| 1. |
- Gong, Guiping, et al.
(författare)
-
GTR 2.0: GRNA-tRNA Array and Cas9-NG Based Genome Disruption and Single-Nucleotide Conversion in Saccharomyces cerevisiae
- 2021
-
Ingår i: ACS Synthetic Biology. - : American Chemical Society (ACS). - 2161-5063. ; 10:6, s. 1328-1337
-
Tidskriftsartikel (refereegranskat)abstract
- Targeted genome disruptions and single-nucleotide conversions with the CRISPR/Cas system have greatly facilitated the development of gene therapy, basic biological research, and synthetic biology. With vast progress in this field, there are still aspects to be optimized, including the target range, the ability to multiplex, the mutation efficiency and specificity, as well as the requirement of adjusting protospacer adjacent motifs (PAMs). Here, we report the development of a highly efficient genome disruption and single-nucleotide conversion tool with a gRNA-tRNA array and SpCas9-NG (GTR 2.0). We performed gene disruptions in yeast cells covering all 16 possible NGN PAMs and all 12 possible single-nucleotide conversions (N to N) with near 100% efficiencies. Moreover, we applied GTR 2.0 for multiplexed single-nucleotide conversions, resulting in 66.67% mutation efficiency in simultaneous generation of 4 single-nucleotide conversions in one gene, as well as 100% mutation efficiency for simultaneously generating 2 single-nucleotide conversions in two different genes. GTR 2.0 will substantially expand the scope, efficiency, and capabilities of yeast genome editing, and will be a versatile and invaluable addition to the toolbox of synthetic biology and metabolic engineering.
|
|
| 2. |
- Qin, Ning, 1990, et al.
(författare)
-
Flux regulation through glycolysis and respiration is balanced by inositol pyrophosphates in yeast
- 2023
-
Ingår i: Cell. - : Elsevier BV. - 0092-8674 .- 1097-4172. ; 186:4, s. 748-763.e15
-
Tidskriftsartikel (refereegranskat)abstract
- Although many prokaryotes have glycolysis alternatives, it's considered as the only energy-generating glucose catabolic pathway in eukaryotes. Here, we managed to create a hybrid-glycolysis yeast. Subsequently, we identified an inositol pyrophosphatase encoded by OCA5 that could regulate glycolysis and respiration by adjusting 5-diphosphoinositol 1,2,3,4,6-pentakisphosphate (5-InsP7) levels. 5-InsP7 levels could regulate the expression of genes involved in glycolysis and respiration, representing a global mechanism that could sense ATP levels and regulate central carbon metabolism. The hybrid-glycolysis yeast did not produce ethanol during growth under excess glucose and could produce 2.68 g/L free fatty acids, which is the highest reported production in shake flask of Saccharomyces cerevisiae. This study demonstrated the significance of hybrid-glycolysis yeast and determined Oca5 as an inositol pyrophosphatase controlling the balance between glycolysis and respiration, which may shed light on the role of inositol pyrophosphates in regulating eukaryotic metabolism.
|
|
| 3. |
- Zhang, Bing, 1982, et al.
(författare)
-
A high-gain microstrip grid array antenna on low temperature co-fired ceramic for 60-GHz applications
- 2013
-
Ingår i: 2013 7th European Conference on Antennas and Propagation, EuCAP 2013. - 9788890701832 ; , s. 103-107
-
Konferensbidrag (refereegranskat)abstract
- This paper presents a high-gain microstrip (MS) grid array antenna (GAA) on low temperature co-fired ceramic (LTCC). The high-gain MS GAA includes four sub-antennas. Dimensions of the sub-antenna are 15 × 15 × 0.5 mm3, which is composed of four sub-arrays. Preliminarily tested results show that the sub-antenna features fractional impedance bandwidth (BW) 58-60 GHz and 62-63.5 GHz, 3-dB gain BW 59.8-65 GHz with the maximum gain 17.3 at 64.3 GHz, and vertical beams in the broadside direction from 57-64 GHz. The highgain MS GAA has dimensions of 30 × 30 × 0.5 mm3. Simulated results show that it has impedance BW 55-64.6 GHz, 3-dB gain BW 57.5-64.8 GHz with the maximum gain of 22.8 dBi at 60.8 GHz, and vertical beams in the broadside direction from 57-64 GHz. It is a capable candidate for 60-GHz applications, and even higher frequency band like the 140 and 220 GHz.
|
|
| 4. |
- Zhang, Bing, 1982, et al.
