JOURNAL OF BIOSCIENCE AND BIOENGINEERING
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2024
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IF 2.3
Mengyao Gui
Humic acid (HA), a common natural organic matter , could affect conventional anoxic denitrification. Aim of this study was to investigate effect of HA on the process of aerobic denitrification in Achromobacter sp. GAD-3, an aerobic denitrifying strain. The findings demonstrated that an increase in HA concentrations (≥5 mg L −1 ) promoted the aerobic denitrification process (excluding N 2 O reduction), manifesting as higher rates of nitrate removal (6.67–11.1 mg L −1 h −1 ) and lower levels of nitrite accumulation (30.2–20.7 mg L −1 ). This was attributed to the increased electron transfer activities and denitrifying reductase activities (including NAR, NIR and NOR) facilitated by HA. Accordingly, the expression of denitrification genes such as napA , cnorB , and nirS was enhanced by HA. Nonetheless, the nosZ gene and N 2 OR activity underwent suppression by HA, which was accountable for N 2 O emission. It is crucial to understand the HA mechanism towards aerobic denitrifiers for wastewater treatment plants to enhance nitrogen removal.
研究领域:
环境生物学
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废水处理
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DOI
PubMed
高影响因子
BIOCHEMICAL ENGINEERING JOURNAL
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2023
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IF 3.9
Juanjuan Ding,Wenyan Ba,Shengping You,Wei Qi,Rongxin Su
γ-aminobutyric acid (GABA) is an important inhibitory neurotransmitter in the brain with many physiological functions. Therefore, this work establishes an efficient biosynthesis process to achieve the high production of food-grade GABA. Firstly, we adopted a directional colorimetric screening method and then obtained the strain Lactobacillus brevis ( Lb. brevis) CGMCC 24975 with 22.61 g/L GABA in shake flasks, much higher than Lb. brevis ATCC 367 (3.07 g/L) due to its more efficient and stable expression of its glutamate decarboxylase (GAD) system. After exploring the effects of optimal fermentation conditions and oxygen on GABA production, we found that anaerobic fermentation could increase GABA production by up-regulating gad operon expression and activating GADase. Finally, we developed an oil-sealed anaerobic fermentation process with 157.90 g/L GABA in a 5 L bioreactor, which was 6.98-fold of that in shake flasks. This work includes a complete process from screening GABA-producing strains to developing efficient fermentation processes, laying the foundation for producing food-safe GABA.
研究领域:
微生物学
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生物技术
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食品科学
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DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2021
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IF 5.279
Derui Zhang,Xiaonan Wei,Ze Liu,Xiangyun Wu,Changjian Bao,Yuzhe Sun,Nana Su,Jin Cui
Quinoa (Chenopodium quinoa Willd.) with a history of 5000 years as food is extremely rich in nutrients and bioactive compounds, including γ-aminobutyric acid (GABA), a natural four-carbon non-protein amino acid with great benefits to human health. In quinoa, GABA generally increases with the germination time, but the underlying molecular mechanism is unclear. Here, we found that the GABA content in quinoa varied significantly among 25 varieties using an automatic amino acid analyzer. Next, six varieties (three low-GABA and three high-GABA varieties) were used for further analyses. The content of GABA in six varieties all showed an increasing trend after germination. In addition, Pearson’s correlation analysis showed that the changes in GABA content were closely related to the transcript level or enzyme activity of three key enzymes including glutamate decarboxylase (GAD), GABA transaminase (GABA-T), and succinate-semialdehyde dehydrogenase (SSADH) in the GABA shunt, especially GAD. Based on RNA-sequencing analysis, eight GAD genes, two GABA-T genes, one SSADH gene, nine polyamine oxidase (PAO) genes, five diamine oxidase (DAO) genes, four 4-aminobutyraldehyde dehydrogenase (BADH) genes, and three thermospermine synthase ACAULIS5 (ACL5) genes were identified. Among these, CqGAD8 and CqGABA-T2 may make a greater contribution to GABA accumulation during quinoa germination.
