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
Nature Communications
·
2024
·Vol. 15
·期 1
·1-12
·
IF 14.7
Li Guangjian,Liang Hui,Gao Ruichen,Qin Ling,Xu Pei,Huang Mingtao,Zong Min-Hua,Cao Yufei,Lou Wen-Yong
Microbial biosynthesis has become the leading commercial approach for large-scale production of terpenoids, a valuable class of natural products. Enhancing terpenoid production, however, requires complex modifications on the host organism. Recently, a two-step isopentenol utilization (IU) pathway relying solely on ATP as the cofactor has been proposed as an alternative to the mevalonate (MVA) pathway, streamlining the synthesis of the common terpenoid precursors. Herein, we find that isopentenol inhibits energy metabolism, leading to reduced efficiency of the IU pathway in Saccharomyces cerevisiae . To overcome this, we engineer an IU pathway-dependent (IUPD) strain, designed for growth-coupled production. The IUPD strain is compelled to enhance the ATP supply, essential for the IU pathway, and incorporates a high-throughput screening method for enzyme evolution. The refined IU pathway surpasses the MVA pathway in synthesizing complex terpenoids. Our work offers valuable insights into developing growth-coupled strains adapted to efficient natural product synthesis.
研究领域:
微生物学
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代谢工程
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生物技术
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生物化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2024
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IF 12.2
Ziwei Guo,Huan He,Kunqian Liu,Zihui Li,Yanting Xi,Zhicheng Liao,Guohua Dao,Bin Huang,Xuejun Pan
Increasing antivirals in surface water caused by their excessive consumption pose serious threats to aquatic organisms . Our recent research found that the input of antiviral drug arbidol to algal bloom water can induce acute toxicity to the growth and metabolism of Microcystis aeruginosa , resulting in growth inhibition, as well as decrease in chlorophyll and ATP contents. However, the toxic mechanisms involved remained obscure, which were further investigated through transcriptomic analysis in this study. The results indicated that 885–1248 genes in algae were differentially expressed after exposure to 0.01–10.0 mg/L of arbidol, with the majority being down-regulated. Analysis of commonly down-regulated genes found that the cellular response to oxidative stress and damaged DNA bonding were affected, implying that the stress defense system and DNA repair function of algae might be damaged. The down-regulation of genes in porphyrin metabolism, photosynthesis , carbon fixation , glycolysis, tricarboxylic acid cycle , and oxidative phosphorylation might inhibit chlorophyll synthesis, photosynthesis, and ATP supply, thereby hindering the growth and metabolism of algae. Moreover, the down-regulation of genes related to nucleotide metabolism and DNA replication might influence the reproduction of algae. These findings provided effective strategies to elucidate toxic mechanisms of contaminants on algae in algal bloom water.
研究领域:
环境科学
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毒理学
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分子生物学
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水生生态学
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DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2022
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IF 16.744
Guanghong Luo,Zihuang Li,Meili Chen,Jiezhou Zheng,Xiaonian Deng,Gang Xu,Mo Cheng,Xianming Li,Yanhong Duo
The mitochondria critically determine the cell fates and therapeutic interventions. Contrary to the conventional and prevalent nanomaterial-based antitumor strategy, this study proposed a novel synergistic solution that accomplied with a dual tumor and mitochondria-specific [email protected] &SNP-TPP&FA (BCS) platform. The Ce6 and SNP were released in response to the tumor microenvironment and 660 nm laser irradiation. This induced the generation of NO, mild temperature, and ROS, and a second dynamic therapy (ONOO − ), destroying the mitochondrial structure and inhibiting the mitochondrial function. The blockade of the mitochondrial function would hinder the cellular respiration and ATP supply, and also perturb the communication and cellular components between the mitochondria and lysosomes. Consequently, the BCS NPs exhibited better antitumor efficacy as well as excellent biosafety than the gas therapy (GT), mild photothermal therapy (mPTT), or photodynamic therapy (PDT) nanoagents individually. This novel cascaded GT/mPTT/PDT synergistic solution offering great potential for numerous anti-cancer treatments.
研究领域:
肿瘤学
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纳米技术
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治疗学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）