Biotechnology and Bioengineering最新文献

l-homoserine is an important platform compound of many valuable products. Construction of microbial cell factory for l-homoserine production from glucose has attracted a great deal of attention. In this study, l-homoserine biosynthesis pathway was divided into three modules, the glucose uptake and upstream pathway, the downstream pathway, and the energy supply module. Metabolomics of the chassis strain HS indicated that the supply of ATP was inadequate, therefore, the energy supply module was firstly modified. By balancing the ATP supply module, the l-homoserine production increased by 66% to 12.55 g/L. Further, the results indicated that the upstream pathway was blocked, and increasing the culture temperature to 37°C could solve this problem and the l-homoserine production reached 21.38 g/L. Then, the downstream synthesis pathways were further strengthened to balance the fluxes, and the l-homoserine production reached the highest reported level of 32.55 g/L in shake flasks. Finally, fed-batch fermentation in a 5-L bioreactor was conducted, and l-homoserine production could reach to 119.96 g/L after 92 h cultivation, with the yield of 0.41 g/g glucose and productivity of 1.31 g/L/h. The study provides a well research foundation for l-homoserine production by microbial fermentation with the capacity for industrial application.

With the rise in engineered biomolecular devices, there is an increased need for tailor-made biological sequences. Often, many similar biological sequences need to be made for a specific application meaning numerous, sometimes prohibitively expensive, lab experiments are necessary for their optimization. This paper presents a transfer learning design of experiments workflow to make this development feasible. By combining a transfer learning surrogate model with Bayesian optimization, we show how the total number of experiments can be reduced by sharing information between optimization tasks. We demonstrate the reduction in the number of experiments using data from the development of DNA competitors for use in an amplification-based diagnostic assay. We use cross-validation to compare the predictive accuracy of different transfer learning models, and then compare the performance of the models for both single objective and penalized optimization tasks.

To reduce carbon emissions and address environmental concerns, the aviation industry is exploring the use of sustainable aviation fuel (SAF) as an alternative to traditional fossil fuels. In this context, bio-alkane is considered a potentially high-value solution. The present study focuses on the enzymes acyl-acyl carrier protein [ACP] reductase (AAR) and aldehyde-deformylating oxygenase (ADO), which are crucial enzymes for alka(e)ne biosynthesis. By using protein engineering techniques, including semi-rational design and site-directed mutagenesis, we aimed to enhance the substrate specificity of AAR and improve alkane production efficiency. The co-expression of a modified AAR (Y26G/Q40M mutant) with wild-type ADO in Escherichia coli significantly increased alka(e)ne production from 28.92 mg/L to 167.30 mg/L, thus notably demonstrating a 36-fold increase in alkane yield. This research highlights the potential of protein engineering in optimizing SAF production, thereby contributing to the development of more sustainable and efficient SAF production methods and promoting greener air travel.

The cover image is based on the Article Quality by design approach to improve quality and decrease cost of in vitro transcription of mRNA using design of experiments by Jimmy Boman and Tjaša Marušič et al., https://doi.org/10.1002/bit.28806.

Synthetic BioBricks introduce novel capabilities to manipulate genetic information, direct transcription-translation processes, and program cellular behaviors in living organisms. To maintain the stability and functionality of synthetic BioBricks, assembled DNA fragments should be mutually compatible without inducing negative effects such as metabolic burden or cellular toxicity in host cells. However, a simple, rapid, and reliable method to evaluate BioBrick compatibility remains to be developed. In this study, we report BP (Blue/Purple, Ban/Pick) evaluation, a method utilizing chromoproteins to facilitate the identification of BioBrick compatibility in one-pot reactions. By visualizing and quantifying the ratio of blue to purple Escherichia coli (E. coli) colonies on LB-agar plates, we can easily validate the compatibility of desired BioBrick constructions. To demonstrate our design, we characterized BioBrick assemblies with antitoxin-toxin pair ccdA-ccdB, lysis protein E, or heterologous protein sfGFP. Among these, we successfully identified several compatible assemblies. We anticipate that BP evaluation will enhance biotechnological assessments of BioBrick compatibility in vivo and expand the application of chromoproteins in synthetic biology.

Due to its high heterogeneity and significant impact on women's health globally, breast cancer necessitates robust preclinical models to understand tumor biology and guide personalized treatment strategies. Three-dimensional (3D) in vitro tumor models hold immense promise in this regard. These tumor models not only mimic the spatial structure and growth environment of tumors in vivo, but also retain the pathological and genetic characteristics of solid tumors. This fidelity makes them powerful tools for accelerating advancements in fundamental research and translational medicine. The diversity, modularity, and efficacy of 3D tumor models are driving a biotechnological revolution. As these technologies become increasingly sophisticated, 3D tumor models are poised to become powerful weapons in the fight against breast cancer. This article expounds on the progress made in utilizing 3D tumor models for breast cancer research.

Pterostilbene (PST), a 3’,5’-O-methylated derivative of resveratrol (RSV), is a potent natural antioxidant produced by some plants in trace amounts as defense compound. It exhibits various health-promoting activities, such as anticancer, antiviral, and antimicrobial effects. Large-scale biosynthesis of PST is crucial due to the challenges associated with extracting it from plants. This study aims to develop an efficient method for PST production using an engineered Escherichia coli strain by feeding RSV as a precursor. We introduced a two-step substrate addition strategy combined with immobilized RSV (IMRSV) on macroporous adsorption resin (MAR) to enhance PST production. Five MARs were selected for RSV immobilization, and the substrate addition strategy and fermentation parameters for PST synthesis were optimized. A maximum PST concentration of 403 ± 9 mg/L was achieved, representing a 239% increase over the control, which in a one-step addition of free RSV. The PST titer reached 395 ± 24 mg/L in a 3-L bioreactor. In conclusion, the combination of a two-step substrate addition system and IMRSV is a promising approach for the economical and industrial-scale production of PST.

Detection of microRNAs (miRNAs) in the serum is an effective liquid biopsy technique for cancer diagnosis. However, conventional diagnostic methods are time-consuming and complex. Therefore, in this study, we established a signaling probe-based DNA microarray system for miRNA detection. PCR, fluorescence labeling, and washing are not necessary for signaling probes. Four probes were designed using different miRNAs as diagnostic cancer markers. The developed system is useful for various miRNAs, regardless of their target lengths (18–26-mer) and GC content (36%–89%). Here, all the assays were performed within 40 min. Overall, our signaling probe-based DNA hybridization system facilitates the simple and rapid detection of serum miRNAs without the need for gene amplification, fluorescence labeling and washing.

Spirulina is the common name for the edible, nonheterocystous, filamentous cyanobacterium Arthrospira platensis that is grown industrially as a food supplement, animal feedstock, and pigment source. Although there are many applications for engineering this organism, until recently no genetic tools or reproducible transformation methods have been published. While recent work showed the production of a diversity of proteins in A. platensis, including single-domain antibodies for oral delivery, there remains a need for a modular, characterized genetic toolkit. Here, we independently establish a reproducible method for the transformation of A. platensis and engineer this bacterium to produce acetaminophen as proof-of-concept for small molecule production in an edible host. This work opens A. platensis to the wider scientific community for future engineering as a functional food for nutritional enhancement, modification of organoleptic traits, and production of pharmaceuticals for oral delivery.