研究领域:
植物科学
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分子生物学
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营养学
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DOI
PubMed
高影响因子
Communications Biology
·
2021
·Vol. 4
·期 1
·1-12
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IF 6.268
Liu Yuan,Tong Ziwen,Shi Jingru,Jia Yuqian,Deng Tian,Wang Zhiqiang
Antimicrobial resistance has been a growing concern that gradually undermines our tradition treatment regimens. The fact that few antibacterial drugs with new scaffolds or targets have been approved in the past two decades aggravates this crisis. Repurposing drugs as potent antibiotic adjuvants offers a cost-effective strategy to mitigate the development of resistance and tackle the increasing infections by multidrug-resistant (MDR) bacteria. Herein, we found that benzydamine, a widely used non‐steroidal anti‐inflammatory drug in clinic, remarkably potentiated broad-spectrum antibiotic-tetracyclines activity against a panel of clinically important pathogens, including MRSA, VRE, MCRPEC and tet (X)-positive Gram-negative bacteria. Mechanistic studies showed that benzydamine dissipated membrane potential ( ▵ Ψ) in both Gram-positive and Gram-negative bacteria, which in turn upregulated the transmembrane proton gradient ( ▵ pH) and promoted the uptake of tetracyclines. Additionally, benzydamine exacerbated the oxidative stress by triggering the production of ROS and suppressing GAD system-mediated oxidative defensive. This mode of action explains the great bactericidal activity of the doxycycline-benzydamine combination against different metabolic states of bacteria involve persister cells. As a proof-of-concept, the in vivo efficacy of this drug combination was evidenced in multiple animal infection models. These findings indicate that benzydamine is a potential tetracyclines adjuvant to address life-threatening infections by MDR bacteria.
研究领域:
微生物学
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药理学
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传染病学
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药物再利用
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PubMed
高影响因子
Food Bioscience
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2022
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IF 5.318
Jiarui Zeng,Feibi Sheng,Xi Hu,Zhenfeng Huang,Xiaofei Tian,Zhenqiang Wu
Brewer's spent grain (BSG) is the main byproduct of the beer industry and is commonly used as a low-value animal feed or food ingredient. This study investigated the role of symbiotic fermentation with Bacillus velezensi s and Levilactobacillus brevis in improving the nutritional value of BSG. The addition of B. velezensis increased the cell growth of L. brevis by over thirty-fold higher than that in the single-strain system. Simultaneously, cellulase and protease activities were substantially increased, and more soluble sugars were produced. Total amino acid, glutamic acid , and γ -aminobutyric acid (GABA) levels increased by 52.2%, 155.1%, and 144.1%, respectively. Conversely, lactic acid production decreased. Genetic analysis showed that the glycolysis-related gene pykA , pentose phosphate pathway gene gnd , and GABA-related gene gad were upregulated, while the heterolactin-related gene xpkA was downregulated, explaining that B. velezensis might inhibit heterolactin fermentation while enhancing GABA biosynthesis . This study provides a potential strategy for the high-value utilization of BSG in the food or feed industry.
研究领域:
食品科学
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微生物学
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生物技术
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营养学
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DOI
高影响因子
JOURNAL OF NANOBIOTECHNOLOGY
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2024
·Vol. 22
·期 1
·1-26
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IF 10.6
Qiu Shui,Cao Lili,Xiang Dingding,Wang Shu,Wang Di,Qian Yiyi,Li Xiaohua,Zhou Xiaoshu
To assess the efficacy of a novel 3D biomimetic hydrogel scaffold with immunomodulatory properties in promoting fracture healing. Immunomodulatory scaffolds were used in cell experiments, osteotomy mice treatment, and single-cell transcriptomic sequencing. In vitro, fluorescence tracing examined macrophage mitochondrial transfer and osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs). Scaffold efficacy was assessed through alkaline phosphatase (ALP), Alizarin Red S (ARS) staining, and in vivo experiments. The scaffold demonstrated excellent biocompatibility and antioxidant-immune regulation. Single-cell sequencing revealed a shift in macrophage distribution towards the M2 phenotype. In vitro experiments showed that macrophage mitochondria promoted BMSCs’ osteogenic differentiation. In vivo experiments confirmed accelerated fracture healing. The GAD/Ag-pIO scaffold enhances osteogenic differentiation and fracture healing through immunomodulation and promotion of macrophage mitochondrial transfer.
研究领域:
生物材料
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组织工程
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再生医学
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免疫学
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干细胞生物学
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DOI
PubMed
高影响因子
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