MOLECULAR CRYSTALS AND LIQUID CRYSTALS
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2023
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IF 0.7
Zihao Meng,Jian Wu,Qingyun Li,Youyan Liu,Aixing Tang
Lipase OF from Candida cylindracea was adsorbed onto surfactant-modified Na-bentonite (Bent), and the effects of the surfactants on the catalytic properties of immobilized lipase were studied in detail. The results showed that both the specific activity and enzyme loading of immobilized lipase varied significantly with modified support of different surfactants. The highest specific activity was obtained with Tween20-modified Bent: 11.9-fold higher than the non-modified sample. Upon modification by a single surfactant, two kinds of surfactants were combined to process the modification. It was surprising to find that the enzyme immobilized on CTAB (60%) and TX-100 (40%) co-modified Bent yielded a specific activity recovery of 133.4% indicating that the enzyme might be “activated”. Kinetic analyses for the hydrolysis of p-nitrophenyl palmitate (p-NPP) showed that Km decreased from 5.57 mg mL−1 of free lipase to 3.43 mg·mL−1 and Vmax increased 1.35-fold higher. The structure, surface morphology, and hydrophobicity of the modified bentonite and immobilize lipase were characterized via X-ray diffraction, Fourier transform-infrared spectroscopy, scanning electron microscopy, and contact angle measurements. We assumed that lipase molecules may be bound to the surface of the carrier, and the surface hydrophobicity and the change of the functional group caused by the modification of surfactant may be the key factor affecting lipase immobilization.
研究领域:
生物化学
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酶工程
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高影响因子
Frontiers in Microbiology
·
2023
·
IF 5.2
Jing Li,Mengnan Hong
Mixed culture fermentation with non- Saccharomyces yeasts and Saccharomyces cerevisiae as multi-starters has more advantages than spontaneous fermentation, and wine products with distinctive and pleasant aromas can fulfill the diverse demands of consumers. This study was carried out to illuminate the effect of sequential inoculation of indigenous Candida railenensis and S. cerevisiae on alcoholic fermentation behavior and chemical and aromatic characteristics of Vidal blanc icewine. During the mixed culture fermentation, C. railenensis was present in the initial and middle stages but was absent after 14 days. The results of basic chemical parameters showed that the glycerol content in the mixed culture-fermented icewine was higher than that of the pure fermented icewine, but the acetic acid content was the opposite. In terms of volatile aroma compounds, C. railenensis in the mixed culture fermentation reduced some metabolites such as lower alcohols, 1-hexanol, 3-methylthiopropanol, and their unpleasant notes and increased the production of some desired volatile aroma compounds such as benzaldehyde, β-damascenone, 2-furanmethanol, and 5-methyl furfural associated with rose, honey, nut, and caramel characteristics. Furthermore, C. railenensis also changed the sensory performance of icewine by participating in the fermentation of S. cerevisiae . These findings suggest that C. railenensis with positive enological properties has the ability to be used in icewine production, which has never been reported before.
研究领域:
食品科学
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微生物学
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PubMed
高影响因子
Soil Ecology Letters
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2024
·Vol. 6
·期 4
·1-8
·
IF 4.5
Liang Fang,Li Zhu,Wang Zinan,Ke Xin,Wu Longhua,Christie Peter,Luo Yongming
Egg hatching of the soil collembolan Folsomia candida and the effects of per- and polyfluoroalkyl substances were investigated.
New and effective laboratory methods for egg hatching studies with soil collembolans were established.
Per- and polyfluoroalkyl compounds (PFASs) have been used industrially worldwide and are persistent organic pollutants in many soils. Twenty eggs laid by synchronized adults of the collembolan Folsomia candida were added to each Petri dish containing compressed soil substrate mixed with perfluorooctanoic acid (PFOA), heptafluorobutyric acid (PFBA), or 6:2 chlorinated polyfluoroalkyl ether sulfonic acid (F-53B), and after 25 d of exposure the number hatched declined on average by 6.9%–49.7%, 10.3%–24.1%, and 3.4%–18.6%, respectively. PFASs delayed the peak of hatching by one day, and at different concentrations reduced the number of eggs hatched during the peak by 16.7%–30% and 23.3%–43.2% in PFOA and PFBA treatments, respectively. In the presence of F-53B the number of eggs hatched declined by 73.3% but the number of individuals increased by 29.3% at higher concentrations. The characteristics of egg hatching were stable and sensitive to PFASs, and may be suitable for use as indicators in the screening of contaminated soils for environmental risk assessment.
