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1.
Heliyon ; 9(7): e17916, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37483761

ABSTRACT

Advances in technology have brought accessibility to garment product fitting procedures with a virtual fitting environment and, in due course, improved the supply chain socially, economically, and environmentally. 3D body measurements, garment sizes, and ease allowance are the necessary factors to ensure end-user satisfaction in the apparel industry. However, designers find it challenging to recognize customers' motivations and emotions towards their preferred fit and define ease allowances in the virtual environment. This study investigates the variations of ease preferences for apparel sizes with body dimensions and psychological orientations by developing a virtual garment fitting prediction model. An artificial neural network (ANN) was employed to develop the model. The ANN model was proved to be effective in predicting ease preferences from two major components. A non-linear relationship was modeled among pattern parameters, body dimensions, and psychographic characteristics. Also, to visualize the fitted bodies, a generative adversarial network (GAN) was applied to generate 3D samples with the predicted pattern parameters from the ANN model. This project promotes mass customization using psychographic orientations and provides the perfect fit to the end users. New size-fitting data is generated for improved ease preference charts, and it enhances end-user satisfaction with garment fit.

2.
Enzyme Microb Technol ; 137: 109533, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32423670

ABSTRACT

Phytate is the major storage form of phosphorus in plants. It is present in cereals and raw materials of vegetable origin used in animal and human diets. However, non-ruminant animals have little phytase activity in their guts and, therefore, cannot digest phytate. As a result, almost all dietary phytate is discharged into the environment, causing phosphorus pollution. Phytate is also considered as an "antinutrient" for its ability to form insoluble and stable complexes with metal ions, thus reducing dietary absorption of essential minerals. It is a dire need to develop sustainable approaches for environmentally-friendly utilization for this valuable and abundant natural resource. To this end, we engineered Pichia pastoris to express and secrete phytase in a "made-to-order" fashion in response to external level of inorganic phosphate (Pi). Responsiveness to external Pi level was achieved by generating a Pi-responsive promoter library using directed evolution. The resultant yeast strains were proven to liberate Pi from wheat-based meal in a simulated in vitro digestion model. These yeast-based whole cell biocatalysts may serve as platform hosts with potential applications in food processing industry and animal waste treatment.


Subject(s)
6-Phytase/genetics , Phosphates/metabolism , Phytic Acid/metabolism , Pichia/enzymology , Pichia/genetics , 6-Phytase/metabolism , Digestion , Enzymes , Hydrolysis , In Vitro Techniques , Metabolic Engineering , Promoter Regions, Genetic
3.
Microb Pathog ; 139: 103896, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31794816

ABSTRACT

INTRODUCTION: Candida albicans possesses the ability to switch rapidly between yeast to hyphal forms. Hyphal formation is a remarkable pathogenic characteristic, which allows C. albicans to invade into host cells. OBJECTIVES: This study was to investigate the role of the C. albicans SAP9 gene in hyphal formation and invasion ability. METHODS: The morphology of fungal cells in the hyphal-inducing liquid media (YPD+10% fetal bovine serum) was observed by the microscopy. And the morphology of the colony on solid agar plates of YPD+10% fetal bovine serum was photographed by the digital camera. The mRNA expressions of hypha-associated genes in serum medium were also analyzed by real time PCR. Then for the interaction between C. albicans and oral epithelial cells, endocytosis essay, invasion essay and damage assay were performed to compare the differences between the sap9Δ/Δ mutant strain and wild type strain. RESULTS: Compared with the wild type strain, the sap9Δ/Δ mutant strain exhibited a deficient yeast-to-hyphal morphological transition under serum hyphal-inducing conditions. Furthermore, the SAP9 knockout strain revealed a significant down-regulation of the expression of EFG1 (~40%), which is a transcription factor gene that mediates hyphae formation in C. albicans. Compared with the wild type strain, a 70% reduction in the endocytosis of the sap9Δ/Δ mutant strain by host cells was observed, as well as a 25% attenuation of active penetration and a 40% attenuation of host cell damage (P <0.05). CONCLUSIONS: Our data strongly suggests that C. albicans Sap9 is a potential hyphal-associated factor that responds to serum hyphal-inducing stimuli via a cAMP-protein kinase A pathway mediated by EFG1, and contributes to the process of invasion of Candida into the epithelial cells, leading to host cell damage.


