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1.
Food Microbiol ; 109: 104154, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36309450

RESUMO

Wooden vats are used in the production of some traditional cheeses as the biofilms on wooden vat surfaces are known to transfer large quantities of microbes to cheese. However, very few studies have investigated the microbial composition of biofilms on newly developed wooden vats and how communities assemble and evolve. In the present study, the microbial communities of biofilms were characterized over the activation process on new wooden vats using amplicon sequencing of bacterial 16s rRNA and fungal internal transcribed spacer genes. Results showed that microbes from the whey effectively developed on wooden vats. Lactococcus was highly dominant throughout the vat activation process with substantial increases in the relative abundance of Acetobacter and Lactobacillus at the end of the vat activation (day 7). This was in contrast with fungal communities that stabilized early (day 1) and were dominated by Kluyveromyces. Predicted functions corresponded with the different stages of biofilm formation whereby functions associated with biofilm initiation were enriched on day 1 and those associated with growth and maturation were enriched on days 4 and 7. Microbial succession on wooden vat surfaces is expected to be reproducible based on the early onset and dominance of the deterministic process.


Assuntos
Queijo , Microbiota , Animais , Queijo/microbiologia , RNA Ribossômico 16S/genética , Leite/microbiologia , Microbiota/genética , Biofilmes
2.
J Hazard Mater ; 442: 129996, 2023 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-36152547

RESUMO

Microplastics could accumulate and enrich antibiotics in the aquatic environment. Despite this, the joint effects of microplastics and antibiotics on aquatic organisms are not clear. Here, we investigated the changes of microbial interactions in both gill and gut of marine medaka exposed to polystyrene microbeads (PS) and/or tetracycline for 30 days by using co-occurrence network analysis based on 16S rRNA gene amplicon sequences. We found that the single and combined effects of PS and tetracycline were more profound on the gut than on the gill microbiome. SourceTracker analysis showed that the relative contributions from the gill microbiome to the gut microbiome increased under combined exposure. Moreover, the combined exposure reduced the complexity and stability of the gut microbial network more than those induced by any single exposure, suggesting the synergistic effects of PS and tetracycline on the gut microbiome. The PS and tetracycline combined exposure also caused a shift in the keystone taxa of the gut microbial network. However, no similar pattern was found for gill microbial networks. Furthermore, single and combined exposure to PS and/or tetracycline altered the associations between the gut network taxa and indicator liver metabolites. Altogether, these findings enhanced our understanding of the hazards of the co-occurring environmental microplastics and antibiotics to the fish commensal microbiome.


Assuntos
Microbiota , Oryzias , Animais , Microplásticos/toxicidade , Oryzias/genética , RNA Ribossômico 16S/genética , Plásticos , Brânquias , Poliestirenos/toxicidade , Tetraciclina/toxicidade , Antibacterianos/toxicidade
3.
Food Chem ; 401: 134148, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36099823

RESUMO

Resistant starch (RS) has caught much attention for its potential to exert a beneficial impact on intestine and certain members of its resident microbiota. In this study, we examined how dietary RS promotes intestinal barrier in meat ducks by microbiome-metabolomics analysis. Ducklings were fed corn-soybean basal diet or RS diet. Dietary RS improved intestinal morphology and enhanced barrier function in ileum, evidenced by lower permeability and upregulated tight junction proteins and Mucin-2 gene expression. Microbiome analysis showed that RS administration elevated the proportion of Firmicutes and butyrate-producing bacteria, and increased butyrate contents in cecum. Furthermore, significant alterations in metabolic profiles were observed, with most of these were associated with the amino acid metabolism (especially tryptophan), lipid metabolism, and intestinal inflammation. Together, diet with RS improved gut integrity and caused corresponding alterations in gut metabolome and microbiome, yielding better insights of the mechanism by RS improved the gut system of ducks.


