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1.
Microbes Environ ; 35(1)2020.
Artigo em Inglês | MEDLINE | ID: mdl-31996500

RESUMO

Recent studies demonstrated that phylogenetically more diverse and abundant bacteria and fungi than previously considered are responsible for denitrification in terrestrial environments. We herein examined the effects of land-use types on the community composition of those denitrifying microbes based on their nitrite reductase gene (nirK and nirS) sequences. These genes can be phylogenetically grouped into several clusters. We used cluster-specific PCR primers to amplify nirK and nirS belonging to each cluster because the most widely used primers only amplify genes belonging to a single cluster. We found that the dominant taxa as well as overall community composition of denitrifying bacteria and fungi, regardless of the cluster they belonged to, differed according to the land-use type. We also identified distinguishing taxa based on individual land-use types, the distribution of which has not previously been characterized, such as denitrifying bacteria or fungi dominant in forest soils, Rhodanobacter having nirK, Penicillium having nirK, and Bradyrhizobium having nirS. These results suggest that land-use management affects the ecological constraints and consequences of denitrification in terrestrial environments through the assembly of distinct communities of denitrifiers.


Assuntos
Bactérias/classificação , Bactérias/metabolismo , Biodiversidade , Fungos/classificação , Fungos/metabolismo , Microbiota , Microbiologia do Solo , Bactérias/genética , Bactérias/isolamento & purificação , Desnitrificação , Fungos/genética , Fungos/isolamento & purificação , Genes Bacterianos , Genes Fúngicos , Nitrito Redutases/genética , Filogenia
2.
J Sci Food Agric ; 100(3): 1256-1264, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31710698

RESUMO

BACKGROUND: Soybean is widely used in food formulations; however, few studies on fungal or mycotoxin contamination have been undertaken. Free, conjugated, and bound phenolic compounds, and their antioxidant and antifungal potential, were therefore evaluated together with the occurrence of aflatoxin B1 (AFB1 ) in soybeans. RESULTS: The conjugated and bound phenolic soybean extracts were more efficient for the inhibition of the 2,2 diphenyl-1-picryl-hydrazyl (DPPH) radical, the peroxidase enzyme, and the fungal α-amylase enzyme. Aflatoxin B1, detected at low levels (0.96 to 1.67 ng g-1 ), confirmed the protective effect of soybean phenolic compounds against mycotoxigenic contamination. Principal component analysis confirmed that syringic, p-hydroxybenzoic, p-coumaric acids and vanillin were essential for antioxidant and antifungal activities. CONCLUSION: This study presented new insights into the functionality of phenolic compounds in soybeans, regarding their potential to protect the crops naturally against fungal contamination, avoiding aflatoxin production, as attested by the correlations between phenolic compounds and antioxidant mechanisms. © 2019 Society of Chemical Industry.


Assuntos
Aflatoxina B1/análise , Antifúngicos/farmacologia , Antioxidantes/farmacologia , Fenóis/farmacologia , Extratos Vegetais/farmacologia , Soja/química , Aflatoxina B1/metabolismo , Antifúngicos/química , Antifúngicos/isolamento & purificação , Antioxidantes/química , Antioxidantes/isolamento & purificação , Fungos/efeitos dos fármacos , Fungos/metabolismo , Fenóis/química , Fenóis/isolamento & purificação , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Soja/microbiologia
3.
Arch Microbiol ; 202(2): 247-255, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31602502

RESUMO

Many researchers proved that plant endophytes manage successful issues to synthesize active chemicals within plant cells. These bioactive compounds might support a range of plant defense mechanism against many pathogenic microorganisms. In this study, a total of 22 isolates representing 21 fungal species belonging to 15 fungal genera in addition to one variety were isolated and identified for the first time from Euphorbia geniculate plants. The genus Aspergillus was the most common fungus isolated from the studied plant. The fungus Isaria feline was recorded in both leaves and stem, while Aspergillus flavus, A. ochraceus, A. terreus var. terreus, Emercilla nidulans var. acristata, Macrophomina phaseolina colonized both stem and root. The isolated fungi showed antagonistic activities against six strains of plant pathogenic fungi viz., Eupenicillium brefeldianum, Penicillium echinulatum, Alternaria phragmospora, Fusarium oxysporum, Fusarium verticilloid, and Alternaria alternata in dual culture assay. The highest antagonistic activity fungal species (Aspergillus flavus, A. fumigatus, and Fusarium lateritium) and the lowest (Cladosprium herbarum, F. culomrum, and Sporotrichum thermophile) showed twining in their secondary metabolites especially terpens and alkaloids with that of their host E. geniculata. Three concentrations of (0.5, 1.0, and 2.0 mg/ml) of these secondary metabolites extracted by ethyl acetate and n-butanol from the above six endophytic fungal species were tested against three pathogenic fungi isolated from infected tomato plant (E. brefeldianum-EBT-1, P. echinulatum-PET-2, and A. phragmospora-APT-3), whereas these pathogens showed promising sensitivity to these fungal secondary metabolites. In conclusion, this is the first report on the isolation of endophytic fungi from E. geniculata and evaluation of their antifungal activity.


