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Heliyon May 2024The growing amount of plastic waste requires new ways of disposal or recycling. Research into the biodegradation of recalcitrant plastic polymers is gathering pace....
The growing amount of plastic waste requires new ways of disposal or recycling. Research into the biodegradation of recalcitrant plastic polymers is gathering pace. Despite some progress, these efforts have not yet led to technologically and economically viable applications. In this study, we show that respirometric screening of environmental fungal isolates in combination with scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy can be used to identify new strains with the potential for the degradation of plastic polymers. We screened 146 fungal strains, 71 isolated from car repair shops, an environment rich in long-chain hydrocarbons, and 75 isolated from hypersaline water capable of growing at high concentrations of NaCl. When grown in a minimal medium with no carbon source, some strains produced significantly more CO when a pure plastic polymer was added to the medium, some only at high salinity. A selection of these strains was shown by FTIR and Raman spectroscopy to alter the properties of plastic polymers: sp. EXF-13502 on polyamide, EXF-13500 on polypropylene, sp. EXF-10630 on low-density polyethylene and EXF-6848 on polyethylene terephthalate. Respirometry in combination with specific spectroscopic methods is an efficient method for screening microorganisms capable of at least partial plastic degradation and can be used to expand the repertoire of potential plastic degraders. This is of particular importance as our results also show that individual strains are only active against certain polymers and under certain conditions. Therefore, efficient biodegradation of plastics is likely to depend on a collection of specialized microorganisms rather than a single universal plastic degrader.
PubMed: 38803974
DOI: 10.1016/j.heliyon.2024.e31130 -
ACS Omega Apr 2024Two unprecedented isomeric secondary metabolites named vibralactones Z () and Z (), in addition to eleven known compounds (-), were isolated from solid-state rice...
Two unprecedented isomeric secondary metabolites named vibralactones Z () and Z (), in addition to eleven known compounds (-), were isolated from solid-state rice culture medium of (Bondarzewiaceae). Chemical structures of the isolated compounds were established via spectral analyses. The new lactone derivatives were weakly active against without any significant cytotoxicity, while the molecules containing an aldehyde functionality showed significant antimicrobial and cytotoxic effects. For instance, erinacine P () and (+)-isovelleral () and erinacine P () were cytotoxic against all tested cell lines at IC values in the ranges of 3.5-14.2 and 2.8-30.2 μM, respectively. In addition, they revealed moderate antimicrobial activity with the lowest minimum inhibitory concentration (MIC) values recorded against (8.3 μg/mL), , and at 16.6 μg/mL.
PubMed: 38680360
DOI: 10.1021/acsomega.4c02011 -
Frontiers in Bioengineering and... 2024Polyalcohols such as arabitol are among the main targets of biorefineries aiming to upcycle wastes and cheap substrates. In previous works WC 1501 emerged as an...
Polyalcohols such as arabitol are among the main targets of biorefineries aiming to upcycle wastes and cheap substrates. In previous works WC 1501 emerged as an excellent arabitol producer utilizing glycerol. Arabitol production by this strain is not growth associated, therefore, in this study, pre-grown cells were entrapped in calcium alginate beads (AB) and utilized for glycerol transformation to arabitol. Flasks experiments aimed to assess the medium composition (i.e., the concentration of inorganic and organic nitrogen sources and phosphates) and to establish the appropriate carrier-to-medium proportion. In flasks, under the best conditions of ammonium limitation and the carrier:medium ratio of 1:3 (w/v), 82.7 g/L glycerol were consumed in 168 h, yielding 31.2 g/L arabitol, with a conversion of 38% and volumetric productivity of 186 mg/mL/h. The process with immobilized cells was transferred to laboratory scale bioreactors with different configurations: stirred tank (STR), packed bed (PBR), fluidized bed (FBR), and airlift (ALR) bioreactors. The STR experienced oxygen limitation due to the need to maintain low stirring to preserve AB integrity and performed worse than flasks. Limitations in diffusion and mass transfer of oxygen and/or nutrients characterized also the PBR and the FBR and were partially relieved only in ALR, where 89.4 g/L glycerol were consumed in 168 h, yielding 38.1 g/L arabitol, with a conversion of 42% and volumetric productivity of 227 mg/mL/h. When the ALR was supplied with successive pulses of concentrated glycerol to replenish the glycerol as it was being consumed, 117 g/L arabitol were generated in 500 h, consuming a total of 285 g/L glycerol, with a 41% and 234 mg/L/h. The study strongly supports the potential of WC 1501 for efficient glycerol-to-arabitol conversion using immobilized cells. While the yeast shows promise by remaining viable and active for extended periods, further optimization is required, especially regarding mixing and oxygenation. Improving the stability of the immobilization process is also crucial for reusing pre-grown cells in multiple cycles, reducing dead times, biomass production costs, and enhancing the economic feasibility of the process.
