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1.
J Infect Dev Ctries ; 18(4): 636-639, 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38728631

RESUMEN

INTRODUCTION: Kodamaea ohmeri is a rare, recognized pathogen that has previously been isolated from environmental sources. The patients commonly affected by this yeast include immunocompromised as well as immunocompetent patients having several associated risk factors. METHODOLOGY: We report three cases in which K. ohmeri was isolated from blood using Bact T/ALERT. Identification was carried out by MALDI-TOF MS (Vitek-MS, BioMérieux, Marcy-l'Etoile, France) in addition to color characteristics on chromogenic media. The patients had diminished immune response on account of a multitude of comorbidities. RESULTS: K. ohmeri can be misidentified as Candida tropicalis, Candida albicans, or Candida hemolounii by conventional methods; correct and timely identification can be achieved by MALDI-TOF MS. Antifungal susceptibility breakpoints for K. ohmeri are currently not defined. An Echinocandin was added to the treatment regimen of all three of the cases. CONCLUSIONS: Identification of K. ohmeri using conventional methods is difficult and unusual yeasts should be carefully observed, especially upon prolonged incubation.


Asunto(s)
Antifúngicos , Huésped Inmunocomprometido , Saccharomycetales , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Humanos , Antifúngicos/uso terapéutico , Antifúngicos/farmacología , Masculino , Saccharomycetales/aislamiento & purificación , Saccharomycetales/efectos de los fármacos , Femenino , Persona de Mediana Edad , Anciano , Infecciones Fúngicas Invasoras/tratamiento farmacológico , Infecciones Fúngicas Invasoras/diagnóstico , Infecciones Fúngicas Invasoras/microbiología , Técnicas Microbiológicas
2.
J Cell Biol ; 223(8)2024 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-38722822

RESUMEN

Cell growth is required for cell cycle progression. The amount of growth required for cell cycle progression is reduced in poor nutrients, which leads to a reduction in cell size. In budding yeast, nutrients can influence cell size by modulating the extent of bud growth, which occurs predominantly in mitosis. However, the mechanisms are unknown. Here, we used mass spectrometry to identify proteins that modulate bud growth in response to nutrient availability. This led to the discovery that nutrients regulate numerous components of the mitotic exit network (MEN), which controls exit from mitosis. A key component of the MEN undergoes gradual multisite phosphorylation during bud growth that is dependent upon bud growth and correlated with the extent of growth. Furthermore, activation of the MEN is sufficient to override a growth requirement for mitotic exit. The data suggest a model in which the MEN ensures that mitotic exit occurs only when an appropriate amount of bud growth has occurred.


Asunto(s)
Mitosis , Saccharomyces cerevisiae , Transducción de Señal , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Nutrientes/metabolismo , Fosforilación , Saccharomyces cerevisiae/citología , Saccharomyces cerevisiae/crecimiento & desarrollo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Saccharomycetales/metabolismo , Saccharomycetales/crecimiento & desarrollo
3.
PLoS One ; 19(5): e0303795, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38771745

RESUMEN

Recombinant proteins are essential in various industries, and scientists employ genetic engineering and synthetic biology to enhance the host cell's protein production capacity. Stress response pathways have been found effective in augmenting protein secretion. Cold atmospheric pressure plasma (CAP) can induce oxidative stress and enhance protein production. Previous studies have confirmed the applicability of CAP jets on Phytase and green fluorescent protein (GFP) production in Pichia pastoris hosts. This study investigates the effect of CAP treatment on another valuable recombinant protein, Endoglucanase II (EgII), integrated into the Pichia pastoris genome. The results demonstrated that plasma induction via two different ignition modes: sinusoidal alternating current (AC) and pulsed direct current (DC) for 120, 180, and 240 s has boosted protein secretion without affecting cell growth and viability. The AC-driven jet exhibited a higher percentage increase in secretion, up to 45%. Simulation of plasma function using COMSOL software provided a pattern of electron temperature (Te) and density distribution, which determine the plasma cocktail's chemistry and reactive species production. Furthermore, electron density (ne) and temperature were estimated from the recorded optical spectrum. The difference in electron properties may explain the moderately different impressions on expression capability. However, cell engineering to improve secretion often remains a trial-and-error approach, and improvements are, at least partially, specific to the protein produced.


