scholarly journals Lignocellulosic Fermentation of Wild Grass Employing Recombinant Hydrolytic Enzymes and Fermentative Microbes with Effective Bioethanol Recovery

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Saprativ P. Das ◽  
Arabinda Ghosh ◽  
Ashutosh Gupta ◽  
Arun Goyal ◽  
Debasish Das
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Hydrolytic Enzymes ◽  
Batch Mode ◽  
E Coli ◽  
Wild Grass ◽  
Cell Biomass ◽  
Single Culture ◽  
Leafy Biomass ◽  
Single Enzyme ◽  
Simultaneous Saccharification

Simultaneous saccharification and fermentation (SSF) studies of steam exploded and alkali pretreated different leafy biomass were accomplished by recombinantClostridium thermocellumhydrolytic enzymes and fermentative microbes for bioethanol production. The recombinantC. thermocellumGH5 cellulase and GH43 hemicellulase genes expressed inEscherichia colicells were grown in repetitive batch mode, with the aim of enhancing the cell biomass production and enzyme activity. In batch mode, the cell biomass (A600 nm) ofE. colicells and enzyme activities of GH5 cellulase and GH43 hemicellulase were 1.4 and 1.6 with 2.8 and 2.2 U·mg−1, which were augmented to 2.8 and 2.9 with 5.6 and 3.8 U·mg−1in repetitive batch mode, respectively. Steam exploded wild grass (Achnatherum hymenoides) provided the best ethanol titres as compared to other biomasses. Mixed enzyme (GH5 cellulase, GH43 hemicellulase) mixed culture (Saccharomyces cerevisiae, Candida shehatae) system gave 2-fold higher ethanol titre than single enzyme (GH5 cellulase) single culture (Saccharomyces cerevisiae) system employing 1% (w/v) pretreated substrate. 5% (w/v) substrate gave 11.2 g·L−1of ethanol at shake flask level which on scaling up to 2 L bioreactor resulted in 23 g·L−1ethanol. 91.6% (v/v) ethanol was recovered by rotary evaporator with 21.2% purification efficiency.

scholarly journals High-throughput microbioreactor provides a capable tool for early stage bioprocess development

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mathias Fink ◽  
Monika Cserjan-Puschmann ◽  
Daniela Reinisch ◽  
Gerald Striedner
Keyword(s):  
High Throughput ◽  
Process Development ◽  
Early Stage ◽  
Explanatory Power ◽  
Batch Mode ◽  
E Coli ◽  
Speed Up ◽  
Bioreactor System ◽  
Cell Densities ◽  
Microbial Systems

AbstractTremendous advancements in cell and protein engineering methodologies and bioinformatics have led to a vast increase in bacterial production clones and recombinant protein variants to be screened and evaluated. Consequently, an urgent need exists for efficient high-throughput (HTP) screening approaches to improve the efficiency in early process development as a basis to speed-up all subsequent steps in the course of process design and engineering. In this study, we selected the BioLector micro-bioreactor (µ-bioreactor) system as an HTP cultivation platform to screen E. coli expression clones producing representative protein candidates for biopharmaceutical applications. We evaluated the extent to which generated clones and condition screening results were transferable and comparable to results from fully controlled bioreactor systems operated in fed-batch mode at moderate or high cell densities. Direct comparison of 22 different production clones showed great transferability. We observed the same growth and expression characteristics, and identical clone rankings except one host-Fab-leader combination. This outcome demonstrates the explanatory power of HTP µ-bioreactor data and the suitability of this platform as a screening tool in upstream development of microbial systems. Fast, reliable, and transferable screening data significantly reduce experiments in fully controlled bioreactor systems and accelerate process development at lower cost.

scholarly journals Investigation of in Vivo Roles of the C-terminal Tails of the Small Subunit (ββ′) of Saccharomyces cerevisiae Ribonucleotide Reductase

2013 ◽  
Vol 288 (20) ◽  
pp. 13951-13959 ◽  
Author(s):  
Yan Zhang ◽  
Xiuxiang An ◽  
JoAnne Stubbe ◽  
Mingxia Huang
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ribonucleotide Reductase ◽  
Large Subunit ◽  
Small Subunit ◽  
Cluster Assembly ◽  
E Coli ◽  
Viability Assay ◽  
Docking Model

The small subunit (β2) of class Ia ribonucleotide reductase (RNR) houses a diferric tyrosyl cofactor (Fe2III-Y•) that initiates nucleotide reduction in the large subunit (α2) via a long range radical transfer (RT) pathway in the holo-(α2)m(β2)n complex. The C-terminal tails of β2 are predominantly responsible for interaction with α2, with a conserved tyrosine residue in the tail (Tyr356 in Escherichia coli NrdB) proposed to participate in cofactor assembly/maintenance and in RT. In the absence of structure of any holo-RNR, the role of the β tail in cluster assembly/maintenance and its predisposition within the holo-complex have remained unknown. In this study, we have taken advantage of the unusual heterodimeric nature of the Saccharomyces cerevisiae RNR small subunit (ββ′), of which only β contains a cofactor, to address both of these issues. We demonstrate that neither β-Tyr376 nor β′-Tyr323 (Tyr356 equivalent in NrdB) is required for cofactor assembly in vivo, in contrast to the previously proposed mechanism for E. coli cofactor maintenance and assembly in vitro. Furthermore, studies with reconstituted-ββ′ and an in vivo viability assay show that β-Tyr376 is essential for RT, whereas Tyr323 in β′ is not. Although the C-terminal tail of β′ is dispensable for cofactor formation and RT, it is essential for interactions with β and α to form the active holo-RNR. Together the results provide the first evidence of a directed orientation of the β and β′ C-terminal tails relative to α within the holoenzyme consistent with a docking model of the two subunits and argue against RT across the β β′ interface.