Assuntos
Microbiota , Amido Resistente , Animais , Mucina-2/farmacologia , Triptofano , Amido/metabolismo , Dieta/veterinária , Carboidratos da Dieta , Patos/metabolismo , Butiratos , Proteínas de Junções Íntimas
4.
Chemosphere ; 310: 136863, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36244419

RESUMO

The non-point source pollution of difenoconazole (DIF) has become a serious environmental issue, increasingly causes indelible damages to eco-environment and human health due to its toxicity, persistence, and biomagnification. An eco-friendly, cost-effective, and efficient control technology is imperative towards a cleaner and sustainable agricultural production. Herein, a dominant microflora of efficiently degrading DIF was successfully screened, and its microbial diversity was investigated. Two novel degrading strains were isolated and identified as Phyllobacterium sp. (T-1) and Aeromonas sp. (T-2). The results of growth factor optimization indicated that the degradation rates of DIF (C0 = 20 mg/L) by strain T-1 and T-2 were up to 96.32% and 97.86% within 14 d, respectively, under the optimal conditions. Moreover, there no obvious synergy between strain T-1 and strain T-2. From catalytic kinetics of enzymes, the intracellular enzyme of strain T-1 dominated the degradation of DIF (C0 = 20 mg/L) entirely with the degradation rate of 82.4% (48 h), the extracellular enzyme showed little catalytic activity. However, the degrade rates of DIF (C0 = 20 mg/L) by both intracellular and extracellular enzymes of strain T-2 were 77.99% and 26.73% within 48 h, respectively. Moreover, these enzymes remained an undiminished catalytic activity within 48 h. DIF was degraded by strain T-1 to three main transformation products (DIF-TPs 406, DIF-TPs 216, and DIF-TPs 198) undergoing hydroxyl substitution, hydrolysis, cleavage of ether bond between benzene rings, and rearrangement, while two additional products (DIF-TPs 281 and DIF-TPs 237) were generated with the biodegradation of strain T-2, excepting for DIF-TPs 406 and DIF-TPs 216, involving hydrolysis, hydroxylation, and ether bond cleavage between benzene rings. Moreover, QSAR simulation showed that the by-products were almost much lower toxicity or even non-toxic to three typical aquatic organisms (fish, daphnia, and green algae) than DIF. This study not only provides an in depth understanding of DIF bioelimination, but also be instrumental in cleaner management of DIF-contaminated soil. This study can promote the sustainable development of agriculture.


Assuntos
Benzeno , Microbiota , Biodegradação Ambiental , Éteres
5.
J Hazard Mater ; 443(Pt A): 130113, 2023 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-36252407

RESUMO

Mechanism of microbiome assembly and function driven by cathode potential in electro-stimulated microbial reductive dechlorination system remain poorly understood. Here, core microbiome structure, interaction, function and assembly regulating by cathode potential were investigated in a 2,4,6-trichlorophenol bio-dechlorination system. The highest dechlorination rate (24.30 µM/d) was observed under - 0.36 V with phenol as a major end metabolite, while, lower (-0.56 V) or higher (0.04 V or -0.16 V) potentials resulted in 1.3-3.8 times decreased of dechlorination kinetic constant. The lower the cathode potential, the higher the generated CH4, revealing cathode participated in hydrogenotrophic methanogenesis. Taxonomic and functional structure of core microbiome significantly shifted within groups of - 0.36 V and - 0.56 V, with dechlorinators (Desulfitobacterium, Dehalobacter), fermenters (norank_f_Propionibacteriaceae, Dysgonomonas) and methanogen (Methanosarcina) highly enriched, and the more positive interactions between functional genera were found. The lowest number of nodes and links and the highest positive correlations were observed among constructed sub-networks classified by function, revealing simplified and strengthened cooperation of functional genera driven by group of - 0.36 V. Cathode potential plays one important driver controlling core microbiome assembly, and the low potentials drove the assembly of major dechlorinating, methanogenic and electro-active genera to be more deterministic, while, the major fermenting genera were mostly governed by stochastic processes.