Asunto(s)
Celulasa , Gases em Plasma , Proteínas Recombinantes , Gases em Plasma/farmacología , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/genética , Celulasa/metabolismo , Celulasa/genética , Presión Atmosférica , Simulación por Computador , Saccharomycetales/genética , Saccharomycetales/metabolismo
4.
Mar Genomics ; 75: 101111, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38735674

RESUMEN

Hortaea werneckii M-3, a black yeast isolated from the marine sediment of the West Pacific, can utilize polyester polyurethane (PU, Impranil DLN) as a sole carbon source. Here, we present the complete genome of Hortaea werneckii M-3 with the focus on PU degradation enzymes. The total genome size is 38,167,921 bp, consisting of 186 contigs with a N50 length of 651,266 bp and a GC content of 53.06%. Genome annotation analysis predicts a total of 13,462 coding genes, which include 99 tRNAs and 105 rRNAs. Some genes encoding PU degrading enzymes including cutinase and urease are identified in this genome. The genome analysis of Hortaea werneckii M-3 will be helpful for further understanding the degradation mechanism of polyester PU by marine yeasts.


Asunto(s)
Genoma Fúngico , Poliuretanos , Secuenciación Completa del Genoma , Saccharomycetales/genética , Poliésteres/metabolismo , Sedimentos Geológicos/microbiología
5.
World J Microbiol Biotechnol ; 40(7): 200, 2024 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-38730212

RESUMEN

Recombinant protein production technology is widely applied to the manufacture of biologics used as drug substances and industrial proteins such as recombinant enzymes and bioactive proteins. Various heterologous protein production systems have been developed using prokaryotic and eukaryotic hosts. Especially methylotrophic yeast in eukaryotic hosts is suggested to be particularly valuable because such systems have the following advantages: protein secretion into culture broth, eukaryotic quality control systems, a post-translational modification system, rapid growth, and established recombinant DNA tools and technologies such as strong promoters, effective selection markers, and gene knock-in and -out systems. Many methylotrophic yeasts such as the genera Candida, Ogataea, and Komagataella have been studied since methylotrophic yeast was first isolated in 1969. The methanol-consumption-related genes in methylotrophic yeast are strongly and strictly regulated under methanol-containing conditions. The well-regulated gene expression systems under the methanol-inducible gene promoter lead to the potential application of heterologous protein production in methylotrophic yeast. In this review, we describe the recent progress of heterologous protein production technology in methylotrophic yeast and introduce Ogataea minuta as an alternative production host as a substitute for K. phaffii and O. polymorpha.


Asunto(s)
Metanol , Regiones Promotoras Genéticas , Proteínas Recombinantes , Saccharomycetales , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Metanol/metabolismo , Saccharomycetales/genética , Saccharomycetales/metabolismo , Regulación Fúngica de la Expresión Génica
6.
Sci Rep ; 14(1): 11537, 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38773211

RESUMEN

The Martian surface and shallow subsurface lacks stable liquid water, yet hygroscopic salts in the regolith may enable the transient formation of liquid brines. This study investigated the combined impact of water scarcity, UV exposure, and regolith depth on microbial survival under Mars-like environmental conditions. Both vegetative cells of Debaryomyces hansenii and Planococcus halocryophilus, alongside with spores of Aspergillus niger, were exposed to an experimental chamber simulating Martian environmental conditions (constant temperatures of about - 11 °C, low pressure of approximately 6 mbar, a CO2 atmosphere, and 2 h of daily UV irradiation). We evaluated colony-forming units (CFU) and water content at three different regolith depths before and after exposure periods of 3 and 7 days, respectively. Each organism was tested under three conditions: one without the addition of salts to the regolith, one containing sodium chlorate, and one with sodium perchlorate. Our results reveal that the residual water content after the exposure experiments increased with regolith depth, along with the organism survival rates in chlorate-containing and salt-free samples. The survival rates of the three organisms in perchlorate-containing regolith were consistently lower for all organisms and depths compared to chlorate, with the most significant difference being observed at a depth of 10-12 cm, which corresponds to the depth with the highest residual water content. The postulated reason for this is an increase in the salt concentration at this depth due to the freezing of water, showing that for these organisms, perchlorate brines are more toxic than chlorate brines under the experimental conditions. This underscores the significance of chlorate salts when considering the habitability of Martian environments.