(författare)
-
Integration of Quadruple Linearly-Polarized Microstrip Grid Array Antennas for 60-GHz Antenna-in-Package Applications
- 2013
-
Ingår i: IEEE Transactions on Components, Packaging and Manufacturing Technology. - : Institute of Electrical and Electronics Engineers (IEEE). - 2156-3985 .- 2156-3950. ; 3:8, s. 1293-1300
-
Tidskriftsartikel (refereegranskat)abstract
- This paper demonstrates the integration of quadruple linearly-polarized microstrip grid array antennas in Ferro A6M low-temperature cofired ceramic technology for 60-GHz antenna-in-package (AiP) applications. An emphasis is given to the optimization of via transitions in the design of the low-loss array feeding network based on stripline quarter-wave matched T-junctions for the multilayer AiP structure. This paper also demonstrates the capabilities of a fully automatic probe-based antenna measurement setup for 3-D radiation pattern at 60 GHz. A special focus is placed on the calibration procedure to achieve an overall uncertainty of +/- 1 dB for the measurement of the realized gain of any antenna. The AiP module of dimensions 15x15x1 mm is fabricated and measured. The measured results are in good agreement with the simulated ones, showing that the AiP achieves excellent antenna performance: 10-dB impedance bandwidth (BW) from 50 to 65.6 GHz (or 25.4% at 61.5 GHz), broadside radiation from 55 to 67 GHz (or 19.5%), and 3-dB gain BW from 58.5 to 67 GHz (or 13.8%) with the maximum gain of 15 dBi at 62 GHz.
|
|
| 5. |
- Zhang, B., et al.
(författare)
-
Investigation on 3-D-Printing Technologies for Millimeter-Wave and Terahertz Applications
- 2017
-
Ingår i: Proceedings of the IEEE. - 1558-2256 .- 0018-9219. ; 105:4, s. 723-736
-
Tidskriftsartikel (refereegranskat)abstract
- Three-dimensional-printing technologies have been receiving great attention for a wide variety of applications in recent years for cost effectiveness, eco-friendliness, and process simplicity in complicated structures. This paper describes the-challenges and solutions of applying 3-D-printing technologies in fabricating passive millimeter-wave (mmWave) and terahertz (THz) devices. First, we review the state-of-the-art dielectric 3-D-printed passive mmWave and THz devices. Then, we focus on our novel 3-D-printed metallic passive mmWave and THz devices such as horn antennas and waveguides. Next, we analyze the dimensional tolerance and surface roughness of various 3-D-printing technologies in order to provide a guide for choosing an appropriate technology for specific applications. Finally, we summarize the current work and identify the future studies in material powder refinement, surface treatment, optimization of the print process, development of hybrid dielectric and metallic 3-D-printing technology for realizing not only simple mmWave and THz devices but also sophisticated mmWave and THz systems.
|
|
| 6. |
- Zhang, Yueping, et al.
(författare)
-
A gRNA-tRNA array for CRISPR-Cas9 based rapid multiplexed genome editing in Saccharomyces cerevisiae
- 2019
-
Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723 .- 2041-1723. ; 10:1
-
Tidskriftsartikel (refereegranskat)abstract
- With rapid progress in DNA synthesis and sequencing, strain engineering starts to be the rate-limiting step in synthetic biology. Here, we report a gRNA-tRNA array for CRISPR-Cas9 (GTR-CRISPR) for multiplexed engineering of Saccharomyces cerevisiae. Using reported gRNAs shown to be effective, this system enables simultaneous disruption of 8 genes with 87% efficiency. We further report an accelerated Lightning GTR-CRISPR that avoids the cloning step in Escherichia coli by directly transforming the Golden Gate reaction mix to yeast. This approach enables disruption of 6 genes in 3 days with 60% efficiency using reported gRNAs and 23% using un-optimized gRNAs. Moreover, we applied the Lightning GTR-CRISPR to simplify yeast lipid networks, resulting in a 30-fold increase in free fatty acid production in 10 days using just two-round deletions of eight previously identified genes. The GTR-CRISPR should be an invaluable addition to the toolbox of synthetic biology and automation.
|
|
| 7. |
- Dai, Zongijie, 1986, et al.