Assuntos
Antibiose/fisiologia , Endófitos/química , Euphorbia/microbiologia , Fungos/química , Plantas Medicinais/microbiologia , Antifúngicos/isolamento & purificação , Endófitos/isolamento & purificação , Fungos/isolamento & purificação , Fungos/metabolismo , Folhas de Planta/microbiologia
4.
J Sci Food Agric ; 100(4): 1448-1457, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31756265

RESUMO

BACKGROUND: Baixi sufu (BS) is a traditional Chinese spicy fermented bean curd manufactured with a natural starter. In this study, the bacterial and fungal communities during BS fermentation were determined by culture and by the culture-independent method of high-throughput sequencing (HTS). Correlation analyses were performed to select the microorganisms potentially contributing to this fermentation. RESULTS: During the fermentation of BS, 162 bacterial and 97 fungal strains were isolated and identified, and a total of 268 314 bacterial and 287 844 fungal high-quality sequences were analyzed. In general, lactic acid bacteria (LAB), especially Enterococcus and Lactococcus, were dominant in the early stage of fermentation, and spore-forming bacteria, especially Bacillus spp., became the predominant bacteria by the end of fermentation. Geotrichum, Mortierella, and unclassified Ascomycota, were the major fungal populations, which could not be detected in the final product. Correlation analyses indicated that Enterococcus, Bacillus, Geotrichum, and unclassified Ascomycota correlated significantly and positively with amino nitrogen. However, due to the sporulation characteristics of Bacillus, they may have little effect on BS ripening. The presence of Bifidobacterium spp. in sufu is reported for the first time, but the excessive counts of the Bacillus cereus group (>105 CFU g-1 ) indicate a potential hazard to consumers. CONCLUSION: The profiles obtained from this study will contribute to the development of autochthonous starter cultures to control BS fermentation, and may lead to the development of novel strategies to shorten the fermentation time of sufu products. © 2019 Society of Chemical Industry.


Assuntos
Fabaceae/microbiologia , Fungos/metabolismo , Lactobacillales/metabolismo , Micobioma , Fabaceae/metabolismo , Fermentação , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Sequenciamento de Nucleotídeos em Larga Escala , Lactobacillales/classificação , Lactobacillales/genética , Lactobacillales/isolamento & purificação
5.
Chemosphere ; 238: 124710, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31545216

RESUMO

The purpose of study was to examine the residual effects of two types of biochar amendments, two phosphorus (P) fertilizer levels, phosphorus solubilizing bacteria (PSB) and arbuscular mycorrhizal fungs (AMF) on plant growth, nutrients absorption and root architecture of Zea mays L. in texturally different soils. Biochar signficantly increased nutrients absorption and plant biomass production with P-fertilization and microbial inoculantion. Texturally different soils enhanced the plant biomass and nutrients absorption in their independent capacity on addition of biochar, microbial inoculants and P-fertilization. It was shown that mycorrhizal inoculation had positive influence on plant root and shoot biomass in both soils irrespective to the biochar type used. Root colonization was notably increased in biochar + mycorrhizae (B + M) inocultaed plants. It was shown that mycorrhizal inoculation had positive influence on nutrients absorption by plant roots and it had high content of P, potassium, calcium and magnesium in plants at all biochar and P levels. Without P fertilization, biochar amendments significantly promoted shoot P content and root colonization. The P application significantly influenced soil microbial activity in terms of nutrient concentration and plant growth. Root attributes were significantly inclined by microbial inoculation. Residual effects of biochar and P significantly enhanced the nutreints absorption and maize plant growth. Thus, we concluded that residual biochar and P fertilizer showed positive effects on nutrients absorption and maize plant growth promotion in differently textured soils. Microbial inoculants further stimulated the plant biomass production and nutrients absorption due to effective root colonization.


