Algal Research-Biomass Biofuels and Bioproducts
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2019
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IF 3.723
Nitin Keshari,Muriel Gugger,Tao Zhu,Xuefeng Lu
Cyanobacteria are promising cell factories for producing high-value bioproducts . They accumulate low molecular mass organic molecules under salinity stress conditions, which are known as compatible solutes, e.g. sucrose , trehalose , and glucosylglycerol (GG). The physiological properties of compatible solutes sort them as the potential bioproducts for applications in the field of health, pharmacy, and cosmetic sectors. During last few decades, mostly model cyanobacterial strains (unicellular from freshwater and marine habitats) have been targeted for the biochemical and molecular characterization of compatible solutes accumulation, while, the study on other cyanobacteria from extreme/stressful habitats are scanty. The advantage for selecting multicellular cyanobacteria in the present study is their easier harvesting mode over unicellular strains which are one of the primary concerns for the cost-effective production of desired products at pilot scale. Therefore, five cyanobacterial strains with diverse morphotypes belonging to subsection I (Unicellular), II (Baeocytous), III (Filamentous), and V (Ramified) isolated from extreme/stressful habitats (sewage pond and hot spring including freshwater strain as a reference) were screened for salt tolerance , compatible solutes profiling, and sugar feedstock production. High GG, sucrose, and glycogen production were found in Leptolyngbya sp. PCC 8913, Chroogloeocystis siderophila NIES-1031 and Fischerella major NIES-592, respectively. Under salt stress, Leptolyngbya sp. PCC 8913 showed a GG production of 101 ± 12 mg/L/OD 730 , which is significantly higher than that of the model strain Synechocystis sp. PCC 6803. Fischerella major NIES-592 and Oscillatoria laetevirens NIES-31 were identified as novel trehalose-producing cyanobacteria. The key genes involved in production of compatible solutes among these cyanobacteria were also studied. Thus, the results not only displayed the potential cyanobacteria for production of GG, sucrose, trehalose and glycogen but also address the metabolic pathways for the compatible solutes biosynthesis in diversified cyanobacteria, which can be further targeted for the in-depth study to enhance the production using molecular approaches.
研究领域:
微生物学
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生物技术
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生物化学
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分子生物学
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产品关联
DOI
高影响因子
Biotechnology for Biofuels
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2018
·Vol. 11
·期 1
·1-16
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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
Water
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2025
·Vol. 17
·期 17
·2561
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IF 3
Xiaojia Huang,Yuanyuan Hu,Xiaowei Cheng,Weibin Pan
Cylindrospermopsis raciborskiiis a toxin-producing cyanobacterium that is easy to overlook. It has strong environmental adaptability and is currently spreading around the world and gradually dominating to form a persistent bloom, causing ecological and environmental risks and drinking water safety issues. In this study, we systematically investigated the inhibitory effects of oleic acid onC. raciborskiiand elucidated the underlying mechanisms through morphological observation, physiological assays, and bioinformatics analysis. Our results demonstrated that oleic acid strongly inhibits the growth ofC. raciborskii, with a 72 h half-maximal effective concentration (EC50) of 0.903 mg·L−1. At 1.6 mg·L−1, oleic acid achieved an inhibition rate of 99.5% within 48 h, indicating rapid suppression of cyanobacterial growth. Physiological analyses revealed that oleic acid severely impaired photosynthetic activity, as evidenced by significant reductions in key parameters (rETRmax, α, Fv/Fm, and Fv/Fo) and altered photosynthetic pigment composition, suggesting structural and functional damage to the photosynthetic apparatus. Morphological observations further showed that oleic acid disrupted filament integrity, inducing cell shrinkage, cytoplasmic vacuolation, cell wall detachment, membrane rupture, and eventual cellular disintegration. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis indicated that oleic acid interferes with multiple metabolic processes, including nutrient and cofactor synthesis, membrane transport, and signal transduction, ultimately triggering algal cell death. This study highlights oleic acid as a promising eco-friendly agent for mitigatingC. raciborskiiblooms, offering potential applications in ecological prevention and emergency bloom control.
