CARBOHYDRATE POLYMERS
·
2016
·
IF 4.219
Honghua Jia,Tingting Shao,Chao Zhong,Hengxiang Li,Min Jiang,Hua Zhou,Ping Wei
In this paper, we produced hemicellulosic hydrolysate from corncob by tetrabutylammonium hydroxide (TBAH) extraction and dilute acid hydrolysis combined, further evaluating the feasibility of the resultant corncob hemicellulosic hydrolysate used in xylitol production by Candida tropicalis . Optimized conditions for corncob hemicellulose extraction by TBAH was obtained via response surface methodology: time of 90 min, temperature of 60 °C, liquid/solid ratio of 12 (v/w), and TBAH concentration of 55%, resulting in a hemicellulose extraction of 80.07% under these conditions. The FT-IR spectrum of the extracted corncob hemicellulose is consistent with that of birchwood hemicellulose and exhibits specific absorbance of hemicelluloses at 1380, 1168, 1050, and 900 cm −1 . In addition, we found that C. tropicalis can ferment the resulting corncob hemicellulosic hydrolysate with pH adjustment and activated charcoal treatment leading to a high xylitol yield and productivity of 0.77 g/g and 2.45 g/(L h), respectively.
研究领域:
生物化学
·
发酵工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF ANTIMICROBIAL AGENTS
·
2025
·
IF 4.6
Yingzhe Wang,Shigan Ye,Yuan Deng,Yingting Huang,Xiaoliang Zhu
Biofilm formation is one of the causes of azole resistance in Candida albicans . Although zinc is an essential trace element involved in biofilm regulation, its specific mechanistic role remains unclear. Here, we systematically evaluated the effects and mechanisms of zinc deficiency on biofilm formation and drug resistance. Intracellular zinc deficiency was induced using the zinc chelator N,N,N′,N′-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) and a CSR1 knockout strain, as confirmed using zinquin fluorescence. Biofilm formation and susceptibility were assessed using standardized microdilution techniques, including sessile minimum inhibitory concentration (sMIC) determinations via the XTT reduction assay, while drug interactions were assessed using a checkerboard assay. Efflux pump activity was measured using a Rhodamine 6G assay, and transcriptomic analysis was performed to elucidate underlying mechanisms. Pathogenicity was validated using a Galleria mellonella infection model. The results show that zinc deficiency inhibited biofilm development at all stages. Low-concentration TPEN (5µM) reduced the sMIC of fluconazole by more than 16-fold and ultimately reversed its azole resistance. This effect was mechanistically associated with the downregulation of key biofilm-related transcription factors and multidrug efflux pumps, as revealed by transcriptomic analysis, which also indicated that zinc deficiency triggered ribosomal remodeling and activated glucose metabolism. Survival analysis in the G. mellonella infection model confirmed that zinc deficiency reduced the overall pathogenicity of C. albicans biofilms. These results validate zinc homeostasis as a novel therapeutic strategy against drug-resistant and recurrent fungal infections, especially those involving biofilms.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2022
·Vol. 102
·期 2
·400-411
·
IF 2.606
Yue Wenda,Liang Jun,Wang Honghai,Zhang Yu,Li Chunli,Su Weiyi
In the entrapment of enzymes by sol-gel method, the special procedures for obtaining the unique structure of xerogel are sometimes destructive to enzymes, while the internal structure of xerogels is easily broken. To solve the above problems, we present an economical, bio-friendly procedure for the entrapment of Candida antarctica lipase B in silica xerogel. In this procedure, an encapsulation-structured enzyme-carrying silica xerogel was produced by controlling the evaporation rate of the solvent at ambient pressure during drying, while tetramethoxysilane and methyltrimethoxysilane were used as the co-precursors. The xerogel synthesis was modified and optimized for improving the stability and reusability of the enzyme, while the xerogel characteristic structure was preserved. Moreover, the effects of the co-precursors amount on the mechanical strength, pore structure, hydrophobicity, enzyme loading, and enzyme stability of the enzyme-carrying silica xerogels were systematically investigated. And the best performance was observed at the co-precursors content of 30.28 wt%. Finally, the catalytic performance of the enzyme-carrying silica xerogels on the transesterification of n -butanol with ethyl acetate was demonstrated.