(författare)
-
Elucidating the contributions of multiple aldehyde/alcohol dehydrogenases to butanol and ethanol production in Clostridium acetobutylicum
- 2016
-
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322 .- 2045-2322. ; 6
-
Tidskriftsartikel (refereegranskat)abstract
- Ethanol and butanol biosynthesis in Clostridium acetobutylicum share common aldehyde/alcohol dehydrogenases. However, little is known about the relative contributions of these multiple dehydrogenases to ethanol and butanol production respectively. The contributions of six aldehyde/alcohol dehydrogenases of C. acetobutylicum on butanol and ethanol production were evaluated through inactivation of the corresponding genes respectively. For butanol production, the relative contributions from these enzymes were: AdhE1 > BdhB > BdhA approximate to YqhD > SMB_P058 > AdhE2. For ethanol production, the contributions were: AdhE1 > BdhB > YqhD > SMB_P058 > AdhE2 > BdhA. AdhE1 and BdhB are two essential enzymes for butanol and ethanol production. AdhE1 was relatively specific for butanol production over ethanol, while BdhB, YqhD, and SMB_P058 favor ethanol production over butanol. Butanol synthesis was increased in the adhE2 mutant, which had a higher butanol/ethanol ratio (8.15:1) compared with wild type strain (6.65:1). Both the SMB_P058 mutant and yqhD mutant produced less ethanol without loss of butanol formation, which led to higher butanol/ethanol ratio, 10.12:1 and 10.17:1, respectively. To engineer a more efficient butanol-producing strain, adhE1 could be overexpressed, furthermore, adhE2, SMB_P058, yqhD are promising gene inactivation targets. This work provides useful information guiding future strain improvement for butanol production.
|
|
| 8. |
- Hong, Wonbin, et al.
(författare)
-
Guest Editorial Antenna-in-Package, Antenna-on-Chip, Antenna-IC Interface: Joint Design and Cointegration
- 2019
-
Ingår i: IEEE Antennas and Wireless Propagation Letters. - 1548-5757 .- 1536-1225. ; 18:11, s. 2345-2350
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The twenty peer-reviewed letters in this special section examine the design and cointegration of antenna-in-package (AiP), antenna-on-chip (AoC), and antenna ICs (AIC). The letters are categorized in the four distinctive categories: 1) Fabrication technologies (four); 2) Measurement strategies; 3) Applications; and 4) New design and integration strategies. Fruition of major thrusts such as 5G/6G, high-resolution radar and imaging, autonomous driving, and space technology are highly intertwined with the advance of applied electromagnetics. Miniaturization and seamless integration of microwave components and radio systems can enable superior performance, form factor, and cost efficiencies leading to enhanced proliferation of such applications. Historically, radio frequency front ends, antennas, and microwave components have separately evolved using distinct fabrication and measurement technologies.
|
|
| 9. |
- Liu, Can, et al.
(författare)
-
Immobilized Crosslinked Pectinase Preparation on Porous ZSM-5 Zeolites as Reusable Biocatalysts for Ultra-Efficient Hydrolysis of beta-Glycosidic Bonds
- 2021
-
Ingår i: Frontiers in Chemistry. - : Frontiers Media SA. - 2296-2646. ; 9
-
Tidskriftsartikel (refereegranskat)abstract
- In this study, we immobilized pectinase preparation on porous zeolite ZSM-5 as an enzyme carrier. We realized this immobilized enzyme catalyst, pectinase preparation@ZSM-5, via a simple combined strategy involving the van der Waals adsorption of pectinase preparation followed by crosslinking of the adsorbed pectinase preparation with glutaraldehyde over ZSM-5. Conformal pectinase preparation coverage of various ZSM-5 supports was achieved for the as-prepared pectinase preparation@ZSM-5. The porous pectinase preparation@ZSM-5 catalyst exhibited ultra-efficient biocatalytic activity for hydrolyzing the beta-glycosidic bonds in the model substrate 4-nitrophenyl beta-D-glucopyranoside, with a broad operating temperature range, high thermal stability, and excellent reusability. The relative activity of pectinase preparation@ZSM-5 at a high temperature (70 degrees C) was nine times higher than that of free pectinase preparation. Using thermal inactivation kinetic analysis based on the Arrhenius law, pectinase preparation@ZSM-5 showed higher activation energy for denaturation (315 kJ mol(-1)) and a longer half-life (62 min(-1)) than free pectinase preparation. Moreover, a Michaelis-Menten enzyme kinetic analysis indicated a higher maximal reaction velocity for pectinase preparation@ZSM-5 (0.22 mu mol mg(-1) min(-1)). This enhanced reactivity was attributed to the microstructure of the immobilized pectinase preparation@ZSM-5, which offered a heterogeneous reaction system that decreased the substrate-pectinase preparation binding affinity and modulated the kinetic characteristics of the enzyme. Additionally, pectinase preparation@ZSM-5 showed the best ethanol tolerance among all the reported pectinase preparation-immobilized catalysts, and an activity 247% higher than that of free pectinase preparation at a 10% (v/v) ethanol concentration was measured. Furthermore, pectinase preparation@ZSM-5 exhibited potential for practical engineering applications, promoting the hydrolysis of beta-glycosidic bonds in baicalin to convert it into baicalein. This was achieved with a 98% conversion rate, i.e., 320% higher than that of the free enzyme.
|
|
| 10. |
- Liu, Zihe, 1984, et al.