研究领域:
生态毒理学
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环境科学
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高影响因子
Emerging Microbes & Infections
·
2024
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IF 8.4
Yaqin Peng,Yue Liu,Xuegao Yu,Jingchun Fang,Zhaowang Guo,Kang Liao,Peisong Chen,Penghao Guo
Candida auris is an emerging multidrug-resistant fungal pathogen worldwide. To date, it has not been reported in Guangdong, China. For the first time, we reported 7 cases of C. auris candidemia from two hospitals in Guangdong. The clinical and microbiological characteristics of these cases were investigated carefully. Two geographic clades, i.e. III and I, were found popular in different hospitals by whole genome sequencing analyses. All C. auris isolates from bloodstream were resistant to fluconazole, 5 of which belonged to Clade III harbouring VF125AL mutation in the ERG11 gene. The isolates with Clade I presented Y132F mutation in the ERG11 gene as well as resistance to amphotericin B. All isolates exhibited strong biofilm-forming capacity and non-aggregative phenotype. The mean time from admission to onset of C. auris candidemia was 39.4 days (range: 12 - 80 days). Despite performing appropriate therapeutic regimen, 42.9% (3/7) of patients experienced occurrences of C. auris candidemia and colonization after the first positive bloodstream. C. auris colonization was still observed after the first C. auris candidemia for 81 days in some patient. Microbiologic eradication from bloodstream was achieved in 85.7% (6/7) of patients at discharge. In conclusion, this study offers a crucial insight into unravelling the multiple origins of C. auris in Guangdong, highlighting great challenges in clinical prevention and control.
研究领域:
医学真菌学
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感染病学
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抗真菌药物研究
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PubMed
高影响因子
RSC Advances
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2018
·Vol. 8
·期 18
·10081-10088
·
IF 2.936
Xiaofeng Li,Haixia Xu,Guanglei Zhao,Hui Wu,Yigang Yu,Furao Lai,Xinglong Xiao
Acylation modification of phenol glycosides is currently of great interest due to the improved bioavailability and multiple functions. In this work, mono- or diesters of arbutin, an important phenol glycoside derivative, can be controllably synthesized by using whole-cell biocatalytic systems. Among fourteen microbial strains selected, Candida parapsilosis cells showed the best catalytic activity and high organic solvent tolerance. Compared with the best pure solvent tetrahydrofuran, the use of a binary solvent pyridine-isooctane gave a slightly lower conversion (98.3% vs. 97.2%) and selectivity (85.3% vs. 80.5%) and much higher substrate solubility (37.1 vs. 214.0 mg mL−1), in a 24 h bioconversion of arbutin with a VP-arbutin molar ratio of 15 and whole cell dosage of 30 mg mL−1. The production of various arbutin esters with different fatty acid chain lengths can be realized by using this whole-cell strategy, with the substrate conversion and 6′-regioselectivity of 54.1–98.3% and 83.2–99.0%, respectively.
研究领域:
生物化学
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药物化学
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微生物学
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DOI
PubMed
高影响因子
Microorganisms
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2025
·Vol. 13
·期 5
·1103
·
IF 4.2
Yuwei Xing,Cong Liu,Xumeng Cui,Haonan Lv,Jun Wang
Nymphaea candida Presl is a rare hardy water lily at risk of extinction and has been included on the ‘Red List’ of threatened species of the International Union for the Conservation of Nature. To protect germplasm resources and propagate N. candida seedlings, this study conducted tissue culture and found that pathogenic endophytic fungal infection was the main reason for failure of tissue culture. Compared with the stems and leaves, the roots of N. candida had the highest rates of fungal infection during tissue culture. Subsequently, three isolated endophytic fungi, Fusarium oxysporum , Phytopythium helicoides , and Alternaria sp., showed the highest frequency of occurrence in tissue culture. Furthermore, an antifungal formulation comprising 0.1 μg/mL pyrimidin suspension, 1 μg/mL mancozeb wettable powder, and 1 μg/mL carbendazim was constructed and could reduce the infection rates of root and stem tissues to 7.5% and 0%, respectively. Finally, the usefulness of this antifungal formulation for inhibition of endophytic fungi in tissue culture of N. candida was validated. This study not only provides important technical support for mass production of seedlings of N. candida , but also provides a scientific reference for the protection of endangered aquatic plant species.