Assuntos
Bactérias/metabolismo , Carvão Vegetal/farmacologia , Fungos/metabolismo , Fósforo/farmacologia , Zea mays/crescimento & desenvolvimento , Inoculantes Agrícolas , Biomassa , Fertilizantes/análise , Micorrizas/efeitos dos fármacos , Nutrientes , Desenvolvimento Vegetal/efeitos dos fármacos , Raízes de Plantas/química , Raízes de Plantas/microbiologia , Solo/classificação , Poluentes do Solo/análise , Zea mays/metabolismo
6.
J Appl Microbiol ; 128(1): 138-150, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31495045

RESUMO

AIMS: In order to understand the response of soil microbial communities to the long-term of decomposed straw return, the modifications of soil microbial community structure and composition induced by more than 10 years of fresh and decomposed straw return was investigated and the key environmental factors were analysed. METHODS AND RESULTS: Phospholipid fatty acid analysis and high-through sequencing technique were applied to analyse the structure and composition of the soil microbial communities. Compared with fresh straw, returning decomposed straw increased the relative abundance of bacteria and fungi by 1·9 and 7·7% at a rate of ~3750 kg ha-1 , and increased by 23·1 and 5·7%, at a rate of ~7500 kg ha-1 respectively. The relative abundance of the bacteria related to soil nitrification increased, but the ones related to soil denitrification decreased with decomposed straw return, which led to higher total nitrogen contents in soils. Moreover, returning decomposed straw reduced pathogenic fungal populations (genus of Alternara), which had significantly positive correlation with soil electric conductivity. It indicated that the long-term of decomposed straw return might have lower risk of soil-borne disease mainly for the reasonable soil salinity. CONCLUSIONS: Long-term of decomposed straw return could provide suitable nutrient and salinity for healthier development of soil microbial community, both in abundance and structure, compared with fresh straw return. SIGNIFICANCE AND IMPACT OF THE STUDY: The results of the study helps to better understand how the microbial community modifications induced by decomposed straw return benefit on soil health. The obtained key factors impacting soil microbial community variations is meaningful in soil health management under conditions of straw return.


Assuntos
Agricultura/métodos , Conservação dos Recursos Naturais , Microbiota , Microbiologia do Solo , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Condutividade Elétrica , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Fungos/metabolismo , Nitrificação , Nitrogênio/análise , Solo/química
7.
J Appl Microbiol ; 128(1): 242-254, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31559664

RESUMO

AIMS: To study the antimicrobial agents of the Bacillus velezensis strain HC6 and assess the application potential of B. velezensis HC6 in maize. METHODS AND RESULTS: We applied a dual culture technique to test the antimicrobial activity of B. velezensis HC6 against bacteria and fungi of common contaminated crops. Bacillus velezensis HC6 showed antagonistic action on pathogenic fungi, including Aspergillus and Fusarium, as well as pathogenic bacteria (especially Listeria monocytogenes). When applied in maize, B. velezensis HC6 could also inhibit the growth of multiple pathogenic fungi and reduce their production of aflatoxin and ochratoxin. Three kinds of antimicrobial lipopeptides, including iturin, fengycin and surfactin were identified in B. velezensis HC6 culture supernatant by high-performance liquid chromatography and MALDI-TOF mass spectrometry. Iturin and fengycin showed obvious antimicrobial activity to the tested fungal strains. CONCLUSIONS: Bacillus velezensis HC6 produces three kinds of lipopeptides which showed antimicrobial activity against several common pathogenic fungi and bacteria. Bacillus velezensis HC6 is potential to be biocontrol bacteria in maize. SIGNIFICANCE AND IMPACT OF THE STUDY: Bacillus velezensis HC6 shows obvious antimicrobial activity to important crops pathogenic fungi which usually produce mycotoxins that are harmful to animal and human health. We demonstrate that three different types of lipopeptides produced by B. velezensis contributed to the antimicrobial activity. Bacillus velezensis HC6 has the potential to be effective biocontrol agent in crops.


