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Food Research International (Ottawa,... Apr 2024Meat dry aging consists in storing unpackaged meat in a cold room, and at a specific and controlled relative humidity (RH), for a period of 1 to 5 weeks or more. This...
Meat dry aging consists in storing unpackaged meat in a cold room, and at a specific and controlled relative humidity (RH), for a period of 1 to 5 weeks or more. This practice has become widespread in recent years due to its positive effect on the tenderness of the meat but also on other organoleptic characteristics and therefore its market value. The objective of this work was to study the bacterial and fungal microbiota of dry-aged beef at the commercial stage by both culture-dependent and -independent approaches. Fifty-eight samples of dry-aged meat from different producer types (meat processing plants, artisanal and supermarket butchers) were studied. The dry-aging conditions (temperature, RH) of the meats, as well as the surface pH and a, were measured. The main microbial groups were enumerated by culture on various dedicated media. Concerning fungi, isolates of yeasts and molds (n = 257) were identified after dereplication by FTIR spectroscopy and/or sequencing of taxonomically relevant genes (26S rDNA, ITS, β-tubulin, actin). Metagenetic analyzes targeting the V3-V4 regions of 16S rDNA and ITS2 were also performed. Overall, ripening practices were diversified with temperatures and RH between 0.5 and 2.8 °C (median = 2 °C) and 47 and 88 % (median = 70 %), respectively. The aerobic colony count varied between 1.97 and 10.91 log CFU/g (median = 8.32 log CFU/g) and was similar to that of Pseudomonas spp., indicating that this bacterial group was dominant. Yeast populations varied between <2 and 9.41 log CFU/g, while molds showed abundances between <2 and 7.7 log TFU/g, the highest values being found in meats matured with a high RH. Bacterial and mold counts were positively correlated with the dry-aging RH and, to a lesser extent, temperature. The main yeast species were Candida zeylanoides and Yarrowia alimentaria as well as Itersonilia pannonica (identified only in metagenetics). The dominant mold species were psychrophilic or psychrotrophic species, namely Mucor complex flavus and Helycostylum elegans/pulchrum that have already been shown to be associated with dry-aged beef meat. This study has identified the main microorganisms associated with dry-aged meat in France, which raises the question of their role in the organoleptic quality of these higher value products.
Topics: Animals; Cattle; Microbiota; Mycobiome; France; DNA, Ribosomal; Mucor
PubMed: 38448091
DOI: 10.1016/j.foodres.2024.114118 -
PeerJ 2016Ultrasound (US), Thermo-sonication (TS) and High Pressure Homogenization (HPH) were studied as tools to inactivate the spores of Penicillium spp. and Mucor spp....
Ultrasound (US), Thermo-sonication (TS) and High Pressure Homogenization (HPH) were studied as tools to inactivate the spores of Penicillium spp. and Mucor spp. inoculated in distilled water. For US, the power ranged from 40% to 100%, pulse from 2 to 10 s, and duration of the treatment from 2 to 10 min. TS was performed combining US (40-80% of power, for 8 min and pulse of 2 s) with a thermal treatment (50, 55 and 60°C at 4, 8 and 12 min). Homogenization was done at 30-150 MPa for 1, 2 and 3 times. Power was the most important factors to determine the antifungal effect of US and TS towards the conidia of Penicillium spp.; on the other hand, in US treatments Mucor spp. was also affected by pulse and time. HPH exerted a significant antifungal effect only if the highest pressures were applied for 2-3 times.
PubMed: 27375964
DOI: 10.7717/peerj.2020 -
Scientific Reports Jul 2020Our purpose was to classify acute invasive fungal rhinosinusitis (AIFR) caused by Mucor versus Aspergillus species by evaluating computed tomography radiological...