Graphical abstract
研究领域:
生物化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2017
·Vol. 22
·期 1
·179
·
IF 2.861
Chunfang Li,Shuhui Jiang,Xinying Zhao,Hao Liang
In this paper we report a facile method for preparing co-immobilized enzyme and magnetic nanoparticles (MNPs) using metal coordinated hydrogel nanofibers.Candida rugosalipase (CRL) was selected as guest protein. For good aqueous dispersity, low price and other unique properties, citric acid-modified magnetic iron oxide nanoparticles (CA-Fe3O4NPs) have been widely used for immobilizing enzymes. As a result, the relative activity of CA-Fe3O4@Zn/AMP nanofiber-immobilized CRL increased by 8-fold at pH 10.0 and nearly 1-fold in a 50 °C water bath after 30 min, compared to free CRL. Moreover, the immobilized CRL had excellent long-term storage stability (nearly 80% releative activity after storage for 13 days). This work indicated that metal-nucleotide nanofibers could efficiently co-immobilize enzymes and MNPs simultaneously, and improve the stability of biocatalysts.Keywords:metal;nucleotide;magnetic iron oxide nanoparticles;Candida rugoselipase (CRL);immobilized enzyme
研究领域:
生物化学
·
纳米技术
·
酶工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Bioengineered
·
2021
·
IF 3.269
Na Liu,Nan Zhang,Shengrong Zhang,Lifang Zhang,Qing Liu
Oral candidiasis is one of the most common types of fungal infection caused by Candida albicans (C. albicans). The present study aims to investigate the antifungal effects of phloretin (a dihydrochalcone flavonoid) against the C. albicans pathogenicity. In this work, we treated C. albicans SC5314 with 37.28, 74.55, or 149.10 μg/mL (equivalent to 0.5×, 1× or 2× MIC) phloretin in vitro. Besides, we established a mice model of oral candidiasis by a sublingual infection of C. albicans suspension (1 × 107 colony-forming unit/mL), and mice were treated with phloretin (3.73 or 7.46 mg/mL, which were equivalent to 50× or 100× MIC) twice a day starting on day one post-infection. The results showed that the MIC of phloretin against C. albicans was 74.55 μg/mL. Phloretin exerted antifungal activity by inhibiting the biofilm formation and suppressing the yeast-to-hyphae transition upon the downregulation of hypha-associated genes including enhanced adherence to polystyrene 1, the extent of cell elongation gene 1, hyphal wall protein 1 gene, and agglutinin-like sequence gene 3. Next, phloretin repressed the secretion of proteases and phospholipases via reducing the expression of protease-encoding genes secreted aspartyl proteases (SAP)1 and SAP2, as well as phospholipase B1. Subsequently, the in vivo antifungal activity of phloretin was testified by the reverse of the enhanced lesion severity, inflammatory infiltration, and the increased colony-forming unit counts caused by C. albicans of tongue tissues in oral candidiasis mice. In conclusion, phloretin suppressed the pathogenicity and virulence factors against C. albicans both in vivo and in vitro.
研究领域:
微生物学
·
药理学
·
分子生物学
·
传染病学
✓ 已验证
DOI
PubMed
高影响因子
BIORESOURCE TECHNOLOGY
·
2026
·
IF 8.2
Xiaoying Gui,Jiaxuan Ji,Shuxian Hu,Xiyun Zhang,Yufeng Dong,Chenyang Wu,Yuanyuan Xia,Haiquan Yang,Wei Shen,Yu Cao,Li Zhou,Xianzhong Chen
Candida tropicalis was engineered as a novel chassis for efficient de novo astaxanthin production. • Promoter engineering balances CrtW / CrtZ to optimize metabolic flux toward astaxanthin. • Multiplex subcellular compartmentalization enhances astaxanthin biosynthesis. • ER expansion and lipid droplet engineering synergistically enhance product storage. • Fermentation optimization (additives, temperature) boosts astaxanthin production efficiency. Astaxanthin, a red ketocarotenoid, exhibits strong antioxidant, anti-inflammatory, pigmentation, and immunomodulatory activities. In this study, a high-β-carotene-producing Candida tropicalis strain was engineered for efficient astaxanthin biosynthesis using multiplex engineering strategies. First, promoter engineering was applied to balance the expression of β-carotene ketolase and hydroxylase, and an optimized promoter combination was identified, leading to an astaxanthin titer of 126.7 mg/L. Subsequently, subcellular compartmentalization was implemented by targeting the key enzymes to the cytosol, peroxisomes, and lipid droplets, followed by co-expression across multiple compartments, which raised the astaxanthin titer to 192.0 mg/L. Further enhancement was achieved through endoplasmic reticulum engineering to expand membrane-associated enzyme capacity and lipid engineering to improve product storage, increasing astaxanthin production to 249.8 mg/L. Finally, fermentation optimization significantly improved the shake-flask performance, yielding 320.1 mg/L astaxanthin. In a 5-L bioreactor, the astaxanthin titer reached 3096.2 mg/L, comparable to the highest reported production to date. This work represents the first efficient biosynthesis of astaxanthin in C. tropicalis and provides a novel chassis and technical framework for the industrial production of astaxanthin. Download: Download high-res image (46KB) Download: Download full-size image
✓ 已验证
DOI
PubMed
高影响因子
MYCOSES
·
2026