Assuntos
Clorofenóis , Microbiota , Biodegradação Ambiental , Clorofenóis/metabolismo , Eletrodos
6.
J Hazard Mater ; 443(Pt A): 130241, 2023 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-36308929

RESUMO

Mining activities in metal mine areas cause serious environmental pollution, thereby imposing stresses to soil ecosystems. Investigating the ecological pattern underlying contaminated soil microbial diversity is essential to understand ecosystem responses to environment changes. Here we collected 624 soil samples from 49 representative metal mines across eastern China and analyzed their soil microbial diversity and biogeographic patterns by using 16 S rRNA gene amplicons. The results showed that deterministic factors dominated in regulating the microbial community in non-contaminated and contaminated soils. Soil pH played a key role in climatic influences on the heavy metal-contaminated soil microbial community. A core microbiome consisting of 25 taxa, which could be employed for the restoration of contaminated soils, was identified. Unlike the non-contaminated soil, stochastic processes were important in shaping the heavy metal-contaminated soil microbial community. The largest source of variations in the soil microbial community was land use type. This result suggests that varied specific ecological remediation strategy ought to be developed for differed land use types. These findings will enhance our understanding of the microbial responses to anthropogenically induced environmental changes and will further help to improve the practices of soil heavy metal contamination remediation.


Assuntos
Metais Pesados , Microbiota , Poluentes do Solo , Solo , Poluentes do Solo/análise , Microbiologia do Solo , Metais Pesados/toxicidade , Metais Pesados/análise , China
7.
J Hazard Mater ; 443(Pt A): 130208, 2023 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-36308937

RESUMO

Biodegradable plastics, if they are not properly managed at their end-of-life, can have the same hazardous environmental consequences as conventional plastics. This study investigates the treatment of the main biodegradable plastics under mesophilic and thermophilic anaerobic digestion using biochemical methane potential test and the microorganisms involved in the process using amplicon sequencing of the 16 S rRNA. Here we showed that, only PHB and TPS undergone important and rapid biodegradation under mesophilic condition (38 °C). By contrast, PCL and PLA exhibited very low biodegradation rate as 500 days were required to reach the ultimate methane yield. Little or no degradation occurred for PBAT and PBS at 38 °C. Under thermophilic conditions (58 °C), TPS, PHB, and PLA reached high levels of biodegradation in a relatively short period (< 100 d). While PBS, PBAT, and PCL could not be converted into methane at 58 °C. PHB degraders (Enterobacter and Cupriavidus) and lactate-utilizing bacteria (Moorella and Tepidimicrobium) appeared to play an important role in the PHB and PLA degradation, respectively. This work not only provides crucial data on the anaerobic digestion of the main biodegradable plastics but also enriches the understanding of the microorganisms involved in this process, which are of great importance for future development of the treatment of biodegradable plastics in anaerobic digestion systems.


Assuntos
Plásticos Biodegradáveis , Microbiota , Anaerobiose , Reatores Biológicos , Biodegradação Ambiental , Metano , Plásticos , Poliésteres
8.
J Sci Food Agric ; 103(1): 164-175, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-35837792

RESUMO

BACKGROUND: Sophora alopecuroides L. is a leguminous plant commonly found in northwest China. In Xinjiang, the fresh herb of S. alopecuroides is often applied as a green fertilizer to the rhizosphere of melon (Cucumis melo) plants at the end of their flowering period, to improve the taste of the fruits. However, the effects of S. alopecuroides-based fertilizers on the microbial community structure of soil and crop-root systems are unclear. In order to study the sweetening mechanism of the S. alopecuroides organic fertilizer, three different varieties of melon were selected. The untreated plants were used as the control (CK) group, and the plants treated with S. alopecuroides-based organic fertilizer were selected as the treatment (T) group. The physical and chemical properties, enzyme activities and microbial community structure of the rhizosphere samples were also determined, and a correlation analysis with the fruit sweetness index was conducted. RESULTS: Sugar content of group T was at least 40% higher than that of group CK. The increase in fruit sugar content positively correlated with the increase in the abundance of beneficial microorganisms, including Pseudomonas, Bacillus, Mycobacterium, Burkholderia, Streptomyces, Acinetobacter, Proteobacteria, Lysobacter, Actinomycetes, Penicillium and Aspergillus. CONCLUSION: Sophora alopecuroides organic fertilizer could alter the composition and function of bacterial and fungal communities and promote the growth of beneficial bacteria in the melon plant rhizosphere. Further, it could increase the content of soluble solids and sugar in the fruits to achieve a sweetening effect. This fertilizer can be applied as a fruit sweetener in melon cultivation, improving the sugar content of the fruit and consequently the sweetness. © 2022 Society of Chemical Industry.


