75 research outputs found
Advances in fermented foods revealed by multi-omics: A new direction toward precisely clarifying the roles of microorganisms
Fermented foods generally comprise a complex micro-ecosystem with beneficial microbiota, functional products, and special flavors and qualities that are welcomed globally. Single-omics analysis allows for a comprehensive characterization of the main microbial factors influencing the function, flavor, and quality of fermented foods. However, the species, relative abundance, viability, growth patterns, and metabolic processes of microorganisms vary with changes in processing and environmental conditions during fermentation. Furthermore, the mechanisms underlying the complex interaction among microorganisms are still difficult to completely understand and analyze. Recently, multi-omics analysis and the integration of multiple types of omics data allowed researchers to more comprehensively explore microbial communities and understand the precise relationship between fermented foods and their functions, flavors, and qualities. Multi-omics approaches might help clarify the mechanisms underpinning the fermentation processes, metabolites, and functional components of these communities. This review clarified the recent advances in the roles of microorganisms in fermented foods based on multi-omics data. Current research achievements may allow for the precise control of the whole industrial processing technology of fermented foods, meeting consumers’ expectations of healthy products
Isolation, Identification, Screening and Fermentation Process Optimization of Bacillus Producing High Antimicrobial Lipopeptide
In order to screen out Bacillus sp. with high production of antimicrobial lipopeptide and determine its optimal fermentation conditions, the study isolated and identified antimicrobial lipopeptide-producing Bacillus sp. strains from traditional fermented soybean paste, and adopted orthogonal test to investigate how lipopeptide production by Bacillus sp was affected by fermentation conditions, such as fermentation inoculum amount, fermentation filling volume, fermentation time and fermentation temperature. The results showed that 27 strains of Bacillus sp. were isolated and screened out from 9 portions traditional fermented soybean paste of the Northeast, among which 6 strains were identified by 16S rDNA as having the genes sfp, fenB and ituA for synthesizing lipopeptide. According to the determination of lipopeptide yield and inhibition effect, Bacillus subtilis SN-20 and Bacillus amyloliquefaciens SN-46 showed excellent performance with the yield of 106 and 72 mg of lipopeptide per unit, and strong inhibition effect on both gram-positive and negative indicator bacteria. The optimal fermentation process of Bacillus subtilis SN-20 was found to be 3% inoculum, 20% fermentation filler, 36 h fermentation time and 32 ℃. The optimal fermentation process of Bacillus subtilis SN-46 was 2% inoculum, 40% fermentation filler, 24 h fermentation time and 32 ℃. Under these conditions, the unit biomass yields of lipopeptides for the two strains of Bacillus before optimization were 106.11 and 76.23 mg/g, respectively. After optimization, they increased by 21.85% and 23.84%, respectively. The study results effectively increased the production of antimicrobial lipopeptides from Bacillus
Whole Genome Sequencing of Bacillus subtilis SNBS-3 and Prediction of Its Antimicrobial Substances
As an extension of the previous research, this study aimed to comprehensively characterize the genome of Bacillus subtilis SNBS-3. Illumina second-generation sequencing technology and the third-generation high-throughput Pacbio sequencing platform were used for whole-genome sequencing of B. subtilis SNBS-3 isolated from traditional bean paste to obtain the key information of genome characteristics, gene function annotation and classification, phylogenetic evolution, and secondary metabolites. The results showed that the genome of SNBS-3 was a closed circular DNA of 4 076 387 bp in length containing 4 000 protein-coding genes. A total of 3 209, 2 824, 2 560, 147, 12 and 4 functional genes were annotated in the Clusters of Orthologous Groups (COG), Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), Carbohydrate-Active Enzymes (CAZyme), Comprehensive Antibiotic Resistance Database (CARD) and Virulence Factor Database (VFDB), respectively. Using the online software AntiSMASH and Bagel4, we found that it contained genes related to the synthesis of surfactin, mycosubtilin, plipastatin, bacilysin and bacillaene, as well as a complete gene cluster for the synthesis of the bacteriocin subtilosin A. Based on the results of antimicrobial test and proteinase K test, it was hypothesized that B. subtilis SNBS-3 had the ability to synthesize subtilosin A. In conclusion, the whole genome sequencing results of B. subtilis SNBS-3 show that it can produce a variety of bacteriostatic substances and thus have biocontrol potential. The results from this study provide a theoretical basis for further development and application of various bacteriostatic substances including the bacteriocin subtilosin A
6G Network AI Architecture for Everyone-Centric Customized Services