PubMed: 38659644
DOI: 10.3389/fbioe.2024.1375937 -
Food Chemistry: X Jun 2024Distilled , a Korean traditional alcoholic beverage, is produced by fermenting rice with a variety of microorganisms including molds, yeasts, and lactic acid-producing...
Distilled , a Korean traditional alcoholic beverage, is produced by fermenting rice with a variety of microorganisms including molds, yeasts, and lactic acid-producing bacteria, followed by distillation. Our study sought to improve the quality of distilled through co-fermentation with and , known for producing volatile aromatic compounds during the early stages of fermentation. Analysis of volatile aromatic compounds in co-fermented distilled revealed a substantial increase in compounds with boiling points below 200 °C. Among them, ethyl hexanoate, isobutanol, and isoamyl alcohol were identified as the major volatile aromatic compounds based on Log2 fold change analyses of the volatile aromatic compound pattern. In sensory evaluation, co-fermented distilled received higher scores in terms of odor and overall preference. Therefore, incorporating may improve the quality of distilled .
PubMed: 38645938
DOI: 10.1016/j.fochx.2024.101368 -
International Journal of Food... Jun 2024Taggiasca table olives are typical of Liguria, a Northwestern Italian region, produced with a spontaneous fermentation carried out by placing the raw drupes directly...
Monitoring the yeasts ecology and volatiles profile throughout the spontaneous fermentation of Taggiasca cv. table olives through culture-dependent and independent methods.
Taggiasca table olives are typical of Liguria, a Northwestern Italian region, produced with a spontaneous fermentation carried out by placing the raw drupes directly into brine with a salt concentration of 8-12 % w/v. Such concentrations limit the development of unwanted microbes and favor the growth of yeasts. This process usually lasts up to 8 months. Yeasts are found throughout the entire fermentation process and they are mainly involved in the production of volatile organic compounds, which strongly impact the quality of the final product. The aim of this study was to evaluate the dynamics of autochthonous yeasts in brines and olives in a spontaneous process with no lye pre-treatment or addition of acids in the fermenting brine with 10 % NaCl (w/v) in two batches during 2021 harvest. Three hundred seventy-three yeast colonies were isolated, characterized by rep-PCR and identified by the D1/D2 region of the 26S rRNA gene sequencing. Mycobiota was also studied by 26S rRNA gene metataxonomics, while metabolome was assessed through GC-MS analysis. Traditional culture-dependent methods showed the dominance of Candida diddensiae, Wickerhamomyces anomalus, Pichia membranifaciens and Aureobasidium pullulans, with differences in species distribution between batches, sampling time and type of sample (olives/brines). Amplicon-based sequencing confirmed the dominance of W. anomalus in batch 1 throughout the entire fermentation, while Cyteromyces nyonsensis and Aureobasidium spp. were most abundant in the fermentation in batch 2. Volatilome results were analyzed and correlated to the mycobiota data, confirming differences between fermentation stages. Given the high appreciation for this traditional food, this study helps elucidate the mycobiota associated to Taggiasca cv. table olives and its relationship with the quality of the final product.
