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1.
Environ Pollut ; 346: 123704, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38442823

RESUMO

East Yunnan province in southwest China is a region with elevated natural abundance (high geological background levels) of Cd due to high metal (loid) contents in the soils. Enzyme activities are useful indicators of metal (loid) toxicity in contaminated soils and whether Cd inhibits enzyme activities in paddy soils in high geological background areas is of considerable public concern. A pot experiment combined with field investigation was conducted to assess the effects of Cd on six soil enzymes that are essential to the cycling of C, N, and P in soils. Inhibitory effects of Cd fractions on enzyme activities were assessed using ecological dose-response models. The impact of soil properties on the inhibition of sensitive soil enzymes by Cd were assessed using linear and structural equation models. Cadmium was enriched in the paddy soils with 72.2 % of soil samples from high geological background areas exceeding the Chinese threshold values (GB 15618-2018) of Cd. Enzyme responses to Cd contamination varied markedly with a negative response by catalase but a positive response by invertase. Urease, ß-glucosidase, and alkaline phosphatase activities were stimulated at low Cd concentrations and inhibited at high concentrations. The average inhibition ratios of ß-glucosidase, urease, and catalase in high Cd levels were 19.9, 38.9, and 51.9%, respectively. Ecological dose-response models indicate that catalase and urease were the most Cd-sensitive of the enzymes studied and were suitable indicators of soil quality in high geological background areas. Structural equation modeling (SEM) indicates that soil properties influenced sensitive enzymes through various pathways, indicating that soil properties were factors determining Cd inhibition of enzyme activities. This suggests that Cd concentrations and soil physicochemical properties under a range of environmental conditions should be considered in addressing soil Cd pollution.


Assuntos
Celulases , Oryza , Poluentes do Solo , Cádmio/análise , Solo/química , Catalase , Urease/metabolismo , Poluentes do Solo/análise , China , Oryza/metabolismo
2.
Antonie Van Leeuwenhoek ; 117(1): 58, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38502333

RESUMO

Genes flbA-E are involved in sporulation and vegetative growth in Aspergillus nidulans. Inactivation of either of these genes results in a fluffy phenotype with delayed or even abolished sporulation. Previously, a non-sporulating phenotype was obtained by inactivating flbA in Aspergillus niger, which was accompanied by lysis, thinner cell walls, and an increased secretome complexity. Here, we further studied the role of the flb genes of A. niger. Strains ΔflbA, ΔflbB and ΔflbE showed increased biomass formation, while inactivation of flbA-D reduced, or even abolished, formation of conidia. Strain ΔflbA was more sensitive to H2O2, DTT, and the cell wall integrity stress compounds SDS and Congo Red (CR). Also, ΔflbC was more sensitive to SDS, while ΔflbB, ΔflbD, and ΔflbE were more sensitive to CR. On the other hand, inactivation of flbE increased resistance to H2O2. Enzyme secretion was impacted when the Δflb strains were grown on xylose. Strain ΔflbE showed reduced xylanase, cellulase and amylase secretion. On the other hand, amylase secretion at the periphery of the ΔflbA colony was reduced but not in its center, while secretion of this enzyme was increased in the center of the ΔflbB colony but not at its periphery. Inactivation of flbC and flbD also impacted zonal cellulase and amylase activity. Together, the Flb protein family of A. niger function in biomass formation, sporulation, stress response, and protein secretion.


Assuntos
Aspergillus niger , Celulases , Animais , Aspergillus niger/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Peróxido de Hidrogênio/metabolismo , Estágios do Ciclo de Vida , Celulases/metabolismo , Amilases/metabolismo , Esporos Fúngicos
3.
Microb Cell Fact ; 23(1): 73, 2024 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-38431598

