Biotechnology for Biofuels
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2018
·Vol. 11
·期 1
·1-15
·
IF 5.497
Xu Chunxiao,Sun Tao,Li Shubin,Chen Lei,Zhang Weiwen
Background Cadmium has been a significant threat to environment and human health due to its high toxicity and wide application in fossil-fuel burning and battery industry. Cyanobacteria are one of the most dominant prokaryotes, and the previous studies suggested that they could be valuable in removing Cd2+ from waste water. However, currently, the tolerance to cadmium is very low in cyanobacteria. To further engineer cyanobacteria for the environmental application, it is thus necessary to determine the mechanism that they respond to high concentration of cadmium.Results In this study, a robust strain of Synechocystis PCC 6803 (named ALE-9.0) tolerant to CdSO4 with a concentration up to 9.0 µM was successfully isolated via adaptive laboratory evolution over 802-day continuous passages under cadmium stress. Whole-genome re-sequencing was then performed and nine mutations were identified for the evolved strain compared to the wild-type strain. Among these mutations, a large fragment deletion in slr0454 encoding a cation or drug efflux system protein was found to contribute directly to the resistance to Cd2+ stress. In addition, five other mutations were also demonstrated related to the improved Cd2+ tolerance in ALE-9.0. Moreover, the evolved ALE-9.0 strain was found to obtain cross tolerance to some other heavy metals like zinc and cobalt as well as higher resistance to high light.Conclusion sThe work here identified six genes and their mutations related to Cd2+ tolerance in Synechocystis PCC 6803, and demonstrated the feasibility of adaptive laboratory evolution in tolerance modifications. This work also provided valuable information regarding the cadmium tolerance mechanism in Synechocystis PCC 6803, and useful insights for cyanobacterial robustness and tolerance engineering.
研究领域:
环境科学
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微生物学
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基因组学
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生物技术
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DOI
PubMed
高影响因子
Frontiers in Microbiology
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2020
·
IF 4.236
Wang Xiaoshuai,Chen Lei,Liu Jing,Sun Tao,Zhang Weiwen
myo-inositol (MI) is an essential growth factor, nutritional source, and important precursor for many derivatives like D-chiro-inositol. In this study, attempts were made to achieve the “green biosynthesis” of MI in a model photosynthetic cyanobacterium Synechocystis sp. PCC 6803. First, several genes encoding myo-inositol-1-phosphate synthases and myo-inositol-1-monophosphatase, catalyzing the first or the second step of MI synthesis, were introduced, respectively, into Synechocystis. The results showed that the engineered strain carrying myo-inositol-1-phosphate synthase gene from Saccharomyces cerevisiae was able to produce MI at 0.97 mg L–1. Second, the combined overexpression of genes related to the two catalyzing processes increased the production up to 1.42 mg L–1. Third, to re-direct more cellular carbon flux into MI synthesis, an inducible small RNA regulatory tool, based on MicC-Hfq, was utilized to control the competing pathways of MI biosynthesis, resulting in MI production of ∼7.93 mg L–1. Finally, by optimizing the cultivation condition via supplying bicarbonate to enhance carbon fixation, a final MI production up to 12.72 mg L–1 was achieved, representing a ∼12-fold increase compared with the initial MI-producing strain. This study provides a light-driven green synthetic strategy for MI directly from CO2 in cyanobacterial chassis and represents a renewable alternative that may deserve further optimization in the future.
研究领域:
微生物学
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生物技术
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合成生物学
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DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2024
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IF 7.1
Tong Zhang,Shubin Li,Lei Chen,Weiwen Zhang,Tao Sun
Cyanobacteria are known to be photoautotrophic cell factories capable of converting CO2 into valuable chemicals. The newly discovered marine cyanobacterium Synechococcus sp. PCC 11901 (hereafter PCC 11901) offers several advantages like rapid growth, high biomass, and high salinity tolerance, representing a promising chassis. To promote its application, we developed genetic toolboxes applicable to PCC 11901 in this study. First, a cobalamin (VB12)-independent chassis was constructed, allowing for cheaper cultivation. Second, genome copy numbers and transformation methods were, respectively, measured and optimized. Then, 14 neutral sites were identified and characterized within the genome PCC 11901, providing locations for genetic integration of exogenous cassettes. Subsequently, promoter libraries were developed, reaching an expression range of approximately 800 folds for constitutive promoters and an induction fold of up to approximately 400 for inducible promotors, respectively. As a proof of concept, natural production of the total lipid and phycocyanin was investigated using VB12-independent chassis, which realized an increase of 14.91% with lipid content compared with that of the wild-type strain. Further, we engineered the synthetic pathways of glucosylglycerol (GG) into PCC 11901 using the established toolboxes, reaching 590.41 ± 21.48 mg/L for GG production and self-sedimentation in photoreactors with the highest OD750 nm at 17.57 ± 0.77. Finally, the GG-producing strain grew well in seawater, reaching 324.50 ± 5.34 mg/L in shaking flask, which provided new strategies for cyanobacteria cultivation and production. Our work here made it possible to develop the fast-growing PCC 11901 as efficient carbon-neutral cell factory in the future.
