-
Heliyon Nov 2023Red dragon fruit (RDF) is well-known for its high nutritional content, especially the red pigment betacyanins that possess high antioxidant activity. Natural...
Red dragon fruit (RDF) is well-known for its high nutritional content, especially the red pigment betacyanins that possess high antioxidant activity. Natural fermentation is an ancient yet outstanding technique that relies on the autochthonous microbiota from fruits and vegetables surfaces to preserve and improve the nutritional values and quality of the food product. The present study was to evaluate and identify the indigenous microbial community (bacteria and fungi) that are involved in the natural fermentation of RDF. Results revealed a total of twenty bacterial pure cultures and nine fungal pure cultures were successfully isolated from fermented red dragon fruit drink (FRDFD). For the first time, the PCR amplification of 16S rRNA and ITS regions and sequence analysis suggested nine genera of bacteria and three genera of fungi (, , and ) present in the FRDFD. Four dominant (≥10 % isolates) bacteria species identified from FRDFD were , , and . The carbohydrate fermentation test showed that all the indigenous microbes identified were able to serve as useful starter culture by fermenting sucrose and glucose, thereby producing acid to lower the pH of FRDFD to around pH 4 for better betacyanins stability. The present study provides a more comprehensive understanding of the indigenous microbial community that serves as the starter culture in the fermentation of RDF. Besides, this study provides a useful guide for future research to be conducted on studying the rare bacterial strains (such as ) identified from the FRDFD for their potential bioactivities and applications in medical treatment and functional foods industries.
PubMed: 38027851
DOI: 10.1016/j.heliyon.2023.e21940 -
Preparative Biochemistry & Biotechnology Nov 2023LB83 is a versatile biocatalyst that produces a plethora of bioactive products thriving on a variety of feedstocks under the varying culture conditions. In our last...
LB83 is a versatile biocatalyst that produces a plethora of bioactive products thriving on a variety of feedstocks under the varying culture conditions. In our last study using this microorganism, we found cellulase activity (FPase, 2.27 U/ml; CMCase, 7.42 U/ml) and other plant cell wall degrading enzyme activities grown on sugarcane bagasse and soybean meal as carbon source and nitrogen, respectively. In the present study, we provide insights on the secretome analysis of this enzymatic cocktail. The secretome analysis of LB83 by Liquid Chromatography coupled to Mass Spectroscopy (LC-MS/MS) revealed 38 classes of Carbohydrate Active enZymes (CAZymes) of a total of 464 identified proteins. These CAZymes consisted of 21 glycoside hydrolases (55.26%), 12 glycoside hydrolases harboring carbohydrate-binding module (31.58%), 4 carbohydrate esterases (10.53%) and one glycosyl transferase (2.63%). To the best of our knowledge, this is the first report on the secretome analysis of LB83.
PubMed: 37966162
DOI: 10.1080/10826068.2023.2279109 -
Journal of the Science of Food and... Mar 2024Pile fermentation is one of the key steps in developing the Liupao tea (LBT) quality and unique characteristics. The complex biochemical profile of LBT results from...
BACKGROUND
Pile fermentation is one of the key steps in developing the Liupao tea (LBT) quality and unique characteristics. The complex biochemical profile of LBT results from microorganisms present during the pile-fermentation process. However, the critical underlying microorganisms and the marker compounds still need to be determined.
RESULTS
Staphylococcus, Brevibacterium, Kocuria, Aspergillus, and Blastobotrys were the common dominant microorganisms at the end of the pile fermentation of LBT. Staphylococcus, Aspergillus, Blastobotrys, and nine other genera carried by raw tea are the core microorganisms in the LBT during pile fermentation. A total of 29 critical compounds contributed to the metabolic changes caused by the processing of LBT. Of these, gallic acid, adenine, hypoxanthine, uridine, betaine, 3,4-dihydroxybenzaldehyde, and α-linolenic acid could be characterized as potential marker compounds. Correlation analysis showed that the core microorganisms, including Sphingomonas, Staphylococcus, Kocuria, Aureobasidium, Blastobotrys, Debaryomyce, and Trichomonascus, were closely related to major chemical components and differential compounds. Moreover, the mutually promoting Staphylococcus, Kocuria, Blastobotrys, and Trichomonascus were correlated with the enrichment of marker compounds. Integrated molecular networking and metabolic pathways revealed relevant compounds and enzymes that possibly affect the enrichment of marker compounds.
CONCLUSION
This study analyzed the LBT fermentation samples by omics analysis to reveal the stable microbial community structure, critical microorganisms, and markers compounds affecting the quality of LBT, which contributes to a better understanding of pile fermentation of LBT and the fermentation theory of dark tea. © 2023 Society of Chemical Industry.
Topics: Fermentation; Tea; Aspergillus; Microbiota; Saccharomycetales
PubMed: 38017631
DOI: 10.1002/jsfa.13177 -
Journal of Water and Health Aug 2023The European Union currently has no specific regulations on fungi in water. The only country where fungi are listed as the parameter is Sweden, with the maximal number...