Asunto(s)
Cloratos , Medio Ambiente Extraterrestre , Marte , Percloratos , Percloratos/metabolismo , Cloratos/metabolismo , Aspergillus niger/metabolismo , Saccharomycetales/metabolismo , Agua/química , Viabilidad Microbiana
7.
Appl Microbiol Biotechnol ; 108(1): 320, 2024 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-38709366

RESUMEN

The unspecific peroxygenase (UPO) from Cyclocybe aegerita (AaeUPO) can selectively oxidize C-H bonds using hydrogen peroxide as an oxygen donor without cofactors, which has drawn significant industrial attention. Many studies have made efforts to enhance the overall activity of AaeUPO expressed in Komagataella phaffii by employing strategies such as enzyme-directed evolution, utilizing appropriate promoters, and screening secretion peptides. Building upon these previous studies, the objective of this study was to further enhance the expression of a mutant of AaeUPO with improved activity (PaDa-I) by increasing the gene copy number, co-expressing chaperones, and optimizing culture conditions. Our results demonstrated that a strain carrying approximately three copies of expression cassettes and co-expressing the protein disulfide isomerase showed an approximately 10.7-fold increase in volumetric enzyme activity, using the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) as the substrate. After optimizing the culture conditions, the volumetric enzyme activity of this strain further increased by approximately 48.7%, reaching 117.3 U/mL. Additionally, the purified catalytic domain of PaDa-I displayed regioselective hydroxylation of R-2-phenoxypropionic acid. The results of this study may facilitate the industrial application of UPOs. KEY POINTS: • The secretion of the catalytic domain of PaDa-I can be significantly enhanced through increasing gene copy numbers and co-expressing of protein disulfide isomerase. • After optimizing the culture conditions, the volumetric enzyme activity can reach 117.3 U/mL, using the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) as the substrate. • The R-2-phenoxypropionic acid can undergo the specific hydroxylation reaction catalyzed by catalytic domain of PaDa-I, resulting in the formation of R-2-(4-hydroxyphenoxy)propionic acid.


Asunto(s)
Oxigenasas de Función Mixta , Oxigenasas de Función Mixta/genética , Oxigenasas de Función Mixta/metabolismo , Oxigenasas de Función Mixta/química , Saccharomycetales/genética , Saccharomycetales/enzimología , Saccharomycetales/metabolismo , Dosificación de Gen , Proteína Disulfuro Isomerasas/genética , Proteína Disulfuro Isomerasas/metabolismo , Expresión Génica , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/química
8.
Microb Cell Fact ; 23(1): 131, 2024 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-38711081

RESUMEN

BACKGROUND: Komagataella phaffii (Pichia pastoris) has emerged as a common and robust biotechnological platform organism, to produce recombinant proteins and other bioproducts of commercial interest. Key advantage of K. phaffii is the secretion of recombinant proteins, coupled with a low host protein secretion. This facilitates downstream processing, resulting in high purity of the target protein. However, a significant but often overlooked aspect is the presence of an unknown polysaccharide impurity in the supernatant. Surprisingly, this impurity has received limited attention in the literature, and its presence and quantification are rarely addressed. RESULTS: This study aims to quantify this exopolysaccharide in high cell density recombinant protein production processes and identify its origin. In stirred tank fed-batch fermentations with a maximal cell dry weight of 155 g/L, the polysaccharide concentration in the supernatant can reach up to 8.7 g/L. This level is similar to the achievable target protein concentration. Importantly, the results demonstrate that exopolysaccharide production is independent of the substrate and the protein production process itself. Instead, it is directly correlated with biomass formation and proportional to cell dry weight. Cell lysis can confidently be ruled out as the source of this exopolysaccharide in the culture medium. Furthermore, the polysaccharide secretion can be linked to a mutation in the HOC1 gene, featured by all derivatives of strain NRRL Y-11430, leading to a characteristic thinner cell wall. CONCLUSIONS: This research sheds light on a previously disregarded aspect of K. phaffii fermentations, emphasizing the importance of monitoring and addressing the exopolysaccharide impurity in biotechnological applications, independent of the recombinant protein produced.