Mobile communication standards were developed for enhancing transmission and
network performance by using more radio resources and improving spectrum and
energy efficiency. How to effectively address diverse user requirements and
guarantee everyone's Quality of Experience (QoE) remains an open problem. The
Sixth Generation (6G) mobile systems will solve this problem by utilizing
heterogenous network resources and pervasive intelligence to support
everyone-centric customized services anywhere and anytime. In this article, we
first coin the concept of Service Requirement Zone (SRZ) on the user side to
characterize and visualize the integrated service requirements and preferences
of specific tasks of individual users. On the system side, we further introduce
the concept of User Satisfaction Ratio (USR) to evaluate the system's overall
service ability of satisfying a variety of tasks with different SRZs. Then, we
propose a network Artificial Intelligence (AI) architecture with integrated
network resources and pervasive AI capabilities for supporting customized
services with guaranteed QoEs. Finally, extensive simulations show that the
proposed network AI architecture can consistently offer a higher USR
performance than the cloud AI and edge AI architectures with respect to
different task scheduling algorithms, random service requirements, and dynamic
network conditions
Analysis of Large Phenotypic Variability of EEC and SHFM4 Syndromes Caused by K193E Mutation of the TP63 Gene
EEC (ectrodactyly, ectodermal dysplasia, clefting; OMIM 604292) is an autosomal dominant developmental disorder resulting mainly from pathogenic mutations of the DNA-binding domain (DBD) of the TP63 gene. In this study, we showed that K193E mutation in nine affected individuals of a four-generation kindred with a large degree of phenotypic variability causes four different syndromes or TP63-related disorders: EEC, Ectrodactyly-ectodermal dysplasia (EE), isolated ectodermal dysplasia, and isolated Split Hand/Foot Malformation type 4 (SHFM4). Genotype-phenotype and DBD structural modeling analysis showed that the K193-located loop L2-A is associated with R280 through hydrogen bonding interactions, while R280 mutations also often cause large phenotypic variability of EEC and SHFM4. Thus, we speculate that K193 and several other DBD mutation-associated syndromes may share similar pathogenic mechanisms, particularly in the case of the same mutation with different phenotypes. Our study and others also suggest that the phenotypic variability of EEC is attributed, at least partially, to genetic and/or epigenetic modifiers
Research progress on gas resource evaluation, extraction and utilization in abandoned coal mines in China
China has a large number of abandoned coal mines, many of which are highly gassy mines. Considering the pros and cons of gas occurrence in abandoned coal mine and its timeliness characteristics, it is considered that there is an urgent need to develop and utilize gas resources in abandoned coal mines. This paper starts with two key steps of gas resource development and utilization in abandoned coal mine: gas resource evaluation, gas extraction and utilization in abandoned coal mine, to systematically summarize and analyze the current research progress in gas occurrence scope, gas source and gas occurrence state, gas resource estimation model, gas enrichment distribution law and optimization of extraction well distribution. The existing problems in the evaluation, extraction and utilization of gas resources in abandoned coal mines are obtained, and the next research direction is pointed out
Numerical modeling of the thermoelectric cooler with a complementary equation for heat circulation in air gaps
In this paper, a numerical model is developed by combining thermodynamics with heat transfer theory. Taking inner and external multi-irreversibility into account, it is with a complementary equation for heat circulation in air gaps of a steady cooling system with commercial thermoelectric modules operating in refrigeration mode. With two modes concerned, the equation presents the heat flowing through air gaps which forms heat circulations between both sides of thermoelectric coolers (TECs). In numerical modelling, a TEC is separated as two temperature controlled constant heat flux reservoirs in a thermal resistance network. In order to obtain the parameter values, an experimental apparatus with a commercial thermoelectric cooler was built to characterize the performance of a TEC with heat source and sink assembly. At constant power dissipation, steady temperatures of heat source and both sides of the thermoelectric cooler were compared with those in a standard numerical model. The method displayed that the relationship between Φf and the ratio
Φc′/Φc
was linear as expected. Then, for verifying the accuracy of proposed numerical model, the data in another system were recorded. It is evident that the experimental results are in good agreement with simulation(proposed model) data at different heat transfer rates. The error is small and mainly results from the instabilities of thermal resistances with temperature change and heat flux, heat loss of the device vertical surfaces and measurements
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