研究领域:
环境微生物学
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水生生态学
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毒理学
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分子生理学
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藻类生物学
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生态毒理学
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产品关联
DOI
高影响因子
ENVIRONMENTAL POLLUTION
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2024
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IF 7.6
Xuefei Wu,Wei Jia,Zhipeng Fang,Hualong Sun,Gang Wang,Li Liu,Mengqi Zheng,Guowei Chen
Cyanobacterial blooms are expanding world-wide in freshwater and marine environments, and can cause serious ecological and environmental issues , which also contribute to the spread of antibiotic resistance genes (ARGs). However, the mechanistic understanding of cyanobacteria-mediated resistance dynamics is not fully elucidated yet. We selected Microcystis aeruginosa as a model cyanobacteria to illustrate how cyanobacteria mediate the evolution and transfer processes of bacterial antibiotic resistance . The results show that the presence of cyanobacteria significantly decreased the abundance of antibiotic resistant bacteria (ARB) and antibiotic resistant genes (ARGs) by 3%–99% and 2%–18%, respectively. In addition, it clearly altered bacterial community structure, with the dominant genera evolving from Acinetobacter (27%) and Enterobacter (42%) to Porphyrobacter (59%). The abundance of ARGs positively correlated with Proteobacteria and Firmicutes , rather than Cyanobacteria, and Bacteroidetes . In the presence of cyanobacteria, the transfer events of bacterial resistance genes via conjugation were found to decrease by 10%–89% (p < 0.05). Surprisingly, we found an extradentary high transfer frequency (about 0.1) for the ARGs via plasmid conjugation from the bacteria into M. aeruginosa population. It confirmed the role of cyanobacterial population as the competent hosts to facilitate ARGs spreading. Our findings provide valuable information on the risk evaluation of ARGs caused by cyanobacterial blooms in aquatic environments , key for the protection and assessment of aquatic environmental quality.
研究领域:
环境科学
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微生物学
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水生生态学
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分子生物学
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DOI
PubMed
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
Algal Research-Biomass Biofuels and Bioproducts
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2025
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IF 4.5
Gaijuan Hou,Yihan Liu,Wenbin Liu,Meiyan Zhang,Huijun Ding,Wenguang Zhou
Whether antibiotic resistance driven by environmental pollutant represents a transient ecological response or a permanent evolutionary shift remains a critical knowledge gap in global health. Here, we tracked the antibiotic tolerance evolution of the primary producer Synechocystis sp. PCC 6803 under chronic exposure (140 d) to environmentally relevant concentrations of copper [Cu(II): 250 μg/L] and the fluoroquinolone antibiotic moxifloxacin [MOX: 20 μg/L], respectively. The evolved cyanobacterial populations acquired high-level tolerance without obvious fitness costs. Notably, this tolerance exhibited dual characteristics: multidrug cross-tolerance was transient and fully reversible upon stressor removal, whereas tolerance to the selective agent itself [Cu(II) or MOX] was stable and heritable. Multi-omics analyses revealed the mechanistic basis for this divergence. Transient tolerance was driven by a highly dynamic form of phenotypic plasticity—manifested as transcriptional reprogramming and large-scale genomic variations that conferred a temporary fitness advantage but were rapidly lost without selective pressures. In contrast, the persistent resistance was cemented by the point mutation in rpoB gene. Our findings demonstrate that pollutants in the environment may drive the antibiotic resistance evolution in cyanobacteria and foster persistent stress tolerance. This highlights the potential risks of primary producers in the aquatic environment as an antibiotic resistance reservoir and vectors for antibiotic resistance dissemination, underscoring the necessity of integrated risk assessment and source control strategies under the “One Health” framework.