研究领域:
合成生物学
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微生物学
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生物工程
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DOI
高影响因子
Frontiers in Bioengineering and Biotechnology
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2021
·
IF 5.89
Yang Ruigang,Zhu Lingyun,Li Tao,Zhu Lv-yun,Ye Zi,Zhang Dongyi
Metabolic engineering of cyanobacteria has received much attention as a sustainable strategy to convert CO2 to various longer carbon chain fuels. Pinene has become increasingly attractive since pinene dimers contain high volumetric energy and have been proposed to act as potential aircraft fuels. However, cyanobacteria cannot directly convert geranyl pyrophosphate into pinene due to the lack of endogenous pinene synthase. Herein, we integrated the gene encoding Abies grandis pinene synthase into the model cyanobacterium Synechococcus sp. PCC 7002 through homologous recombination. The genetically modified cyanobacteria achieved a pinene titer of 1.525 ± 0.l45 mg L−1 in the lab-scale tube photobioreactor with CO2 aeration. Specifically, the results showed a mixture of α- and β-pinene (∼33:67 ratio). The ratio of β-pinene in the product was significantly increased compared with that previously reported in the engineered Escherichia coli. Furthermore, we investigated the photoautotrophic growth performances of Synechococcus overlaid with different concentrations of dodecane. The work demonstrates that the engineered Synechococcus is a suitable potential platform for β-pinene production.
研究领域:
生物技术
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环境科学
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生物化学
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DOI
PubMed
高影响因子
Biotechnology for Biofuels
·
2018
·Vol. 11
·期 1
·1-16
·
IF 5.497
Sun Tao,Li Shubin,Song Xinyu,Pei Guangsheng,Diao Jinjin,Cui Jinyu,Shi Mengliang,Chen Lei,Zhang Weiwen
Background Photosynthetic cyanobacteria have attracted a significant attention as promising chassis to produce renewable fuels and chemicals due to their capability to utilizing solar energy and CO 2 . Notably, the enhancing supply of key precursors like malonyl-CoA would benefit the production of many bio-compounds. Nevertheless, the lacking of genetic tools in cyanobacteria, especially the knockdown strategies for essential pathways, has seriously restricted the attempts to re-direct carbon flux from the central carbohydrate metabolism to the synthesis of bioproducts. Results Aiming at developing new genetic tools, two small RNA regulatory tools are reported for the model cyanobacterium Synechocystis sp. PCC6803, based on paired termini RNAs as well as the exogenous Hfq chaperone and MicC scaffold (Hfq-MicC) previously developed in Escherichia coli . Both regulatory tools functioned well in regulating exogenous reporter gene lacZ and endogenous glgC gene in Synechocystis sp. PCC6803, achieving a downregulation of gene expression up to 90% compared with wildtype. In addition, the Hfq-MicC tool was developed to simultaneously regulate multiple genes related to essential fatty acids biosynthesis, which led to decreased fatty acids content by 11%. Furthermore, aiming to re-direct the carbon flux, the Hfq-MicC tool was utilized to interfere the competing pathway of malonyl-CoA, achieving an increased intracellular malonyl-CoA abundance up to 41% (~ 698.3 pg/mL/OD 730 nm ) compared to the wildtype. Finally, the Hfq-MicC system was further modified into an inducible system based on the theophylline-inducible riboswitch. Conclusions In this study, two small RNA regulatory tools for manipulating essential metabolic pathways and re-directing carbon flux are reported for Synechocystis sp. PCC6803. The work introduces efficient and valuable metabolic regulatory strategies for photosynthetic cyanobacteria.
研究领域:
微生物学
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代谢工程
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合成生物学
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DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2023
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IF 15.1
Qinghong Ji,Xinxin Sheng,Xiaolong Li,Shuang Liu,Qiufei Chen,Pengzong Guo,Yabi Yang,Youyou Huang,Guoliang Zhang,Xiang Lu,Jinping Qu
Infrared stealth materials are in increasing demand with the development of infrared detection technology. However, most reported materials focus solely on emissivity control or temperature control, resulting in brief and less ideal infrared stealth effect. Herein, a double layer MXene@polyvinyl alcohol (PVA)/phase change capsules (PCC) aerogel composite inspired by the skin-fat structure of camel for infrared camouflage was successfully fabricated via a facile freeze-drying followed by spraying method. The PVA/PCC aerogel composite with high latent heat (155.2 J/g) and strong mechanical properties (772.6 kPa), obtained by an in-situ one-step method, is adopted as a temperature control layer, benefiting from the prominent thermal insulation of porous structure and effective heat absorption of PCC. The low emissivity (0.249) of the MXene layer on the surface of aerogel composite makes its radiation temperature recognized by the thermal imager much lower than its actual temperature. By integrating thermal insulation, heat absorption and emissivity reduction strategies, MXene@PVA/PCC aerogel shows no difference with the background in the infrared thermal imager (radiation temperature difference less than 10 °C), achieving superior infrared stealth for medium and low temperature scenarios, and provides novel ideas for developing more high-performance infrared stealth materials.
