MOLECULES
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2019
·Vol. 24
·期 8
·1593
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IF 3.06
Xin-Jun Yu,Chang-Yi Huang,Hong Chen,Dong-Sheng Wang,Jing-Liang Chen,Hui-Juan Li,Xiao-Yan Liu,Zhao Wang,Jie Sun,Zhi-Peng Wang
The traditional biochemical methods for analyzing cellular composition of oleaginous microorganisms are time-consuming, polluting, and expensive. In the present study, an FT-IR method was used to analyze the cellular composition of the marine oleaginous protistAurantiochytriumsp. during various research processes, such as strains screening, medium optimization, and fermentation, and was evaluated as a green, low-cost, high throughput, and accurate method compared with the traditional methods. A total of 109Aurantiochytriumsp. strains were screened for lipid and carbohydrate production and the best results were found for the strains No. 6 and No. 32. The yields and productivities could reach up to 47.2 g/L and 0.72 g/L/h for lipid, 21.6 g/L and 0.33 g/L/h for docosahexaenoic acid (DHA) in the strain No. 6, and 15.4 g/L and 0.18 g/L/h for carbohydrate in the strain No. 32, under the optimal conditions, respectively. These results confirmed potentials of the twoAurantiochytriumsp. strains for lipid, DHA, and carbohydrate productions at industrial scales. The FT-IR method in this study will facilitate research on the oleaginousAurantiochytriumsp., and the obtained two strains for lipid and carbohydrate productions will provide the foundations for their applications in medical, food, and feed industries.Keywords:Aurantiochytriumsp., carbohydrate;DHA;feed;FT-IR;high-throughput
研究领域:
生物技术
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海洋生物学
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高影响因子
REACTIVE & FUNCTIONAL POLYMERS
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2017
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IF 3.151
Zhenfeng Huang,Runqi Liuyang,Chengyun Dong,Yufeng Lei,Anqiang Zhang,Yaling Lin
Polymeric quaternary ammonium salts (PQAS) have been widely used to prevent microbial contamination, but little is known about their activity against phytopathogenic fungi. Our previous report described the synthesis of two novel PQAS, namely a homopolymer of (2-methacrylamido) propyltetrabenzyldimethylammonium chloride (PQD-BC) and dimethylaminopropyl benzyl chloride-grafted polysiloxanes (PDMS-g-BC); we demonstrated their structure-activity relationship against phytopathogenic fungi such as R . solani and Fusarium oxysporum f. sp. cubense tropical race 4 (Foc4). Here, we analyzed the structure-activity relationship and toxicity mechanism of these compounds at the molecular level against Foc4 compared with the low molecular-weight quaternary ammonium salt benzalkonium chloride (BC). The results revealed that PQD-BC and PDMS-g-BC application inhibited the growth of Foc4 in a concentration-dependent manner and that PDMS-g-BC exhibited higher activity than PQD-BC. In addition, these polymers were found to induce cell death in Foc4 by disrupting the cellular structure integrity, such as the loss of the cell wall and plasma membrane integrity and oxidative stress (lipid peroxidation), leading to the release of intracellular contents and inducing mitochondrial dysfunction and interference with genomic DNA . The newly elucidated mechanism provides possible applications in which PQAS can be used against phytopathogenic fungi.