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DOI
高影响因子
Nature Communications
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2024
·Vol. 15
·期 1
·1-15
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IF 14.7
Tang Si,Cheng Xueyu,Liu Yaqing,Liu Lu,Liu Dai,Yan Qi,Zhu Jianming,Zhou Jin,Jiang Yuyang,Hammerschmidt Katrin,Cai Zhonghua
Diazotrophic cyanobacteria can fix nitrogen gas (N 2 ) but are usually scarce in nitrogen-limited coastal waters, which poses an apparent ecological paradox. One hypothesis is that high salinities (> 10 g/L NaCl) may inhibit cyanobacterial N 2 fixation. However, here we show that N 2 fixation in a unicellular coastal cyanobacterium exclusively depends on sodium ions and is inhibited at low NaCl concentrations (< 4 g/L). In the absence of Na + , cells of Cyanothece sp. ATCC 51142 (recently reclassified as Crocosphaera subtropica ) upregulate the expression of nifHDK genes and synthesise a higher amount of nitrogenase, but do not fix N 2 and do not grow. We find that the loss of N 2 -fixing ability in the absence of Na + is due to insufficient ATP supply. Additional experiments suggest that N 2 fixation in this organism is driven by sodium energetics and mixed-acid fermentation, rather than proton energetics and aerobic respiration, even though cells were cultured aerobically. Further work is needed to clarify the underlying mechanisms and whether our findings are relevant to other coastal cyanobacteria.
研究领域:
微生物学
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海洋生物学
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生物化学
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DOI
PubMed
高影响因子
Water
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2022
·Vol. 14
·期 19
·3097
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IF 3.53
Xiuping Liu,Ningdong Xie,Jiaqian Li,Mohan Bai,Biswarup Sen,Guangyi Wang
Upwelling, a common oceanographic event, can make great contributions, directly or indirectly, to deep ocean carbon sequestration. However, the extent of its contribution indirectly depends on the composition of microbial communities and the interactions between bacterioplankton and other microorganisms. This study provides insights into the influence of upwelling on bacterioplankton at the whole community level and predicts their potential functional profiles. The α diversity of the bacterial community exhibited no significant differences between the upwelling area and non-upwelling area, while the community composition varied clearly in different habitats. Proteobacteria, Cyanobacteria, Bacteroidota, Firmicutes, and Actinobacteria were the five dominant phyla in all of the habitats. The proportions of members of Firmicutes were increased whereas Cyanobacteria were reduced in upwelling water. However, the percentage of Cyanobacteria was enhanced in the upwelling deep water. Functional genes that are involved in signal transductions, which belong to environmental information processing, were more active in upwelling surface water than in the other habitats. Closer and more complex relationships between bacterioplankton and microbial eukaryotes were found in the upwelling area, which altered with the variation of the external environmental conditions. Cyanobacteria showed a positive correlation with microbial eukaryotes in upwelling deep water. Combined with the high proportions of Cyanobacteria in upwelling deep water, this might be strong evidence that Cyanobacteria contribute to a deep ocean carbon sink. Overall, our study reveals the impacts of upwelling on the bacterial community composition, metabolic functions, and microbial interactions, which are significant to further understanding the carbon sink effects of upwelling.Keywords:upwelling;bacterioplankton;signaling function;interactions;carbon sequestration
研究领域:
海洋生物学
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微生物学
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环境科学
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生态学
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DOI
高影响因子
Frontiers in Bioengineering and Biotechnology
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2021
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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
ACS Sustainable Chemistry & Engineering
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2020
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IF 7.632
Yu Chi,Zhaohuan Li,Guilong Zhang,Lina Zhao,Yanhong Gao,Dongfang Wang,Lichao Liu,Dongqing Cai,Zhengyan Wu
Desertification and water body eutrophication are two severe environmental problems worldwide. To alleviate these two problems simultaneously, a new idea, introducing aquatic cyanobacteria (AC) from Lake Chaohu to the surface of the Tengger Desert to encourage the growth of biological soil crusts, was proposed. A network-structured nanocomposite (SXA) consisting of sodium polyacrylate (SP), xanthan gum (XG), and attapulgite (ATP) was also fabricated. The SXA showed high water-retention ability, viscosity, and biosafety and could provide a suitable microenvironment for AC and desert cyanobacteria (DC) growth. It was found that the combination of AC and SXA effectively increased sand nutrient levels, facilitating the growth of DC and biological soil crusts. Importantly, the resultant biological soil crusts maintained stability for at least 210 days and played a key role in stabilizing the sand surface. Therefore, this work provides a novel technology not only for desert immobilization but also for the utilization of aquatic blooms.