研究领域:
材料科学
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纳米技术
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热工程
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红外技术
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DOI
高影响因子
MOLECULES
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2020
·Vol. 25
·期 9
·2109
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IF 3.267
Changzhou Chen,Peng Liu,Haihong Xia,Minghao Zhou,Jiaping Zhao,Brajendra K. Sharma,Jianchun Jiang
It is of great importance to explore the selective hydrogenolysis of β-O-4 linkages, which account for 45–60% of all linkages in native lignin, to produce valued-added chemicals and fuels from biomass employing UV light as catalyst. TiO2exhibited satisfactory catalytic performances in various photochemical reactions, due to its versatile advantages involving high catalytic activity, low cost and non-toxicity. In this work, 20 wt.% Ni/TiO2and oxidant PCC (Pyridinium chlorochromate) were employed to promote the cleavage of β-O-4 alcohol to obtain high value chemicals under UV irradiation at room temperature. The Ni/TiO2photocatalyst can be magnetically recovered and efficiently reused in the following four consecutive recycling tests in the cleavage of β-O-4 ether bond in lignin. Mechanism studies suggested that the oxidation of β-O-4 alcohol to β-O-4 ketone by oxidant PCC first occurred during the reaction, and was followed by the photocatalysis of the obtained β-O-4 ketone to corresponding acetophenone and phenol derivates. Furthermore, the system was tested on a variety of lignin model substrates containing β-O-4 linkage for the generation of fragmentation products in good to excellent results.Keywords:lignin;β-O-4;photocatalyst;Ni/TiO2;oxidant PCC
研究领域:
化学工程
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环境科学
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PubMed
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
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2019
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IF 3.218
Huanhuan Zhang,Xuan Cai,Hongli Zhao,Wenqian Sun,Zhenxing Wang,Minbo Lan
Developing nanomaterials as alternatives of enzymes is of great significance to realize qualification and quantitation of superoxide anion (O 2 − ), which has been proved to play a crucial role in physiological condition. In this work, a novel electrochemical catalyst of cobalt nanoparticle doped porous cubic carbon (Co-PCC) was prepared through the calcination of zeolitic imidazolate framework-67 (ZIF-67), which was obtained from one-step synthesis. Then Co-PCC was used to construct enzyme-free electrochemical sensor for the detection of O 2 − . The response of H 2 O 2 , though much lower than that of O 2 − , was also caught by the Co-PCC/SPCE. The fabricated sensor exhibited obvious response towards O 2 − in the range of 0.8–76.8 μM (R 2 = 0.997) with a high sensitivity of 3.59 × 10 −4 mA μM −1 cm −2 and a limit of detection of 0.41 μM (S/N = 3). In addition, the proposed sensor can be used to detect O 2 − released from SK-BR-3 cells, which makes it possible to monitor the dynamic change of O 2 − in living cells.
研究领域:
生物化学
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材料科学
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医学检测
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DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2022
·Vol. 140
·期 6
·e53427
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IF 3.057
Bing Yin,Xujiang Hua,Fangyu Fan,Dongmei Qi,Kailu Han,Youqing Hou,Dongshuai Hou
Improving the permeability of concrete is one of the important measures to extend the service life of concrete. In addition, for marine engineering, sewerage projects, and so on, mechanical stability and microbial induced corrosion of concrete structures cannot be ignored. We demonstrated a method to prepare high-performance super-hydrophobic (SHP) coating using functional zirconium phosphate (ZrP) and polydopamine (PDA) as the primary materials. The micro-nano rough structures were constructed on the concrete surface by alternating organic–inorganic assembly guided by each other. The coatings' apparent morphology, composition, and structure were analyzed using various surface analysis techniques. Based on the construction of micro-nano rough structures by the induced assembly of functional ZrP, the silane treatment significantly improved the water contact angle of the coating (WCA = 154° ± 3°), and the coating exhibited relatively high wear resistance, reaching 135° WCA even after 30 friction cycles. The water absorption of the specimens treated with the SHP composite coating was reduced by 79% to treated with silane. Meanwhile, the SHP composite coating showed excellent antimicrobial and anti-ice properties, due to the role of the functional ZrP and alternating organic–inorganic assembly. It was expected that the composite coating might potentially promote and accelerate applied superhydrophobic anticorrosive coating development for marine concrete durability.