Asunto(s)
Fermentación , Proteínas Recombinantes , Saccharomycetales , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/genética , Saccharomycetales/metabolismo , Saccharomycetales/genética , Biomasa , Técnicas de Cultivo Celular por Lotes , Polisacáridos/metabolismo , Polisacáridos/biosíntesis
9.
J Insect Sci ; 24(3)2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38713543

RESUMEN

The black soldier fly, Hermetia illucens L. (Diptera: Stratiomyidae), is commonly used for organic waste recycling and animal feed production. However, the often inadequate nutrients in organic waste necessitate nutritional enhancement of black soldier fly larvae, e.g., by fungal supplementation of its diet. We investigated the amino acid composition of two fungi, Candida tropicalis (Castell.) Berkhout (Saccharomycetales: Saccharomycetaceae) and Pichia kudriavzevii Boidin, Pignal & Besson (Saccharomycetales: Pichiaceae), from the black soldier fly gut, and commercial baker's yeast, Saccharomyces cerevisiae Meyen ex E.C. Hansen (Saccharomycetales: Saccharomycetaceae), and their effects on larval growth and hemolymph metabolites in fifth-instar black soldier fly larvae. Liquid chromatography-mass spectrometry was used to study the effect of fungal metabolites on black soldier fly larval metabolism. Amino acid analysis revealed significant variation among the fungi. Fungal supplementation led to increased larval body mass and differential metabolite accumulation. The three fungal species caused distinct metabolic changes, with each over-accumulating and down-accumulating various metabolites. We identified significant alteration of histidine metabolism, aminoacyl-tRNA biosynthesis, and glycerophospholipid metabolism in BSF larvae treated with C. tropicalis. Treatment with P. kudriavzevii affected histidine metabolism and citrate cycle metabolites, while both P. kudriavzevii and S. cerevisiae treatments impacted tyrosine metabolism. Treatment with S. cerevisiae resulted in down-accumulation of metabolites related to glycine, serine, and threonine metabolism. This study suggests that adding fungi to the larval diet significantly affects black soldier fly larval metabolomics. Further research is needed to understand how individual amino acids and their metabolites contributed by fungi affect black soldier fly larval physiology, growth, and development, to elucidate the interaction between fungal nutrients and black soldier fly physiology.


Asunto(s)
Dípteros , Hemolinfa , Larva , Animales , Larva/crecimiento & desarrollo , Larva/metabolismo , Dípteros/metabolismo , Dípteros/crecimiento & desarrollo , Hemolinfa/metabolismo , Pichia/metabolismo , Saccharomyces cerevisiae/metabolismo , Aminoácidos/metabolismo , Dieta , Saccharomycetales/metabolismo , Alimentación Animal/análisis , Candida/metabolismo , Candida/crecimiento & desarrollo
10.
Carbohydr Polym ; 337: 122158, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-38710555

RESUMEN

Chondroitin sulfate (CS) stands as a pivotal compound in dietary supplements for osteoarthritis treatment, propelling significant interest in the biotechnological pursuit of environmentally friendly and safe CS production. Enzymatic synthesis of CS for instance CSA has been considered as one of the most promising methods. However, the bottleneck consistently encountered is the active expression of chondroitin 4-O-sulfotransferase (C4ST) during CSA biosynthesis. This study meticulously delved into optimizing C4ST expression through systematic enhancements in transcription, translation, and secretion mechanisms via modifications in the 5' untranslated region, the N-terminal encoding sequence, and the Komagataella phaffii chassis. Ultimately, the active C4ST expression escalated to 2713.1 U/L, representing a striking 43.7-fold increase. By applying the culture broth supernatant of C4ST and integrating the 3'-phosphoadenosine-5'-phosphosulfate (PAPS) biosynthesis module, we constructed a one-pot enzymatic system for CSA biosynthesis, achieving a remarkable sulfonation degree of up to 97.0 %. The substantial enhancement in C4ST expression and the development of an engineered one-pot enzymatic synthesis system promises to expedite large-scale CSA biosynthesis with customizable sulfonation degrees.