The European Union currently has no specific regulations on fungi in water. The only country where fungi are listed as the parameter is Sweden, with the maximal number of 100 CFU per 100 mL. The present study thus compared culturable mycobiota from Swedish drinking water with Slovenian, which has no specific requirements for fungi. Fungi were isolated with up to 38 CFU/L from 75% of Swedish samples. The most common were the genera Varicosporellopsis (27.3%), Paracremonium (14.5%), and black yeasts Cadophora, Cyphellophora, and Exophiala (18.2%). Using the same sampling and isolation methods, 90% of tap water samples in Slovenia were positive for fungi, with Aspergillus spp. (46%), Aureobasidium melanogenum (36%), and Exophiala spp. (24%) being the most common. The observed differences between countries are likely the consequence of geographical location, the use of different raw water sources, and water treatment methods. However, the core species and emerging fungi Aspergillus fumigatus, Candida parapsilosis sensu stricto, Exophiala phaeomuriformis, Bisifusarium dimerum, and Rhodotorula mucilaginosa were isolated in both studies. These findings point out the relevance of tracking the presence of emerging fungi with known effects on health in drinking water and encourage further studies on their transmission from raw water sources to the end-users.
Topics: Humans; Drinking Water; Sweden; Slovenia; European Union; Hydrotherapy
PubMed: 37632381
DOI: 10.2166/wh.2023.089 -
Antioxidants (Basel, Switzerland) Dec 2023The zoonotic pathogens spp. infection disrupted intestinal epithelial barrier function and induced local gastroenteritis and systemic inflammation in humans and...
Sophy β-Glucan from the Black Yeast Attenuates -Induced Intestinal Epithelial Barrier Injury in Caco-2 Cell Monolayers via Exerting Anti-Oxidant and Anti-Inflammatory Properties.
The zoonotic pathogens spp. infection disrupted intestinal epithelial barrier function and induced local gastroenteritis and systemic inflammation in humans and animals. Sophy β-glucan, a water-soluble β-1,3/1,6-glucan synthesized from the black yeast , was reported with immune-regulatory, anti-inflammatory, and anti-infective properties. Here, we investigated the protective role of sophy β-glucan on serotype Enteritidis (SE)-challenged Caco-2 cells monolayer and explored underlying action mechanisms. The results showed that pretreatment with sophy β-glucan blocked the adhesion and invasion of SE onto Caco-2 cells along with alleviating SE-induced epithelial barrier injury, as evidenced by increased trans-epithelial electrical resistance, decreased fluorescently-labeled dextran 4 flux permeability, and an enhanced Claudin-4 protein level in the SE-stimulated Caco-2 cell monolayer. Moreover, treatment with β-glucan down-regulated pro-inflammatory factors (IL-1β, IL-8, and TNF-α) while up-regulating anti-inflammatory factors IL-10 at mRNA and protein levels in SE-infected Caco-2 cells. Furthermore, sophy β-glucan strengthened the anti-oxidative capacity of Caco-2 monolayers cells by elevating T-AOC and SOD activity and inhibiting MDA production defending SE. Together, our data showed that sophy β-glucan could prevent intestinal epithelial injury induced by SE, possibly by exerting anti-oxidant and anti-inflammatory properties, and it might be helpful for controlling SE infection.
PubMed: 38247473
DOI: 10.3390/antiox13010048 -
Journal of Bioscience and Bioengineering May 2024A high-yielding microbial polysaccharide-producing strain, named RM1603, was isolated from rhizosphere soil and identified by morphological and phylogenetic analysis....
A high-yielding microbial polysaccharide-producing strain, named RM1603, was isolated from rhizosphere soil and identified by morphological and phylogenetic analysis. The extracellular polysaccharides (EPS) were identified by thin-layer chromatography and infrared spectroscopy. The fermentation conditions were optimized by single factor experiments in shake flasks and a 5-L fermentor. The results of morphological and phylogenetic tree analysis showed that RM1603 was a strain of Aureobasidium pullulans. Its microbial polysaccharide was identified as pullulan, and the EPS production capacity reached 33.07 ± 1.03 g L in shake flasks. The fermentation conditions were optimized in a 5-L fermentor, and were found to encompass an initial pH of 6.5, aeration rate of 2 vvm, rotor speed of 600 rpm, and inoculum size of 2 %. Under these conditions, the pullulan yield of RM1603 reached 62.52 ± 0.24 g L. Thus, this study contributes RM1603 as a new isolation with high-yielding pullulan and potential application value in biotechnology.
Topics: Fermentation; Phylogeny; Ascomycota; Polysaccharides; Aureobasidium; Glucans
PubMed: 38413318
DOI: 10.1016/j.jbiosc.2023.12.018 -
Food Chemistry: X Oct 2023Microbial activity during spontaneous fermentation in alcoholic beverages have driven in developing the chemical and aromatic characteristic of products but not clear in...