研究领域:
植物病理学
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植物化学
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微生物学
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VETERINARY PARASITOLOGY
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2026
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IF 2.7
Xialian Bu,Yuwen Dong,Lei Huang,Weisong Ma,Xianqi Peng,Xuemei Yuan,Jing Chen,Jinbiao Jiao,Chen Niu,Xinzhi Weng,Jiayun Yao
A Trypanosoma infection model was established in largemouth bass. • Metronidazole cleared trypanosomes in most fish and prevented fish mortality. • Acute toxicity showed its safety to largemouth bass. • Metronidazole may inhibit trypanosome growth by enhancing host immune responses and strengthening antioxidant capacity. Outbreaks of trypanosomiasis in cage-cultured large yellow croaker in China has caused significant economic losses, however, to date, there are no effective drugs available for the prevention and treatment of this disease. Metronidazole is a nitroimidazole derivative with a wide range of biological activity ranging from antiparasitic to antibacterial, and is especially useful for the treatment of anaerobic protozoan infections. Nevertheless, studies on its efficacy against protozoan parasites in aquatic animals are lacking. In this study, an efficacy trial of metronidazole against trypanosomes isolated from large yellow croaker was conducted, based on the established infection model using largemouth bass, with an intraperitoneal injection dose of 10⁵ cells/mL (100 μL per fish) and maintained at 25°C. The in vivo anti-parasitic efficacy results showed that 300 mg/kg metronidazole significantly reduced the trypanosomes load, resulting in complete parasite clearance in most fish (88.9%) and prevented mortality of fish (95.56%). Acute toxicity test results indicated that 1500 mg/kg metronidazole remained safe for largemouth bass. Meanwhile, histopathological analysis revealed that in the 300 mg/kg metronidazole-treated group, the number of red blood cells increased and their morphology normalized in the liver, spleen, and head kidney. Besides, enzyme activity assays proved the differential expression of alanine aminotransferase (ALT), acid phosphatase (ACP), and total superoxide dismutase (T-SOD) among the positive control (PC), negative control (NC), and metronidazole-treated groups. qPCR results showed that metronidazole can increase the expression level of TNF-α, IFN-γ, and IL-1β, and IL-10. In conclusion, this study demonstrated the promising efficacy of metronidazole against fish trypanosomiasis, laying a solid theoretical and practical basis for controlling aquatic animal parasitic diseases.
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高影响因子
BMC MICROBIOLOGY
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2026
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IF 5.4
Yuan Junjie,Wang Jing,Wang Hui,He Zhenzhen,Chen Zhongju,Hu Yating,Zhou Xuan,Yan Shaozhen,Wei Lijie,He Mengzhou,Jiang Yi,Su Rui,Yu Huihui,Wang Shaoshuai,Tan Weidong,Ding Wencheng,Feng Ling,Wang Zerui
Background Members of the genus Corynebacterium are widely distributed across human mucosal surfaces and are increasingly recognized as important components of the female reproductive tract microbiota. However, their diversity is underestimated due to limitations of conventional cultivation approaches. Results In this study, a novel bacterial strain, designated TJG_1 T , was isolated from vaginal swab samples of a pregnant woman with preeclampsia (PE) using droplet-based microfluidic single-cell cultivation. Strain TJG_1 T was characterized as a Gram-positive, non-spore-forming, non-motile short rod. Phylogenetic analysis based on the 16 S rRNA gene sequence placed the strain within the genus Corynebacterium , with the highest sequence similarity to Corynebacterium coyleae (97.39%). Whole-genome sequencing revealed a genome size of 2,481,283 bp with a G + C content of 61.52 mol%. Average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) values between strain TJG_1 T and its closest relatives were below the accepted species thresholds, supporting its classification as a novel species. Functional genome annotation identified genes associated with metabolism, transport systems, putative antimicrobial resistance, and predicted host interaction-related traits. In vitro assays showed that neither bacterial metabolites nor live cells significantly affected trophoblast cell viability or oxidative stress-related gene expression under the tested conditions. Although alterations in cell migration behavior were observed following exposure to live bacteria, these changes were not accompanied by significant differences in migration-related gene expression. Conclusions Strain TJG_1 T represents a novel species within the genus Corynebacterium . This study highlights the utility of droplet-based cultivation for recovering previously underrepresented vaginal bacteria and expands current knowledge of Corynebacterium diversity in the female reproductive tract.