Subject(s)
Aspartic Acid Endopeptidases/metabolism , Candida albicans/physiology , Candidiasis, Oral/metabolism , Candidiasis, Oral/microbiology , Fungal Proteins/metabolism , Host-Pathogen Interactions , Mouth Mucosa/metabolism , Mouth Mucosa/microbiology , Aspartic Acid Endopeptidases/genetics , Candidiasis, Oral/pathology , Cell Line , Fungal Proteins/genetics , Gene Expression Regulation, Fungal , Hyphae , Mouth Mucosa/pathology , Mutation
4.
PLoS One ; 12(12): e0189219, 2017.
Article in English | MEDLINE | ID: mdl-29216308

ABSTRACT

Candida albicans is a clinically important human fungal pathogen. We previously identified the presence of cell-associated phytase activity in C. albicans. Here, we reveal for the first time, that orf19.3727 contributes to phytase activity in C. albicans and ultimately to its virulence potency. Compared with its wild type counterpart, disruption of C. albicans orf19.3727 led to decreased phytase activity, reduced ability to form hyphae, attenuated in vitro adhesion, and reduced ability to penetrate human epithelium, which are the major virulence attributes of this yeast. Thus, orf19.3727 of C. albicans plays a key role in fungal pathogenesis. Further, our data uncover a putative novel strategy for anti-Candidal drug design through inhibition of phytase activity of this common pathogen.


Subject(s)
6-Phytase/metabolism , Candida albicans/genetics , Candida albicans/enzymology , Candida albicans/pathogenicity , Open Reading Frames , Virulence
7.
PLoS One ; 8(12): e86032, 2013.
Article in English | MEDLINE | ID: mdl-24376900

ABSTRACT

Candida dubliniensis is an important human fungal pathogen that causes oral infections in patients with AIDS and diabetes mellitus. However, C. Dubliniensis has been frequently reported in bloodstream infections in clinical settings. Like its phylogenetically related virulent species C. albicans, C. Dubliniensis is able to grow and switch between yeast form and filamentous form (hyphae) and develops biofilms on both abiotic and biotic surfaces. Biofilms are recalcitrant to antifungal therapies and C. Dubliniensis readily turns drug resistant upon repeated exposure. More than 80% of infections are associated with biofilms. Suppression of fungal biofilms may therefore represent a viable antifungal strategy with clinical relevance. Here, we report that C. dubliniensis biofilms were inhibited by purpurin, a natural anthraquinone pigment isolated from madder root. Purpurin inhibited C. dubliniensis biofilm formation in a concentration-dependent manner; while mature biofilms were less susceptible to purpurin. Scanning electron microscopy (SEM) analysis revealed scanty structure consisting of yeast cells in purpurin-treated C. dubliniensis biofilms. We sought to delineate the mechanisms of the anti-biofilm activity of purpurin on C. Dubliniensis. Intracellular ROS levels were significantly elevated in fungal biofilms and depolarization of MMP was evident upon purpurin treatment in a concentration-dependent manner. DNA degradation was evident. However, no activated metacaspase could be detected. Together, purpurin triggered metacaspase-independent apoptosis in C. dubliniensis biofilms.


Subject(s)
Anthraquinones/pharmacology , Apoptosis/drug effects , Biofilms/drug effects , Candida/physiology , Apoptosis/physiology , Candida/drug effects , Candida/ultrastructure , Drug Resistance, Fungal/physiology , In Situ Nick-End Labeling , Microscopy, Electron, Scanning , Reactive Oxygen Species/metabolism , Statistics, Nonparametric
8.
PLoS One ; 7(11): e50866, 2012.
Article in English | MEDLINE | ID: mdl-23226409

ABSTRACT

A striking and clinically relevant virulence trait of the human fungal pathogen Candida albicans is its ability to grow and switch reversibly among different morphological forms. Inhibition of yeast-to-hypha transition in C. albicans represents a new paradigm for antifungal intervention. We have previously demonstrated the novel antifungal activity of purpurin against Candida fungi. In this study, we extended our investigation by examining the in vitro effect of purpurin on C. albicans morphogenesis and biofilms. The susceptibility of C. albicans biofilms to purpurin was examined quantitatively by 2,3-bis(2-methoxy-4-nitro-5-sulfo-phenyl)-2H-tetrazolium-5-carboxanilide reduction assay. Hyphal formation and biofilm ultrastructure were examined qualitatively by scanning electron microscopy (SEM). Quantitative reverse transcription-PCR (qRT-PCR) was used to evaluate the expression of hypha-specific genes and hyphal regulator in purpurin-treated fungal cells. The results showed that, at sub-lethal concentration (3 µg/ml), purpurin blocked the yeast-to-hypha transition under hypha-inducing conditions. Purpurin also inhibited C. albicans biofilm formation and reduced the metabolic activity of mature biofilms in a concentration-dependent manner. SEM images showed that purpurin-treated C. albicans biofilms were scanty and exclusively consisted of aggregates of blastospores. qRT-PCR analyses indicated that purpurin downregulated the expression of hypha-specific genes (ALS3, ECE1, HWP1, HYR1) and the hyphal regulator RAS1. The data strongly suggested that purpurin suppressed C. albicans morphogenesis and caused distorted biofilm formation. By virtue of the ability to block these two virulence traits in C. albicans, purpurin may represent a potential candidate that deserves further investigations in the development of antifungal strategies against this notorious human fungal pathogen in vivo.


