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BMC Microbiology Apr 2023The production of biopolymers from waste resources is a growing trend, especially in high-population countries like Egypt. Beta-glucan (β-glucan) belongs to natural...
BACKGROUND
The production of biopolymers from waste resources is a growing trend, especially in high-population countries like Egypt. Beta-glucan (β-glucan) belongs to natural polysaccharides that are derived from plant and microbial origins. In this study, following increasing demands for β-glucan owing to its bioactive properties, a statistical model to enhance microbial β-glucan production was evaluated for its usefulness to the food and pharmaceutical industries. In addition, a trial to convert β-glucan polymer to nanostructure form was done to increase its bioactivity.
RESULTS
Ingredients of low-cost media based on agro-industrial wastes were described using Plackett-Burman and central composite design of response surface methodology for optimizing yeast β-glucan. Minerals and vitamin concentrations significantly influenced β-glucan yield for Kluyveromyces lactis and nitrogen and phosphate sources for Meyerozyma guilliermondii. The maximum predicted yields of β-glucan recovered from K. lactis and M. guilliermondii after optimizing the medium ingredients were 407 and 1188 mg/100 ml; respectively. For the first time, yeast β-glucan nanoparticles (βGN) were synthesized from the β-glucan polymer using N-dimethylformamide as a stabilizer and characterized using UV-vis spectroscopy, transmission electron microscope (TEM), dynamic light scattering (DLS) and Fourier transform infrared spectroscopy (FT-IR). The average size of βGN was about 300 nm as determined by DLS. The quantitative variation of functional groups between β-glucan polymer and βGN was evaluated by FT-IR for explaining the difference in their biological activity against Normal Homo sapiens-Hela contaminant and Hepatic cancer cell lines.
CONCLUSIONS
Enriching the low-cost media based on agro-industrial wastes with nutritional ingredients improves the yield of yeast β-glucan. The present study succeeds to form β-glucan nanoparticles by a simple method.
Topics: Humans; beta-Glucans; Spectroscopy, Fourier Transform Infrared; Industrial Waste; Nanoparticles; Nanotechnology
PubMed: 37081407
DOI: 10.1186/s12866-023-02845-6 -
FEMS Yeast Research Jun 2019Xylitol is a five-carbon polyol of economic interest that can be produced by microbial xylose reduction from renewable resources. The current study sought to investigate...
Xylitol is a five-carbon polyol of economic interest that can be produced by microbial xylose reduction from renewable resources. The current study sought to investigate the potential of two yeast strains, isolated from Brazilian Cerrado biome, in the production of xylitol as well as the genomic characteristics that may impact this process. Xylose conversion capacity by the new isolates Spathaspora sp. JA1 and Meyerozyma caribbica JA9 was evaluated and compared with control strains on xylose and sugarcane biomass hydrolysate. Among the evaluated strains, Spathaspora sp. JA1 was the strongest xylitol producer, reaching product yield and productivity as high as 0.74 g/g and 0.20 g/(L.h) on xylose, and 0.58 g/g and 0.44 g/(L.h) on non-detoxified hydrolysate. Genome sequences of Spathaspora sp. JA1 and M. caribbica JA9 were obtained and annotated. Comparative genomic analysis revealed that the predicted xylose metabolic pathway is conserved among the xylitol-producing yeasts Spathaspora sp. JA1, M. caribbica JA9 and Meyerozyma guilliermondii, but not in Spathaspora passalidarum, an efficient ethanol-producing yeast. Xylitol-producing yeasts showed strictly NADPH-dependent xylose reductase and NAD+-dependent xylitol-dehydrogenase activities. This imbalance of cofactors favors the high xylitol yield shown by Spathaspora sp. JA1, which is similar to the most efficient xylitol producers described so far.