·Vol. 69
·期 4
·e70176
·
IF 3.4
Mingjing Wei,Jian Guo,Li Li,Junhao Zhu,Yuyuan Xue,Guo Chen,Fan Yang,Wenjuan Wu,Min Zhu
Background Candida auris is a globally emerging multidrug-resistant fungus. Its dissemination is driven by patient movement and asymptomatic carriers. However, molecular epidemiological studies linking imported cases to local strains in large metropolitan areas remain limited. Objectives To analyse the molecular epidemiology and resistance mechanisms of 33 clinical isolates in Shanghai and propose an integrated infection control strategy tailored to metropolitan healthcare settings. Methods Isolates from 19 patients were identified via MALDI-TOF MS and sequencing. Antifungal susceptibility and biofilm formation were assessed. Environmental contamination was evaluated using PCR. Whole-genome sequencing (WGS) was employed to identify resistance mutations and perform phylogenetic analysis. Results All 33 isolates were fluconazole-resistant. Resistance to amphotericin B and echinocandins was observed in 9 and 4 isolates, respectively. All echinocandin-resistant strains harboured the Fks1-S639F mutation. Phylogenetic analysis revealed that Clade III (South African clade) was the dominant lineage. Colonisation was concentrated in the urinary tract and inguinal regions, while bedside tables were identified as key environmental reservoirs. All strains exhibited strong biofilm-forming capacity. Conclusions ICU patients serve as primary reservoirs, with transmission driven by interregional movement. The distinct colonisation patterns and environmental hotspots provide specific targets for screening. Integrating PCR-based environmental monitoring with culture methods constitutes an effective strategy. These findings underscore the need for a standardised protocol integrating molecular diagnostics to optimise infection control in urban hospitals.
✓ 已验证
DOI
PubMed
高影响因子
Advanced Healthcare Materials
·
2022
·Vol. 11
·期 16
·2200268
·
IF 11.092
Pengqi Wan,Wei Guo,Yongjie Wang,Mingxiao Deng,Chunsheng Xiao,Xuesi Chen
Persistent fungal infections caused by biofilms seriously endanger human health. In this study, a photosensitizer-polypeptide conjugate (PPa-cP) comprising a photosensitizer, pyropheophorbide a (PPa), and a cationic polypeptide (cP) is readily synthesized for effective antifungal and antibiofilm treatment. Compared with free PPa, the cationic PPa-cP shows enhanced binding ability to the negatively charged surface of Candida albicans ( C. albicans ) through electrostatic interactions. As a result, PPa-cP exhibits effective antifungal efficiency against both C. albicans and fluconazole-resistant C. albicans in vitro under light irradiation. The minimum inhibitory concentration (MIC) of PPa-cP for both C. albicans and fluconazole-resistant C. albicans is 1 µ m . In addition, PPa-cP also shows improved penetration in a C. albicans biofilm, thus effectively eliminating the C. albicans biofilm by photodynamic effects. More importantly, PPa-cP demonstrats significantly enhanced therapeutic effects in a fluconazole-resistant C. albicans -infected rat model with minimal side effects. In conclusion, the current work presents an effective strategy to combat biofilm infections associated with biomedical equipment.
研究领域:
微生物学
·
药理学
·
医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Infection and Drug Resistance
·
2022
·
IF 4.177
Yu Wang,Zejun Pei,Zaixiang Lou,Hongxin Wang
Introduction The opportunistic pathogen Candida albicans can form biofilms, resulting in drug resistance with great risk to medical treatment.Methodology We investigated the ability of C. albicans to form biofilms on different materials, as well as the inhibitory and eradicating effects of cordycepin on biofilm. The action mechanism of cordycepin against biofilm was studied by crystal violet staining, XTT [2, 3-bis (2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] reduction method, phenol-sulfuric acid method, cellular superficial hydrophobicity (CSH) assay, and confocal laser scanning microscope observation. We also evaluated the acute toxicity of cordycepin in vivo.Results The results showed facile formation of biofilms by C. albicans on polypropylene. The 50% minimum inhibitory concentration (MIC50) of cordycepin was 0.062 mg/mL. A concentration of 0.125 mg/mL significantly decreased biofilm formation, metabolic activity, secretion of extracellular polysaccharides, and relative CSH. Cordycepin could inhibit biofilm formation at low concentration without affecting fungal growth. In addition, cordycepin effectively eradicated 59.14% of mature biofilms of C. albicans at a concentration of 0.5 mg/mL. For acute toxicity, the LD50 (50% of lethal dose) of cordycepin was determined as higher than 500 mg/kg for mice.Conclusion The results of this study show that cordycepin significantly inhibited and eradicated biofilms by decreasing metabolic activity, the ratio of living cells, the hydrophobicity, and damaging the extracellular polysaccharides of biofilm. These findings should facilitate more effective application of cordycepin and suggest a new direction for the treatment of fungal infections.
