Engineering in Life Sciences最新文献

Lignocellulosic biomass, the most abundant natural resource on earth, can be used for cellulosic ethanol production but requires a pretreatment to improve enzyme access to the polymeric sugars while obtaining value from the other components. γ-Valerolactone (GVL) is a promising candidate for biomass pretreatment since it is renewable and bio-based. In the present work, the effect of a pretreatment based on GVL on the enzymatic saccharification of white birch was evaluated at a laboratory scale and the importance of the washing procedure for the subsequent saccharification was demonstrated. Both the saccharification yield and the production of cellulosic ethanol were higher using a noncommercial enzyme crude from Talaromyces amestolkiae than with the commercial cocktail Cellic CTec2 from Novozymes. Furthermore, the production of extracellular cellulases by T. amestolkiae has been optimized in 2 L bioreactors, with improvements ranging from 40% to 75%. Finally, it was corroborated by isoelectric focus that optimization of cellulase secretion by T. amestolkiae did not affect the pattern production of the main β-glucosidases and endoglucanases secreted by this fungus.

While bioactivity and a favorable safety profile for biotherapeutics is of utmost importance, manufacturability is also worth of consideration to ease the manufacturing process. Manufacturability in the scientific literature is mostly related to stability of formulated drug substances, with limited focus on downstream process-related manufacturability, that is, how easily can a protein be purified. Process-related impurities or biological impurities like viruses and host cell proteins (HCP) are present in the harvest which have mostly acid isoelectric points and need to be removed to ensure patient safety. Therefore, during molecule design, the surface charge of the target molecule should preferably differ sufficiently from the surface charge of the impurities to enable an efficient purification strategy. In this feasibility study, we evaluated the possibility of improving manufacturability by adapting the surface charge of the target protein. We generated several variants of a GLP1-receptor-agonist-Fc-domain-FGF21-fusion protein and demonstrated proof of concept exemplarily for an anion exchange chromatography step which then can be operated at high pH values with maximal product recovery allowing removal of HCP and viruses. Altering the surface charge distribution of biotherapeutic proteins can thus be useful allowing for an efficient manufacturing process for removing HCP and viruses, thereby reducing manufacturing costs.

The utilization of Streptomyces as a microbial chassis for developing innovative drugs and medicinal compounds showcases its capability to produce bioactive natural substances. Recent focus on the clustered regularly interspaced short palindromic repeat (CRISPR) technology highlights its potential in genome editing. However, applying CRISPR technology in certain microbial strains, particularly Streptomyces, encounters specific challenges. These challenges include achieving efficient gene expression and maintaining genetic stability, which are critical for successful genome editing. To overcome these obstacles, an innovative approach has been developed that combines several key elements: activation-induced cytidine deaminase (AID), nuclease-deficient cas9 variants (dCas9), and Petromyzon marinus cytidine deaminase 1 (PmCDA1). In this study, this novel strategy was employed to engineer a Streptomyces coelicolor strain. The target gene was actVA-ORF4 (SCO5079), which is involved in actinorhodin production. The engineering process involved introducing a specific construct [pGM1190-dcas9-pmCDA-UGI-AAV-actVA-ORF4 (SCO5079)] to create a CrA10 mutant strain. The resulting CrA10 mutant strain did not produce actinorhodin. This outcome highlights the potential of this combined approach in the genetic manipulation of Streptomyces. The failure of the CrA10 mutant to produce actinorhodin conclusively demonstrates the success of gene editing at the targeted site, affirming the effectiveness of this method for precise genetic modifications in Streptomyces.