研究领域:
材料科学
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土木工程
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化学工程
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DOI
高影响因子
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
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2023
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IF 3.1
Yilan Li,Haowei Wang,Lingfang Tang,Huawei Zhu
Photosynthetic microorganisms such as cyanobacteria can convert photons into electrons, providing ideal eco-friendly materials for converting solar energy into electricity. However, the electrons are hardly transported outside the cyanobacterial cells due to the insulation feature of the cell wall/membrane. Various nanomaterials have been reported to enhance extracellular electron transfer of heterotrophic electroactive microorganisms, but its effect on intact photosynthetic microorganisms remains unclear. In this study, we investigated the effect of six different nanomaterials on the photocurrent generation of cyanobacterium Synechocystis sp. PCC 6803. Among the nanomaterials tested, titanium dioxide (TiO 2 ) nanoparticles increased the photocurrent generation of Synechocystis sp. PCC 6803 up to four-fold at the optimum concentration of 2 mg/mL. Transmission electron microscopy and scanning electron microscopy showed that TiO 2 bound to cyanobacterial cells and likely penetrated inside of cell membrane. Photochemical analyses for photosystems showed that TiO 2 blocked the electrons transfer downstream in PS I, implying a possible extracellular electron pathway mediated by TiO 2 . This study provides an alternative approach for enhancing the photocurrent generation of cyanobacteria, showing the potential of photosynthetic-nanomaterial hybrids.
研究领域:
生物技术
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纳米技术
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环境科学
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微生物学
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DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 6
·1-8
·
IF 5.479
Li Yufei,Zhang Huanhuan,Cai Xuan,Zhao Hongli,Magdassi Shlomo,Lan Minbo
Two kinds of carbon-based nanozymes were constructed from the same precursor of zeolitic imidazolate framework-8 (ZIF-8) for O 2 •− determination. Hollow carbon cubic nanomaterial (labelled as HCC) was obtained by chemically etching ZIF-8 with tannic acid and a subsequent calcination. A porous carbon cubic nanomaterial (labelled as PCC) was prepared by directly pyrolysis. Then HCC and PCC were immobilized on the surface of screen printed carbon electrodes (SPCE), fabricating HCC and PCC modified electrodes (denoted as HCC/SPCE and PCC/SPCE). HCC/SPCE, best operated at −0.5 V (vs. Ag/AgCl), has a sensitivity of 6.55 × 10 2 nA μM −1 cm −2 with a detection limit of 207 nM (at S/ N = 3) for O 2 •− sensing. And PCC/SPCE, best operated at −0.4 V (vs. Ag/AgCl), exhibited a superior performance for O 2 •− detection with a sensitivity of 1.14 × 10 3 nA μM −1 cm −2 and a low detection limit of 140 nM (at S/ N = 3). The two sensors possess excellent reproducibility and stability. They were used to sense O 2 •− released from HeLa cells.
Illustration of the synthesis of the hollow carbon cubic nanomaterial (HCC) and of the porous carbon cubic nanomaterial (PCC), and the scheme for detection of superoxide anions in HeLa cell.
研究领域:
材料科学
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生物化学
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分析化学
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纳米技术
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产品关联
DOI
PubMed
高影响因子
Journal of Cleaner Production
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2025
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IF 10
Dongyu Chen,Meizhu Chen,Xiangming Zhou,Shouwei Jian,Jianwei Zhang,Xinkui Yang,Yuechao Zhao
Minimizing indoor temperature fluctuations reduces dependence on heating and cooling systems, thereby lowering building energy consumption and carbon emissions and subsequently helping tackle global climate challenges. In this study, phase change capsules (PCCs) based on waste cooking oil derivative, Ca-alginate and nano SiO 2 were developed for foamed concrete (FC). The effects of nano SiO 2 dosage on PCC morphology, durability, thermal stability, and heat storage performance were systematically investigated. The distribution of PCCs within FC and the mechanical and thermal regulation properties of FC containing PCC were evaluated. The experimental results indicate that PCCs with 2 wt% nano SiO 2 exhibit a compressive strength of 26.29 N at 15 °C, the thermal decomposition onset above 200 °C with a notable mass loss of 40 %, and phase change enthalpy and temperature are 68.86 J/g and 20.1 °C, respectively. Ca-alginate/nano SiO 2 PCCs were uniformly dispersed and structurally intact within the FC matrix. Incorporation of 3 wt% Ca-alginate/Nano SiO 2 PCCs led to a 10.8 % reduction in compressive strength while exceeding the minimum strength requirements (>8.13 MPa) and achieving a 3.6 °C reduction in FC temperature variation. This study offers a sustainable strategy for improving building energy efficiency while promoting the recycling of waste cooking oil.
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高影响因子
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