RESUMO

BACKGROUND: Lignocellulosic biomass provides a great starting point for the production of energy, chemicals, and fuels. The major component of lignocellulosic biomass is cellulose, the employment of highly effective enzymatic cocktails, which can be produced by a variety of microorganisms including species of the genus Aspergillus, is necessary for its utilization in a more productive manner. In this regard, molecular biology techniques should be utilized to promote the economics of enzyme production, whereas strategies like protoplast fusion could be employed to improve the efficacy of the hydrolytic process. RESULTS: The current study focuses on cellulase production in Aspergillus species using intrageneric protoplast fusion, statistical optimization of growth parameters, and determination of antioxidant activity of fermentation hydrolysate. Protoplast fusion was conducted between A. flavus X A. terreus (PFFT), A. nidulans X A. tamarii (PFNT) and A. oryzae X A. tubingensis (PFOT), and the resultant fusant PFNT revealed higher activity level compared with the other fusants. Thus, this study aimed to optimize lignocellulosic wastes-based medium for cellulase production by Aspergillus spp. fusant (PFNT) and studying the antioxidant effect of fermentation hydrolysate. The experimental strategy Plackett-Burman (PBD) was used to assess how culture conditions affected cellulase output, the best level of the three major variables namely, SCB, pH, and incubation temperature were then determined using Box-Behnken design (BBD). Consequently, by utilizing an optimized medium instead of a basal medium, cellulase activity increased from 3.11 U/ml to 7.689 U/ml CMCase. The following medium composition was thought to be ideal based on this optimization: sugarcane bagasse (SCB), 6.82 gm; wheat bran (WB), 4; Moisture, 80%; pH, 4; inoculum size, (3 × 106 spores/ml); and incubation Temp. 31.8 °C for 4 days and the fermentation hydrolysate has 28.13% scavenging activities. CONCLUSION: The results obtained in this study demonstrated the significant activity of the selected fusant and the higher sugar yield from cellulose hydrolysis over its parental strains, suggesting the possibility of enhancing cellulase activity by protoplast fusion using an experimental strategy and the fermentation hydrolysate showed antioxidant activity.


Assuntos
Celulase , Celulases , Saccharum , Celulose/metabolismo , Protoplastos/metabolismo , Antioxidantes , Saccharum/metabolismo , Aspergillus/metabolismo , Fermentação , Celulase/química , Hidrólise
4.
Antonie Van Leeuwenhoek ; 117(1): 33, 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38334837

RESUMO

Plant probiotics are live microbial cells or cultures that support plant growth and control plant pathogens through different mechanisms. They have various effects on plants, including plant growth promotion through the production of indole acetic acid (IAA), biological control activity (BCA), and production of cellulase enzymes, thus inducing systemic resistance and increasing the availability of mineral elements. The present work aimed to study the potential of Achromobacter marplatensis and Bacillus velezensis as plant probiotics for the field cultivation of potatoes. In vitro studies have demonstrated the ability of selected probiotics to produce IAA and cellulase, as well as antimicrobial activity against two plant pathogens that infect Solanum tuberosum as Fusarium oxysporum and Ralstonia solanacearum under different conditions at a broad range of different temperatures and pH values. In vivo study of the effects of the probiotics A. marplatensis and B. velezensis on S. tuberosum plants grown in sandy clay loamy soil was detected after cultivation for 90 days. Probiotic isolates A. marplatensis and B. velezensis were able to tolerate ultraviolet radiation (UV) exposure for up to two hours, the dose response curve exhibited that the D10 values of A. marplatensis and B. velezensis were 28 and 16 respectively. In the case of loading both probiotics with broth, the shoot dry weight was increased significantly from 28 in the control to 50 g, shoot length increased from 24 to 45.7 cm, branches numbers increased from 40 to 70 branch, leaves number increased from 99 to 130 leaf, root dry weight increased from 9.3 to 12.9 g, root length increased from 24 to 35.7 cm, tuber weight increased from 15 to 37.0 g and tubers number increased from 9 to 24.4 tuber, the rot percentage was reduced to 0%. The addition of both probiotic isolates, either broth or wheat grains load separately has enhanced all the growth parameters; however, better results and increased production were in favor of adding probiotics with broth more than wheat. On the other hand, both probiotics showed a remarkable protective effect against potato pathogens separately and reduced the negative impact of the infection using them together.


Assuntos
Celulases , Fusarium , Ralstonia solanacearum , Solanum tuberosum , Raios Ultravioleta , Plantas , Celulases/farmacologia , Doenças das Plantas/prevenção & controle
5.
FEMS Yeast Res ; 242024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38400543