Assuntos
Cucurbitaceae , Microbiota , Sophora , Fertilizantes/análise , Rizosfera , Frutas/química , Microbiologia do Solo , Solo/química , Bactérias/genética , Açúcares
9.
J Sci Food Agric ; 103(1): 243-254, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-35857424

RESUMO

BACKGROUND: Significant changes occurd in Daqu bricks on the 15th day of incubation, and brick color (yellow, brown, or dark) is generally used as a standard for quality evaluation by experienced workers. This study aimed to explore the basis behind the phenomenon through multi-omics studies. The physicochemical properties of different high-temperature Daqu were compared. Furthermore, PacBio sequencing and the ultra-high-performance liquid chromatographic-Q-exactive-mass spectrometric approach were employed to analyze the differences in the microbiome and metabolome among different Daqu samples. RESULTS: Bacillus was the biomarker of yellow Daqu, Thermoactinomyces and Thermoascus were the key genera in brown Daqu, and Burkholderiales, Sphingomonas, and Ralstonia were biomarkers in dark Daqu. The physicochemical characteristics (especially the color values) of different high-temperature Daqu showed strong correlations with the bacterial alpha diversity and the relative abundance of dominant bacterial genera. Amino acid metabolism pathways including tryptophan metabolism, ß-alanine metabolism, and arginine biosynthesis were the key factors resulting in the characteristic differences where Bacillus, Burkholderia, Ralstonia, and Sphingomonas were pivotal bacterial genera. The relative abundance of Bacillus had a positive correlation with the content of 3-hydroxykynurenamine, l-glutamic acid, and pantothenic acid, while it showed a negative correlation with indoleacetic acid, l-tryptophan, N-acetylserotonin, l-histidine, l-aspartic acid, phosphatidylserine, 5-methoxyindoleacetate, and L-serine. Burkholderia, Ralstonia, and Sphingomonas had the opposite effects. CONCLUSION: Microbes play different roles in amino acid metabolism pathways, producing different metabolites, contributing to the differences in Daqu appearance and quality. © 2022 Society of Chemical Industry.


Assuntos
Bacillus , Microbiota , Humanos , Fermentação , Temperatura , Bactérias , Bacillus/metabolismo , Aminoácidos/metabolismo
10.
J Sci Food Agric ; 103(1): 273-282, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-35859417

RESUMO

BACKGROUND: Bio-augmented Daqu is used to improve the microbial community and physicochemical parameters of fermented grains, thus affecting the flavor and quality of baijiu. This study investigated the effects of bio-augmented Daqu inoculated with Aspergillus niger NCUF413.1 and Saccharomyces cerevisiae NCUF304.1 on the microbial community, aroma compounds, and physicochemical parameters of fermented grains during special-flavor baijiu brewing. RESULTS: Compared with the control group (CG), the utilization of starch and production of ethanol in the inoculated group (IG) increased by 3.55% and 12.59%, respectively. The use of bio-augmented Daqu changed the bacterial communities. For example, Kroppenstedsia was the dominant bacterial genus (the relative abundance was about 22%) in the CG while Lactobacillus was the main dominant genus (the relative abundance was more than 30%) in the IG on days 20-30. Lactobacillus showed a significant positive correlation with the aroma compounds. The use of bio-augmented Daqu increased the aroma compound content - such as the ethyl heptanoate and ethyl hexanoate content. CONCLUSION: The addition of bio-augmented Daqu with A. niger and S. cerevisiae could change microbial communities, resulting in an increase in the yield of ethanol and the aroma compound content of fermented grains, thus improving the quality of baijiu. © 2022 Society of Chemical Industry.