Topics: Fermentation; Olea; Volatile Organic Compounds; Yeasts; Food Microbiology; Italy; Salts
PubMed: 38615425
DOI: 10.1016/j.ijfoodmicro.2024.110688 -
Pathogens (Basel, Switzerland) Mar 2024has been previously classified as , , and and was recently reclassified in the genus after phylogenetic analysis of its genetic sequence. An increasing number of... (Review)
Review
has been previously classified as , , and and was recently reclassified in the genus after phylogenetic analysis of its genetic sequence. An increasing number of reports of human infections by have emerged, suggesting that this microorganism is an emerging pathogen. The present review aimed to provide data on the epidemiology, antifungal resistance, clinical characteristics, treatment, and outcomes of fungemia by by extracting all the available information from published original reports in the literature. PubMed/Medline, Cochrane Library, and Scopus databases were searched for eligible articles reporting data on patients with this disease. In total, 36 studies involving 170 patients were included. The age of patients with fungemia by ranged from 0 to 89 years; the mean age was 22.8 years, the median age was 2.2 years, with more than 37 patients being less than one month old, and 54% (88 out of 163 patients) were male. Regarding patients' history, 70.4% had a central venous catheter use (CVC), 28.7% were on total parenteral nutrition (TPN), 97% of neonates were hospitalized in the neonatal ICU (NICU), and 39.4% of the rest of the patients were hospitalized in the intensive care unit (ICU). Previous antimicrobial use was noted in 65.9% of patients. The most common identification method was the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) in 34.1%, VITEK and VITEK 2 in 20.6%, and ID32 C in 15.3%. had minimal antifungal resistance to fluconazole, echinocandins, and amphotericin B, the most commonly used antifungals for treatment. Fever and sepsis were the most common clinical presentation noted in 95.8% and 86%, respectively. Overall mortality was 20% and was slightly higher in patients older than one year. Due to the rarity of this disease, future multicenter studies should be performed to adequately characterize patients' characteristics, treatment, and outcomes, which will increase our understanding and allow drawing safer conclusions regarding optimal management.
PubMed: 38535612
DOI: 10.3390/pathogens13030269 -
Scientific Reports Mar 2024Arabica coffee is the most popular and best-selling type of coffee. During coffee fermentation, microorganisms are essential for the production of metabolites and...
Arabica coffee is the most popular and best-selling type of coffee. During coffee fermentation, microorganisms are essential for the production of metabolites and volatile compounds that affect coffee flavor quality. This work aimed to study the mutation, selection, and characterization of the Wickerhamomyces anomalus strain YWP1-3 as a starter culture to enhance the flavor quality of Arabica coffee. The results revealed that six mutants could produce relatively high levels of the pectinase enzyme on pectin agar media and exhibited high activity levels, ranging from 332.35 to 415.88 U/ml in mucilage broth. Strains UV22-2, UV22-3, UV41-1 and UV32-1 displayed higher levels of amylase activity than did the wild type. The UV22-2 and UV22-3 mutants exhibited the highest pectin degradation indices of 49.22% and 45.97%, respectively, and displayed significantly enhanced growth rates in nitrogen yeast base media supplemented with various sugars; thus, these mutants were evaluated for their ability to serve as a starter for fermentation of Arabica coffee. The cupping scores of coffees derived from UV22-2 and UV22-3 were 83.5 ± 1.5 and 82.0 ± 2.14, respectively. The volatile compounds in the roasted coffee fermented by UV22-2 were analyzed by GC‒MS, which revealed higher levels of furfuryl alcohol and furfuryl acetate than did the other samples. These findings suggested that UV22-2 could be an influential starter culture for Arabica coffee fermentation.