Asunto(s)
Sulfatos de Condroitina , Sulfotransferasas , Sulfatos de Condroitina/química , Sulfatos de Condroitina/biosíntesis , Sulfatos de Condroitina/metabolismo , Sulfotransferasas/metabolismo , Sulfotransferasas/genética , Saccharomycetales/enzimología , Saccharomycetales/metabolismo , Saccharomycetales/genética
11.
Artículo en Inglés | MEDLINE | ID: mdl-38713197

RESUMEN

Two isolates representing a novel species of the genus Wickerhamiella were obtained in India from nectar of flowers of Lantana camara, an ornamental exotic species native to Central and South America. Phylogenetic analyses of the D1/D2 domain of the 26S large subunit (LSU) rRNA gene, internal transcribed spacer (ITS) region, and physiological characteristics, supported the recognition of the novel species, that we designate Wickerhamiella lachancei sp. nov (MycoBank no. MB851709), with MCC 9929T as the holotype and PYCC 10003T as the isotype. Considering pairwise sequence similarity, the type strain of the novel species differs from the type strain of the most closely related species, Wickerhamiella drosophilae CBS 8459T, by 16 nucleotide substitutions and two gaps (3.9 % sequence variation) in the D1/D2 region (560 bp compared) and 28 nucleotide substitutions and five gaps (7.22 % sequence variation) in the ITS region (444 bp compared).


Asunto(s)
ADN de Hongos , ADN Espaciador Ribosómico , Flores , Lantana , Filogenia , Análisis de Secuencia de ADN , India , Flores/microbiología , ADN de Hongos/genética , Lantana/microbiología , ADN Espaciador Ribosómico/genética , Datos de Secuencia Molecular , Técnicas de Tipificación Micológica , ARN Ribosómico/genética , Saccharomycetales/genética , Saccharomycetales/aislamiento & purificación , Saccharomycetales/clasificación
12.
Microb Cell Fact ; 23(1): 99, 2024 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-38566096

RESUMEN

BACKGROUND: The yeast Komagataella phaffii has become a very popular host for heterologous protein expression, very often based on the use of the AOX1 promoter, which becomes activated when cells are grown with methanol as a carbon source. However, the use of methanol in industrial settings is not devoid of problems, and therefore, the search for alternative expression methods has become a priority in the last few years. RESULTS: We recently reported that moderate alkalinization of the medium triggers a fast and wide transcriptional response in K. phaffii. Here, we present the utilization of three alkaline pH-responsive promoters (pTSA1, pHSP12 and pPHO89) to drive the expression of a secreted phytase enzyme by simply shifting the pH of the medium to 8.0. These promoters offer a wide range of strengths, and the production of phytase could be modulated by adjusting the pH to specific values. The TSA1 and PHO89 promoters offered exquisite regulation, with virtually no enzyme production at acidic pH, while limitation of Pi in the medium further potentiated alkaline pH-driven phytase expression from the PHO89 promoter. An evolved strain based on this promoter was able to produce twice as much phytase as the reference pAOX1-based strain. Functional mapping of the TSA1 and HSP12 promoters suggests that both contain at least two alkaline pH-sensitive regulatory regions. CONCLUSIONS: Our work shows that the use of alkaline pH-regulatable promoters could be a useful alternative to methanol-based expression systems, offering advantages in terms of simplicity, safety and economy.


Asunto(s)
6-Fitasa , Saccharomycetales , Pichia/metabolismo , Metanol/metabolismo , 6-Fitasa/genética , 6-Fitasa/metabolismo , Saccharomycetales/genética , Saccharomycetales/metabolismo , Concentración de Iones de Hidrógeno , Proteínas Recombinantes/metabolismo
13.
Artículo en Inglés | MEDLINE | ID: mdl-38591772