Assuntos
Microbiota , Odorantes , Odorantes/análise , Fermentação , Bebidas Alcoólicas/análise , Saccharomyces cerevisiae , Bactérias , Lactobacillus , Etanol , China
11.
Methods Mol Biol ; 2555: 13-21, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36306076

RESUMO

Microbial communities play an important role in marine ecosystem processes. Although the number of studies targeting marker genes such as the 16S rRNA gene has increased during the last years, the vast majority of marine diversity are rather unexplored. Moreover, most studies focused on the entire microbial community and thus do not assess the active fraction of the microbial community. Here, we describe a detailed protocol for the simultaneous extraction of DNA and RNA from marine water samples and the generation of cDNA from the isolated RNA that can be used as a universal template in various marker gene studies.


Assuntos
DNA , Microbiota , DNA Complementar/genética , RNA Ribossômico 16S/genética , DNA/genética , Análise de Sequência de DNA , Metagenômica/métodos , Filogenia
12.
Methods Mol Biol ; 2555: 115-123, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36306082

RESUMO

The ability to produce high-value products using bacteria will increasingly rely on continued research to make large-scale bacterial fermentation cost-efficient. Engineering bacteria to use alternate carbon sources as feedstock provides an opportunity to reduce production costs. Using inexpensive carbon sources from various forms of waste provides an opportunity to substantially reduce feedstock costs. Functional carbon metabolism pathways can be identified by the introduction of metagenomic libraries into the organism of interest followed by screening for the desired phenotype. We present here a method to transfer metagenomic libraries from E. coli to Pseudomonas alloputida, followed by screening for use of galactose as a sole carbon source.


Assuntos
Carbono , Microbiota , Carbono/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Metagenoma , Metagenômica , Fermentação
13.
Food Microbiol ; 109: 104138, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36309440

RESUMO

The bacterial diversity and load on equipment in food processing facilities is constantly influenced by raw material, water, air, and staff. Despite regular cleaning and disinfection, some bacteria may persist and thereby potentially compromise food quality and safety. Little is known about how bacterial communities in a new food processing facility gradually establish themselves. Here, the development of bacterial communities in a newly opened salmon processing plant was studied from the first day and during the first year of operation. To focus on the persisting bacterial communities, surface sampling was done on strategical sampling points after cleaning and disinfection. To study the diversity dynamics, isolates from selected sampling and time points were classified by Oxford Nanopore Technology-based rep-PCR amplicon sequencing (ON-rep-seq) supplemented by 16S rRNA gene or rpoD gene sequencing (for Pseudomonas). An overall increase in bacterial numbers was only observed for food-contact surfaces in the slaughter department, but not in filleting department, on non-food contact surfaces or on the fish. Changes in temporal and spatial diversity and community composition were observed and our approach revealed highly point-specific bacterial communities.


Assuntos
Microbiologia de Alimentos , Salmão , Animais , Bactérias , Manipulação de Alimentos , RNA Ribossômico 16S/genética , Microbiota
14.
Food Chem ; 403: 134440, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36183470

RESUMO

Daqu, an indispensable starter, significantly affects the quality and yield of Chinese baijiu. To explore the bioturbation effect of space mutation and biofortification on strong-flavor Daqu, the microbial community, physicochemical properties and overall metabolic profile were investigated. Lactobacillus and Aspergillus were significantly reduced after bioturbation, while seven genera (e.g., Bacillus and Pichia) and five genera (e.g., Enterococcus and Thermomyces) were enriched by space mutation and biofortification, respectively, resulting in improved enzymatic activities. Among the 14 aroma-active volatiles and 51 differential metabolites identified, most had a higher content after bioturbation, including pyrazines, alcohols, small peptides and carbohydrates. Moreover, correlation analysis and integrated metabolic pathway showed that differences in flavor quality among these Daqu were mainly associated with bacterial communities, especially Bacillus, Kroppenstedtia, Thermoactinomyces and Scopulibacillus. These results are useful for elucidating the mechanism of flavor formation in Daqu and promoting the further application of bioturbation technology in the traditional fermentation industry.