Topics: Coffee; Fermentation; Coffea; Yeasts; Pectins
PubMed: 38480775
DOI: 10.1038/s41598-024-56298-6 -
Food Chemistry: X Jun 2024Workshop with different fermentation years plays an essential role in the yield and quality of Baijiu. In actual production, the quality of base Baijiu in newly built...
Workshop with different fermentation years plays an essential role in the yield and quality of Baijiu. In actual production, the quality of base Baijiu in newly built workshop is inferior to the older one. In this study, the microbiota of workshop environment and fermentation process from two workshops namely N (ferment 2 years) and O (ferment 20 years) and flavor compounds were studied during Xiasha round. Results showed workshop O accumulated more environmental microorganisms and fungi including , and mainly came from ground. Yeasts including , , and were responsible for flavor substances formation in O while was in N. This study for the first time explored the reasons for the brewing differences among N and O workshop from perspectives of workshop environment, microbial community and flavor substances, providing new ideas for guiding production as well as improvement of Baijiu quality.
PubMed: 38468635
DOI: 10.1016/j.fochx.2024.101264 -
Cureus Feb 2024We report the case of an 84-year-old man with a history of IgG4-related sclerosing cholangitis who was diagnosed with advanced esophageal cancer and underwent radiation...
We report the case of an 84-year-old man with a history of IgG4-related sclerosing cholangitis who was diagnosed with advanced esophageal cancer and underwent radiation and chemotherapy. An implantable central venous access port was placed for chemotherapy and total parenteral nutrition. The patient presented with a fever and received antimicrobial therapy for acute cholangitis but remained febrile, and subsequently, yeast was detected in the aerobic bottle of blood culture obtained from the central venous line. The yeast was identified as . Liposomal amphotericin B was administered, and the central line access port was removed. After confirmation of negative blood cultures and 14 days post treatment, he underwent reinsertion of the central line access port. Due to persistent pain at the insertion site, fluconazole was added for an additional 14 days, and the patient was discharged and transferred to another hospital. is a rare fungal infection with other synonyms including , , and . A literature review of 53 case reports of , , , and was conducted, with a total of 211 cases reviewed. Fungemia was reported in 94% of cases, with central venous catheterization, parental feeding, low birth weight, and immunocompromised status identified as major risk factors. The majority of cases were pediatric, particularly neonatal, and there were reports of nosocomial infections causing outbreaks, with some cases involving the eye such as endophthalmitis or keratitis.
PubMed: 38445156
DOI: 10.7759/cureus.53550 -
Molecules (Basel, Switzerland) Jan 2024Soluble dietary fiber (SDF) benefits human health, and different extraction methods might modify the structure and functions of the SDFs. Radish is rich in dietary...
Soluble dietary fiber (SDF) benefits human health, and different extraction methods might modify the structure and functions of the SDFs. Radish is rich in dietary fiber. To assess the impact of various extraction techniques on the properties and functions of radish SDF, the SDFs were obtained from white radish pomace using alkaline, ultrasonic-assisted, and fermentation-assisted extraction methods. Analysis was conducted on the structure, physicochemical characteristics, thermal properties, and functional attributes of the SDFs. The study revealed that various extraction techniques can impact the monosaccharides composition and functionality of the SDFs. Compared with the other two extraction methods, the surface structures of SDFs obtained by fermentation-assisted extraction were looser and more porous, and the SDF had better water solubility and water/oil holding capacity. The adsorption capacities of glucose and cholesterol of the SDFs obtained from fermentation-assisted extraction were also improved. YFJ252 seems the most appropriate strain to ferment white radish pomace to acquire SDF; the water holding, oil holding, glucose absorption capacity, and cholesterol absorption capacity at pH 2 and pH 7 have a 3.06, 1.65, 3.19, 1.27, and 1.83 fold increase than the SDF extracted through alkaline extraction method.
Topics: Humans; Raphanus; Water; Glucose; Cholesterol; Dietary Fiber
PubMed: 38276578
DOI: 10.3390/molecules29020500