Assuntos
Anti-Infecciosos , Bacillus/fisiologia , Agentes de Controle Biológico , Lipopeptídeos/metabolismo , Zea mays/microbiologia , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Bacillus/química , Bactérias/efeitos dos fármacos , Fungos/efeitos dos fármacos , Fungos/crescimento & desenvolvimento , Fungos/metabolismo , Lipopeptídeos/química , Lipopeptídeos/farmacologia , Micotoxinas/metabolismo , Doenças das Plantas/microbiologia
8.
J Appl Microbiol ; 128(1): 209-224, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31559682

RESUMO

AIMS: The work investigates the impact of grapes processing at the beginning of winemaking on the composition of microbiota during the oenological fermentations and on the composition of obtained wines. METHODS AND RESULTS: The experiments were conducted in a biodynamic winery to exclude interference due to microbial starters. Three winemaking protocols, with different pre-fermentative management of grapes, were followed by plate count and next generation sequencing on 16S for bacteria and internal transcribed spacer sequencing (ITS) for yeast. Chemical and sensory characterization of wine was performed. The grape processing influenced the evolution of microbiota (especially lactic and acetic acid bacteria) and the fermentation rate. The highest biodiversity was observed in the experiment carried out with whole grapes and carbonic maceration, with the presence of bacterial groups not usually found in winemaking (Bacteroidales, Clostridiales, Oscillospira). The different microbiotas influenced the organic acid profile of wines, the content of biogenic ammines and the perception of organoleptic descriptors linked to the vine cultivar (Syrah). CONCLUSIONS: Carbonic maceration impacts on the evolution of the microbiota and the wine features. The absence of addition of starters and sulphur dioxide would seem to be correlated with the high microbial biodiversity. SIGNIFICANCE AND IMPACT OF THE STUDY: Carbonic maceration is a traditional winemaking practice, today there are difficulties in its managing because the anaerobiosis stimulates spoilage micro-organisms. The work elucidates the reasons of these difficulties and identified some microbial groups rarely associated with winemaking. The ratio of ethanol accumulation along with physical management of grapes and the supply of oxygen during the early stages of winemaking are powerful instruments of oenological variability, able to offer new possibilities to winemakers in order to defining the quality of red wines.


Assuntos
Manipulação de Alimentos/métodos , Microbiota , Vitis/microbiologia , Vinho/microbiologia , Ácidos/análise , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Etanol/análise , Fermentação , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Fungos/metabolismo , Oxigênio/metabolismo , Vinho/análise
9.
J Appl Microbiol ; 128(1): 265-279, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31574191

RESUMO

AIMS: Many physiological and microbial characteristics influence the biocontrol performance of the biological control agents (BCAs) in agricultural fields. To implement effective biocontrol, the contribution of specific genes, mechanisms and traits to the biocontrol performance of BCAs need to be characterized and explored in greater detail. METHODS AND RESULTS: In this study, a transposon (Tn) mutant library using the BCA Pseudomonas fluorescens NBC275 (Pf275) was generated to explore genes and bacterial characteristics involved in antifungal activity and biocontrol performance. Among the Tn mutants, 205 strains showing variations in antifungal activity compared to wild-type (WT) were selected and further analysed for biocontrol efficacy against gray mold in pepper fruits. The genes involved in pyoverdine biosynthesis (pvdI and pvdD) and chitin-binding protein (gbpA) played essential roles in the antifungal activity and biocontrol capacity of Pf275. In addition, a mutation in phlD completely abolished the antifungal activity and significantly suppressed the biocontrol ability of the strain. Genes affecting antifungal activity of Pf275 significantly influenced swimming motility, which was identified as an important trait for the biocontrol ability of the bacterial strain. CONCLUSIONS: Overall, our results suggest that antifungal compound production, siderophore biosynthesis and swimming motility synergistically contribute to Pf275 biocontrol performance. The utility of this library was demonstrated by identifying genes for antagonism and biocontrol ability in this BCA strain. The functional roles of many genes identified as contributing to antagonism and in vivo biocontrol activity require further study. SIGNIFICANCE AND IMPACT OF THIS STUDY: Genes contributing to antifungal activity and biocontrol performance of P. fluorescens were identified and highlighted by Tn mutagenesis, which will give insight to improve the biocontrol performance of this BCA.