(författare)
-
Synthetic Biology of Yeast
- 2019
-
Ingår i: Biochemistry. - : American Chemical Society (ACS). - 1520-4995 .- 0006-2960. ; 58:11, s. 1511-1520
-
Forskningsöversikt (refereegranskat)abstract
- With the rapid development of DNA synthesis and next-generation sequencing, synthetic biology that aims to standardize, modularize, and innovate cellular functions, has achieved vast progress. Here we review key advances in synthetic biology of the yeast Saccharomyces cerevisiae, which serves as an important eukaryal model organism and widely applied cell factory. This covers the development of new building blocks, i.e., promoters, terminators and enzymes, pathway engineering, tools developments, and gene circuits utilization. We will also summarize impacts of synthetic biology on both basic and applied biology, and end with further directions for advancing synthetic biology in yeast.
|
|
| 11. |
- Zhang, Yueping, et al.
(författare)
-
Engineering yeast metabolism for production of terpenoids for use as perfume ingredients, pharmaceuticals and biofuels
- 2017
-
Ingår i: FEMS Yeast Research. - : Oxford University Press (OUP). - 1567-1356 .- 1567-1364. ; 17:8
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Terpenoids represent a large class of natural products with significant commercial applications. These chemicals are currently mainly obtained through extraction from plants and microbes or through chemical synthesis. However, these sources often face challenges of unsustainability and low productivity. In order to address these issues, Escherichia coli and yeast have been metabolic engineered to produce non-native terpenoids. With recent reports of engineering yeast metabolism to produce several terpenoids at high yields, it has become possible to establish commercial yeast production of terpenoids that find applications as perfume ingredients, pharmaceuticals and advanced biofuels. In this review, we describe the strategies to rewire the yeast pathway for terpenoid biosynthesis. Recent advances will be discussed together with challenges and perspectives of yeast as a cell factory to produce different terpenoids.
|
|
| 12. |
- Zhao, Yijin, et al.
(författare)
-
Production of β-carotene in Saccharomyces cerevisiae through altering yeast lipid metabolism
- 2021
-
Ingår i: Biotechnology and Bioengineering. - : Wiley. - 0006-3592 .- 1097-0290. ; 118:5, s. 2043-2052
-
Tidskriftsartikel (refereegranskat)abstract
- Saccharomyces cerevisiae is a widely used cell factory for the production of fuels and chemicals. However, as a non-oleaginous yeast, S. cerevisiae has a limited production capacity for lipophilic compounds, such as β-carotene. To increase its accumulation of β-carotene, we engineered different lipid metabolic pathways in a β-carotene producing strain and investigated the relationship between lipid components and the accumulation of β-carotene. We found that overexpression of sterol ester synthesis genes ARE1 and ARE2 increased β-carotene yield by 1.5-fold. Deletion of phosphatidate phosphatase (PAP) genes (PAH1, DPP1, and LPP1) also increased β-carotene yield by twofold. Combining these two strategies resulted in a 2.4-fold improvement in β-carotene production compared with the starting strain. These results demonstrated that regulating lipid metabolism pathways is important for β-carotene accumulation in S. cerevisiae, and may also shed insights to the accumulation of other lipophilic compounds in yeast.
|
|
| 13. |
- Zhao, Yijin, et al.
(författare)
-
Protein engineering of invertase for enhancing yeast dough fermentation under high-sucrose conditions
- 2023
-
Ingår i: Folia Microbiologica. - : Springer Science and Business Media LLC. - 0015-5632 .- 1874-9356. ; 68:2, s. 207-217
-
Tidskriftsartikel (refereegranskat)abstract
- During yeast dough fermentation, such as the high-sucrose bread-making process, the yeast cells are subjected to considerable osmotic stress, resulting in poor outcomes. Invertase is important for catalyzing the irreversible hydrolysis of sucrose to free glucose and fructose, and decreasing the catalytic activity of the invertase may reduce the glucose osmotic stress on the yeast. In this study, we performed structural design and site-directed mutagenesis (SDM) on the Saccharomyces cerevisiae invertase (ScInV) in an Escherichia coli expression system to study the catalytic activity of ScInV mutants in vitro. In addition, we generated the same mutation sites in the yeast endogenous genome and tested their invertase activity in yeast and dough fermentation ability. Our results indicated that appropriately reduced invertase activity of yeast ScInV can enhance dough fermentation activity under high-sucrose conditions by 52%. Our systems have greatly accelerated the engineering of yeast endogenous enzymes both in vitro and in yeast, and shed light on future metabolic engineering of yeast.
|
|