研究领域:
植物学
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保护生物学
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微生物学
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PubMed
高影响因子
CHEMOSPHERE
·
2024
·
IF 8.1
Ying Ding,Jin-Ting Zheng,Ya-Ning Wang,Di Wu,Dong Zhu
There is growing interest in interactions of microplastics (MPs) with other pollutants. However, there is limited understanding of the combined effects of MPs and silver nanoparticles (AgNPs) on nontarget soil organisms. This work aimed to examine the effects of exposure to various AgNPs' concentrations alone (0, 0.1, 1, 10, 100, 1000 mg kg −1 , 50 nm) and in combination with polyvinyl chloride microplastics (PVC MPs, 80−250 μm) at 0.1% concentration for 28 days on reproduction, Ag accumulation, C/N ratio, and isotopic fractionation of the standard soil fauna collembolan Folsomia candida . Results showed that compared to the AgNPs exposure alone, the presence of MPs significantly reduced reproduction by 51.4% and markedly increased Ag content in collembolans by 87.7% at 1000 mg kg −1 AgNPs, which evidenced a synergistic effect. Co-exposure to MPs and AgNPs resulted in a noticeable reduction in the C/N ratio in F. candida body tissues by 9.90% and 5.27% at 1 and 10 mg kg −1 AgNPs, respectively, showing additive and synergistic effects. Additionally, this co-exposure altered stable isotope fractionation, with the highest increments of δ 15 N by 32.3% and inhibition of δ 13 C by 2.62%, demonstrating the turnover of nutrients shift in the collembolan tissues. Collectively, this study demonstrates that con-current exposure to environmentally relevant concentration of MPs and relatively high doses of AgNPs synergistically induces toxic effects on F. candida , leading to Ag accumulation and reproduction decline. These findings imply that MPs could alter collembolans' responses to AgNPs exposure, potentially enhancing the metal ions’ bioavailability in soil environments and posing ecotoxicological threats to soil-dwelling organisms.
研究领域:
环境科学
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生态毒理学
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PubMed
高影响因子
PREPARATIVE BIOCHEMISTRY & BIOTECHNOLOGY
·
2025
·
IF 1.9
Shuhan Yang,Shouqi Zhao,Yingying Ning,Dan Zhao
Previous studies have shown that co-culture methods can enhance exopolysaccharide production, no studies have reported this enhancement in co-cultures between Weissella confusa and Candida shehatae. This study developed an efficient co-culture system combining W. confusa XG-3 and C. shehatae (1:1 ratio), and employed response surface methodology to optimize both exopolysaccharide yield and properties. The initial co-culture produced 56.82 ± 0.12 g/L exopolysaccharide, a 1.63-fold increase over single culture. Optimization (sucrose: 105.97 g/L; yeast extract: 5.81 g/L; peptone: 6.24 g/L) further increased the yield to 115.66 g/L, a 2.04-fold improvement. The co-cultured exopolysaccharide had high water solubility (60.45 ± 0.70%) and water holding capacity (614.74 ± 9.26%). The co-cultured EPS showed significant antioxidant activity. At 5 mg/mL, the scavenging rates of ABTS, DPPH, hydroxyl, superoxide, H2O2 and total reducing power reached the highest 52.22 ± 0.47%, 50.79 ± 2.86%, 55.80 ± 2.56%, 36.05 ± 2.07%, 66.85 ± 0.30%, and 0.39 ± 0.01. It also had a superior effect on the proliferation of several probiotics compared with commercial prebiotics and exhibited high thermostability with a degradation threshold at 292.5 °C. These results demonstrate a novel, scalable strategy for producing multifunctional EPS with broad applications in the food industry.
研究领域:
微生物学
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食品科学
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生物技术
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PubMed
高影响因子
ENZYME AND MICROBIAL TECHNOLOGY
·
2017
·
IF 2.502
Kun Zhang,Zhiyou Pan,Zhoujian Diao,Shuli Liang,Shuangyan Han,Suiping Zheng,Ying Lin
Kinetic resolution of sec -alcohols is a green process with biocatalyst. Candida antarctica lipase B (CALB) displayed on Pichia pastoris cell-surface (Pp-CALB) was characterized in kinetic resolution of sec -alcohols with different structures. The reaction parameters including acyl donors, molar ratio of substrates, solvents and temperatures were examined with 2-octanol as model substrate. 47.4% molar conversion of 2-octanol and 99.7% ee p were obtained after a 5 h reaction with Pp-CALB, and 90% of its original activity still remained after being reused for 10 cycles. Pp-CALB was then used to several sec -alcohols and it showed great enzymatic activity and enantioselectivity to all tested sec -alcohols, more than 93.1% of ee p . The enantioselective characteristics of Pp-CALB catalysed sec -alcohols with different structures were compared with Novozyme 435 which was almost the same. Solvent free system as one way of green chemistry was applied to Pp-CALB and Pp-CALB showed great catalytic activity and enantioselectivity. Pp-CALB was potential biocatalyst of high enzymatic activity and enantioselectivity using in resolution of sec -alcohols.