Assuntos
Bacillus , Microbiota , Biofortificação , Microbiota/genética , Fermentação , Sequenciamento de Nucleotídeos em Larga Escala , Metabolômica , Bacillus/genética , Mutação
15.
Chemosphere ; 310: 136731, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36209855

RESUMO

Multiple stage anaerobic system was found to be an effective strategy for reductive decolorization of azo dyes in the presence of sulfate. Bulk color removal (56-90%) was achieved concomitant with acidogenic activity in the 1st-stage reactor (R1), while organic matter removal (≤100%) and sulfate reduction (≤100%) occurred predominantly in the 2nd-stage reactor (R2). However, azo dye reduction mechanism and metabolic routes involved remain unclear. The involved microbial communities and conditions affecting the azo dye removal in a two-stage anaerobic digestion (AD) system were elucidated using amplicon sequencing (16S rRNA, fhs, dsrB and mcrA) and correlation analysis. Reductive decolorization was found to be co-metabolic and mainly associated with hydrogen-producing pathways. We also found evidence of the involvement of an azoreductase from Lactococcus lactis. Bacterial community in R1 was sensitive and shifted in the presence of the azo dye, while microorganisms in R2 were more protected. Higher diversity of syntrophic-acetate oxidizers, sulfate reducers and methanogens in R2 highlights the role of the 2nd-stage in organic matter and sulfate removals, and these communities might be involved in further transformations of the azo dye reduction products. The results improve our understanding on the role of different microbial communities in anaerobic treatment of azo dyes and can help in the design of better solutions for the treatment of textile effluents.


Assuntos
Compostos Azo , Microbiota , Compostos Azo/metabolismo , Reatores Biológicos/microbiologia , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo , Corantes/metabolismo , Sulfatos , Redes e Vias Metabólicas
16.
Chemosphere ; 310: 136784, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36241104

RESUMO

With the wide application of nanomaterials (NMs) in agriculture, it is particularly important to assess the impact of these NMs on soil microorganisms. In this study, different varieties of soybean rhizosphere microorganisms (RM) were employed to simulate the alleviate effect of molybdenum nanoparticles (Mo NPs) induced stress in presence of soybean plants. Mo NPs caused serious toxic effects on soybean growth and nitrogen fixation at a concentration of 100 mg kg-1: plant height and biomass were reduced by 56.4% and 82.8%, respectively, and the ability to fix nitrogen was almostly lost. However, after adding different varieties of soybean RM (RM-Williams 82, RM-Youchun 1204, and RM-Zhongdou 41), the stress caused by high concentrations of Mo NPs on soybean plants was significantly reduced. The plant height, root length, biomass, and nitrogen fixation ability were improved by 70.8%, 80.7%, 145.8%, and 349.8%, respectively, following the addition of soybean RM-Williams 82. High-throughput sequencing revealed that Mo NPs treatment affected the microbial community structure. Among them, Flavisolibacter and Caulobacter genera abundance increased significantly, which might be the key factor in relieving Mo NPs-induced stress on soybean growth. These findings suggest a novel mode of RM as a promising strategy to prevent deleterious effects of stress with NPs on plants in the future.


