-
Frontiers in Microbiology 2022Diquat is used in agricultural contexts to control the growth of broadleaf and grassy weeds in both terrestrial and aquatic areas. Diquat can be readily absorbed by the...
Diquat is used in agricultural contexts to control the growth of broadleaf and grassy weeds in both terrestrial and aquatic areas. Diquat can be readily absorbed by the soil and can remain therein for extended periods of time, altering the local microenvironment. In this study, the Wyslmt yeast strain, which has the capacity to degrade Diquat, was isolated from soil exposed to long-term Diquat treatment. Over a 7-day incubation period, this strain was able to remove 42.51% of available Diquat (100 mg/L). RNA-Seq was performed to assess changes in gene expression in this yeast strain over the course of Diquat degradation, revealing 63 and 151 upregulated and downregulated genes, respectively. KEGG pathway enrichment analysis revealed these genes to be most highly enriched in the carbohydrate metabolism pathway. Through functional annotation and gene expression analyses, we identified seven genes were predicted to be involved in Diquat biodegradation. Results of qRT-PCR assays indicated that the relative mRNA expression levels of these seven genes were significantly higher relative to the control group. Together these analyses led to the identification of as a candidate Diquat-degrading gene. When a pET- vector was expressed in BL21, this strain was able to remove 12.49% of provided Diquat (100 mg/L) over the course of a 7-day incubation. These results thus confirmed that the gene can promote Diquat degradation, with these studies having yielded an engineered BL21-pET- bacterial strain capable of degrading Diquat.
PubMed: 36118229
DOI: 10.3389/fmicb.2022.993721 -
Food Chemistry Jan 2023This study evaluated the inoculation of Meyerozyma guilliermondii and Bacillus licheniformis, separately or in co-culture, in wet-processed conilon coffee. Wet...
This study evaluated the inoculation of Meyerozyma guilliermondii and Bacillus licheniformis, separately or in co-culture, in wet-processed conilon coffee. Wet fermentation was conducted for 48 h. Mesophilic bacteria, lactic acid bacteria, yeasts, and filamentous fungi were counted during fermentation. The inoculation of B. licheniformis and M. guilliermondii stimulated the multiplication of lactic acid bacteria. Acetic, citric, lactic, oxalic, malic, succinic, tartaric acids, glucose, and fructose were identified in all treatments at different concentrations. Methyl salicylate, 2-heptanol, 2-nonanol, and heptanone were found during fermentation. Methylpyrazine, 2,6-dimethylpyrazine, 2,5-dimethylpyrazine, and 3-ethyl-2,5-dimethylpyrazine identified after roasting assigned notes of "almond" and "chocolate" to the beverages. All treatments were classified as "premium," with the B. licheniformis treatment receiving the highest score. Bacillus licheniformis obtained better performance in fermentation, increasing coffee score and producing volatile compounds that provided positive sensory notes to the beverage.
Topics: Bacteria; Coffea; Coffee; Fructose; Glucose; Heptanol; Lactobacillales; Yeasts
PubMed: 36087481
DOI: 10.1016/j.foodchem.2022.134107 -
3 Biotech Feb 2018The tolerance of the pentose-fermenting yeast to the inhibitors released after the biomass hydrolysis, such as acetic acid and furfural, was surveyed. We first verified...
The tolerance of the pentose-fermenting yeast to the inhibitors released after the biomass hydrolysis, such as acetic acid and furfural, was surveyed. We first verified the effects of acetic acid and cell concentrations and initial pH on the growth of a strain in a semi-synthetic medium containing acetic acid as the sole carbon source. Second, the single and combined effects of furfural, acetic acid, and sugars (xylose, arabinose, and glucose) on the sugar uptake, cell growth, and ethanol production were also analysed. Growth inhibition occurred in concentrations higher than 10.5 g l acetic acid and initial pH 3.5. The maximum specific growth rate (µ) was 0.023 h and the saturation constant (ks) was 0.75 g l acetic acid. Initial cell concentration also influenced µ. Acetic acid (initial concentration 5 g l) was co-consumed with sugars even in the presence of 20 mg l furfural without inhibition to the yeast growth. The yeast grew and fermented sugars in a sugar-based medium with acetic acid and furfural in concentrations much higher than those usually found in hemicellulosic hydrolysates.
PubMed: 29430380
DOI: 10.1007/s13205-018-1143-0 -
Indian Journal of Microbiology Mar 2022With the consumption of energy and the spread of COVID-19, the demand for ethanol production is increasing in the world. The industrial ethanol fermentation microbes...
