scholarly journals Metagenomics, gene discovery and the ideal biocatalyst

2004 ◽  
Vol 32 (2) ◽  
pp. 298-302 ◽  
Author(s):  
D.A. Cowan ◽  
A. Arslanoglu ◽  
S.G. Burton ◽  
G.C. Baker ◽  
R.A. Cameron ◽  
...  

With the rapid development of powerful protein evolution and enzyme-screening technologies, there is a growing belief that optimum conditions for biotransformation processes can be established without the constraints of the properties of the biocatalyst. These technologies can then be applied to find the ‘ideal biocatalyst’ for the process. In identifying the ideal biocatalyst, the processes of gene discovery and enzyme evolution play major roles. However, in order to expand the pool genes for in vitro evolution, new technologies, which circumvent the limitations of microbial culturability, must be applied. These technologies, which currently include metagenomic library screening, gene-specific amplification methods and even full metagenomic sequencing, provide access to a volume of ‘sequence space’ that is not addressed by traditional screening.

2017 ◽  
Vol 2 (3) ◽  
pp. 150-163
Author(s):  
Ekajayanti Kining ◽  
Syamsul Falah ◽  
Novik Nurhidayat

Pseudomonas aeruginosa is one of opportunistic pathogen forming bacterial biofilm. The biofilm sustains the bacterial survival and infections. This study aimed to assess the activity of water extract of papaya leaves on inhibition of cells attachment, growth and degradation of the biofilm using crystal violet (CV) biofilm assay. Research results showed that water extract of papaya leaves contains alkaloids, tanins, flavonoids, and steroids/terpenoids and showed antibacterial activity and antibiofilm against P. aeruginosa. Addition of extract can inhibit the cell attachment and was able to degrade the biofilm of 40.92% and 48.058% respectively at optimum conditions: extract concentration of 25% (v/v), temperature 37.5 °C and contact time 45 minutes. With a concentration of 25% (v/v), temperature of 50 °C and the contact time of 3 days, extract of papaya leaves can inhibit the growth of biofilms of 39.837% v/v.


2019 ◽  
Vol 19 (3) ◽  
pp. 147-171
Author(s):  
Cia-Hin Lau ◽  
Chung Tin

Gene therapy and transgenic research have advanced quickly in recent years due to the development of CRISPR technology. The rapid development of CRISPR technology has been largely benefited by chemical engineering. Firstly, chemical or synthetic substance enables spatiotemporal and conditional control of Cas9 or dCas9 activities. It prevents the leaky expression of CRISPR components, as well as minimizes toxicity and off-target effects. Multi-input logic operations and complex genetic circuits can also be implemented via multiplexed and orthogonal regulation of target genes. Secondly, rational chemical modifications to the sgRNA enhance gene editing efficiency and specificity by improving sgRNA stability and binding affinity to on-target genomic loci, and hence reducing off-target mismatches and systemic immunogenicity. Chemically-modified Cas9 mRNA is also more active and less immunogenic than the native mRNA. Thirdly, nonviral vehicles can circumvent the challenges associated with viral packaging and production through the delivery of Cas9-sgRNA ribonucleoprotein complex or large Cas9 expression plasmids. Multi-functional nanovectors enhance genome editing in vivo by overcoming multiple physiological barriers, enabling ligand-targeted cellular uptake, and blood-brain barrier crossing. Chemical engineering can also facilitate viral-based delivery by improving vector internalization, allowing tissue-specific transgene expression, and preventing inactivation of the viral vectors in vivo. This review aims to discuss how chemical engineering has helped improve existing CRISPR applications and enable new technologies for biomedical research. The usefulness, advantages, and molecular action for each chemical engineering approach are also highlighted.


2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Hee-Gyeong Yi ◽  
Hyeonji Kim ◽  
Junyoung Kwon ◽  
Yeong-Jin Choi ◽  
Jinah Jang ◽  
...  

AbstractRapid development of vaccines and therapeutics is necessary to tackle the emergence of new pathogens and infectious diseases. To speed up the drug discovery process, the conventional development pipeline can be retooled by introducing advanced in vitro models as alternatives to conventional infectious disease models and by employing advanced technology for the production of medicine and cell/drug delivery systems. In this regard, layer-by-layer construction with a 3D bioprinting system or other technologies provides a beneficial method for developing highly biomimetic and reliable in vitro models for infectious disease research. In addition, the high flexibility and versatility of 3D bioprinting offer advantages in the effective production of vaccines, therapeutics, and relevant delivery systems. Herein, we discuss the potential of 3D bioprinting technologies for the control of infectious diseases. We also suggest that 3D bioprinting in infectious disease research and drug development could be a significant platform technology for the rapid and automated production of tissue/organ models and medicines in the near future.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Olanrewaju Ayodeji Durojaye ◽  
Nkwachukwu Oziamara Okoro ◽  
Arome Solomon Odiba