Subject(s)
Anthraquinones/pharmacology , Biofilms/drug effects , Biofilms/growth & development , Candida albicans/drug effects , Candida albicans/physiology , Hyphae/growth & development , Anthraquinones/toxicity , Candida albicans/genetics , Candida albicans/ultrastructure , Cell Death/drug effects , Fibroblasts/cytology , Fibroblasts/drug effects , Fungal Proteins/genetics , Fungal Proteins/metabolism , Gene Expression Regulation, Fungal/drug effects , Humans , Hyphae/drug effects , Hyphae/genetics , Hyphae/ultrastructure , Reverse Transcriptase Polymerase Chain Reaction
9.
Mycopathologia ; 172(6): 473-9, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21792623

ABSTRACT

The present study was undertaken to evaluate and characterize the phytase activity in different Candida species. A total of 113 Candida isolates representing eight species were examined for phytase activity by an agar plate assay using the calcium salt of phytic acid as the sole phosphorus source. A phytase-positive phenotype was identified by the formation of a clear halo around a fungal colony. Cell-bound differential phytase activity was observed in Candida isolates at inter- and intra-species levels. Although phytase activity was not affected by the supplementation of external phosphate in C. albicans, C. dubliniensis, C. glabrata, and C. kefyr, elevated phytase activity was evident in C. guilliermondii, C. krusei, C. parapsilosis, and C. tropicalis in phosphate-free medium. Further characterization showed that, in general, relatively higher phytase activity was observed at more acidic pHs, and the phytase activity increased with incubation temperature, reaching a maximum at 55 or 65°C. Taken together, the findings demonstrated, for the first time, differential phytase activities in different Candida species. Phytase activity may be a contributing factor to fungal survival and proliferation within the human gastrointestinal tract, where nutrients are usually scarce.


Subject(s)
6-Phytase/metabolism , Candida/enzymology , Candida/metabolism , Phytic Acid/metabolism , 6-Phytase/chemistry , Agar , Candida/classification , Candida/isolation & purification , Culture Media/chemistry , Enzyme Stability , Humans , Hydrogen-Ion Concentration , Mouth/microbiology , Phosphates/metabolism , Temperature
10.
Fungal Biol ; 115(3): 302-9, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21354537

ABSTRACT

Metergoline possesses potent antifungal activity against Candida krusei, a notorious yeast species that is inherently resistant to the common antifungal agents. In an attempt to elucidate the action mechanisms of metergoline, the present study was designed to investigate its effects on a number of classical markers of apoptosis in C. krusei. The results showed that transient exposure (2h) to metergoline led to a massive intracellular accumulation of reactive oxygen species (ROS) and depolarization of mitochondrial membrane potential in a concentration-dependent fashion. Analyses of the treated fungal cells after prolonged incubation (12h) with metergoline by flow cytometry and fluorescence microscopy clearly demonstrated phosphatidylserine externalization, the presence of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling-positive cells and fungal cells undergoing necrosis. Taken together, our data provide evidence that metergoline elicited cell death process in C. krusei through elevation of the intracellular ROS level and perturbation of mitochondrial homeostasis, followed by damage of nucleus and eventual cell demise.


Subject(s)
Antifungal Agents/pharmacology , Apoptosis/drug effects , Candida/drug effects , Metergoline/pharmacology , Necrosis/chemically induced , Candida/classification , Candida/ultrastructure , Cell Membrane/drug effects , DNA Fragmentation , Flow Cytometry , In Situ Nick-End Labeling , Membrane Potential, Mitochondrial/drug effects , Microbial Sensitivity Tests , Microscopy, Confocal , Reactive Oxygen Species/metabolism
11.
Mycopathologia ; 170(6): 391-6, 2010 Dec.
Article in English | MEDLINE | ID: mdl-20614252

ABSTRACT

The present study was designed to evaluate the antifungal activity of baicalein against Candida krusei isolates. Using a broth microdilution assay, baicalein exhibited potent in vitro antifungal activity against C. krusei isolates with a minimum inhibitory concentration of 2.7 µg/ml. Flow cytometric study indicated that baicalein depolarized mitochondrial membrane potential in a concentration-dependent manner. However, mechanistic analyses showed that the intracellular reactive oxygen species (ROS) level was virtually unchanged, and massive DNA fragmentation was not observed in C. krusei isolates after baicalein treatment even at a concentration which was apoptotic in C. albicans. Taken together, we conclude that the antifungal activity of baicalein in C. krusei isolates occurs through perturbation in mitochondrial homeostasis without causing elevation of the intracellular ROS level and does not involve apoptosis.