研究领域:
微生物学
·
药理学
·
医学真菌学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIORESOURCE TECHNOLOGY
·
2024
·
IF 9.7
Zhang Kai,Xin Jiaying,Lu Xuechun
This study established a Candida rugosa lipase (CRL) system to catalyze triolein and ethyl ferulate interesterification. The products were identified, and the binding mode between the substrates and CRL was predicted through molecular docking. Three methods for preparing CRL-AuNPs were proposed and characterized. It was found that the addition of 40 mL of 15 nm gold nanoparticles increased the CRL activity from 3.05 U/mg to 4.75 U/mg, but the hybridization efficiency was only 32.7 %. By using 4 mL of 0.1 mg/mL chloroauric acid, the hybridization efficiency was improved to 50.7 %, but the enzyme activity was sharply decreased. However, when the molar ratio of Mb to HAuCl 4 was 0.2, the hybridization efficiency increased to 71.8 %, and the CRL activity was also enhanced to 5.98 U/mg. Under optimal conditions, the enzyme activity of CRL-AuNPs③ was maintained at 95 % after 6 repetitions and 85.6 % after 30 days at room temperature.
研究领域:
生物化学
·
酶工程
·
纳米生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Food Bioscience
·
2024
·
IF 4.8
Yuyang Zhang,Ting Feng,Xing Ni,Jiaojiao Xia,Hongbo Suo,Lishi Yan,Bin Zou
In this study, Candida rugosa lipase (CRL) was immobilized on the silica carrier SBA-15 by physical adsorption , then mixed with hydrophobically modified sodium alginate and dropped into calcium chloride solution. Finally, the adsorption-embedding immobilized lipase (L-SBA-15-Mgel) was successfully prepared. The conformation of the carrier before and after lipase immobilization were analyzed by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR) and other characterization techniques. The molecular docking and molecular dynamics simulation of CRL and modifier dodecyl glycidyl ether (DGE) ligand were carried out to analyze the potential influence of modifier on enzyme characteristics. The basic enzymatic properties including the activity, stability and reaction kinetic parameters of the immobilized lipase L-SBA-15-Mgel were studied. L-SBA-15-Mgel showed good storage stability and reusability. After 16 days of storage, the activity retention was 47.85%, and there was still 63.20% of the residual activity after seven cycles of reuse. The immobilized lipase was applied to the efficient synthesis of food flavor ester isoamyl acetate . Under the reaction conditions of 50 °C and 200 rpm, the highest yield of isoamyl acetate catalyzed by L-SBA-15-Mgel was 85.19%.
研究领域:
生物化学
·
酶工程
·
食品科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
·
2020
·Vol. 101
·期 8
·3186-3192
·
IF 2.614
Xia Jiaojiao,Zou Bin,Zhou Ruoyu,Adesanya I Onyinye
BACKGROUND In order to improve the stability of vitamin E and broaden its scope of application, an effective solution is to convert vitamin E into its derivatives. This work developed a new Candida rugosa lipase (CRL) nanogel based on modification of ionic liquid with vinyl functional groups. This novel CRL nanogel was used in the preparation process of vitamin E succinate based on the principle of non-aqueous enzymology. At the same time, various factors including enzyme concentration, substrate molar ratio, reaction temperature and reaction time, that affect the yield of vitamin E succinate were optimized and analyzed. RESULTS Different solvents with various hydrophobicity parameters (Log P values) from −1.3 to 3.5 were studied, it was found that dimethyl sulfoxide (DMSO) had the lowest Log P value among organic solvents but vitamin E succinate had the highest yield in DMSO. Furthermore, the effect of different operating conditions, such as molar ratios of substrate, enzyme concentration, reaction temperature and reaction time was studied. Under the optimal process conditions (enzyme concentration 6 mg mL −1 , substrate molar ratio 4:1, reaction temperature 55 °C and reaction time 15 h), the product yield was 62.58 ± 1.16%. CRL and CRL nanogel were characterized using Fourier-transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). It was shown that CRL nanogel influenced the catalytic behavior of lipase significantly by changing the structure and surface properties of CRL. CONCLUSION Novel lipase nanogel was an excellent biocatalyst for enzymatic synthesis of vitamin E succinate. © 2020 Society of Chemical Industry
研究领域:
生物化学
·
酶工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）