Topics: Biomass; Brazil; Fermentation; Genome, Fungal; Genomics; Industrial Microbiology; Metabolic Networks and Pathways; Saccharomycetales; Xylitol; Xylose
PubMed: 31073598
DOI: 10.1093/femsyr/foz034 -
International Journal of Food... Sep 2021Fermented soy sauces are used as food seasonings in Eastern countries and all over the world. Depending on their cultural origins, their production differs in parameters... (Review)
Review
Fermented soy sauces are used as food seasonings in Eastern countries and all over the world. Depending on their cultural origins, their production differs in parameters such as wheat addition, temperature, and salt concentration. The fermentation of lupine seeds presents an alternative to the use of soybeans; however, the microbiota and influencing factors are currently unknown. In this study, we analyse the microbiota of lupine Moromi (mash) fermentations for a period of six months and determine the influence of different salt concentrations on the microbiota dynamics and the volatile compound composition. Cultured microorganisms were identified by protein profiling using matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS), and 16S rRNA gene amplicon sequencing provided an overview of the microbiota including non-cultured bacteria. The volatile compounds were determined by gas chromatography-mass spectrometry (GC-MS). At all salt concentrations, we found that Tetragenococcus halophilus (up to 1.4 × 10 colony forming units (CFU)/mL on day 21) and Chromohalobacter japonicus (1.9 × 10 CFU/mL, day 28) were the dominating bacteria during Moromi fermentation. Debaryomyces hansenii (3.6 × 10 CFU/mL, day 42) and Candida guilliermondii (2.2 × 10 CFU/mL, day 2) were found to be the most prevalent yeast species. Interestingly, Zygosaccharomyces rouxii and other yeasts described as typical for soy Moromi were not found. With increasing salinity, we found lower diversity in the microbiota, the prevalence-gain of typical species was delayed, and ratios differed depending on their halo- or acid tolerance. GC-MS analysis revealed aroma-active compounds, such as pyrazines, acids, and some furanones, which were mostly different from the aroma compounds found in soy sauce. The absence of wheat may have caused a change in yeast microbiota, and the use of lupine seeds may have led to the differing aromatic composition. Salt reduction resulted in a more complex microbiome, higher cell counts, and did not show any spoiling organisms. With these findings, we show that seasoning sauce that uses lupine seeds as the sole substrate is a suitable gluten-free, soy-free and salt reduced alternative to common soy sauces with a unique flavour.
Topics: Chromohalobacter; Enterococcaceae; Fermented Foods; Food Microbiology; Lupinus; Microbiota; RNA, Ribosomal, 16S; Saccharomycetales; Seeds; Sodium Chloride
PubMed: 34247020
DOI: 10.1016/j.ijfoodmicro.2021.109316 -
Analytical Biochemistry May 2023In eukaryotes, serine proteases are cellular localized hydrolases reported to regulate essential biological reactions. Improved industrial applications of proteins are...
In eukaryotes, serine proteases are cellular localized hydrolases reported to regulate essential biological reactions. Improved industrial applications of proteins are aided by prediction and analysis of their 3-dimensional structures (3D). A serine protease was identified from CTG-clade yeast Meyerozyma guilliermondii strain SO and its 3D structure as well as its catalytic attributes have not been fully understood yet, thus we seek to report on the catalytic mechanism of M. guilliermondii strain SO MgPRB1 using substrate PMSF via in silico docking as well as its stability by way of disulfide bonds formation. Herein, bioinformatics tools and techniques were used to predict, validate and analyze the possible changes of CUG ambiguity (if any) in strain SO using template PDB ID: 3F7O. Structural assessments confirmed the classic catalytic triad Asp305, His337, and Ser499. Superimposition of MgPRB1 and template 3F7O structures revealed the unlinked cysteine residues between Cys341, Cys440, Cys471 and Cys506 of MgPRB1 compared to template 3F7O with two disulfide bonds formation, which confers structural stability. In conclusion, serine protease structure from strain SO was successfully predicted and studies towards understanding at the molecular level may be undertaken for its potential applications in the degradation of peptide bonds.
Topics: Serine Proteases; Saccharomycetales; Serine Endopeptidases; Disulfides
PubMed: 36889624
DOI: 10.1016/j.ab.2023.115092 -
Medical Mycology Jan 2024Fungal flora in coastal/inland beach sand and recreational water is a neglected field of study, despite its potential impact on human health. A joint International... (Review)
Review
Fungal flora in coastal/inland beach sand and recreational water is a neglected field of study, despite its potential impact on human health. A joint International Society for Human and Animal Mycology/European Confederation for Medical Mycology (ISHAM/ECMM) working group was formed in 2019 with the task to set up a vast international initiative aimed at studying the fungal contamination of beaches and bathing waters. Here we review the importance of the topic, and list the main results and achievements from 12 scientific publications. Fungal contamination exists at different levels, and the genera most frequently found were Aspergillus spp., Candida spp., Fusarium spp., and Cryptococcus spp., both in sand and in water. A site-blind median was found to be 89 colony-forming units of fungi per gram of sand in coastal/inland freshwaters. This threshold has been used for the sand quality criterion of the blue flag in Portugal. Additionally, our data were considered pivotal and therefore used for the first inclusion of fungi as a biological taxon of interest in water quality and sand monitoring recommendations of the World Health Organization's new guidelines on recreational water quality (Vol.1-Chap7). The findings of the consortium also suggest how environmental conditions (climate, salinity, soil pH, nitrogen, etc.) influence microbial communities in different regions, and that yeast species like Candida glabrata, Clavispora lusitaniae, and Meyerozyma guilliermondii have been identified as potential fungal indicators of fecal contamination. Climate change and natural disasters may affect fungal populations in different environments, and because this is still a field of study under exploration, we also propose to depict the future challenges of research and unmet needs.