RESUMO

Successful conversion of cellulosic biomass into biofuels requires organisms capable of efficiently utilizing xylose as well as cellodextrins and glucose. Ogataea (Hansenula) polymorpha is the natural xylose-metabolizing organism and is one of the most thermotolerant yeasts known, with a maximum growth temperature above 50°C. Cellobiose-fermenting strains, derivatives of an improved ethanol producer from xylose O. polymorpha BEP/cat8∆, were constructed in this work by the introduction of heterologous genes encoding cellodextrin transporters (CDTs) and intracellular enzymes (ß-glucosidase or cellobiose phosphorylase) that hydrolyze cellobiose. For this purpose, the genes gh1-1 of ß-glucosidase, CDT-1m and CDT-2m of cellodextrin transporters from Neurospora crassa and the CBP gene coding for cellobiose phosphorylase from Saccharophagus degradans, were successfully expressed in O. polymorpha. Through metabolic engineering and mutagenesis, strains BEP/cat8∆/gh1-1/CDT-1m and BEP/cat8∆/CBP-1/CDT-2mAM were developed, showing improved parameters for high-temperature alcoholic fermentation of cellobiose. The study highlights the need for further optimization to enhance ethanol yields and elucidate cellobiose metabolism intricacies in O. polymorpha yeast. This is the first report of the successful development of stable methylotrophic thermotolerant strains of O. polymorpha capable of coutilizing cellobiose, glucose, and xylose under high-temperature alcoholic fermentation conditions at 45°C.


Assuntos
Celulases , Saccharomycetales , Celobiose/metabolismo , Temperatura , Fermentação , Xilose/metabolismo , Saccharomycetales/metabolismo , Etanol/metabolismo , Engenharia Metabólica , Glucose
6.
Bioresour Technol ; 397: 130490, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38403168

RESUMO

This study aimed to increase the value of brewers' spent grain (BSG) by using it as feedstock to produce lignocellulolytic enzymes and lactic acid (LA). Twenty-two fungal strains were screened for lignocellulolytic enzyme production from BSG. Among them, Trichoderma sp. showed the highest cellulase activity (35.84 ± 0.27 U/g-BSG) and considerably high activities of xylanase (599.61 ± 23.09 U/g-BSG) and ß-glucosidase (16.97 ± 0.77 U/g-BSG) under successive solid-state and submerged fermentation. The processes were successfully scaled up in a bioreactor. The enzyme cocktail was recovered and characterized. The maximum cellulase and xylanase activities were found at pH 5.0 and 50 °C, and the activities were highly stable at pH 4-8 and 30-50 °C. The enzyme cocktail was applied in simultaneous saccharification and fermentation of acid-pretreated BSG for LA production. The maximum LA obtained was 59.3 ± 1.0 g/L. This study has shown the efficient biovalorization of BSG, and this approach may also be applicable to other agro-industrial wastes.


Assuntos
Celulases , Ácido Láctico , Fermentação , Reatores Biológicos , Resíduos Industriais/análise , Grão Comestível/química
7.
J Agric Food Chem ; 72(10): 5428-5438, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38415591

RESUMO

Food-fermenting lactobacilli convert glycosylated phytochemicals to glycosyl hydrolases and thereby alter their biological activity. This study aimed to investigate the microbial transformation of ß-glucosides of phytochemicals in comparison with utilization of cellobiose. Four homofermentative and four heterofermentative lactobacilli were selected to represent the metabolic diversity of Lactobacillaceae. The genomes of Lactobacillus crispatus, Companilactobacillus paralimentarius, Lacticaseibacillus paracasei, and Lactiplantibacillus plantarum encoded for 8 to 22 enzymes, predominantly phospho-ß-glucosidases, with predicted activity on ß-glucosides. Levilactobacillus hammesii and Furfurilactobacillus milii encoded for 3 ß-glucosidases, Furfurilactobacillus rossiae for one, and Fructilactobacillus sanfranciscensis for none. The hydrolysis of amygdalin, esculin, salicin, glucosides of quercetin and genistein, and ginsenosides demonstrated that several strains hydrolyzed ß-glucosides of phytochemicals but not cellobiose. Taken together, several of the carbohydrate-active enzymes of food-fermenting lactobacilli are specific for glycosides of phytochemicals.


Assuntos
Celulases , Dissacarídeos , Glucosídeos/metabolismo , Lactobacillaceae/metabolismo , Celobiose , Compostos Fitoquímicos
8.
BMC Vet Res ; 20(1): 61, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38378526