RESUMEN

Two yeast strains, designated as 19-39-3 and 19-40-2, obtained from the fruiting bodies of Trametes versicolor and Marasmius siccus collected in Yunwu Mountain Forest Park, PR China, have been identified as representing a novel asexual ascomycetous yeast species. From the results of phylogenetic analyses of the sequences of the D1/D2 domains of the large subunit (LSU) rRNA, small subunit (SSU) rRNA and translation elongation factor 1-α (TEF1) genes, it was determined that these strains represent a member of the genus Wickerhamomyces, with Wickerhamomyces alni and Candida ulmi as the closest relatives. The novel species exhibited 6.6 and 6.7% differences in the D1/D2 domains compared with W. alni and C. ulmi, respectively. Additionally, distinct biochemical and physiological differences were observed between the novel species and its related counterparts. No sexual reproduction was observed in these strains, leading to the proposal of the name Wickerhamomyces corioli f.a., sp. nov. for this newly discovered species.


Asunto(s)
Agaricales , Saccharomycetales , Filogenia , ADN Espaciador Ribosómico/genética , Agaricales/genética , Trametes/genética , Análisis de Secuencia de ADN , Composición de Base , ARN Ribosómico 16S/genética , ADN Bacteriano/genética , Técnicas de Tipificación Bacteriana , Ácidos Grasos/química , Saccharomycetales/genética , ADN de Hongos/genética , Técnicas de Tipificación Micológica
14.
Artículo en Inglés | MEDLINE | ID: mdl-38591773

RESUMEN

Four yeast strains, representing a novel anamorphic species, were isolated in Thailand. The two strains (ST-3660T and ST-3647) were obtained from two different estuarine water samples in a mangrove forest. Strain DMKU-FW1-37 was derived from a grease sample, and another strain (TSU57) was isolated from a fruiting body of Phallus sp. Pairwise sequence analysis showed that the four strains had identical or differed by only one nucleotide substitution in the D1/D2 domains of the large subunit (LSU) rRNA gene, and differed by one to three nucleotide substitutions in the internal transcribed spacer (ITS) regions. Savitreea pentosicarens is the most closely related species to the four strains, but with 9-10 (1.57-1.72 %) nucleotide substitutions in the D1/D2 domains of the LSU rRNA gene and 29-31 (4.22-4.45 %) nucleotide substitutions in the ITS regions. Phylogenetic analyses based on the concatenated sequences of the ITS regions and the D1/D2 domains of the LSU rRNA gene showed that the four strains form a well-separated lineage from S. pentosicarens with high bootstrap support, confirming that they represent a distinct species. Therefore, the four strains are assigned as representives of a novel species of the genus Savitreea, for which the name Savitreea siamensis sp. nov. is proposed. The holotype is TBRC 4481T and the ex-type is PYCC 9794T (=ST-3660T). The MycoBank number of the novel species is MB 851951.


Asunto(s)
Ácidos Grasos , Saccharomycetales , Filogenia , ADN Espaciador Ribosómico/genética , Tailandia , Análisis de Secuencia de ADN , ADN de Hongos/genética , Técnicas de Tipificación Micológica , ARN Ribosómico 16S/genética , ADN Bacteriano/genética , Técnicas de Tipificación Bacteriana , Composición de Base , Ácidos Grasos/química , Nucleótidos
15.
Elife ; 132024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38629949

RESUMEN

Mapping proteins in and associated with the Golgi apparatus reveals how this cellular compartment emerges in budding yeast and progresses over time.


Asunto(s)
Aparato de Golgi , Saccharomycetales
16.
Appl Microbiol Biotechnol ; 108(1): 296, 2024 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-38607413

RESUMEN

Sophorolipids (SLs) are promising glycolipid biosurfactants as they are easily produced and functional. SLs from microorganisms are comprised of mixtures of multiple derivatives that have different structures and properties, including well-known acidic and lactonic SL (ASLs and LSLs, respectively). In this study, we established a method for analyzing all SL derivatives in the products of Starmerella bombicola, a typical SL-producing yeast. Detailed component analyses of S. bombicola products were carried out using reversed-phase high-performance liquid chromatography and mass spectrometry. Methanol was used as the eluent as it is a good solvent for all SL derivatives. With this approach, it was possible to not only quantify the ratio of the main components of ASL, LSL, and SL glycerides but also confirm trace components such as SL mono-glyceride and bola-form SL (sophorose at both ends); notably, this is the first time these components have been isolated and identified successfully in naturally occurring SLs. In addition, our results revealed a novel SL derivative in which a fatty acid is bonded in series to the ASL, which had not been reported previously. Using the present analysis method, it was possible to easily track compositional changes in the SL components during culture. Our results showed that LSL and ASL are produced initially and that SL glycerides accumulate from the middle stage during the fermentation process. KEY POINTS: • An easy and detailed component analysis method for sophorolipids (SLs) is introduced. • Multiple SL derivatives were identified different from known SLs. • A novel hydrophobic acidic SL was isolated and characterized.