Assuntos
Antibiose/genética , Agentes de Controle Biológico , Genes Bacterianos , Pseudomonas fluorescens/genética , Antifúngicos/metabolismo , Agentes de Controle Biológico/metabolismo , Fungos/metabolismo , Locomoção/genética , Mutação , Doenças das Plantas/microbiologia , Sideróforos/genética , Sideróforos/metabolismo
10.
J Sci Food Agric ; 100(1): 441-446, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31512241

RESUMO

BACKGROUND: The production of mycelium from endophytic fungi is of interest for applications ranging from inoculants and biofertilizers for crop production to fermentations for enzyme and metabolite production. The purpose of this study was to test the capacity of a solid growth medium based on beet pulp for growing different strains of endophytes. RESULTS: The ergosterol content of inoculated medium was measured to estimate fungal growth. Several parameters related to the preparation of the growth medium, such as water content, calcium salts and incubation time, were evaluated. The greatest fungal biomass production was observed in a medium prepared with a 1:2 (beet pulp:water) ratio, containing calcium sulfate and carbonate. Strains belonging to different fungal species grew well in the growth medium finally selected, producing yields ranging from 50 to 500 g mycelium per kilogram of dry culture, after 22-27 days. Cultures containing up to 400 g beet pulp grew successfully, and could be scaled up. CONCLUSION: A solid culture medium based on beet pulp supported the growth of diverse taxa of fungal endophytes. Both the water and calcium salt content of the growth medium affected the efficiency of mycelium production. Considering these factors, beet pulp medium was an excellent endophyte cultivation medium because of the high yield of fungal biomass observed, together with its ease of handling and scaling-up production. © 2019 Society of Chemical Industry.


Assuntos
Beta vulgaris/microbiologia , Meios de Cultura/metabolismo , Endófitos/crescimento & desenvolvimento , Fungos/crescimento & desenvolvimento , Beta vulgaris/química , Biomassa , Meios de Cultura/química , Endófitos/metabolismo , Fermentação , Fungos/metabolismo , Micélio/crescimento & desenvolvimento , Micélio/metabolismo
11.
Chemosphere ; 240: 124876, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31542577

RESUMO

4-t-octylphenol (4-t-OP), a well-known endocrine disrupting compound, is frequently found in various environmental compartments at levels that may cause adverse effects to the ecosystem and public health. To date, most of the studies that investigate microbial transformations of 4-t-OP have focused on the process mediated by bacteria, ligninolytic fungi, or microbial consortia. There is no report on the complete degradation mechanism of 4-t-OP by non-ligninolytic fungi. In this study, we conducted laboratory experiments to explore and characterize the non-ligninolytic fungal strain Fusarium falciforme RRK20 to degrade 4-t-OP. Using the response surface methodology, the initial biomass concentration and temperature were the factors identified to be more influential on the efficiency of the biodegradation process as compared with pH. Under the optimized conditions (i.e., 28 °C, pH 6.5 with an initial inoculum density of 0.6 g L-1), 25 mg L-1 4-t-OP served as sole carbon source was completely depleted within a 14-d incubation; addition of low dosage of glucose was shown to significantly accelerate 4-t-OP degradation. The yeast estrogenic screening assay further confirmed the loss of estrogenic activity during the biodegradation process, though a longer incubation period was required for complete removal of estrogenicity. Metabolites identified by LC-MS/MS revealed that strain RRK20 might degrade 4-t-OP as sole energy source via alkyl chain oxidation and aromatic ring hydroxylation pathways. Together, these results not only suggest the potential use of non-ligninolytic fungi like strain RRK20 in remediation of 4-t-OP contaminated environments but may also improve our understanding of the environmental fate of 4-t-OP.


Assuntos
Biodegradação Ambiental , Fusarium/química , Fenóis/química , Fungos/metabolismo
12.
Phytochemistry ; 169: 112160, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31600654

RESUMO

Filamentous fungi is a huge phylum of lower eukaryotes with diverse activities towards various substrates, however, their biocatalytic potential towards steroids remains greatly underestimated. In this study, more than forty Ascomycota and Zygomycota fungal strains of 23 different genera were screened for the ability to catalyze structural modifications of 3-oxo-androstane steroids, - androst-4-ene-3,17-dione (AD) and androsta-1,4-diene-3,17-dione (ADD). Previously unexplored for these purposes strains of Absidia, Acremonium, Beauveria, Cunninghamella, Doratomyces, Drechslera, Fusarium, Gibberella genera were revealed capable of producing in a good yield valuable 7α-, 7ß-, 11α- and 14α-hydroxylated derivatives, as well as 17ß-reduced and 1(2)-dehydrogenated androstanes. The bioconversion routes of AD and ADD were proposed based on the key intermediates identification and time courses of the bioprocesses. Six ascomycete strains were discovered to provide effective 7ß-hydroxylation of ADD which has not been so far reported. The structures of major products and intermediates were confirmed by HPLC, mass-spectrometry (MS), 1H and 13C NMR analyses. The results contribute to the knowledge on the functional diversity of steroid-transforming filamentous fungi. Previously unexplored fungal biocatalysts capable of effective performing structural modification of AD and ADD can be applied for industrial bioprocesses of new generation.