研究领域:
环境科学
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生态学
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材料科学
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微生物学
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产品关联
DOI
高影响因子
ACS Nano
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2024
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IF 15.8
Tao Sun,Huaishu Huo,Yingying Zhang,Yaru Xie,Yize Li,Kungang Pan,Fenfang Zhang,Jing Liu,Yindong Tong,Weiwen Zhang,Lei Chen
The pollution caused by heavy metals (HMs) represents a global concern due to their serious environmental threat. Photosynthetic cyanobacteria have a natural niche and the ability to remediate HMs such as cadmium. However, their practical application is hindered by a low tolerance to HMs and issues related to recycling. In response to these challenges, this study focuses on the development and evaluation of engineered cyanobacteria-based living materials for HMs bioremediation. Genes encoding phytochelatins (PCSs) and metallothioneins (MTs) were introduced into the model cyanobacterium Synechocystis sp. PCC 6803, creating PM/6803. The strain exhibited improved tolerance to multiple HMs and effectively removed a combination of Cd2+, Zn2+, and Cu2+. Using Cd2+ as a representative, PM/6803 achieved a bioremediation rate of approximately 21 μg of Cd2+/OD750 under the given test conditions. To facilitate its controllable application, PM/6803 was encapsulated using sodium alginate-based hydrogels (PM/6803@SA) to create “living materials” with different shapes. This system was feasible, biocompatible, and effective for removing Cd2+ under simulated conditions of zebrafish and mice models. Briefly, in vitro application of PM/6803@SA efficiently rescued zebrafish from polluted water containing Cd2+, while in vivo use of PM/6803@SA significantly decreased the Cd2+ content in mice bodies and restored their active behavior. The study offers feasible strategies for HMs bioremediation using the interesting biomaterials of engineered cyanobacteria both in vitro and in vivo.
研究领域:
环境科学
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微生物学
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生物技术
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材料科学
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产品关联
DOI
PubMed
高影响因子
Small
·
2022
·Vol. 19
·期 13
·2201305
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IF 15.153
Boyu Yang,Shubin Li,Wei Mu,Zhao Wang,Xiaojun Han
The bottom-up constructed artificial cells help to understand the cell working mechanism and provide the evolution clues for organisms. The energy supply and metabolism mimicry are the key issues in the field of artificial cells. Herein, an artificial cell containing cyanobacteria capable of light harvesting and carbon dioxide fixation is demonstrated to produce glucose molecules by converting light energy into chemical energy. Two downstream “metabolic” pathways starting from glucose molecules are investigated. One involves enzyme cascade reaction to produce H 2 O 2 (assisted by glucose oxidase) first, followed by converting Amplex red to resorufin (assisted by horseradish peroxidase). The other pathway is more biologically relevant. Glucose molecules are dehydrogenated to transfer hydrogens to nicotinamide adenine dinucleotide (NAD + ) for the production of nicotinamide adenine dinucleotide hydride (NADH) molecules in the presence of glucose dehydrogenase. Further, NADH molecules are oxidized into NAD + by pyruvate catalyzed by lactate dehydrogenase, meanwhile, lactate is obtained. Therefore, the cascade cycling of NADH/NAD + is built. The artificial cells built here pave the way for investigating more complicated energy-supplied metabolism inside artificial cells.
研究领域:
生物技术
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生物化学
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合成生物学
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细胞工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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