Our purpose was to classify acute invasive fungal rhinosinusitis (AIFR) caused by Mucor versus Aspergillus species by evaluating computed tomography radiological findings. Two blinded readers retrospectively graded radiological abnormalities of the craniofacial region observed on craniofacial CT examinations obtained during initial evaluation of 38 patients with eventually pathology-proven AIFR (13:25, Mucor:Aspergillus). Binomial logistic regression was used to analyze correlation between variables and type of fungi. Score-based models were implemented for analyzing differences in laterality of findings, including the 'unilateral presence' and 'bilateral mean' models. Binary logistic regression was used, with Score as the only predictor and Group (Mucor vs Aspergillus) as the only outcome. Specificity, sensitivity, positive predictive value, negative predictive value and accuracy were determined for the evaluated models. Given the low predictive value of any single evaluated anatomical site, a 'bilateral mean' score-based model including the nasal cavity, maxillary sinuses, ethmoid air cells, sphenoid sinus and frontal sinuses yielded the highest prediction accuracy, with Mucor induced AIFR correlating with higher prevalence of bilateral findings. The odds ratio for the model while integrating the above anatomical sites was 12.3 (p < 0.001). PPV, NPV, sensitivity, specificity and accuracy were 0.85, 0.82, 0.92, 0.69 and 0.84 respectively. The abnormal radiological findings on craniofacial CT scans of Mucor and Aspergillus induced AIFR could be differentiated based on laterality, with Mucor induced AIFR associated with higher prevalence of bilateral findings.
Topics: Adult; Aspergillosis; Female; Humans; Male; Middle Aged; Mucormycosis; Retrospective Studies; Rhinitis; Sinusitis; Tomography, X-Ray Computed
PubMed: 32724102
DOI: 10.1038/s41598-020-69446-5 -
Fungal Biology 2023The dry ageing is a historically relevant method of meat preservation, now used as a way to produce the dry-aged beef (DAB) known for its pronounced flavour. Partially...
The dry ageing is a historically relevant method of meat preservation, now used as a way to produce the dry-aged beef (DAB) known for its pronounced flavour. Partially responsible for the taste of the DAB may be various microorganisms that grow on the surface of the meat. Historically, the fungal species colonising the DAB were described as members of the genera Thamnidium and Mucor. In this study we used both culture based approach as well as ITS2 rDNA metabarcoding analysis to investigate the fungal community of the DAB, with special emphasis on the mucoralean taxa. Isolated fungi were members of 6 different species from the family Mucoraceae, belonging to the genera Mucor and Helicostylum. Metabarcoding data provided supplementary information regarding the presence of other fungi including those from the Thamnidium genus. In both approaches used in this study isolates closely related to the Mucor flavus strain CBS 992.68 dominated.
Topics: Animals; Cattle; Mucorales; DNA, Ribosomal; Taste; Sequence Analysis, DNA; Mycobiome; Fungi
PubMed: 37993251
DOI: 10.1016/j.funbio.2023.09.005 -
Genomics Dec 2019Mucor species belong to the Mucorales order within the Mucoromycota phylum, an early diverging fungal lineage. Although Mucor species are often ubiquitous some species... (Comparative Study)
Comparative Study
Mucor species belong to the Mucorales order within the Mucoromycota phylum, an early diverging fungal lineage. Although Mucor species are often ubiquitous some species have been reported to specifically occur in certain ecological niches. In this study, similarities and differences of a representative set of Mucor species with contrasted lifestyles were investigated at the transcriptome level. Five strains pertaining to five different species were studied, namely M. fuscus and M. lanceolatus, two species used in cheese production (during ripening), M. racemosus, a recurrent cheese spoiler sometimes described as an opportunistic pathogen, M. circinelloides, often described as an opportunistic pathogen and M. endophyticus, a plant endophyte. A core transcriptome was delimited and a phylogenetic analysis led to an altered phylogenetic placement of M. endophyticus compared to previously published topologies. Interestingly, the core transcriptome comprising 5566 orthogroups included genes potentially involved in secondary metabolism. As expected, given the wide taxonomic range investigated, the five transcriptomes also displayed specificities that can be, for some of them, linked to the different lifestyles such as differences in the composition of transcripts identified as virulence factors or carbohydrate transporters.
Topics: Fungal Proteins; Gene Expression Profiling; Mucor; Multigene Family; Sequence Analysis, RNA; Transcriptome
PubMed: 30195068
DOI: 10.1016/j.ygeno.2018.09.003 -
Journal of Fungi (Basel, Switzerland) Jun 2022Species in the genus have a worldwide distribution and are isolated from various substrata and hosts, including soil, dung, freshwater, and fruits. However, their...