Subject(s)
Antifungal Agents/pharmacology , Apoptosis , Flavanones/pharmacology , Pichia/drug effects , DNA Fragmentation , Flow Cytometry , Membrane Potential, Mitochondrial , Microbial Sensitivity Tests , Pichia/chemistry , Reactive Oxygen Species/analysis
12.
Med Mycol ; 48(7): 904-11, 2010 Nov.
Article in English | MEDLINE | ID: mdl-20392152

ABSTRACT

The antifungal activity of purpurin (1,2,4-trihydroxy-9,10-anthraquinone), a natural red anthraquinone pigment in madder root (Rubia tinctorum L.), was evaluated by a broth microdilution assay against a total of 24 Candida isolates representing six species. The minimum inhibitory concentration (MIC) range of purpurin was 1.28-5.12 µg/ml. Mechanistic studies using the rhodamine 6G extrusion assay indicated that purpurin inhibited the energy-dependent efflux pumps of the Candida isolates in a dose-dependent manner. Furthermore, purpurin demonstrated a dose-dependent depolarization of mitochondrial membrane potential, one of the biochemical checkpoints regulating cell death in eukaryotic cells, suggesting a possible linkage between purpurin antifungal mechanism and Candida apoptosis.


Subject(s)
Anthraquinones/pharmacology , Antifungal Agents/pharmacology , Candida/drug effects , Dose-Response Relationship, Drug , Humans , Membrane Potentials/drug effects , Microbial Sensitivity Tests , Mitochondria/physiology
13.
Yeast ; 27(1): 53-8, 2010 Jan.
Article in English | MEDLINE | ID: mdl-19908199

ABSTRACT

Candida kefyr is a common yeast species that can be found in fermented milk and cheeses. As a first step to developing a gene transfer system for C. kefyr, the orotidine-5'-phosphate decarboxylase (URA3) gene was cloned, using degenerate PCR and genome walking. The uninterrupted open reading frame of the C. kefyr URA3 gene spans 801 bp, corresponding to 267 amino acid residues. The functionality of the gene was confirmed by complementation of ura3 auxotrophs of C. albicans and Saccharomyces cerevisiae. Phylogenetic analysis of the deduced amino acid sequence indicated that it shares a high degree of homology with other Candida URA3 homologues.


Subject(s)
Candida/enzymology , Fungal Proteins/metabolism , Gene Expression Regulation, Enzymologic/physiology , Gene Expression Regulation, Fungal/physiology , Orotidine-5'-Phosphate Decarboxylase/metabolism , Amino Acid Sequence , Cloning, Molecular , Fungal Proteins/genetics , Orotidine-5'-Phosphate Decarboxylase/genetics , Phylogeny
14.
N Biotechnol ; 27(1): 78-84, 2010 Feb 28.
Article in English | MEDLINE | ID: mdl-19909828

ABSTRACT

The industrial importance of Trigonopsis variabilisd-amino acid oxidase (TvDAAO) is represented by its biocatalytic oxidative deamination of cephalosporin C (CPC) to yield glutaryl-7-aminocephalosporanic acid (GL-7-ACA). The process has been incorporated into a two-step bioconversion to produce 7-aminocephalosporanic acid, the crucial synthetic nucleus for several semi-synthetic cephalosporin antibiotics. A homology model of TvDAAO indicated that residue F54 is in a close proximity to the in silico docked CPC. Substitution of this F54 to Tyr (F54Y) resulted in 6-fold improvement in k(cat,app) and approximately 2.5-fold increase in K(i) of GL-7-ACA. Heat treatment (55 degrees C, 60 min) did not decrease the activity of F54Y. It is suggested that the Tyr substitution might initiate hydrogen bond formation with the amino group of CPC and facilitate deamination. Faster substrate turnover, reduced GL-7-ACA inhibition and improved thermostability of the F54Y substitution render it a useful candidate in industrial production of semi-synthetic cephems.


Subject(s)
Amino Acid Substitution , D-Amino-Acid Oxidase , Enzyme Stability , Fungal Proteins , Protein Structure, Tertiary , Saccharomycetales/enzymology , Amino Acid Sequence , Animals , Catalysis , Cephalosporins/chemical synthesis , Cephalosporins/chemistry , Cephalosporins/metabolism , D-Amino-Acid Oxidase/chemistry , D-Amino-Acid Oxidase/genetics , D-Amino-Acid Oxidase/metabolism , Fungal Proteins/genetics , Fungal Proteins/metabolism , Humans , Models, Molecular , Molecular Sequence Data , Mutagenesis, Site-Directed , Phenylalanine/chemistry , Phenylalanine/genetics , Sequence Alignment , Temperature , Tyrosine/chemistry , Tyrosine/genetics
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