Biotechnology Journal最新文献

Hepatitis C Virus (HCV) is a pervasive bloodborne virus and the leading cause of chronic liver disease and cancer. Thus, the development of an HCV vaccine is of great importance. Prior work has developed candidate vaccines, including more potent glycoengineered viral proteins and secreted forms of the E1E2 envelope heterodimer (sE1E2). However, efforts to express them recombinantly in Chinese hamster ovary (CHO) cells have resulted in very low titers. To address this challenge, here we employed a multi-omics approach to identify protein interactors that may enhance the secretion of an sE1E2 vaccine candidate. We detected protein-protein interactions (PPIs) using the Biotinylation by Antibody Recognition (BAR) assay and integrated these data with RNA-Seq. Through this, we identified and overexpressed proteins that interact with sE1E2 in CHO cells. Among these, CUL4A and YWHAH enhanced sE1E2 secretion in our glycoengineered CHO cells. The integration of omics techniques and genetic engineering in this study provides valuable insights into the host cell proteins that interact with the HCV E1E2 heterodimer, and how they may be harnessed to improve protein secretion in CHO cells to enable more affordable and accessible biotherapeutics.

Nucleotides are indispensable biomolecules, playing vital roles in genetic information transfer, energy metabolism, cofactor biosynthesis, and cellular communication. These compounds (including purine nucleotides, nucleosides, and nucleobases) have become increasingly valuable as foodstuff additives and pharmaceutical intermediates. Although microbial production offers an eco-friendly alternative, its efficiency remains constrained by complex metabolic networks and growth-production tradeoffs. Systems metabolic engineering has emerged as a powerful approach to optimize purine biosynthesis in microorganisms. This review provides a systematic synthesis of recent advances in microbial purine biosynthesis. First, a comprehensive analysis of purine biosynthetic pathways and their regulatory networks in industrial microorganisms are presented, along with a comparative evaluation of current metabolic engineering approaches. Second, systems metabolic engineering strategies for production enhancement are examined, focusing on multi-omics integration, metabolic flux analysis, genome-scale metabolic models, dynamic regulation, and high-throughput screening platforms. Finally, the major challenges confronting efficient microbial production of purine compounds are identified, with proposed strategies to overcome these limitations.

Ramie fiber, an exceptional natural textile material, requires degumming treatment to obtain spinnable mature fibers. Pectate lyase stands as the most effective enzyme for degumming by specifically removing pectin that binds multiple gummy components. However, commercial enzyme cocktails often contain cellulase activities causing significant fiber damage. Furthermore, the high-temperature and strongly alkaline conditions inherent to ramie processing render conventional pectate lyases incompatible with this specialized industrial environment. Consequently, developing thermostable and alkali-tolerant pectate lyases tailored for ramie degumming holds critical importance. This study identified a novel alkali-thermostable pectate lyase (pel114) from Paenibacillus tarimensis and achieved its heterologous expression in Pichia pastoris. Biochemical characterization revealed that pel114 exhibits optimal activity(910 U·mg⁻¹) at 60°C and pH 10.0, while maintaining remarkable stability across a broad pH range (6.0–12.0). Through integrated strategies combining FireProt-predicted stability hotspots, molecular dynamics simulations of flexible regions, and consensus mutation design, we engineered the V467P/A566P double mutant, demonstrating superior thermostability, with a specific activity of 891 U·mg⁻¹ against polygalacturonic acid. The mutant displayed a 65°C half-life of 429.9 min—a 10-fold enhancement over the wild type (WT) (42.9 min). These findings present a promising biocatalyst with substantial potential for advancing enzymatic degumming technologies in ramie processing.

Efficient carbon-sequestering microorganisms are crucial for enhancing soil quality and reducing carbon emissions, particularly in semiarid coal mining areas. In this study, we analyzed the soil carbon-fixing microbial taxa and pathways in the Shendong mining area via high-throughput sequencing, and concluded that their main carbon sequestering pathway is the reduced citrate cycle (rTCA cycle), which has the potential for microbial carbon sequestration. Bacterial strains with high CO₂ sequestration efficiency were isolated and identified, and their potential for improving soil carbon storage and quality was assessed. Through a systematic process of isolation, identification, and functional assessment, three dominant strains, Streptomyces marokkonensis FC1, Streptomyces viridochromogenes FC2, and Dyadobacter endophyticus FC3 with significant CO₂ sequestration capacity were obtained. Their adaptability and carbon fixation efficiency were confirmed through physiological, biochemical, and genetic analyses. The results from indoor ¹³C isotope labeling experiments and 42-day soil improvement experiments demonstrated that CO₂ sequestration and soil improvement effects were achieved in coal mine soils under semiarid conditions. Among the strains, FC2 presented the highest carbon fixation potential and soil improvement efficiency at approximately 8% soil water content. This highlights the potential application of carbon-fixing bacteria in microbial-based strategies for the ecological restoration of degraded mining soils.

Schizochytrium sp., a marine alga prized for docosahexaenoic acid (DHA), was subjected to UV mutagenesis to boost industrial yields. The stable mutant UV1-3 achieved 5.01 g/L DHA—40.34% higher than wild-type S31. Transcriptomic and metabolomic analyses demonstrated that UV1-3 promotes docosahexaenoic acid (DHA) biosynthesis through coordinated metabolic regulation. Downregulation of key fatty acid synthase (FAS) pathway genes (ACSL, SLC27A2, FabI) reduced substrate competition for DHA precursors. Concurrently, RT-qPCR confirmed the upregulation of core polyketide synthase (PKS) pathway genes (orfA, orfB, orfC), directly enhancing DHA production. Furthermore, suppressed oxidative phosphorylation (evidenced by COX downregulation) and redirected carbon/nitrogen flux—achieved through diminished tricarboxylic acid (TCA) cycle activity (via downregulation of HAL and proC)—collectively favored DHA accumulation. These findings establish UV1-3 as a high-yielding industrial strain for DHA production and provide fundamental insights into metabolic flux regulation in Schizochytrium sp. These insights advance scalable, cost-effective microbial DHA production and deepen understanding of algal biosynthesis mechanisms, supporting sustainable omega-3 sourcing strategies.