Abstract Background The novel coronavirus SARS-CoV-2 is currently a global threat to health and economies. Therapeutics and vaccines are in rapid development; however, none of these therapeutics are considered as absolute cure, and the potential to mutate makes it necessary to find therapeutics that target a highly conserved regions of the viral structure. Results In this study, we characterized an essential but poorly understood coronavirus accessory X4 protein, a core and stable component of the SARS-CoV family. Sequence analysis shows a conserved ~ 90% identity between the SARS-CoV-2 and previously characterized X4 protein in the database. QMEAN Z score of the model protein shows a value of around 0.5, within the acceptable range 0–1. A MolProbity score of 2.96 was obtained for the model protein and indicates a good quality model. The model has Ramachandran values of φ = − 57o and ψ = − 47o for α-helices and values of φ = − 130o and ψ = + 140o for twisted sheets. Conclusions The protein data obtained from this study provides robust information for further in vitro and in vivo experiment, targeted at devising therapeutics against the virus. Phylogenetic analysis further supports previous evidence that the SARS-CoV-2 is positioned with the SL-CoVZC45, BtRs-BetaCoV/YN2018B and the RS4231 Bat SARS-like corona viruses.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1125
Author(s):  
Raluca Nicu ◽  
Florin Ciolacu ◽  
Diana E. Ciolacu

Nanocelluloses (NCs), with their remarkable characteristics, have proven to be one of the most promising “green” materials of our times and have received special attention from researchers in nanomaterials. A diversity of new functional materials with a wide range of biomedical applications has been designed based on the most desirable properties of NCs, such as biocompatibility, biodegradability, and their special physicochemical properties. In this context and under the pressure of rapid development of this field, it is imperative to synthesize the successes and the new requirements in a comprehensive review. The first part of this work provides a brief review of the characteristics of the NCs (cellulose nanocrystals—CNC, cellulose nanofibrils—CNF, and bacterial nanocellulose—BNC), as well as of the main functional materials based on NCs (hydrogels, nanogels, and nanocomposites). The second part presents an extensive review of research over the past five years on promising pharmaceutical and medical applications of nanocellulose-based materials, which have been discussed in three important areas: drug-delivery systems, materials for wound-healing applications, as well as tissue engineering. Finally, an in-depth assessment of the in vitro and in vivo cytotoxicity of NCs-based materials, as well as the challenges related to their biodegradability, is performed.


2000 ◽  
Vol 29 (4) ◽  
pp. 849-854 ◽  
Author(s):  
Ronaldo Reis Jr. ◽  
Lima ◽  
Evaldo F. Vilela ◽  
Raimundo S. Barros

To accomplish systematic studies with coffee leafminer, it is necessary to establish a mass rearing system under artificial conditions. It is possible to rear this species, from egg to adult, under laboratory conditions, without using coffee seedlings but detached leaves maintained in vitro. Synthetic cytokinins are routinely used for maintenance of plant cell and plant tissues in vitro. Two plant growth regulators, benzyladenin and kinetin, in concentrations 10-6 and 10-7 M were used to mantain the leaves. Green leaves collected in the field were maintained in the solution to be tested. Distilled water served as control. The experiment lasted 30 days, a period longer than the necessary for the complete development of the insect. Both artificial cytokinines indeed increased the lifetime of the coffee leaves, maintaining them green and healthy. Leaves placed in the cages for oviposition were attractive to the insect, with significant number of eggs per leaf. In most cases, eggs resulted in individuals that completed the whole developmental cycle. Tests with regulator in different concentrations with healthy leaves showed efficiency. However, we believe that hormone concentrations to be used with mined leaves should be larger, because these when maintained at 10-7 M leaves did not present a satisfactory lifetime. Therefore, tests with mined leaves with different hormone concentrations should be made to find out the ideal concentration for leaf survival. In our laboratory we are successfully using 10-6 M benzyladenin for the maintenance of mined leaves.


2001 ◽  
Vol 45 (3) ◽  
pp. 727-733 ◽  
Author(s):  
Ge Wang ◽  
Trevor J. M. Wilson ◽  
Qin Jiang ◽  
Diane E. Taylor

ABSTRACT In this study, we systematically examined in vitro frequencies and spectra of the spontaneous mutations in Helicobacter pylori that confer resistance to clarithromycin (Clar), metronidazole (Mtzr), amoxicillin (Amxr), ciprofloxacin (Cipr), and rifampin (Rifr). The mutation rate of Rifror Cipr determined in a fluctuation assay is 1 × 10−8 to 2 × 10−8 per cell per division. In contrast, the mutation rates of Clar, Mtzr, and Amxr are much lower (<10−9). However, Mtzr mutants could be readily selected in vitro by using the serial passage method, suggesting that the mutagenic effect and selective effect of a sublethal dose of metronidazole contribute to the rapid development of Mtzr. Analysis of spontaneous Rifr, Clar, and Cipr mutants confirmed previous results indicating that mutations within therpoB gene, the 23S rRNA gene, and thegyrA gene, respectively, are responsible; also, several new mutant alleles were identified. Mtzrmutants resulted most frequently, but not always, from mutations in the rdxA gene. DNA fragments containing each mutant allele could readily transform susceptibleH. pylori strains to resistance, confirming that each mutant allele is responsible for the resistance phenotype.