Assuntos
Fabaceae , Microbiota , Nanoestruturas , Rizosfera , Solo/química , Soja , Microbiologia do Solo , Molibdênio/farmacologia , Nanoestruturas/toxicidade
17.
Chemosphere ; 310: 136864, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36243085

RESUMO

Bioconversion is an important method for transforming food waste (FW) into high value-added products, rendering it harmless, and recycling resources. An artificial microbial consortium (AMC) was constructed to produce FW-based lipopeptides in order to investigate the strategy of FW bioconversion into value-added products. Exogenous fatty acids as a precursor significantly improved the lipopeptide production of Bacillus amyloliquefaciens HM618. To enhance fatty acid synthesis and efflux in AMC, the recombinant Yarrowia lipolytica YL21 (strain YL21) was constructed by screening 12 target genes related to fatty acids to replace exogenous fatty acids in order to improve lipopeptide production. The levels of fengycin, surfactin, and iturin A in the AMC of strains HM618 and YL21 reached 76.19, 192.80, and 31.32 mg L-1, increasing 7.24-, 12.13-, and 3.23-fold compared to the results from the pure culture of strain HM618 in flask with Landy medium, respectively. Furthermore, free fatty acids were almost undetectable in the co-culture of strains HM618 and YL21, although its level was around 1.25 g L-1 in the pure culture of strain YL21 with Landy medium. Interestingly, 470.24 mg L-1 of lipopeptides and 18.11 g L-1 of fatty acids were co-produced in this AMC in a bioreactor with FW medium. To our knowledge, it is the first report of FW biotransformation into co-produce of lipopeptides and fatty acids in the AMC of B. amyloliquefaciens and Y. lipolytica. These results provide new insights into the biotransformation potential of FW for value-added co-products by AMC.


Assuntos
Bacillus amyloliquefaciens , Microbiota , Eliminação de Resíduos , Yarrowia , Bacillus amyloliquefaciens/genética , Bacillus amyloliquefaciens/metabolismo , Yarrowia/genética , Yarrowia/metabolismo , Ácidos Graxos/metabolismo , Alimentos , Lipopeptídeos
18.
Chemosphere ; 310: 136854, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36243093

RESUMO

High ammonia concentration hinders the efficient treatment of antibiotic production wastewater (APW). Developing effective ammonia oxidation wastewater treatment strategies is an ideal approach for facilitating APW treatment. Compared with traditional nitrification strategies, the partial nitrification process is more eco-friendly, less energy-intensive, and less excess sludge. The primary limiting factor of the partial nitrification process is increasing ammonia-oxidizing bacteria (AOB) while decreasing nitrite-oxidizing bacteria (NOB). In this study, an efficient AOB microbiota (named AF2) was obtained via enrichment of an aerobic activated sludge (AS0) collected from a pharmaceutical wastewater treatment plant. After a 52-day enrichment of AS0 in 250 mL flasks, the microbiota AE1 with 69.18% Nitrosomonas microorganisms was obtained. Subsequent scaled-up cultivation in a 10 L fermenter led to the AF2 microbiota with 59.22% Nitrosomonas. Low concentration of free ammonia (FA, < 42.01 mg L-1) had a negligible effect on the activity of AF2, and the nitrite-nitrogen accumulation rate (NAR) of AF2 was 98% when FA concentration was 42.01 mg L-1. The specific ammonia oxidation rates (SAORs) at 30 °C and 15 °C were 3.64 kg NH4+-N·kg MLVSS-1·d-1 and 1.43 kg NH4+-N·kg MLVSS-1·d-1 (MLVSS: mixed liquor volatile suspended solids). The SAOR was 0.52 kg NH4+-N·kg MLVSS-1·d-1 when the NaCl concentration was increased from 0 to 20 g L-1, showing that AF2 functioning was stable in a high-level salt environment. The ammonia oxidation performance of AF2 was verified by treating abamectin and lincomycin production wastewater. The NARs of AF2 used for abamectin and lincomycin production wastewater treatment were >90% and the SAORs were 2.39 kg NH4+-N·kg MLVSS-1·d-1 and 0.54 kg NH4+-N·kg MLVSS-1·d-1, respectively, which was higher than the traditional biological denitrification process. In summary, AF2 was effective for APW treatment via enhanced ammonia removal efficiency, demonstrating great potential for future industrial wastewater treatment.