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PROCESS BIOCHEMISTRY
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2026
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IF 4.4
Liyang Xu,Yujia Wang,Feiyu Yan,Wenjing Pan,Yingjia Tong,Jinsong Gong,Xiaomei Zhang,Jinsong Shi,Zhenghong Xu,Hui Li
Mycolicibacterium is a crucial industrial host for steroid biotransformation, yet its genetic engineering has long been limited by inefficient homologous recombination (HR) and strong non-homologous end joining (NHEJ) activity. Here, we established and optimized a suicide plasmid-based genome editing system for Mycobacterium sp. LY-1. The constructed vector p2NILB, combining kanamycin selection with sacB-mediated counter-selection, enabled precise and markerless allelic exchange. Suppression of NHEJ through deletion of ku or ligD , together with optimization of homology arm length, increased gene knockout efficiency to over 70%. This optimized platform was subsequently applied to metabolic engineering of sterol degradation to enhance 9α-hydroxyandrostenedione (9α-OH-AD) biosynthesis. Sequential deletion of five kstD isoenzymes blocked downstream steroid degradation, with kstD1 identified as the major contributor to product loss. Functional analysis revealed KshA2 as the key 9α-hydroxylase, and its overexpression increased the 9α-OH-AD titer to 3.41 g/L. In addition, deletion of the branched-chain acid transporter gene mmpL3 further enhanced 9α-OH-AD production to 4.19 g/L. To overcome substrate utilization limitations under high phytosterol loading conditions, a soybean oil‑Tween 80 solvent system overcame substrate limitation, enabling 15.71 g/L 9α‑OH‑AD from 30 g/L phytosterols. This study provides a robust genome editing framework and an effective strategy for engineering steroid-producing actinobacteria.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2026
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IF 9.1
Xinrui Zhao,Jiatu Li,Yanli Liu,Hongliang Guo,Sa Wang,Hui Li,Yaqi Jiao,Li Li,Jo-Shu Chang,Duu-Jong Lee
Pretreatment is a critical step in dark fermentation-based hydrogen production, as it directly affects the accessibility of biomass substrates to microbial degradation, with the presence of Fe 3+ -modified biochar. This study aimed to enhance hydrogen production from sugar beet pulp (SBP) via dark fermentation by optimizing alkali pretreatment, screening cellulolytic bacteria, and applying modified biochar. NaOH pretreatment of SBP was optimized, followed by isolation of Klebsiella sp. HDJT1 from sugar beet rhizosphere. Optimal NaOH pretreatment (6% NaOH, 50 °C, 1.5 h) reduced lignin content by 65.8% and increased cellulose exposure, as confirmed by scanning electron microscopy (SEM), revealing a disrupted lignocellulosic structure. Dark fermentation with 10 g/L pretreated SBP yielded 1177 mM H 2 , a 76.4% increase over non-inoculated controls. Fe 3+ -modified biochar (100 mg/L Fe 3+ ) further boosted H 2 production to 1728 mM, enhancing yields by 159% versus controls by improving enzyme stability and microbial community structure, specifically enriching Paraclostridium bifermentans and Pseudomonas veronii —the alkali pretreatment combined with Klebsiella sp. HDJT1 and Fe 3+ -biochar significantly improved SBP valorization for hydrogen production. This integrated approach could optimize substrate accessibility, microbial activity, and catalytic efficiency, providing a sustainable strategy for agricultural waste-to-energy conversion.
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PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
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2026
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IF 7.9
Xin Qi,Ziwei Wang,Qixin Xia,Xiuping Liang,Guiyin Wang,Changlian Xu,Guochun Lv,Junzhuo Cai,Zhang Cheng,Zhanbiao Yang,Liling Wang,Xiaoxun Xu,Hua Yin
Although microbial degradation has been extensively studied for removing 2,2′,4,4′-tetrabrominated diphenyl ether (BDE-47), knowledge regarding the comparative efficiency and safety of degradation by facultative anaerobes under varying oxygen conditions remain limited. This study investigated the degradation of BDE-47 by Pseudomonas sp. strain QS-1 under both aerobic and anaerobic conditions. Our findings revealed that 47.5% and 12.4% of the initially added BDE-47 (0.5 mg/L) were transformed within 7 days under aerobic and anaerobic conditions, respectively. The aerobic transformation involved a complex pathway consisting of debromination, hydroxylation, ether bond cleavage, and ring opening, whereas the anaerobic transformation was limited to debromination. Toxicity assessments using an Escherichia coli model revealed that aerobic degradation products reduced cytotoxicity, whereas anaerobic degradation products induced higher rates of cell apoptosis than the parent BDE-47. Metabolomics analysis attributed this enhanced toxicity of anaerobic products to the specific inhibition of purine metabolism. In soil microcosm experiments, strain QS-1 exhibited stronger colonization and degradation performance under aerobic conditions, shifting the soil microbial community assembly towards more deterministic processes and strengthening network interactions with indigenous taxa. These findings provide insights into the biological effects of BDE-47 degradation products, and inform the assessment of efficacy and safety for bioremediation strategy. Download: Download high-res image (175KB) Download: Download full-size image