Species in the genus have a worldwide distribution and are isolated from various substrata and hosts, including soil, dung, freshwater, and fruits. However, their diversity from insects is still much too little explored. The aim of this study was to characterize three new species of : sp. nov., . sp. nov., and . sp. nov., discovered in Kunryang-ri, Cheongyang in the Chungnam Province of Korea, during an investigation of from cricket insects. The new species are described using morphological characters and molecular data including ITS and LSU rDNA regions. is characterized by the highly variable shape of its columellae, which are subglobose to oblong, obovoid, strawberry-shaped, and sometimes slightly or strongly constricted in the center. is characterized by the production of azygospores and growth at 40 °C. is characterized by the variable shape of its columellae, which are elongated-conical, obovoid, cylindrical ellipsoid, cylindrical, and production of abundant yeast-like cells on PDA, MEA, and SMA media. Based on the sequence analysis of two genetic markers, our phylogenic assessment strongly supported , . and . as new species. Detailed descriptions, illustrations, and phylogenetic trees are provided.
PubMed: 35736084
DOI: 10.3390/jof8060601 -
Chemical & Pharmaceutical Bulletin 20156-Hydroxyflavanone (1) when fermented with fungal culture Cunninghamella blakesleeana (ATCC 8688a) yielded flavanone 6-O-β-D-glucopyranoside (2), flavanone 6-sulfate...
6-Hydroxyflavanone (1) when fermented with fungal culture Cunninghamella blakesleeana (ATCC 8688a) yielded flavanone 6-O-β-D-glucopyranoside (2), flavanone 6-sulfate (3), and 6-hydroxyflavanone 7-sulfate (4). Aspergillus alliaceus (ATCC 10060) also transformed 1 to metabolite 3 as well as 4'-hydroxyflavanone 6-sulfate (5) and 6,4'-dihydroxyflavanone (6). Beauveria bassiana (ATCC 7159) metabolized 1 to 6 and flavanone 6-O-β-D-4-O-methyglucopyranoside (7). Mucor ramannianus (ATCC 9628) transformed 1 to 2,4-cis-6-hydroxyflavan-4-ol (8), 2,4-trans-6-hydroxyflavan-4-ol (9), 2,4-trans-6,4'-dihydroxyflavan-4-ol 5-sulfate (10), 1,3-cis-1-methoxy-1-(2,5-dihydroxyphenyl)-3-phenylpropane (11) and 2,4-trans-flavan-4-ol 6-sulfate (12). Structures of the metabolic products were elucidated by means of spectroscopic data. None of the metabolites tested showed antibacterial, antifungal and antimalarial activities against selected organisms. However, weak antileishmanial activity was observed for metabolite 11 when tested against Leishmania donovani.
Topics: Anti-Infective Agents; Aspergillus; Bacteria; Beauveria; Cunninghamella; Fermentation; Flavanones; Fungi; Humans; Leishmania donovani; Leishmaniasis, Visceral; Mucor
PubMed: 26235165
DOI: 10.1248/cpb.c15-00037 -
Fungal Biology and Biotechnology Jan 2023Oleaginous fungi have versatile metabolism and able to transform a wide range of substrates into lipids, accounting up to 20-70% of their total cell mass. Therefore,...
BACKGROUND
Oleaginous fungi have versatile metabolism and able to transform a wide range of substrates into lipids, accounting up to 20-70% of their total cell mass. Therefore, oleaginous fungi are considered as an alternative source of lipids. Oleaginous fungi can accumulate mainly acyl glycerides and free fatty acids which are localized in lipid droplets. Some of the oleaginous fungi possessing promising lipid productivity are dimorphic and can exhibit three cell forms, flat hyphae, swollen hyphae and yeast-like cells. To develop sustainable targeted fungal lipid production, deep understanding of lipogenesis and lipid droplet chemistry in these cell forms is needed at multiscale level. In this study, we explored the potential of infrared spectroscopy techniques for examining lipid droplet formation and accumulation in different cell forms of the dimorphic and oleaginous fungus Mucor circinelloides.
RESULTS
Both transmission- and reflectance-based spectroscopy techniques are shown to be well suited for studying bulk fungal biomass. Exploring single cells with infrared microspectroscopy reveals differences in chemical profiles and, consequently, lipogenesis process, for different cell forms. Yeast-like cells of M. circinelloides exhibited the highest absorbance intensities for lipid-associated peaks in comparison to hyphae-like cell forms. Lipid-to-protein ratio, which is commonly used in IR spectroscopy to estimate lipid yield was the lowest in flat hyphae. Swollen hyphae are mainly composed of lipids and characterized by more uniform distribution of lipid-to-protein concentration. Yeast-like cells seem to be comprised mostly of lipids having the largest lipid-to-protein ratio among all studied cell forms. With infrared nanospectroscopy, variations in the ratios between lipid fractions triglycerides and free fatty acids and clear evidence of heterogeneity within and between lipid droplets are illustrated for the first time.