Microbial activity during spontaneous fermentation in alcoholic beverages have driven in developing the chemical and aromatic characteristic of products but not clear in apricot wines. We have characterised the composition of fungal communities and volatile metabolites in apricot wine spontaneous fermentation among two Shaanxi regions. Results showed that , , and , were the dominant fungi in apricot wine fermentation. A total of 80 volatiles including esters, alcohols, acids and terpenes were detected from two apricot wines. Their correlations suggested that apricot wine aroma was mainly affected by , rather than we commonly considered. Furthermore, reinforced inoculation of LQD20 has exhibited the commendable potential in enhancing sensory qualities. The results of this study provide fundamental information of the indigenous microbiota in microbial dynamic during apricot wine fermentation, which would be helpful in exploiting the strains with potential for industrial use as starter cultures.
PubMed: 37780311
DOI: 10.1016/j.fochx.2023.100862 -
The Journal of Cell Biology Oct 2024Aureobasidium pullulans is a ubiquitous polymorphic black yeast with industrial and agricultural applications. It has recently gained attention amongst cell biologists...
Aureobasidium pullulans is a ubiquitous polymorphic black yeast with industrial and agricultural applications. It has recently gained attention amongst cell biologists for its unconventional mode of proliferation in which multinucleate yeast cells make multiple buds within a single cell cycle. Here, we combine a chemical transformation method with genome-targeted homologous recombination to yield ∼60 transformants/μg of DNA in just 3 days. This protocol is simple, inexpensive, and requires no specialized equipment. We also describe vectors with codon-optimized green and red fluorescent proteins for A. pullulans and use these tools to explore novel cell biology. Quantitative imaging of a strain expressing cytosolic and nuclear markers showed that although the nuclear number varies considerably among cells of similar volume, total nuclear volume scales with cell volume over an impressive 70-fold size range. The protocols and tools described here expand the toolkit for A. pullulans biologists and will help researchers address the many other puzzles posed by this polyextremotolerant and morphologically plastic organism.
Topics: Aureobasidium; Cell Nucleus; Genetic Vectors; Green Fluorescent Proteins; Homologous Recombination; Luminescent Proteins; Red Fluorescent Protein; Transformation, Genetic; Genetic Techniques
PubMed: 38935076
DOI: 10.1083/jcb.202402114 -
Foods (Basel, Switzerland) Sep 2023Regel () is a healthy edible plant but highly perishable with a short shelf life of 1-2 d. Modified atmosphere packaging (MAP) could inhibit the postharvest senescence...
Polypropylene/Poly(butylene adipate-co-terephthalate) Breathing Film for Inhibiting and Maintaining Microbial Communities and Postharvest Quality of Regel during Storage.
Regel () is a healthy edible plant but highly perishable with a short shelf life of 1-2 d. Modified atmosphere packaging (MAP) could inhibit the postharvest senescence and decay of the vegetables. Thus, the aim of this study was to apply MAP with different gas permeabilities to the storage of and evaluate its effects on maintaining microbial communities and the postharvest quality of . The results showed that polypropylene/poly(butylene adipate-co-terephthalate) (PP/PBAT, abbreviated as PAT) MAP was suitable for the storage of by establishing an optimal atmosphere of 0.5-0.6% O and 6.2-7.1% CO in the bag. It could delay the postharvest senescence of and maintain its quality by slowing down its respiration rate and weight loss, reducing cell membrane permeability and lipid peroxidation, maintaining the cell wall, and reducing infection and the growth of microorganisms. However, in HPT was more perishable than that in PAT during storage. was found to be the main spoilage bacteria, and they could also be effectively inhibited by PAT-MAP. The next-generation sequencing results also showed the growth of , , , , , and , responsible for decay or human disease, was well inhibited by PAT-MAP. The results suggested that PAT-MAP could be used to maintain microbial diversity and the postharvest quality of under cold storage conditions. It provided a feasible solution for the preservation, food quality, and safety control of .
PubMed: 37761079
DOI: 10.3390/foods12183370 -
Microbial Ecology Aug 2023The olive tree is one of the most important agricultural plants, affected by several pests and diseases that cause a severe decline in health status leading to crop...
The olive tree is one of the most important agricultural plants, affected by several pests and diseases that cause a severe decline in health status leading to crop losses. Olive leaf spot disease caused by the fungus Venturia oleaginea can result in complete tree defoliation and consequently lower yield. The aim of the study was to obtain new knowledge related to plant-pathogen interaction, reveal mechanisms of plant defense against the pathogen, and characterize fungal phyllosphere communities on infected and symptomless leaves that could contribute to the development of new plant breeding strategies and identification of novel biocontrol agents. The highly susceptible olive variety "Istrska Belica"' was selected for a detailed evaluation. Microscopy analyses led to the observation of raphides in the mesophyll and parenchyma cells of infected leaves and gave new insight into the complex V. oleaginea pathogenesis. Culturable and total phyllosphere mycobiota, obtained via metabarcoding approach, highlighted Didymella, Aureobasidium, Cladosporium, and Alternaria species as overlapping between infected and symptomless leaves. Only Venturia and Erythrobasidium in infected and Cladosporium in symptomless samples with higher abundance showed statistically significant differences. Based on the ecological role of identified taxa, it can be suggested that Cladosporium species might have potential antagonistic effects on V. oleaginea.
Topics: Olea; Mycobiome; Ascomycota; Basidiomycota; Host-Pathogen Interactions
PubMed: 36307735
DOI: 10.1007/s00248-022-02131-4