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Biotechnology and Bioengineering

Ryan Graham, Hemlata Bhatia, Seongkyu Yoon
Trace metals are supplied to chemically-defined media (CDM) for optimal CHO cell culture performance during the production of monoclonal antibodies (mAbs) and other therapeutic proteins. However, lot-to-lot and vendor-to-vendor variability in raw materials consequently leads to an imbalance of trace metals that are supplied to CDM. This imbalance can yield detrimental effects rooted in several primary mechanisms and pathways including oxidative stress, apoptosis, lactate accumulation, and unfavorable glycan synthesis...
August 12, 2019: Biotechnology and Bioengineering
Lu Yuan, Jamin Koo
Hydrogenases are metalloproteins capable of catalyzing the interconversion between molecular hydrogen and protons & electrons. The iron-sulfur clusters within the enzyme enable rapid relay of electrons which are either consumed or generated at the active site. Their unparalleled catalytic efficiency has attracted attention, especially for potential use in H2 production and/or fuel cell technologies. However, there are limitations to using hydrogenases, especially due to their high O2 sensitivity. The subclass, called [FeFe] hydrogenases, are particularly more vulnerable to O2 but proficient in H2 production...
August 12, 2019: Biotechnology and Bioengineering
Verónica Pazmiño-Ibarra, Adrià Mengual-Martí, Alexandra Marisa Targovnik, Salvador Herrero
The CRISPR (Clustered Regularly Interspaced Short Palindromic repeats) system associated Cas9 endonuclease is a molecular tool that enables specific sequence editing with high efficiency. In this study, we have explored the use of CRISPR/Cas9 system for the engineering of baculovirus. We have shown that the delivering of Cas9-sgRNA ribonucleoprotein (RNP) complex with or without DNA repair template into Sf21 insect cells through lipofection might be efficient to produce knocks-out as well as knocks-in into the baculovirus...
August 12, 2019: Biotechnology and Bioengineering
Yan-Rong Zhou, Xiao-Yan Song, Yue Li, Jin-Chao Shi, Wei-Ling Shi, Xiu-Lan Chen, Wei-Feng Liu, Xiang-Mei Liu, Wei-Xin Zhang, Yu-Zhong Zhang
Trichoderma spp. are main producers of peptide antibiotics known as peptaibols. While peptaibols have been shown to possess a range of biological activities, molecular understanding of the regulation of their production is largely unclear, which hampers the production improvement through genetic engineering. Here, we demonstrated that the orthologue of glucose sensors in the outstanding biocontrol fungus Trichoderma longibrachiatum SMF2, TlSTP1, participates in the regulation of peptaibols production. Deletion of Tlstp1 markedly impaired hyphal growth and conidiation, but significantly increased peptaibols yield by 5-fold for Trichokonins A and 2...
August 12, 2019: Biotechnology and Bioengineering
Masatsugu Takada, Richard P Chandra, John N Saddler
To be effective, steam pretreatment is typically carried out at temperatures/pressures above the glass transition point (Tg) of biomass lignin so that it can partly fluidize and relocate. The relocation of Douglas-fir and corn stover derived lignin was compared with the expectation that, with the corn stover lignin's lower hydrophobicity and molecular weight, it would be more readily fluidized. It was apparent that the Tg of lignin decreased as the moisture increased, with the easier access of steam to the corn stover lignin promoting its plasticization...
August 12, 2019: Biotechnology and Bioengineering
Sidiky Ménil, Jean-Louis Petit, Elise Courvoisier-Dezord, Adrien Debard, Virginie Pellouin, Thomas Reignier, Michelle Sergent, Valérie Deyris, Katia Duquesne, Véronique de Berardinis, Véronique Alphand
The efficiency of a versatile in vivo cascade involving a promiscuous alcohol dehydrogenase, obtained from a biodiversity search, and a Baeyer-Villiger monooxygenase was enhanced by the independent control of the production level of each enzyme to produce ε-caprolactone and 3,4-dihydrocoumarin. This goal was achieved by adjusting the copy number per cell of E. coli plasmids. We started from the observation that this number generally correlates with the amount of produced enzyme and demonstrated that an in vivo multi-enzymatic system can be improved by the judicious choice of plasmid, the lower activity of the enzyme that drives the limiting step being counter-balanced by a higher concentration...
August 7, 2019: Biotechnology and Bioengineering
Heng Liang Tan, Bao Zhu Tan, Winfred Xi Tai Goh, Simeon Cua, Andre Choo
This study describes the use of a previously reported chimerised monoclonal antibody (mAb), ch2448, to kill human embryonic stem cells (hESC) in vivo and prevent or delay the formation of teratomas. ch2448 was raised against hESCs and was previously shown to effectively kill ovarian and breast cancer cells in vitro and in vivo. The antigen target was subsequently found to be Annexin A2, an oncofetal antigen expressed on both embryonic cells and cancer cells. Against cancer cells, ch2448 binds and kills via antibody-dependent cell-mediated cytotoxicity (ADCC) and/or antibody-drug conjugate (ADC) routes...