Topics: Animals; Humans; Sand; Environmental Monitoring; Research Report; Water Microbiology; Yeasts; Feces
PubMed: 38196143
DOI: 10.1093/mmy/myad137 -
Anais Da Academia Brasileira de Ciencias 2023The interest for oleaginous yeasts has grown significantly in the last three decades, mainly due to their potential use as a renewable source of microbial oil or single...
The interest for oleaginous yeasts has grown significantly in the last three decades, mainly due to their potential use as a renewable source of microbial oil or single cell oils (SCOs). However, the methodologies for cell disruption to obtain the microbial oil are considered critical and determinant for a large-scale production. Therefore, this work aimed to evaluate different methods for cell wall disruption for the lipid extraction of Yarrowia lipolytica QU21 and Meyerozyma guilliermondii BI281A. The two strains were separately cultivated in 5 L batch fermenters for 120 hours, at 26 ºC and 400 rpm. Three different lipid extraction processes using Turrax homogenizer, Ultrasonicator and Braun homogenizer combined with bead milling were applied in wet, oven-dried, and freeze-dried biomass of both strains. The treatment with the highest percentage of disrupted cells and highest oil yield was the ultrasonication of oven-dried biomass (37-40% lipid content for both strains). The fact that our results point to one best extraction strategy for two different yeast strains, belonging to different species, is a great news towards the development of a unified technique that could be applied at industrial plants.
Topics: Yarrowia; Oils; Biomass
PubMed: 38055604
DOI: 10.1590/0001-3765202320191256 -
Journal, Genetic Engineering &... Sep 2020Meyerozyma guilliermondii is a yeast which could be isolated from a variety of environments. The vka1 strain isolated and purified from the organic compost was found to...
BACKGROUND
Meyerozyma guilliermondii is a yeast which could be isolated from a variety of environments. The vka1 strain isolated and purified from the organic compost was found to have composting potential. To better understand the genes assisting the composting potential in this yeast, whole genome sequencing and sequence annotation were performed.
RESULTS
The genome of M. guilliermondii vka1 strain was sequenced using a hybrid approach, on Illumina Hiseq-2500 platform at 100× coverage followed by Nanopore platform at 20× coverage. The de novo assembly using dual-fold approach had given draft genome of 10.8 Mb size. The genome was found to contain 5385 genes. The annotation of the genes was performed, and the enzymes identified to have roles in the degradation of macromolecules are discussed in relation to its composting potential. Annotation of the genome assembly of the related strains had revealed the unique biodegradation related genes in this strain. Phylogenetic analysis using the rDNA region has confirmed the position of this strain in the Ascomycota family. Raw reads are made public, and the genome wide proteome profile is presented to facilitate further studies on this organism.
CONCLUSIONS
Meyerozyma guilliermondii vka1 strain was sequenced through hybrid approach and the reads were de novo assembled. Draft genome size and the number of genes in the strain were assessed and discussed in relation to the related strains. Scientific insights into the composting potential of this strain are also presented in relation to the unique genes identified in this strain.
PubMed: 32996036
DOI: 10.1186/s43141-020-00074-2 -
Journal of Cellular Physiology Dec 2017This research explored the effects of protein and polysaccharide in Meyerozyma guilliermondii on active compounds in Glycyrrhiza uralensis Fisch adventitious roots. In...
LSP1, a responsive protein from Meyerozyma guilliermondii, elicits defence response and improves glycyrrhizic acid biosynthesis in Glycyrrhiza uralensis Fisch adventitious roots.
