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Biotechnology and Bioengineering

Maximilian Lularevic, Andrew J Racher, Colin Jaques, Alex Kiparissides
Constraint based modelling methods, such as Flux Balance Analysis (FBA), have been extensively used to decipher complex, information rich -omics datasets in order to elicit system-wide behavioral patterns of cellular metabolism. FBA has been successfully used to gain insight in a wide range of applications, such as range of substrate utilization, product yields and to design metabolic engineering strategies to improve bioprocess performance. A well-known challenge associated with large genome-scale metabolic networks (GEMs) is that they result in underdetermined problem formulations...
May 21, 2019: Biotechnology and Bioengineering
Marsela Jorgolli, Tanner Nevill, Aaron Winters, Irwin Chen, Su Chong, Fen-Fen Lin, Marissa Mock, Ching Chen, Kim Le, Christopher Tan, Philip Jess, Han Xu, Agi Hamburger, Jennitte Stevens, Trent Munro, Ming Wu, Philip Tagari, Les P Miranda
The new and rapid advancement in the complexity of biologics drug discovery has been driven by a deeper understanding of biological systems combined with innovative new therapeutic modalities, paving the way to breakthrough therapies for previously intractable diseases. These exciting times in biomedical innovation require the development of novel technologies to facilitate the sophisticated, multi-faceted, high-paced workflows necessary to support modern large molecule drug discovery. A high-level aspiration is true integration of "lab-on-a-chip" methods that vastly miniaturize cellular and biochemical experiments could transform the speed, cost, and success of multiple workstreams in biologics development...
May 21, 2019: Biotechnology and Bioengineering
Meng-Jung Chiang, Mark Pagkaliwangan, Scott Lute, Glen Bolton, Kurt Brorson, Mark Schofield
Continuous bioprocessing holds the potential to improve product consistency, accelerate productivity and lower cost of production. However, switching a bioprocess from traditional batch to continuous mode requires surmounting business and regulatory challenges. A key regulatory requirement for all biopharmaceuticals is virus safety, which is assured through a combination of testing and virus clearance through purification unit operations. For continuous processing, unit operations such as capture chromatography have aspects that could be impacted by a change to continuous multi-column operation; for example, do they clear viruses as well as a traditional batch single column...
May 21, 2019: Biotechnology and Bioengineering
Wan Lin Yeo, Elena Heng, Lee Ling Tan, Yi Wee Lim, Yee Hwee Lim, Shawn Hoon, Huimin Zhao, Mingzi M Zhang, Fong Tian Wong
Application of the well-characterized Streptococcus pyogenes CRISPR-Cas9 system in actinomycetes streptomycetes has enabled high efficiency multiplex genome editing and CRISPRi-mediated transcriptional regulation in these prolific bioactive metabolite producers. Nonetheless, SpCas9 has its limitations and can be ineffective depending on the strains and target sites. Here, we built and tested alternative CRISPR-Cas constructs based on the standalone pCRISPomyces-2 editing plasmid. We showed that Streptococcus thermophilus CRISPR1 (sth1Cas9), Staphylococcus aureus Cas9 (saCas9), and Francisella tularensis subsp...
May 15, 2019: Biotechnology and Bioengineering
Sophia Li, Bin Yu, Gabriel Byrne, Meredith Wright, Sara O'Rourke, Kathryn Mesa, Phillip W Berman
Proteolysis associated with recombinant protein expression in Chinese Hamster Ovary (CHO) cells has hindered the development of biologics including HIV vaccines. When expressed in CHO cells, the recombinant HIV envelope protein, gp120, undergoes proteolytic clipping by a serine protease at a key epitope recognized by neutralizing antibodies. The problem is particularly acute for envelope proteins from clade B viruses that represent the major genetic subtype circulating in much of the developed world, including the US and Europe...
May 14, 2019: Biotechnology and Bioengineering
Nicholas Vecchiarello, Steven M Timmick, Chaz Goodwine, Laura E Crowell, Kerry R Love, J Christopher Love, Steven M Cramer
Integrated designs of chromatographic processes for purification of biopharmaceuticals provides potential gains in operational efficiency and reductions of costs and material requirements. We describe a combined method using screening and in silico algorithms for ranking chromatographic steps to rapidly design orthogonally selective integrated processes for purifying protein therapeutics from both process- and product-related impurities. IFN-α2b produced in Pichia pastoris containing a significant product variant challenge was employed as a case study...
May 13, 2019: Biotechnology and Bioengineering
Pingping Zhou, Ruimiao Yao, Hongsen Zhang, Jie Bao
Toxic inhibitory compounds from lignocellulose pretreatment are the major obstacle to achieve high bioconversion efficiency in biorefinery fermentations. This study shows a unique glucose oxidation catalysis of Gluconobacter oxydans with its gluconic acid productivity free of inhibitor disturbance. The microbial experimentations and the transcriptome analysis revealed that both the activity of the membrane-bound glucose dehydrogenase (mGDH) and the transcription level of the genes in periplasmic glucose oxidation respiratory chain of G...