August 7, 2019: Biotechnology and Bioengineering
Courtney M Gardner, Savannah J Volkoff, Claudia K Gunsch
The consumption of transgenic crops and their by-products has become increasingly common in the United States. Yet, uncertainty remains regarding the fate and behavior of DNA within food matrices once it exits the digestive track and enters into wastewater treatment plants (WWTPs). Because many transgenic crops have historically contained ARGs as selection markers, understanding the behavior and uptake of these transgenes by environmental microbes is of critical importance. To investigate the behavior of free transgenic crop DNA, thermophilic anaerobic batch reactors were amended with varying concentrations of transgenic crop genes (i...
August 7, 2019: Biotechnology and Bioengineering
Shohei Chikae, Akifumi Kubota, Haruka Nakamura, Atsushi Oda, Akihiro Yamanaka, Takami Akagi, Mitsuru Akashi
Three-dimensional (3D) printers are attracting attention as a method for arranging and building cells in three dimensions. Bioprinting technology has potential in tissue engineering for the fabrication of scaffolds, cells, and tissues. However, these various printing technologies have limitations with respect to print resolution and due to the characteristics of bioink such as viscosity. We report a method for constructing of 3D tissues with a "microscopic painting device using a painting needle method" that, when used with the layer-by-layer (LbL) cell coating technique, replaces conventional methods...
August 1, 2019: Biotechnology and Bioengineering
Ehecatl Antonio Del Rio-Chanona, Nur Rashid Ahmed, Jonathan Wagner, Yinghua Lu, Dongda Zhang, Keju Jing
The development of digital bioprocessing technologies is critical to operate modern industrial bioprocesses. This study conducted the first investigation on the efficiency of using physics-based and data-driven models for the dynamic optimisation of long-term bioprocess. More specifically, this research exploits a predictive kinetic model and a cutting-edge data-driven model to compute open-loop optimisation strategies for the production of microalgal lutein during a fed-batch operation. Light intensity and nitrate inflow rate are used as control variables given their key impact on biomass growth and lutein synthesis...
July 30, 2019: Biotechnology and Bioengineering
Azizan Amizon, Sieben Michaela, Wandrey Georg, Büchs Jochen
Shake flasks are still the most relevant experimental tool in the development of viscous fermentation processes. The phase number, which defines the onset of the unfavorable out-of-phase phenomenon in shake flasks, was previously defined via specific power input measurements. In the out-of-phase state, the bulk liquid no longer follows the orbital movement of the imposed centrifugal force, which is e.g. detrimental to oxygen transfer. In this work, an optical fluorescence technique was used to measure the three-dimensional liquid distribution in shake flasks...
July 27, 2019: Biotechnology and Bioengineering
Joana Barbosa, Tânia Caetano, Eva Moesker, Roderich D Suessmuth, Sónia Mendo
Lantibiotics are ribosomally synthesized and posttranslationally modified antimicrobial peptides that arise as an alternative to the traditional antibiotics. Lichenicidin is active against clinically relevant bacteria and it was the first lantibiotic to be fully produced in vivo in the Gram-negative host E. coli. Here, we present the results of a library of lichenicidin mutants, in which the mutations were generated based on the extensive bibliographical search available for other lantibiotics. The antibacterial activity of two-peptide lantibiotics, as is lichenicidin, requires the synergistic activity of two peptides...
July 27, 2019: Biotechnology and Bioengineering
Tanja Hernández Rodríguez, Christoph Posch, Julia Schmutzhard, Josef Stettner, Claus Weihs, Ralf Pörtner, Björn Frahm
For production of biopharmaceuticals in suspension cell culture, seed trains are required to increase the cell number from cell thawing up to production scale. Since cultivation conditions during the seed train have a significant impact on cell performance in production scale, seed train design, monitoring and development of optimization strategies is important. This can be facilitated by model-assisted prediction methods, whereby the performance depends on the prediction accuracy, which can be improved by inclusion of prior process knowledge, especially when only few high-quality data is available, and description of inference uncertainty, providing, apart from a 'best fit'-prediction, information about the probable deviation in form of a prediction interval...
July 26, 2019: Biotechnology and Bioengineering
Johannes Möller, Krathika Bhat, Kristoffer Riecken, Ralf Pörtner, An-Ping Zeng, Uwe Jandt
The influence of process strategies on the dynamics of cell population heterogeneities in mammalian cell culture is still not well understood. We recently found that the progression of cells through the cell cycle causes metabolic regulations with variable productivities in antibody-producing CHO cells. On the other hand, it is so far unknown how bulk cultivation conditions, e.g. variable nutrient concentrations depending on process strategies, can influence cell cycle-derived population dynamics. In this study, process-induced cell cycle synchronization was assessed in repeated-batch and fed-batch cultures...