2021 ◽  
Vol 22 (7) ◽  
pp. 3311
Author(s):  
Satish Kumar ◽  
Joanne E. Curran ◽  
Kashish Kumar ◽  
Erica DeLeon ◽  
Ana C. Leandro ◽  
...  

The in vitro modeling of cardiac development and cardiomyopathies in human induced pluripotent stem cell (iPSC)-derived cardiomyocytes (CMs) provides opportunities to aid the discovery of genetic, molecular, and developmental changes that are causal to, or influence, cardiomyopathies and related diseases. To better understand the functional and disease modeling potential of iPSC-differentiated CMs and to provide a proof of principle for large, epidemiological-scale disease gene discovery approaches into cardiomyopathies, well-characterized CMs, generated from validated iPSCs of 12 individuals who belong to four sibships, and one of whom reported a major adverse cardiac event (MACE), were analyzed by genome-wide mRNA sequencing. The generated CMs expressed CM-specific genes and were highly concordant in their total expressed transcriptome across the 12 samples (correlation coefficient at 95% CI =0.92 ± 0.02). The functional annotation and enrichment analysis of the 2116 genes that were significantly upregulated in CMs suggest that generated CMs have a transcriptomic and functional profile of immature atrial-like CMs; however, the CMs-upregulated transcriptome also showed high overlap and significant enrichment in primary cardiomyocyte (p-value = 4.36 × 10−9), primary heart tissue (p-value = 1.37 × 10−41) and cardiomyopathy (p-value = 1.13 × 10−21) associated gene sets. Modeling the effect of MACE in the generated CMs-upregulated transcriptome identified gene expression phenotypes consistent with the predisposition of the MACE-affected sibship to arrhythmia, prothrombotic, and atherosclerosis risk.


2009 ◽  
Vol 16 (6) ◽  
pp. 798-805 ◽  
Author(s):  
Soad Nady ◽  
James Ignatz-Hoover ◽  
Mohamed T. Shata

ABSTRACT Recently, a new lineage of CD4+ T cells in humans and in mice has been reported. This T helper cell secretes interleukin-17 (IL-17) and has been defined as T helper 17 (Th17). Th17 cells express the IL-23 receptor (IL-23R) and play an important pathogenic role in different inflammatory conditions. In this study, our aim was to characterize the optimum conditions for isolation and propagation of human peripheral blood Th17 cells in vitro and the optimum conditions for isolation of Th17 clones. To isolate Th17 cells, two steps were taken. Initially, we negatively isolated CD4+ T cells from peripheral blood mononuclear cells of a normal human blood donor. Then, we isolated the IL-23R+ cells from the CD4+ T cells. Functional studies revealed that CD4+ IL-23R+ cells could be stimulated ex vivo with anti-CD3/CD28 to secrete both IL-17 and gamma interferon (IFN-γ). Furthermore, we expanded the CD4+ IL-23R+ cells for 1 week in the presence of anti-CD3/CD28, irradiated autologous feeder cells, and different cytokines. Our data indicate that cytokine treatment increased the number of propagated cells 14- to 99-fold. Functional evaluation of the expanded number of CD4+ IL-23R+ cells in the presence of different cytokines with anti-CD3/CD28 revealed that all cytokines used (IL-2, IL-7, IL-12, IL-15, and IL-23) increased the amount of IFN-γ secreted by IL-23R+ CD4+ cells at different levels. Our results indicate that IL-7 plus IL-12 was the optimum combination of cytokines for the expansion of IL-23R+ CD4+ cells and the secretion of IFN-γ, while IL-12 preferentially stimulated these cells to secrete predominately IL-17.


Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1043
Author(s):  
Abdallah A. Smadi ◽  
Babatunde Tobi Ajao ◽  
Brian K. Johnson ◽  
Hangtian Lei ◽  
Yacine Chakhchoukh ◽  
...  

The integration of improved control techniques with advanced information technologies enables the rapid development of smart grids. The necessity of having an efficient, reliable, and flexible communication infrastructure is achieved by enabling real-time data exchange between numerous intelligent and traditional electrical grid elements. The performance and efficiency of the power grid are enhanced with the incorporation of communication networks, intelligent automation, advanced sensors, and information technologies. Although smart grid technologies bring about valuable economic, social, and environmental benefits, testing the combination of heterogeneous and co-existing Cyber-Physical-Smart Grids (CP-SGs) with conventional technologies presents many challenges. The examination for both hardware and software components of the Smart Grid (SG) system is essential prior to the deployment in real-time systems. This can take place by developing a prototype to mimic the real operational circumstances with adequate configurations and precision. Therefore, it is essential to summarize state-of-the-art technologies of industrial control system testbeds and evaluate new technologies and vulnerabilities with the motivation of stimulating discoveries and designs. In this paper, a comprehensive review of the advancement of CP-SGs with their corresponding testbeds including diverse testing paradigms has been performed. In particular, we broadly discuss CP-SG testbed architectures along with the associated functions and main vulnerabilities. The testbed requirements, constraints, and applications are also discussed. Finally, the trends and future research directions are highlighted and specified.


Sign in / Sign up

Export Citation Format

Share Document