May 13, 2019: Biotechnology and Bioengineering
Fatemeh Fallahianbijan, Sal Giglia, Christina Carbrello, David Bell, Andrew L Zydney
Virus filtration is a robust size-based technique that can provide the high level of viral clearance required for the production of mammalian-derived biotherapeutics such as monoclonal antibodies. Several studies have shown that the retention characteristics of some, but not all, virus filters can be significantly affected by membrane fouling, but there have been no direct measurements of how protein fouling might alter the location of virus capture within these membranes. The objective of this work was to directly examine the effect of protein fouling by human immunoglobulin G (IgG) on virus capture within the Viresolve® Pro and Viresolve® NFP membranes by scanning electron microscopy using different size gold nanoparticles...
May 13, 2019: Biotechnology and Bioengineering
Meiyappan Lakshmanan, Yee Jiun Kok, Alison P Lee, Sarantos Kyriakopoulos, Hsueh Lee Lim, Gavin Teo, Swan Li Poh, Wen Qin Tang, Jongkwang Hong, Andy Hee-Meng Tan, Xuezhi Bi, Ying Swan Ho, Peiqing Zhang, Say Kong Ng, Dong-Yup Lee
Chinese hamster ovary (CHO) cells are the most prevalent mammalian cell factories for producing recombinant therapeutic proteins due to their ability to synthesize human-like post-translational modifications and ease of maintenance in suspension cultures. Currently, a wide variety of CHO host cell lines have been developed; substantial differences exist in their phenotypes even when transfected with the same target vector. However, relatively less is known about the influence of their inherited genetic heterogeneity on phenotypic traits and production potential from the bioprocessing point of view...
May 8, 2019: Biotechnology and Bioengineering
O Zeriouh, A Rocamora Marco, J V Reinoso-Moreno, L López-Rosales, F García-Camacho, E Molina-Grima
The biofouling formation of the marine microalga N. gaditana on non-toxic surfaces was quantified on rigid materials, both coated (with Fouling Release Coatings and nanoparticle coatings) and non-coated, to cover a wide range of surface properties from strongly hydrophobic to markedly hydrophilic under conditions similar to those prevailing in outdoor massive cultures of marine microalgae. The effect of seawater on surfaces that presented the best antibiofouling properties was also evaluated. The adhesion intensity on the different surfaces was compared with the predictions of the biocompatibility theories developed by Baier and Vogler using water adhesion tension (τo ) as the quantitative parameter of surface wettability...
May 7, 2019: Biotechnology and Bioengineering
James Angelo, Srinivas Chollangi, Thomas Müller-Späth, Simona Jusyte, Xuankuo Xu, Sanchayita Ghose, Zhengjian Li
Multi-column capture chromatography (MCC) is gaining increased attention lately due to the significant economic and process advantages it offers compared to traditional batch mode chromatography. However, for wide adoption of this technology in clinical and commercial space, it requires scalable models for executing viral validation studies. In this study, viral validation studies were conducted under cGLP guidelines to assess retro- (X-MuLV) and parvo-virus (MVM) clearance across twin-column continuous capture chromatography (CaptureSMB)...
May 7, 2019: Biotechnology and Bioengineering
Feng Cheng, Jianhua Yang, Ulrich Schwaneberg, Leilei Zhu
Arginine deiminase (ADI) is a therapeutic protein for cancer therapy of arginine-auxotrophic tumors. However, its application as anti-cancer drug is hampered by its poor stability under physiological conditions in blood stream. Commonly, random PEGylation is being used for increasing the stability of ADI and in turn the improved half-life. However, the traditional random PEGylation usually leads to poor PEGylation efficiency due to the limited number of Lys on the protein surface. In order to boost the PEGylation efficiency and enhance the stability of ADI further, surface engineering of PpADI (an ADI from Pseudomonas plecoglossicida) to increase the suitable PEGylation sites was carried out...
May 7, 2019: Biotechnology and Bioengineering
John Schmitt, Brandon Downey, Justin Beller, Brian Russell, Anthony Quach, David Lyon, Meredith Curran, Bhanu Chandra Mulukutla, Chia Chu
Biomanufacturing exhibits inherent variability that can lead to variation in performance attributes and batch failure. To help ensure process consistency and product quality the development of predictive models and integrated control strategies is a promising approach. In this work, a feedback controller was developed to limit excessive lactate production, a widespread metabolic phenomenon that is negatively associated with culture performance and product quality. The controller was developed by applying machine learning strategies to historical process development data, resulting in a forecast model that could identify whether a run would result in lactate consumption or accumulation...