Efecto proapoptótico y antimetastásico en líneas tumorales humanas colorrectales de una proteína secretada por la bacteria Rizosférica Antártica Bacillus sp. K2I17

2019 ◽  
Author(s):  
Alequis Tomás Pavón Oro
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Staphylococcus Aureus ◽  
Candida Albicans ◽  
Deschampsia Antarctica ◽  
Bacillus Sp ◽  
E Coli ◽  
Cáncer Colorrectal

El cáncer es la segunda causa de muerte en el mundo, y específicamente en Chile el cáncer colorrectal es el único que presenta un aumento sostenido de la mortalidad en la última década. La búsqueda de nuevos agentes quimioterapeúticos anticancerígenos ha propuesto a los microorganismos extremófilos como una fuente potencial para obtener moléculas citotóxicas, que induzcan apoptosis en las células tumorales. Las condiciones extremas del continente antártico y las presiones selectivas por el espacio y los nutrientes que se producen entre los microorganismos del rizobioma de la planta Deschampsia antarctica Desv sugirieron como hipótesis que las bacterias rizosféricas aisladas en la Antártica secretan al sobrenadante de cultivo moléculas bioactivas que inhiben la invasión y proliferación de líneas tumorales humanas de origen colorrectal mediante un mecanismo apoptótico. En este sentido, el objetivo general del trabajo fue identificar y caracterizar a moléculas bioactivas con acción antinvasiva y antiproliferativa, además, determinar el mecanismo inhibitorio de la proliferación en líneas tumorales humanas de origen colorrectal. Los resultados del primer objetivo específico demostraron que los sobrenadantes de cultivo de los aislados rizosféricos antárticos K2 y MI disminuyeron la viabilidad de la línea celular de adenocarcinoma colorrectal LoVo en el ensayo de reducción metabólica del MTT. Además, como los sobrenadantes no tuvieron efecto en la viabilidad de las bacterias E. coli y Staphylococcus aureus, y tampoco en los hongos unicelulares Candida albicans y Saccharomyces cerevisiae, el resultado indicó que la actividad antiproliferativa fue selectiva hacia la línea celular LoVo.

scholarly journals Antibiotic Sensitivity of Strains of E. coli Isolated from Poultry Sheds Fed with Additive Saccharomyces cerevisiae and without Additive

OALib ◽  
2015 ◽  
Vol 02 (03) ◽  
pp. 1-5
Author(s):  
Nora Guida ◽  
Marcela Mascolo ◽  
Mariano Laino ◽  
Carla Bustos ◽  
Pablo Franco
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Antibiotic Sensitivity ◽  
E Coli

scholarly journals A MATLAB Toolbox for Modeling Genetic Circuits in Cell-Free Systems

2020 ◽  
Author(s):  
Vipul Singhal ◽  
Zoltan A. Tuza ◽  
Zachary Z. Sun ◽  
Richard M. Murray
Keyword(s):  
Reaction Rate ◽  
Behavior Prediction ◽  
Genetic Circuits ◽  
Matlab Toolbox ◽  
Parameter Inference ◽  
Batch Mode ◽  
E Coli ◽  
Entire Duration ◽  
Resource Loading

AbstractWe introduce a MATLAB based simulation toolbox, called txtlsim, for an E. coli based Transcription-Translation (TX-TL) system. This toolbox accounts for several cell-free related phenomena, such as resource loading, consumption, and degradation, and in doing so, models the dynamics of TX-TL reactions for the entire duration of batch-mode experiments. We use a Bayesian parameter inference approach to characterize the reaction rate parameters associated with the core transcription, translation and mRNA degradation mechanics of the toolbox, allowing it to reproduce constitutive mRNA and protien expression trajectories. We demonstrate the use of this characterized toolbox in a circuit behavior prediction case study for an incoherent feed-forward loop.

scholarly journals Secondary Metabolites from Leaves of Polyalthia lateriflora and Their Antimicrobial Activity

2020 ◽  
Vol 11 (3) ◽  
pp. 4353-4358
Author(s):  
Saripah Salbiah Syed Abdul Azziz ◽  
Ahmed Kareem Obaid Aldulaimi ◽  
Saadon Abdulla Aowda ◽  
Yuhanis Mhd Bakri ◽  
Ali Arkan Majhool ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Antimicrobial Activity ◽  
Secondary Metabolites ◽  
Betulinic Acid ◽  
2D Nmr ◽  
Significant Inhibition ◽  
Spectroscopic Techniques ◽  
E Coli ◽  
Phytochemical Components ◽  
Antibacterial Potential

The study aimed to isolate and identify the phytochemical components of Polyalthia lateriflora leaves and evaluate the antimicrobial activity. Six well-known compounds, including three triterpene lupeol (1) betulinic acid (2), β-Sitosterol-β-D-glucoside (3) and three oxoaporphine alkaloids O-methylmoschotaline (4), liriodenine (5) and atherosperminine (6). Structural elucidation of compounds were established through spectroscopic techniques such as 1D and 2D NMR (1H and 13C, DEPT, COSY, NOESY, HMBC, HMQC), IR and LC-MS. The isolated compounds and crude extracted were tested for their antibacterial potential against several microorganisms including P. aeruginosa, E. coli, s, S. aureus, B. subtilis and Saccharomyces cerevisiae and its showed significant inhibition toward the organisms species with different concentration range.

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