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Innovative Food Science & Emerging Technologies
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2024
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IF 6.3
Debao Niu,Yuanxin Feng,Xin-An Zeng,Jun-Hu Cheng
Pulsed electric fields (PEF) can affect enzyme activity in fruit and vegetable juice, but its effect on microbial cellular enzymes has not been fully revealed. Alcohol dehydrogenase (ADH) is a key cellular enzyme of Acetobacter sp. to convert alcohol to acetic acid by metabolism. In this study, the effect of PEF treatment on the ADH activity of Acetobacter sp. and the structural changes of the enzyme were systematically investigated. The results showed that the activity of cellular ADH in Acetobacter sp. was decreased by PEF treatment. The α -helix structure of ADH molecules decreased and the random coil structure increased, indicating a change in secondary structure. The tertiary structure of ADH was expanded and the microenvironment of aromatic amino acid residues was changed, while the primary structure of molecules remained intact. In conclusion, the decrease of ADH activity after PEF treatment may be caused by the transformation of spatial conformation.
研究领域:
微生物学
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生物化学
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食品科学
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酶学
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2021
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IF 7.312
Changyong Cai,Xueying Chen,Fenfang Li,Zhijian Tan
Three-phase partitioning (TPP) had been developed for lipids extraction from microalgae . However, the volatile and flammable organic solvents (typically t -butanol) were widely used in the conventional TPP. In this study, CO 2 -responsive deep eutectic solvents (DESs) were used as the alternative solvents and applied for lipid extraction from Nannochloropsis sp . by using a TPP system. These DESs can be separated from lipid and easily recycled by bubbling CO 2 and N 2 after extraction. The response characteristics of the optimal DES-3 (HBA: HBD = 3:1) were studied by FT-IR, 1 H NMR, and 13 C NMR. Furthermore, factors influencing the extraction process were studied in detail. The maximal extraction yield (172 mg/g) was obtained under the optimized conditions: ammonium sulfate of 20 wt%, liquid–solid ratio of 35:1, extraction temperature of 80 °C, and extraction time of 90 min, which was much higher than the t -butanol-based TPP system (135 mg/g). The lipid was recovered from DES after extraction, and the fatty acid composition was analyzed after TPP. Finally, the recovered DES was reused for lipid extraction, and the results indicated good cyclic stability for this DES after five cycles. This study presents a green, efficient, and sustainable strategy for lipid extraction and further biofuel production.
研究领域:
生物能源
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绿色化学
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微藻生物技术
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提取技术
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可持续工程
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DOI
高影响因子
Natural Product Communications
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2019
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IF 0.554
Hong Zhou,Yu He,Yongqi Tian,Bailin Cong,Huanghao Yang
Bacilohydrin A, a new cyclic lipopeptide composed of seven mixed D/L-amino acids (L-Ile1—L-Leu2—D-Asp3—L-Val4—L-Leu5—L-Leu6—L-Gln7) and a (R)-3-hydroxy-12-methyltetradecanoic acid (HMT) residue, was isolated from the crude culture extract of Bacillus sp. SY27F, which was obtained from the Indian Ocean hydrothermal vent. Its planar structure was elucidated by spectroscopic analyses, including 1D and 2D NMR spectroscopy, mass spectrometry (MS), and secondary ion mass spectrometry (MS/MS), whereas its absolute configuration was determined by modified Marfey's analysis. Bacilohydrin A displayed significant cytotoxicities against DU-145, MCF-7 and HepG2 cancer cell lines with IC50 values of 50.3-175.1 nM. Additionally, this is the first time to determine the absolute configuration of a D-aspartic acid residue in surfactin class.