Assuntos
Androstadienos/metabolismo , Androstenodiona/metabolismo , Fungos/metabolismo , Androstadienos/química , Androstadienos/isolamento & purificação , Androstenodiona/química , Androstenodiona/isolamento & purificação , Biotransformação , Fungos/química , Fungos/classificação , Conformação Molecular
13.
Food Microbiol ; 86: 103347, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31703852

RESUMO

Gutian Hong Qu glutinous rice wine (GHQW) is a representative alcoholic beverage in China. During its traditional brewing process, multiple strains are involved. However, the roles of these microorganisms, particularly their contributions to aroma formation, are poorly understood. Therefore, in this study, the dynamics of volatile components and microbial succession during the traditional fermentation process of GHQW were monitored, by using HS-SPME-GC/MS and high throughput 16 S rRNA and ITS sequencing techniques. Following a 32-day semi-open solid-state fermentation, massive changes in volatile profile and microbial communities were observed. Based on these, the potential correlations between volatile components and microorganisms during the fermentation were explored by using Pearson correlation analysis. It was revealed that 3 bacterial taxa, including Lactococcus lactis, Burkholderia gladioli and Cronobacter helveticus, and 5 fungal taxa, including Wickerhamomyces anomalus, Saccharomyces cerevisiae, Aspergillus vitricola, Aspergillus penicillioides and Monascus purpureus, showed strong connections with various volatile components. Thus these bacteria and fungi might play crucial roles in volatile components biosynthesis, and thus were preliminary considered as core functional microorganisms for GHQW brewing. The detailed information on the dynamic changes of volatile components and microbial communities throughout GHQW brewing can further expand our understanding of the formation mechanisms of GHQW aroma.


Assuntos
Bactérias/metabolismo , Fungos/metabolismo , Oryza/microbiologia , Compostos Orgânicos Voláteis/metabolismo , Vinho/análise , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , China , Fermentação , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Cromatografia Gasosa-Espectrometria de Massas , Microbiota , Oryza/química , Compostos Orgânicos Voláteis/química , Vinho/microbiologia
14.
Food Microbiol ; 86: 103340, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31703864

RESUMO

Red sufu is a traditional food produced by the fermentation of soybean. In this study, sufu samples were periodically collected during the whole fermentation to investigate the dynamic changes of fungal and bacterial communities using high-throughput sequencing technology. The overall process can be divided into pre- and post-fermentation. During post-fermentation, the pH value showed a gradual decrease over time while the amino nitrogen content increased. Trichosporon, Actinomucor and Cryptococcus were the main genera in pre-fermentation while Monascus and Aspergillus were dominant in post-fermentation. This huge shift in fungal composition was caused by process procedure of pouring dressing mixture. However, the bacterial composition was not greatly changed after pouring dressing mixture, the Acinetobacter and Enterobacter were the predominant genera throughout the whole process. Furthermore, Bacillus species were first detected after adding dressing mixture, but declined abruptly to a very low level (0.07%) by the end of the fermentation. Our work demonstrates the dynamic changes of physicochemical properties and microbial composition in every fermentation stage, the knowledge of which could potentially serve as a foundation for improving the safety and quality of sufu in the future.


Assuntos
Bactérias/isolamento & purificação , Fungos/isolamento & purificação , Microbiota , Alimentos de Soja/microbiologia , Soja/microbiologia , Bactérias/classificação , Bactérias/genética , Bactérias/metabolismo , Fermentação , Fungos/classificação , Fungos/genética , Fungos/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala , Alimentos de Soja/análise , Soja/metabolismo
15.
Food Microbiol ; 86: 103329, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31703874