Asunto(s)
Ácidos Oléicos , Saccharomycetales , Ácidos Grasos , Glicéridos
17.
Microb Cell Fact ; 23(1): 110, 2024 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-38609906

RESUMEN

BACKGROUND: The wasabi receptor, also known as the Transient Receptor Potential Ankyrin 1 (TRPA1) ion channel, is a potential target for development of repellents for insects, like the pine weevil (Hylobius abietis) feeding on conifer seedlings and causing damage in forestry. Heterologous expression of TRPA1 from pine weevil in the yeast Pichia pastoris can potentially provide protein for structural and functional studies. Here we take advantage of the Green Fluorescent Protein (GFP) tag to examine the various steps of heterologous expression, to get more insight in clone selection, expression and isolation of the intact purified protein. RESULTS: The sequence of HaTRPA1 is reported and GFP-tagged constructs were made of the full-length protein and a truncated version (Δ1-708 HaTRPA1), lacking the N-terminal ankyrin repeat domain. Clones were screened on GFP expression plates, induced in small liquid cultures and in fed-batch cultures, and evaluated by flow cytometry and fluorescence microscopy. The screening on plates successfully identifies low-expression clones, but fails to predict the ranking of the best performing clones in small-scale liquid cultures. The two constructs differ in their cellular localization. Δ1-708 HaTRPA1 is found in a ring at the perimeter of cell, whereas HaTRPA1 is forming highly fluorescent speckles in interior regions of the cell. The pattern is consistent in different clones of the same construct and persists in fed-batch culture. The expression of Δ1-708 HaTRPA1 decreases the viability more than HaTRPA1, and in fed-batch culture it is clear that intact cells first express Δ1-708 HaTRPA1 and then become damaged. Purifications show that both constructs suffer from degradation of the expressed protein, but especially the HaTRPA1 construct. CONCLUSIONS: The GFP tag makes it possible to follow expression by flow cytometry and fluorescence microscopy. Analyses of localization, cell viability and expression show that the former two parameters are specific for each of the two evaluated constructs, whereas the relative expression of the constructs varies with the cultivation method. High expression is not all that matters, so taking damaged cells into account, something that may be linked to protein degradation, is important when picking the most suitable construct, clone, and expression scheme.


Asunto(s)
Saccharomycetales , Gorgojos , Animales , Proteínas Fluorescentes Verdes/genética , Citometría de Flujo
18.
Microb Cell Fact ; 23(1): 111, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38622625

RESUMEN

BACKGROUND: Ascomycetous budding yeasts are ubiquitous environmental microorganisms important in food production and medicine. Due to recent intensive genomic research, the taxonomy of yeast is becoming more organized based on the identification of monophyletic taxa. This includes genera important to humans, such as Kazachstania. Until now, Kazachstania humilis (previously Candida humilis) was regarded as a sourdough-specific yeast. In addition, any antibacterial activity has not been associated with this species. RESULTS: Previously, we isolated a yeast strain that impaired bio-hydrogen production in a dark fermentation bioreactor and inhibited the growth of Gram-positive and Gram-negative bacteria. Here, using next generation sequencing technologies, we sequenced the genome of this strain named K. humilis MAW1. This is the first genome of a K. humilis isolate not originating from a fermented food. We used novel phylogenetic approach employing the 18 S-ITS-D1-D2 region to show the placement of the K. humilis MAW1 among other members of the Kazachstania genus. This strain was examined by global phenotypic profiling, including carbon sources utilized and the influence of stress conditions on growth. Using the well-recognized bacterial model Escherichia coli AB1157, we show that K. humilis MAW1 cultivated in an acidic medium inhibits bacterial growth by the disturbance of cell division, manifested by filament formation. To gain a greater understanding of the inhibitory effect of K. humilis MAW1, we selected 23 yeast proteins with recognized toxic activity against bacteria and used them for Blast searches of the K. humilis MAW1 genome assembly. The resulting panel of genes present in the K. humilis MAW1 genome included those encoding the 1,3-ß-glucan glycosidase and the 1,3-ß-glucan synthesis inhibitor that might disturb the bacterial cell envelope structures. CONCLUSIONS: We characterized a non-sourdough-derived strain of K. humilis, including its genome sequence and physiological aspects. The MAW1, together with other K. humilis strains, shows the new organization of the mating-type locus. The revealed here pH-dependent ability to inhibit bacterial growth has not been previously recognized in this species. Our study contributes to the building of genome sequence-based classification systems; better understanding of K.humilis as a cell factory in fermentation processes and exploring bacteria-yeast interactions in microbial communities.