研究领域:
生物化学
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酶工程
·
绿色化学
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PubMed
高影响因子
Frontiers in Bioengineering and Biotechnology
·
2022
·
IF 6.064
Xue Yu,Zhang Xiao-Guang,Lu Ze-Ping,Xu Chao,Xu Hua-Jin,Hu Yi
Various betaine ionic liquids composed of different chain lengths and different anions were designed and synthesized to modify Candida antarctica lipase B (CALB). The results showed that the catalytic activity of all modified lipases improved under different temperature and pH conditions, while also exhibiting enhanced thermostability and tolerance to organic solvents. With an increase in ionic liquid chain length, the modification effect was greater. Overall, CALB modified by [BetaineC16][H2PO4] performed best, with the modified CALB enzyme activity increased 3-fold, thermal stability increased 1.5-fold when stored at 70°C for 30 min, with tolerance increased 2.9-fold in 50% DMSO and 2.3-fold in 30% mercaptoethanol. Fluorescence and circular dichroism (CD) spectroscopic analysis showed that the introduction of an ionic liquid caused changes in the microenvironment surrounding some fluorescent groups and the secondary structure of the CALB enzyme protein. In order to establish the enzyme activity and stability change mechanisms of the modified CALB, the structures of CALB modified with [BetaineC4][Cl] and [BetaineC16][Cl] were constructed, while the reaction mechanisms were studied by molecular dynamics simulations. Results showed that the root mean square deviation (RMSD) and total energy of modified CALB were less than those of native CALB, indicating that modified CALB has a more stable structure. Root mean square fluctuation (RMSF) calculations showed that the rigidity of modified CALB was enhanced. Solvent accessibility area (SASA) calculations exhibited that both the hydrophilicity and hydrophobicity of the modified enzyme-proteins were improved. The increase in radial distribution function (RDF) of water molecules confirmed that the number of water molecules around the active sites also increased. Therefore, modified CALB has enhanced structural stability and higher hydrolytic activity.
研究领域:
生物化学
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酶工程
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PubMed
高影响因子
Food Bioscience
·
2023
·
IF 5.2
Kaiyong Yao,Qile Xia,Yan Cao,Bindan Chen,Jie Cai,Chenxing Liu
Yellow wine lees (YWL) are the main byproduct in the yellow wine brewing and can be used as animal feed. The deficiencies in fiber digestibility and amino acid equilibrium of YWL limited its utility value in animal feeding. The nutritional profile of YWL could be moderated after fermentation treatment. We fermented YWL with Candida utilis KF01 and Bacillus subtilis KF02, whose genomes were sequenced. We set three groups in the animal test with 15 Holstein cows : control, YWL, and fermented yellow wine lees (FYWL) group. 206 and 5 amino acid metabolism-related KEGG pathways, as well as 5257 (639 GO and 4618 eggNOG annotations) and 1579 (372 GO and 1207 eggNOG annotations) amino acid metabolism-related gene annotations were found in C. utilis KF01 and B. subtilis KF02. The collected milk samples were analyzed for composition. The contents of mono-unsaturated fatty acid (MUFA, 36.90% relative content), poly-unsaturated fatty acid (PUFA, 5.63% relative content), and essential amino acid (EAA, 2.01%) in the FYWL group milk were significantly (P < 0.05) higher. The content of flavor substances in the FYWL group (146.33 ng/mL) was the highest, followed by the control (89.19 ng/mL) and the YWL group (41.36 ng/mL). The principal component analysis (PCA) result presented the intra-group variations in flavor substances and differences in single substance among all groups. Feeding FYWL had significant effects (P < 0.05) in the Holstein cows on the milk composition.
研究领域:
动物营养学
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微生物学
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食品科学
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高影响因子
BIOTECHNOLOGY LETTERS
·
2019
·Vol. 42
·期 2
·269-276
·
IF 2.154
Cai Xinyong,Zhang Mengjie,Wei Wei,Zhang Yinjun,Wang Zhao,Zheng Jianyong
A novel enzyme immobilization method employing metal–organic framework (MOF) encapsulation and macroporous resin adsorption was developed in this study. Candida antarctica lipase B (CALB) was firstly encapsulated onto metal–organic frame structures (Zeolitic imidazole framework-8, ZIF-8) and further bonded to macroporous resin by physical adsorption. Under optimized immobilization conditions, the activity of the prepared immobilized lipase (CALB-ZIF-8@D101) determined via the methyl esterification of oleic acid was 38.4 U/mg. Compared with free lipase, the immobilized lipase exhibited improved thermal and operational stability and organic solvent tolerance. These results demonstrate that the immobilization method of ZIF-8 encapsulation and macroporous resin adsorption enhanced enzyme properties at a superior level.
研究领域:
生物化学
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酶工程
·
材料科学
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PubMed
高影响因子
危险品化学品经营许可证（带存储）