May 7, 2019: Biotechnology and Bioengineering
Chao Zhong, Christiane Luley-Goedl, Bernd Nidetzky
Soluble cellodextrins (linear β-1,4-D-gluco-oligosaccharides) have interesting applications as ingredients for human and animal nutrition. Their bottom-up synthesis from glucose is promising for bulk production, but to ensure a completely water-soluble product via degree of polymerization (DP) control (DP ≤ 6) is challenging. Here, we show biocatalytic production of cellodextrins with DP centered at 3 - 6 (~96 wt.% of total product) using coupled cellobiose and cellodextrin phosphorylase. The cascade reaction, wherein glucose was elongated sequentially from α-glucose 1-phosphate (αGlc1-P), required optimization and control at two main points...
May 7, 2019: Biotechnology and Bioengineering
Haider Ali, Jannike Solsvik, Jonathan L Wagner, Dongda Zhang, Klaus Hellgardt, Cheol Woo Park
Microalgal biofuels have not yet achieved wide-spread commercialization, partially as a result of the complexities involved with designing and scaling up of their biosystems. The sparger design of a pilot-scale photobioreactor (120 L) was optimized to enable the scale-up of biofuel production. An integrated model coupling computational fluid dynamics and microalgal biofuel synthesis kinetics was used to simulate the biomass growth and novel biofuel production (i.e. bisabolene) in the photobioreactor. Bisabolene production from Chlamydomonas reinhardtii mutant was used as an example to test the proposed model...
May 7, 2019: Biotechnology and Bioengineering
Qiong Wang, Ganglong Yang, Tiexin Wang, Weiming Yang, Michael J Betenbaugh, Hui Zhang
With the increasing demand to provide more detailed quality attributes, more sophisticated glycan analysis tools are highly desirable for biopharmaceutical manufacturing. Here, we performed an intact glycopeptide analysis method to simultaneously analyze the site-specific N- and O-glycan profiles of the recombinant EPO-Fc protein secreted from a CHO-GS stable cell line and compared the effects of two commercial culture media, EX-CELL (EX) and immediate Advantage (IA) media, on the glycosylation profile of the target protein...
May 7, 2019: Biotechnology and Bioengineering
Rosario Vanella, Duy Tien Ta, Michael A Nash
Directed evolution of oxidoreductases to improve their catalytic properties is being ardently pursued in the industrial, biotechnological, and biopharma sectors. Hampering this pursuit are current enzyme screening methods that are limited in terms of throughput, cost, time and complexity. We present a directed evolution strategy that allows for large-scale one-pot screening of glucose oxidase (GOx) enzyme libraries in well-mixed homogeneous solution. We used GOx variants displayed on the outer cell wall of yeasts to initiate a cascade reaction with horseradish peroxidase (HRP), resulting in peroxidase-mediated phenol cross-coupling and encapsulation of individual cells in well-defined fluorescent alginate hydrogel shells within ~10 minutes in mixed cell suspensions...
April 30, 2019: Biotechnology and Bioengineering
Anna Hoschek, Bruno Bühler, Andreas Schmid
Photoautotrophic organisms are promising hosts for biocatalytic oxyfunctionalizations because they supply reduction equivalents as well as O2 via photosynthetic water oxidation. Thus far, research on photosynthesis-driven bioprocesses mainly focuses on strain development and the proof of principle in small-scale biocatalytic reaction setups. This study investigates the long-term applicability of the previously developed cyanobacterial strain Synechocystis sp. PCC 6803_BGT harboring the alkane monooxygenase system AlkBGT catalyzing terminal alkyl group oxyfunctionalization...
April 30, 2019: Biotechnology and Bioengineering
Milla Salmela, Tapio Lehtinen, Elena Efimova, Suvi Santala, Ville Santala
Lignin has potential as a sustainable feedstock for microbial production of industrially relevant molecules. However, the required lignin depolymerization yields a heterogenic mixture of aromatic monomers that are challenging substrates for the microorganisms commonly used in industry. Here, we investigated the properties of lignin related aromatic compounds (LRAs), namely coumarate, ferulate, and caffeate, in the synthesis of biomass and products in a LRA-utilizing bacterial host Acinetobacter baylyi ADP1...
April 30, 2019: Biotechnology and Bioengineering
Yu Zhang, Shuxin Qu, Liming Xu
Virus inactivation validation studies have been widely applied in the risk assessment of biogenic material-based medical products, such as biological products, animal tissue-derived biomaterials, and allogeneic biomaterials, to decrease the risk of virus transmission. Traditional virus detection methods in an inactivation validation study utilize cell culture as a tool to quantify the infectious virus by observing cytopathic effects (CPEs) after virus inactivation. However, this is susceptible to subjective factors, because CPEs must be observed by experts under a microscope during virus titration...
April 30, 2019: Biotechnology and Bioengineering
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