Asunto(s)
Antibacterianos , Saccharomycetales , Humanos , Filogenia , Antibacterianos/metabolismo , Bacterias Gramnegativas , Bacterias Grampositivas , Saccharomycetales/genética , Levaduras/metabolismo , Fermentación
19.
Semin Cell Dev Biol ; 161-162: 31-41, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38598944

RESUMEN

Antagonistic coevolution, arising from genetic conflict, can drive rapid evolution and biological innovation. Conflict can arise both between organisms and within genomes. This review focuses on budding yeasts as a model system for exploring intra- and inter-genomic genetic conflict, highlighting in particular the 2-micron (2µ) plasmid as a model selfish element. The 2µ is found widely in laboratory strains and industrial isolates of Saccharomyces cerevisiae and has long been known to cause host fitness defects. Nevertheless, the plasmid is frequently ignored in the context of genetic, fitness, and evolution studies. Here, I make a case for further exploring the evolutionary impact of the 2µ plasmid as well as other selfish elements of budding yeasts, discuss recent advances, and, finally, future directions for the field.


Asunto(s)
Saccharomycetales , Saccharomycetales/genética , Saccharomyces cerevisiae/genética , Plásmidos/genética , Genoma
20.
Biochem Biophys Res Commun ; 715: 149980, 2024 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-38678780

RESUMEN

The transport of ceramide from the endoplasmic reticulum (ER) to the Golgi is a key step in the synthesis of complex sphingolipids, the main building blocks of the plasma membrane. In yeast, ceramide is transported to the Golgi either through ATP-dependent COPII vesicles of the secretory pathway or by ATP-independent non-vesicular transport that involves tethering proteins at ER-Golgi membrane contact sites. Studies in both mammalian and yeast cells reported that vesicular transport mainly carries ceramide containing very long chain fatty acids, while the main mammalian non-vesicular ceramide transport protein CERT only transports ceramides containing short chain fatty acids. However, if non-vesicular ceramide transport in yeast similarly favors short chain ceramides remained unanswered. Here we employed a yeast GhLag1 strain in which the endogenous ceramide synthase is replaced by the cotton-derived GhLag1 gene, resulting in the production of short chain C18 rather than C26 ceramides. We show that block of vesicular transport through ATP-depletion or the use of temperature-sensitive sec mutants caused a reduction in inositolphosphorylceramide (IPC) synthesis to similar extent in WT and GhLag1 backgrounds. Since the remaining IPC synthesis is a readout for non-vesicular ceramide transport, our results indicate that non-vesicular ceramide transport is neither blocked nor facilitated when only short chain ceramides are present. Therefore, we propose that the sorting of ceramide into non-vesicular transport is independent of acyl chain length in budding yeast.


Asunto(s)
Ceramidas , Aparato de Golgi , Saccharomyces cerevisiae , Ceramidas/metabolismo , Aparato de Golgi/metabolismo , Transporte Biológico , Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/genética , Saccharomycetales/metabolismo , Saccharomycetales/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Retículo Endoplásmico/metabolismo , Adenosina Trifosfato/metabolismo , Glicoesfingolípidos
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