RESUMO

Four sets of doenjang (traditional Korean fermented soybean paste) with 9%, 12%, 15%, and 18% solar salt concentrations were prepared and their pH, microbial abundances and communities, metabolites, and volatile compounds were analyzed periodically during the entire fermentation. The speeds of decrease in pH and increase in microbial abundances, representing microbial activity, were higher during early fermentation in lower (9% and 12%) salt doenjang. Microbial abundances in 15% and 18% salt doenjang were significantly lower than in the 9% and 12% salt doenjang, indicating low microbial activity. Community analysis revealed that Bacillus, Staphylococcus, and Clostridium and Aspergillus, Scopulariopsis, Fusarium, Mucor, and Penicillium, which might be derived from doenjang-meju used for preparing doenjang, were identified as major bacterial and fungal genera, respectively, in all doenjang samples. Weissella, Tetragenococcus, Oceanobacillus, and Debaryomyces, not dominant in doenjang-meju, were also identified as major groups in low salt doenjang. Metabolite analysis showed that amino acid profiles were relatively similar independent of salt concentrations and microbial growth, indicating important roles of indigenous proteases present in doenjang-meju, not microbial activity during doenjang fermentation, in amino acid production. The metabolism of free sugars to organic acids and biogenic amine production were greater in lower salt doenjang, which might be associated with the growth of microbes, particularly lactic acid bacteria. A higher level of and more diverse volatile compounds were identified in lower salt doenjang, indicating close association with microbial growth. This study provides a deeper understanding of doenjang fermentation and insight into the development of low salt doenjang.


Assuntos
/microbiologia , Cloreto de Sódio/análise , Soja/microbiologia , Ácidos/análise , Ácidos/metabolismo , Aminoácidos/análise , Aminoácidos/metabolismo , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Aminas Biogênicas/análise , Aminas Biogênicas/metabolismo , Fermentação , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Fungos/metabolismo , Cloreto de Sódio/metabolismo , Alimentos de Soja/análise , Alimentos de Soja/microbiologia
16.
Sheng Wu Gong Cheng Xue Bao ; 35(11): 2061-2068, 2019 Nov 25.
Artigo em Chinês | MEDLINE | ID: mdl-31814354

RESUMO

Biosynthesis of gold-silver alloy nanoparticles (Au-AgNPs) is a simple operation and ecological friendly, but with limited reports on the availability of fungal resources. In this study, cell-free extracts of Mariannaea sp. HJ was used to synthesize Au-AgNPs, and the effects of the different ratios of Au and Ag ion concentrations on the synthesis of Au-AgNPs were also studied. The results clearly showed that the ratio of Au and Ag ion concentrations had an impact on the composition of Au-AgNPs. With the Ag ion increasing, the color of culture supernatant changed from light purple to brown and an obvious blue shift of characteristic absorption peak was observed in UV-vis spectra, indicating an increase of the percentage of Ag in the Au-AgNPs. Transmission electron microscope showed that the morphologies of the Au-AgNPs were mainly spherical and pseudo spherical, and the average particle sizes of the Au-AgNPs at three different ion concentrations, including 0.5:0.5, 0.5:1.5 and 0.5:3.0, were 19.24 nm, 15.99 nm and 19.33 nm, respectively. X-ray diffraction results showed that the Au-AgNPs had a surface-centered cubic structure. Fourier transform infrared spectroscopy was used to characterize and speculate the involvement of -OH, -NH3 and -COOH functional groups in the reduction and stability process of Au-AgNPs. Furthermore, 4-nitrophenol (4-NP) was used to explore catalytic activity of Au-AgNPs. Catalytic experiments demonstrated that the Au-AgNPs had a good catalytic activity on 4-NP reduction with a catalytic reaction rate constant of 7.85×10⁻³ s⁻¹. In brief, the present study suggested that Mariannaea sp. HJ could synthesize Au-AgNPs with good dispersity, and had a potential application in the catalytic reduction of nitro aromatic hydrocarbons.


Assuntos
Fungos , Ouro , Nanopartículas Metálicas , Prata , Catálise , Fungos/metabolismo , Nanopartículas Metálicas/química , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
18.
BMC Complement Altern Med ; 19(1): 330, 2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31752824