July 24, 2019: Biotechnology and Bioengineering
Ruikang Xue, Benedict Chung, Maryam Tamaddon, James Carr, Chaozong Liu, Sarah Cartmell
Osteochondral tissue engineering aims to regenerate functional tissue mimicking physiological properties of injured cartilage and its subchondral bone. Given the distinct structural and biochemical difference between bone and cartilage, bi-layered scaffolds and bioreactors are commonly employed. We present an osteochondral culture system which co-cultured ATDC5 and MC3T3-E1 cells on an additive manufactured bi-layered scaffold in a dual-chamber perfusion bioreactor. Also, finite element models (FEM) based on the micro-computed tomography (μCT) image of the manufactured scaffold as well as on the computer aided design (CAD) were constructed; the microenvironment inside the two FEM was studied and compared...
July 23, 2019: Biotechnology and Bioengineering
Hansol Kim, Hyukjun Choi, Yoonji Bae, Sebyung Kang
Protein cage nanoparticles are widely used as targeted delivery nanoplatforms, since they have well-defined symmetric architectures, high biocompatibility, and enough plasticity to be modified to produce a range of different functionalities. Targeting peptides and ligands are often incorporated on the surface of protein cage nanoparticles. In this research, we adopted the SpyTag/SpyCatcher protein ligation system to covalently display target-specific affibody molecules on the exterior surface of bacteriophage P22 virus-like particles (VLP) and evaluated their modularity and efficacy of targeted delivery...
July 22, 2019: Biotechnology and Bioengineering
Deepti Susanna, D Rahulgandhi, M Ranjithragavan, V Ramamurthy
Although production of microalgae in open ponds is conventionally practiced due to its economy, exposure of the algae to uncontrollable elements impedes achievement of quality and it is desirable to develop closed reactor cultivation methods for the production of high value products. Nevertheless, there are several constraints which affect growth of in closed reactors, some of which this study aims to address for the production of Spirulina. Periodic introduction of fresh medium resulted in increased trichome numbers and improved algal growth compared to growth in medium that was older than 4 weeks in 20 L polycarbonate bottles...
July 22, 2019: Biotechnology and Bioengineering
Dong Gyun Kang, Chang Sup Kim, Hyung Joon Cha
Recombinant glycoproteins expressed in Chinese hamster ovary (CHO) cells contain two forms of sialic acids; N-acetylneuraminic acid (Neu5Ac) as a major type and N-glycolylneuraminic acid (Neu5Gc) as a minor type. The Neu5Gc glycan moieties in therapeutic glycoproteins can elicit immune responses because they are not existed in human. In the present work, in order to reduce Neu5Gc levels of recombinant glycoproteins from CHO cell cultures, we co-expressed CMP-sialic acid transporter (CMP-SAT) that is an antiporter and transports cytosolic CMP-sialic acids (both forms) into Golgi lumen...
July 18, 2019: Biotechnology and Bioengineering
Erin G Roberts, Vladimir F Kleptsyn, Gregory D Roberts, Katherine J Mossburg, Bei Feng, Ibrahim J Domian, Sitaram M Emani, Joyce Y Wong
Here we propose a bio-MEMS device designed to evaluate contractile force and conduction velocity of cell sheets in response to mechanical and electrical stimulation of the cell source as it grows to form a cellular sheet. Moreover, the design allows for incorporation of patient-specific data and cell sources: an optimized device would allow cell sheets to be cultured, characterized, and conditioned to be compatible with a specific patient's cardiac environment in vitro, prior to implantation. This design draws upon existing methods in the literature but makes an important advance by combining the mechanical and electrical stimulation into a single system for optimized cell sheet growth...
July 18, 2019: Biotechnology and Bioengineering
Dongda Zhang, Ehecatl Antonio Del Rio-Chanona, Panagiotis Petsagkourakis, Jonathan Wagner
Model-based online optimisation has not been widely applied to bioprocesses due to the challenges of modelling complex biological behaviours, low-quality industrial measurements, and lack of visualisation techniques for ongoing processes. This study proposes an innovative hybrid modelling framework which takes advantages of both physics-based and data-driven modelling for bioprocess online monitoring, prediction, and optimisation. The framework initially generates high-quality data by correcting raw process measurements via a physics-based noise filter (a generally available simple kinetic model with high fitting but low predictive performance); then constructs a predictive data-driven model to identify optimal control actions and predict discrete future bioprocess behaviours...
July 17, 2019: Biotechnology and Bioengineering
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