L⁻¹ d⁻¹, which is so far the highest level by plant-derived β-glucosidase. Our work addresses the long-standing challenge of the heterologous expression of plant-derived β-glucosidase in microorganisms and presents new avenues for the efficient production of salidroside and other natural glycosides.

Organoids have emerged as valuable tools for the study of development and disease. Assembloids are formed by integrating multiple organoid types to create more complex models. However, the process by which organoids integrate to form assembloids remains unclear and may play an important role in the resulting organoid structure. Here, a microfluidic platform is developed that allows separate culture of distinct organoid types and provides the capacity to partially control the geometry of the resulting organoid surfaces. Removal of a microfabricated barrier then allows the shaped and positioned organoids to interact and form an assembloid. When midbrain and unguided brain organoids were allowed to assemble with a defined spacing between them, axonal projections from midbrain organoids and cell migration out of unguided organoids were observed and quantitatively measured as the two types of organoids fused together. Axonal projection directions were statistically biased toward other midbrain organoids, and unguided organoid surface geometry was found to affect cell invasion. This platform provides a tool to observe cellular interactions between organoid surfaces that are spaced apart in a controlled manner, and may ultimately have value in exploring neuronal migration, axon targeting, and assembloid formation mechanisms.

The cover image is based on the Research Article Unlocking the formate utilization of wild-type Yarrowia lipolytica through adaptive laboratory evolution by Qian Chen et al., https://doi.org/10.1002/biot.202400290.

Enzymes that degrade β-glucan play important roles in various industries, including those related to brewing, animal feed, and health care. Csph16A, an endo-β-1,3(4)-glucanase encoded by a gene from the halotolerant, xerotolerant, and radiotrophic black fungus Cladosporium sphaerospermum, was cloned and expressed in Pichia pastoris. Two isoforms (Csph16A.1 and Csph16A.2) are produced, arising from differential glycosylation. The proteins were predicted to contain a catalytic Lam16A domain, along with a C-terminal domain (CTD) of unknown function which exhibits minimal secondary structure. Employing PCR-mediated gene truncation, the CTD of Csph16A was excised to assess its functional impact on the enzyme and determine potential alterations in biotechnologically relevant characteristics. The truncated mutant, Csph16A-ΔC, exhibited significantly enhanced thermal stability at 50°C, with D-values 14.8 and 23.5 times greater than those of Csph16A.1 and Csph16A.2, respectively. Moreover, Csph16A-ΔC demonstrated a 20%–25% increase in halotolerance at 1.25 and 1.5 M NaCl, respectively, compared to the full-length enzymes. Notably, specific activity against cereal β-glucan, lichenan, and curdlan was increased by up to 238%. This study represents the first characterization of a glucanase from the stress-tolerant fungus C. sphaerospermum and the first report of a halotolerant and engineered endo-β-1,3(4)-glucanase. Additionally, it sheds light on a group of endo-β-1,3(4)-glucanases from Antarctic rock-inhabiting black fungi harboring a Lam16A catalytic domain and a novel CTD of unknown function.