研究领域:
微生物学
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海洋生物学
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药理学
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癌症研究
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分析化学
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DOI
高影响因子
Microbiology Spectrum
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2022
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IF 9.043
Wenzhi Bao,Xing Li,Jinfeng Liu,Rong Zheng,Lijuan Liu,Haibo Zhang
Phenylpyruvate decarboxylase (PPDC) is a crucial enzyme that plays important roles in 2-phenylethanol (2-PE) biosynthesis. In our previous study, we screened a highly efficient PPDC KDC4427 from the novel 2-PE-producing strain Enterobacter sp. CGMCC 5087. Meanwhile, its decarboxylation activity of indolylpyruvate (IPyA) was also higher than other indolylpyruvate decarboxylases (IPDCs) reported so far. In this study, KDC4427 protein was purified and characterized, and its catalytic mechanisms were analyzed by biological methods. The optimum pH and temperature of KDC4427 was pH 6.5 and 35°C, respectively. The enzyme activity was relatively stable between pH 6 and 8 and over the range of temperatures from 25°C to 45°C. KDC4427 showed the highest catalytic efficiency on phenylpyruvic acid (PPA); meanwhile, it also showed high activity for IPyA and 2-ketobutanoic acid, and it was found that KDC4427 belongs to IPDCs by phylogenetic tree analysis. The coverage of the three-dimensional structure of KDC4427 and EcIPDC from Enterobacter cloacae was 96%. Leucine 542, one of the residues in the substrate-binding pocket, is replaced by isoleucine in KDC4427 compared with EcIPDC. Site-directed mutagenesis showed that the transition from leucine to isoleucine was unlikely to make KDC4427 have high catalytic activity for PPA and IPyA; the mutants at glutamate 468 almost completely lost catalytic activities for both PPA and IPyA, indicating that this glutamate was essential for the catalytic activity. Additionally, alanine 387 plays an important role in the substrate selectivity of KDC4427.IMPORTANCE Compared with the chemical synthesis of 2-phenylethanol (2-PE) by condensation of ethylene oxide and benzene, the biological synthesis of 2-PE is a potential method to replace the traditional process. This makes biotransformation gradually become the main way to produce high-quality 2-PE. Phenylpyruvate decarboxylase (PPDC) is the critical enzyme in 2-PE biosynthesis, and it is a momentous point of penetration to increase the production of 2-PE. In this regard, KDC4427 can catalyze phenylpyruvic acid (PPA) to phenylacetaldehyde more efficiently than any other PPDC previously reported. Moreover, it has high activity of indolepyruvate decarboxylases (IPDCs), which will be a great breakthrough in the synthesis of indole-3-acetic acid (IAA). With this study, we offer insights into the KDC4427 catalytic mechanism and significantly expand the toolbox of available α-ketoacid decarboxylases for application in biosynthesis.
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JOURNAL OF HAZARDOUS MATERIALS
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2022
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IF 14.224
Xingxing Peng,Qihang Zheng,Lei Liu,Yuzhe He,Tianyu Li,Xiaoshan Jia
T2, a gram-positive bacterium capable of rapidly degrading tetrabromobisphenol A (TBBPA), and affiliated with the genus Enterobacter , was isolated for the first time from sludge that had been contaminated for several years. The TBBPA degradation data fitted the first-order model well. Under optimal conditions (pH of 7, temperature of 31 °C, TBBPA concentration of 5 mg L −1 , and inoculum size of 5%), 99.4% of the initially added TBBPA was degraded after 48 h. TBBPA degradation fitted the first-order model with the half-life of 3.3 h. These results illustrated that the TBBPA degradation capability of strain T2 was significantly better than that of previously reported bacteria. A total of 17 intermediates were detected, among which five were reported for the first time. Whole-genome sequencing revealed that strain T2 had a chromosome with the total length of 4 854 376 bp and a plasmid with the total length of 21 444 bp. It harbored essential genes responsible for debromination, such as cyp450 , gstB , gstA , and HADH, and genes responsible for subsequent complete mineralization , such as bioC , yrrM , Tam , and Ubil . A key protein of haloacid dehalogenases responsible for the biodegradation of TBBPA may also be involved in the regulation of TBBPA degradation in natural environment. In soil bioremediation experiments, strain T2 showed excellent environmental adaptation. It was able to biodegrade TBBPA and its typical intermediate bisphenol A efficiently. Therefore, it could potentially be applied to treat TBBPA-contaminated sites.
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高影响因子
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