RESUMO

BACKGROUND: Endophytic fungi are a proven source of bioactive secondary metabolites that may provide lead compounds for novel drug discovery. In this study, crude extracts from fungal endophytes isolated from Datura stramonium were evaluated for cytotoxic activity on two human cancer cell lines. METHODS: Fungal endophytes were isolated from surface sterilized aerial parts of D. stramonium and identified using molecular, morphological and phylogenetic methods. Ethyl acetate crude extracts from these isolates were evaluated for cytotoxic activity on A549 lung carcinoma and UMG87 glioblastoma cell lines. Metabolite profiling was then performed by liquid chromatography coupled to quadrupole time-of-flight with tandem mass spectrometry (LC-QTOF-MS/MS) for the cytotoxic crude extract. RESULTS: Eleven fungal endophytes were identified from D. stramonium. Significant cytotoxicity was only observed from the crude extract of Alternaria sp. KTDL7 on UMG87 glioblastoma cells (IC50 = 21.49 µg/ml). Metabolite profiling of this crude extract tentatively revealed the presence of the following secondary metabolites: 1,8-dihydroxynaphthalene (1), anserinone B (2), phelligridin B (3), metacytofilin (4), phomopsidin (5) and vermixocin A (6). Compounds 2 and 3 have been shown to be cytotoxic in literature. CONCLUSION: The findings in this study suggest that the crude extract of Alternaria sp. KTDL7 possesses compound(s) cytotoxic to glioblastoma multiforme cells. Future studies to isolate and characterize the cytotoxic compound(s) from this fungus could result in lead development of a fungal-based drug for glioblastoma multiforme treatment.


Assuntos
Antineoplásicos/farmacologia , Produtos Biológicos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Datura stramonium/microbiologia , Células A549 , Antineoplásicos/química , Produtos Biológicos/química , Linhagem Celular Tumoral , Cromatografia Líquida , Endófitos/química , Endófitos/genética , Endófitos/metabolismo , Fungos/química , Fungos/genética , Fungos/metabolismo , Humanos , Espectrometria de Massas em Tandem
19.
Adv Exp Med Biol ; 1174: 161-185, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31713199

RESUMO

In recent years, much attention has focused on incorporating biological and bio-inspired nanomaterials into various applications that range from functionalising surfaces and enhancing biomolecule binding properties, to coating drugs for improved bioavailability and delivery. Hydrophobin proteins, which can spontaneously assemble into amphipathic layers at hydrophobic:hydrophilic interfaces, are exciting candidates for use as nanomaterials. These unique proteins, which are only expressed by filamentous fungi, have been the focus of increasing interest from the biotechnology industry, as evidenced by the sharply growing number of hydrophobin-associated publications and patents. Here, we explore the contribution of different hydrophobins to supporting fungal growth and development. We describe the key structural elements of hydrophobins and the molecular characteristics that underlie self-assembly of these proteins at interfaces. We outline the multiple roles that hydrophobins can play in supporting aerial growth of filamentous structures, facilitating spore dispersal and preventing an immune response in the infected host. The growing understanding of the hydrophobin protein structure and self-assembly process highlights the potential for hydrophobin proteins to be engineered for use in a variety of novel applications that require biocompatible coatings.


Assuntos
Proteínas Fúngicas , Nanoestruturas , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Fungos/crescimento & desenvolvimento , Fungos/metabolismo , Interações Hidrofóbicas e Hidrofílicas , Nanoestruturas/química , Conformação Proteica
20.
Mar Drugs ; 17(10)2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31575010

RESUMO

Chlorophenols (CPs) are environmental pollutants that are produced through various anthropogenic activities and introduced in the environment. Living organisms, including humans, are exposed to these toxic xenobiotics and suffer from adverse health effects. More specifically, 2,4-dichlorophenol (2,4-DCP) is released in high amounts in the environment and has been listed as a priority pollutant by the US Environmental Protection Agency. Bioremediation has been proposed as a sustainable alternative to conventional remediation methods for the detoxification of phenolic compounds. In this work, we studied the potential of fungal strains isolated as symbionts of marine invertebrates from the underexplored mesophotic coral ecosystems. Hence, the unspecific metabolic pathways of these fungal strains are being explored in the present study, using the powerful analytical capabilities of a UHPLC-HRMS/MS. The newly identified 2,4-DCP metabolites add significantly to the knowledge of the transformation of such pollutants by fungi, since such reports are scarce.


Assuntos
Organismos Aquáticos/microbiologia , Clorofenóis/metabolismo , Fungos/metabolismo , Invertebrados/microbiologia , Poluentes Químicos da Água/metabolismo , Animais , Antozoários/metabolismo , Biodegradação Ambiental , Ecossistema , Humanos , Redes e Vias Metabólicas/fisiologia , Fenóis/metabolismo , Simbiose/fisiologia , Xenobióticos/metabolismo
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