CONCLUSIONS
Vibrational spectroscopy techniques can provide comprehensive information on lipogenesis in dimorphic and oleaginous fungi at the levels of the bulk of cells, single cells and single lipid droplets. Unicellular spectra showed that various cell forms of M. circinelloides differs in the total lipid content and profile of the accumulated lipids, where yeast-like cells are the fatty ones and, therefore, could be considered as preferable cell form for producing lipid-rich biomass. Spectra of single lipid droplets showed an indication of possible droplet-to-droplet and within-droplet heterogeneity.
PubMed: 36647105
DOI: 10.1186/s40694-023-00148-z -
Journal of Insect Science (Online) Mar 2022Bradysia odoriphaga Yang and Zhang (Diptera: Sciaridae), the Chinese chive root maggot, is a destructive pest of Allium vegetables and flowers that causes severe losses...
Bradysia odoriphaga Yang and Zhang (Diptera: Sciaridae), the Chinese chive root maggot, is a destructive pest of Allium vegetables and flowers that causes severe losses in northern China. Novel biological control technologies are needed for controlling this pest. We identified a new entomopathogenic fungus isolated from infected B. odoriphaga larvae and evaluated the susceptibility of the biological stages of B. odoriphaga and the effects of temperature on fungus growth and pathogenicity. Based on morphological characteristics and molecular phylogeny, the fungus was identified as Mucor hiemalis BO-1 (Mucorales: Mucorales). This fungus had the strongest virulence to B. odoriphaga larvae followed by eggs and pupae, while B. odoriphaga adults were not susceptible. A temperature range of 18-28°C was optimum for the growth and sporulation of M. hiemalis BO-1 and virulence to B. odoriphaga larvae. At 3 and 5 d after inoculation with 105 spores/ml at 23°C, the survival rates were 24.8% and 4.8% (2nd instar larvae), respectively, and 49.6% and 12.8% (4th instar larvae), respectively. The potted plant trials confirmed that M. hiemalis BO-1 exerted excellent control efficiency against B. odoriphaga larvae, and the control exceeded 80% within 5 d when the spore concentration applied exceeded 107 spores/ml. In conclusion, these findings supported the hypotheses that this fungus could serve as an effective control agent against B. odoriphaga larvae and is worth being further tested to determine its full potential as a biocontrol agent.
Topics: Animals; Diptera; Insecticides; Larva; Mucor; Mucorales; Ovum; Virulence
PubMed: 35303105
DOI: 10.1093/jisesa/ieac010 -
Polish Journal of Radiology 2021To assess differentiating features between bacterial, , and skull base osteomyelitis (SBO) with regard to clinical presentation and imaging appearances.
PURPOSE
To assess differentiating features between bacterial, , and skull base osteomyelitis (SBO) with regard to clinical presentation and imaging appearances.
MATERIAL AND METHODS
A literature search was performed in April 2020 for studies on SBO with a minimum sample size of 10 patients. Studies that reported presenting symptoms, cross-sectional imaging findings, complications, and mortality were included in the analysis. The quality of included articles was tested using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. A data extraction form was used to retrieve relevant parameters from each of the articles.
RESULTS
Thirteen articles were included in the final analysis. Diabetes mellitus was the most common predisposing factor (12.5-91.0%). Presenting complaints in all bacterial SBO studies were otogenic, while fungal SBO patients had nasal/ocular complaints. Rates of mortality and surgical intervention in the fungal group were 50-100% and 50%, respectively, as compared to the bacterial group - 7-87% and 10%, respectively. On imaging, the site of initial infection in bacterial SBO was the external auditory canal, while in fungal SBO it was the paranasal sinus. The incidence of orbital extension was < 5% in bacterial and 44-70% in fungal SBO, among which had rates of 65-70%. Bone erosion was less extensive in bacterial SBO, and the patterns differed. The highest incidence of vascular involvement and non-enhancing lesions (23-36%) was seen in showed highest sino-cranial extension (52-55%) and homogenous bright enhancement.
CONCLUSIONS
Systematic analysis of the clinico-radiological parameters in each of the studies revealed differences in presentation, clinical course, extension, bone erosion, and enhancement.
PubMed: 34136049
DOI: 10.5114/pjr.2021.106470