With the consumption of energy and the spread of COVID-19, the demand for ethanol production is increasing in the world. The industrial ethanol fermentation microbes cannot metabolize the alginate component of macro algae, which affects the ethanol yield. In this research, the ethanol production process from macro algae by an alginate fermentation yeast , especially the pretreatment process of was studied. At the same time, the experimental design of Box-Behnken was carried out to achieve the optimum fermentation performance. The concentration of KHPO (A: 2-6 g.L), pH (B: 4-7), reaction time (C: 60-120 h) and temperature (D: 24-34 °C) were variable input parameters. During the ethanol production process, the algae powder was firstly mixed with water at 90 °C for 0.5 h. Later the fermentation culture medium was prepared and then it was fermented by the yeast to produce ethanol. And the optimal fermentation parameters were as follows: fermentation temperature of 28 °C, KHPO dosage of 4.7 g.L, initial pH of 6, and fermentation time of 99 h. The ethanol yield reached 0.268 g.g (ethanol to algae), close to the predicted value of model. The generation of alginate lyase during the fermentation of algae was also examined. The highest alginate lyase activity reached 46.42 U.mL.
PubMed: 34602657
DOI: 10.1007/s12088-021-00985-9 -
Food Microbiology Sep 2023While sequentially inoculating non-Saccharomyces yeasts with Saccharomyces cerevisiae can lower the alcohol contents of wine, the abilities of these yeasts to...
While sequentially inoculating non-Saccharomyces yeasts with Saccharomyces cerevisiae can lower the alcohol contents of wine, the abilities of these yeasts to utilize/produce ethanol or generate other byproducts remained unclear. Metschnikowia pulcherrima or Meyerozyma guilliermondii were inoculated into media with or without S. cerevisiae to assess byproduct formation. Both species metabolized ethanol in a yeast-nitrogen-base medium but produced the alcohol in a synthetic grape juice medium. In fact, Mt. pulcherrima and My. guilliermondii generated less ethanol per gram of metabolized sugar (0.372 and 0.301 g/g, respectively) compared to S. cerevisiae (0.422 g/g). Sequentially inoculating each non-Saccharomyces species with S. cerevisiae into grape juice media achieved up to 3.0% v/v alcohol reduction compared to S. cerevisiae alone while producing variable glycerol, succinic acid, and acetic acid concentrations. However, neither non-Saccharomyces yeasts released appreciable CO under fermentative conditions regardless of incubation temperature. Despite equivalent peak populations, S. cerevisiae produced more biomass (2.98 g/L) than the non-Saccharomyces yeasts while sequential inoculations yielded higher biomass with Mt. pulcherrima (3.97 g/L) but not My. guilliermondii (3.03 g/L). To reduce ethanol concentrations, these non-Saccharomyces species may metabolize ethanol and/or produce less from metabolized sugars compared to S. cerevisiae but also divert carbon towards glycerol, succinic acid, and/or biomass.
Topics: Saccharomyces cerevisiae; Fermentation; Glycerol; Carbon; Succinic Acid; Metschnikowia; Ethanol; Wine; Vitis
PubMed: 37290869
DOI: 10.1016/j.fm.2023.104308 -
ACS Synthetic Biology Dec 2022Synthetic microbial consortia show promising applications for fine chemical production, especially with long metabolic pathways. In this study, a synthetic microbial...
Synthetic microbial consortia show promising applications for fine chemical production, especially with long metabolic pathways. In this study, a synthetic microbial consortium consisting of YLC20 and MG57 was successfully constructed, which could achieve efficient de novo 2-phenylethanol (2-PE) production from glucose. A tyrosine-deficient YLC20 overexpressing genes of and was first constructed, which could accumulate 29.5 g/L of l-phenylalanine (l-Phe) within 96 h from glucose accompanied by the coproduction of acetate and α-ketoglutarate (α-KG). Furthermore, the engineered MG57 was constructed through the stepwise metabolic engineering strategy, which could facilitate the 2-PE synthesis from l-Phe. Moreover, the cosubstrate and material intervention strategies were applied to improve the stability of the microbial consortium and 2-PE production. Finally, the synthetic microbial consortium could de novo synthesize 3.77 g/L of 2-PE from 80 g/L of glucose, providing a reference for the de novo synthesis of fine chemicals with long metabolic pathways.