This research explored the effects of protein and polysaccharide in Meyerozyma guilliermondii on active compounds in Glycyrrhiza uralensis Fisch adventitious roots. In this study, a responsive protein LSP1 was purified from the Meyerozyma guilliermondii since the excellent induction. The contents of total flavonoids (3.46 mg · g ), glycyrrhizic acid (0.41 mg · g ), glycyrrhetinic acid (0.41 mg · g ), and polysaccharide (94.49 mg · g ) in adventitious root peaked at LSP1 group, which were 1.6, 3.4, 2.4, 2.0-fold that of control, respectively. Besides, the responsive protein LSP1 significantly activated the defense signaling, mitogen-activated protein kinases and extremely up-regulated the expression of defense-related genes and functional genes involved in glycyrrhizic acid biosynthesis.
Topics: Chromatography, High Pressure Liquid; Fungal Proteins; Gene Expression Regulation, Plant; Glycyrrhiza uralensis; Glycyrrhizic Acid; Host-Pathogen Interactions; Mitogen-Activated Protein Kinases; Plant Roots; Saccharomycetales; Signal Transduction; Spectrometry, Mass, Electrospray Ionization; Time Factors; Up-Regulation
PubMed: 28105652
DOI: 10.1002/jcp.25811 -
3 Biotech Jul 2019A high-salt-tolerant strain, , has been isolated from activated sludge which has a great effect in the treatment of high-salt wastewater. To identify the salt tolerance...
A high-salt-tolerant strain, , has been isolated from activated sludge which has a great effect in the treatment of high-salt wastewater. To identify the salt tolerance mechanism of the strain, transcriptome sequencing and fluorescence quantitative PCR were used to analyse and compare the thallus, which were growing in the salt-free, low-salt (4%), and high-salt (16%) YPD media for 48 h, respectively, and then the change of intracellular and extracellular glycerol was determined. The results showed that 8220 unigenes were obtained from the sequencing data after de novo splicing, among which 6334 genes had annotation information in the SwissProt library. With salt-free as reference, there were 1135 unigenes that differentially expressed under low-salt stress and 1948 unigenes were differentially expressed under high-salt stress. With low salt as reference, 3056 unigenes were differentially expressed under high-salt stress. The fluorescence quantification results of the six candidate genes selected in this study were consistent with the transcriptome data. Under high-salt stress, the intracellular glycerol of reached a maximum value at about 10 min, then decreased quickly and tended to be stable. This study provided valuable data for the next study of salt tolerance of , and also contributed to the functional study of yeast salt tolerance genes.
PubMed: 31245250
DOI: 10.1007/s13205-019-1817-2 -
Detection of spoilage-causing yeasts and bacteria in tchapalo, the Ivorian traditional sorghum beer.Letters in Applied Microbiology Jul 2022In this study, we aimed to analyse the spoilage potential of the isolated yeast, LAB and AAB species. Thus, 11 strains were inoculated at 0·3% (v/v) into a sterile...
In this study, we aimed to analyse the spoilage potential of the isolated yeast, LAB and AAB species. Thus, 11 strains were inoculated at 0·3% (v/v) into a sterile filtered tchapalo and stored for 3 days at ambient temperature (27-30°C). All the tested strains grew well or remained stable except for Limosilactobacillus fermentum and Pediococcus acidilactici, which decreased throughout the storage time. A significant decrease of total soluble solids was observed only for Saccharomyces cerevisiae (from 7·8 to 5·8 °Brix) and Meyerozyma guilliermondii (from 7·8 to 5·5 °Brix). The tchapalo samples inoculated with the LAB strains Weissella paramesenteroides, P. acidilactici, L. fermentum and the yeast strain Candida tropicalis were judged similar to the control by the panellists. However, the strains of Lacticaseibacillus paracasei and Latilactobacillus curvatus (LAB), S. cerevisiae, M. guilliermondii and Kluyveromyces marxianus (yeasts) and Acetobacter pasteurianus and A. cerevisiae (AAB) induced the spoilage of the tchapalo appearance, smell and/or taste. In the spoiled tchapalo quantitative and qualitative modification of some volatile compounds (VOCs), such as lilac aldehyde, ethyl acetate, ethyl hexanoate, ethyl octanoate and phenethyl acetate, were observed. These results provide information about the microorganisms that need to be removed to extend the shelf life of tchapalo.
Topics: Bacteria; Beer; Cote d'Ivoire; Fermentation; Food Microbiology; Saccharomyces cerevisiae; Sorghum; Yeasts
PubMed: 35344598
DOI: 10.1111/lam.13708