Assuntos
Amônia , Microbiota , Águas Residuárias , Esgotos/microbiologia , Nitritos , Antibacterianos , Furilfuramida , Nitrificação , Nitrosomonas , Reatores Biológicos/microbiologia , Nitrogênio , Oxirredução , Lincomicina
19.
Chemosphere ; 310: 136829, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36265712

RESUMO

Urbanization has dramatically changed the quality and quantity of dissolved organic matter (DOM) fluxes in rivers, thereby affecting the diversity and lifestyle strategies of microbial communities. However, relationships between DOM molecular composition and microbial lifestyle strategies in effluent-dominated rivers are poorly understood. Herein, we investigated the variations in DOM structure and composition of an effluent-dominated river and further revealed how these changes alter the abundance and lifestyle strategies of microbial communities. Results demonstrated that macromolecular (MW > 35 kDa) humic-like substances constituted the major components of effluent-dominated riverine DOM. Also, due to the degradation of humic-like substances, the accumulation of protein-like substances was observed from upstream to downstream areas, corresponding to an apparent decrease in overall aromaticity. The abundance of bacterial, Actinobacteria, and eukaryotic was higher in the upstream and midstream areas but relatively lower in the downstream area. The response of bacterial and Actinobacteria communities to the changes in DOM composition was more prominent as compared to that of eukaryotic. Based on multivariate statistical analysis, the decrease in aromatic components (MW > 35 kDa) was mainly attributed to the degradation of Proteobacteria and Actinobacteria (K-strategists), resulting in a decrease in their relative abundance along the river course. Proteins and polysaccharides (15 kDa < MW < 35 kDa, MW < 6 kDa) were more easily utilized by Firmicutes and Bacteroidetes (r-strategists), leading to an increase in their relative abundance. With the decrease of macromolecular humic-like substances and the increase of protein-like substances, river microbial communities shifted from K-strategists to r-strategists. This work unveils the evolution of DOM in an effluent-dominated river and the influence of the degradation of macromolecular humic-like substances on r/K-strategists.


Assuntos
Matéria Orgânica Dissolvida , Microbiota , Rios/química , Substâncias Húmicas/análise , Urbanização , Bactérias , Espectrometria de Fluorescência/métodos
20.
Chemosphere ; 310: 136916, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36272620

RESUMO

High health risks of vanadium (V) released by the mining of vanadium titanomagnetite (VTM) have been widely recognized, but little is known about the risks and microbial community responses of V pollution as a consequence of the stone coal mining (SCM), another important resource for V mining. In this study, the topsoils and the profile soils were collected from the agricultural soils around a typical SCM in Hunan Province, China, with the investigation of ecological, health risks and microbial community structures. The results showed that ∼97.6% of sampling sites had levels of total V exceeding the Chinese National standard (i.e., 130 mg/kg), and up to 41.1% of V speciation in the topsoils was pentavalent vanadium (V(V)). Meanwhile, the proportions of HQ > 1 and 0.6-1 in the topsoils were ∼8.3% and ∼31.0% respectively, indicating that V might pose a non-carcinogenic risk to children. In addition, the microbial community varied between the topsoils and the profile soils. Both sulfur-oxidizing bacteria (e.g. Thiobacillus, MND1, Ignavibacterium) and sulfate-reducing bacteria (e.g. Desulfatiglans, GOUTB8, GOUTA6) might have been involved in V(V) reductive detoxification. This study helps better understand the pollution and associated risks of V in the soils of SCM and provides a potential strategy for bioremediation of the V-contaminated environment.


Assuntos
Minas de Carvão , Microbiota , Poluentes do Solo , Criança , Humanos , Solo/química , Vanádio/análise , Poluentes do Solo/análise , Mineração , Biodegradação Ambiental , Medição de Risco , Bactérias , China , Monitoramento Ambiental
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