Topics: Phenylethyl Alcohol; Escherichia coli; Glucose; Microbial Consortia; Metabolic Engineering; Phenylalanine
PubMed: 36368021
DOI: 10.1021/acssynbio.2c00368 -
Mycopathologia Dec 2023
Topics: Saccharomycetales; Antifungal Agents
PubMed: 37537295
DOI: 10.1007/s11046-023-00767-5 -
Frontiers in Microbiology 2017A high throughput screening (HTS) methodology for evaluation of cellular lipid content based on Nile red fluorescence reads using black background 96-wells test plates...
A high throughput screening (HTS) methodology for evaluation of cellular lipid content based on Nile red fluorescence reads using black background 96-wells test plates and a plate reader equipment allowed the rapid intracellular lipid estimation of strains from a Brazilian phylloplane yeast collection. A new oleaginous yeast, BI281A, was selected, for which the gravimetric determination of total lipids relative to dry weight was 52.38% for glucose or 34.97% for pure glycerol. The lipid production was optimized obtaining 108 mg/L of neutral lipids using pure glycerol as carbon source, and the strain proved capable of accumulating oil using raw glycerol from a biodiesel refinery. The lipid profile showed monounsaturated fatty acids (MUFA) varying between 56 or 74% in pure or raw glycerol, respectively. BI281A bears potential as a new biodiesel feedstock.
PubMed: 29018411
DOI: 10.3389/fmicb.2017.01776 -
Biotechnology and Applied Biochemistry Sep 2017This study reports the best culture conditions for roots growth and accumulation of active components by optimizing the parameters. Glycyrrhiza uralensis adventitious...
Gene expression of glycyrrhizin acid and accumulation of endogenous signaling molecule in Glycyrrhiza uralensis Fisch adventitious roots after Saccharomyces cerevisiae and Meyerozyma guilliermondii applications.
This study reports the best culture conditions for roots growth and accumulation of active components by optimizing the parameters. Glycyrrhiza uralensis adventitious roots metabolites were significantly increased after adding Saccharomyces cerevisiae and Meyerozyma guilliermondii. The highest contents of polysaccharide, glycyrrhizic acid, glycyrrhetinic acid, and total flavonoids were obtained in M. guilliermondii group; the content of glycyrrhizic acid was 5.3-fold higher than the control. In control and treatment groups, 12 compounds were identified by high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS), among which some new compounds have been detected in elicitor groups including 5,7-dihydroxyflavanone, glycyrrhisoflavanone, licorice saponin J2, uralsaponin B, (3R)-vestitol, and uralenol. Meyerozyma guilliermondii significantly upregulated the expression of the genes such as 3-hydroxy-3-methylglutaryl coenzyme A reductase, farnesyl diphosphate synthase, geranyl diphosphate synthase, squalene synthase, squalene epoxidase, β-amyrin synthase, and CYP88D6 and CYP72A154. Meanwhile, it increased the biosynthesis of signaling molecules (nitric oxide, salicylic acid, and jasmonic acid) in defense mechanism.
Topics: Chromatography, High Pressure Liquid; Gene Expression Regulation, Plant; Glycyrrhiza uralensis; Glycyrrhizic Acid; Metabolic Networks and Pathways; Saccharomyces cerevisiae; Saccharomycetales; Tandem Mass Spectrometry
PubMed: 27644996
DOI: 10.1002/bab.1534 -
Genomics Nov 2021Agrobacterium tumefaciens is considered a prominent phytopathogen, though most isolates are nonpathogenic. Agrobacteria can inhabit plant tissues interacting with other...
Agrobacterium tumefaciens is considered a prominent phytopathogen, though most isolates are nonpathogenic. Agrobacteria can inhabit plant tissues interacting with other microorganisms. Yeasts are likewise part of these communities. We analyzed the quorum sensing (QS) systems of A. tumefaciens strain 6N2, and its relevance for the interaction with the yeast Meyerozyma guilliermondii, both sugarcane endophytes. We show that strain 6N2 is nonpathogenic, produces OHC8-HSL, OHC10-HSL, OC12-HSL and OHC12-HSL as QS signals, and possesses a complex QS architecture, with one truncated, two complete systems, and three additional QS-signal receptors. A proteomic approach showed differences in QS-regulated proteins between pure (64 proteins) and dual (33 proteins) cultures. Seven proteins were consistently regulated by quorum sensing in pure and dual cultures. M. guilliermondii proteins influenced by QS activity were also evaluated. Several up- and down- regulated proteins differed depending on the bacterial QS. These results show the QS regulation in the bacteria-yeast interactions.
Topics: Agrobacterium tumefaciens; Bacterial Proteins; Proteomics; Quorum Sensing; Saccharomycetales
PubMed: 34793950
DOI: 10.1016/j.ygeno.2021.11.017