RESUMO

BACKGROUND: As the foal grows, the amount of breast milk produced by the donkey decreases. In such cases, early supplemental feeding is particularly important to meet the growth needs of the foal. Foals have an incompletely developed gastrointestinal tract with a homogenous microbiota and produce insufficient amounts of digestive enzymes, which limit their ability to digest and utilize forage. Improving the utilization of early supplemental feeds, promoting gastrointestinal tract development, and enriching microbial diversity are the hotspots of rapid growth research in dairy foals. Plant-based feeds usually contain non-starch polysaccharides (NSPs), including cellulose, xylan, mannan, and glucan, which hinder nutrient digestion and absorption. In addition, proteins and starch (both biomolecules) form a composite system mainly through non-covalent interactions. The proteins wrap around the surface of starch granules and act as a physical obstacle, thereby inhibiting water absorption and expansion of starch and decreasing the enzyme's catalytic effect on starch. Glyanase, ß-mannanase, ß-glucanase, cellulase, protease, and amylase added to cereal diets can alleviate the adverse effects of NSPs. The current study determined the effects of adding multienzymes (glyanase, ß-mannanase, ß-glucanase, cellulase, protease, and amylase) to the diet of 2-month-old suckling donkeys on their growth performance, apparent nutrient digestibility, fecal volatile fatty acid (VFA) and pH, fecal bacterial composition, and blood biochemical indices. RESULTS: On day 120 of the trial, fecal samples were collected from the rectum of donkeys for determining bacterial diversity, VFA content, and pH. Moreover, fresh fecal samples were collected from each donkey on days 110 and 115 to determine apparent digestibility. The multienzymes supplementations did not affect growth performance and apparent nutrient digestibility in the donkeys; however, they tended to increase total height gain (P = 0.0544). At the end of the study, the multienzymes supplementations increased (P < 0.05) the Observed species, ACE, Chao1, and Shannon indices by 10.56%, 10.47%, 10.49%, and 5.01%, respectively. The multienzymes supplementations also increased (P < 0.05) the abundance of Firmicutes, Oscillospiraceae, Lachnospiraceae, Christensenellaceae, Christensenellaceae_R-7_group, and Streptococcus in feces, whereas decreased (P = 0.0086) the abundance of Proteobacteria. CONCLUSIONS: Multienzymes supplementations added to a basal diet for suckling donkeys can increase fecal microbial diversity and abundance.


Assuntos
Celulases , Digestão , Humanos , Feminino , Cavalos , Animais , Equidae , beta-Manosidase/análise , beta-Manosidase/farmacologia , Dieta/veterinária , Fezes/microbiologia , Amilases , Amido/metabolismo , Nutrientes , Ácidos Graxos Voláteis/metabolismo , Peptídeo Hidrolases , Celulases/análise , Celulases/farmacologia , Ração Animal/análise
9.
Biomolecules ; 14(2)2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38397385

RESUMO

The regulation of plant biomass degradation by fungi is critical to the carbon cycle, and applications in bioproducts and biocontrol. Trichoderma harzianum is an important plant biomass degrader, enzyme producer, and biocontrol agent, but few putative major transcriptional regulators have been deleted in this species. The T. harzianum ortholog of the transcriptional activator XYR1/XlnR/XLR-1 was deleted, and the mutant strains were analyzed through growth profiling, enzymatic activities, and transcriptomics on cellulose. From plate cultures, the Δxyr1 mutant had reduced growth on D-xylose, xylan, and cellulose, and from shake-flask cultures with cellulose, the Δxyr1 mutant had ~90% lower ß-glucosidase activity, and no detectable ß-xylosidase or cellulase activity. The comparison of the transcriptomes from 18 h shake-flask cultures on D-fructose, without a carbon source, and cellulose, showed major effects of XYR1 deletion whereby the Δxyr1 mutant on cellulose was transcriptionally most similar to the cultures without a carbon source. The cellulose induced 43 plant biomass-degrading CAZymes including xylanases as well as cellulases, and most of these had massively lower expression in the Δxyr1 mutant. The expression of a subset of carbon catabolic enzymes, other transcription factors, and sugar transporters was also lower in the Δxyr1 mutant on cellulose. In summary, T. harzianum XYR1 is the master regulator of cellulases and xylanases, as well as regulating carbon catabolic enzymes.


Assuntos
Celulases , Hypocreales , Biomassa , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Fatores de Transcrição/metabolismo , Perfilação da Expressão Gênica , Hypocreales/metabolismo , Celulose , Carbono
10.
Sensors (Basel) ; 24(3)2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38339480

RESUMO

Interest in enzymes capable of neutralizing various mycotoxins is quite high. The methods used for the screening and selection of enzymes that catalyze the detoxification of mycotoxins should be sensitive and fast. However toxic compounds can be generated under the action of such enzymes. Thus, the assessment of the overall reduction in the toxic properties of reaction media towards bioluminescent bacteria seems to be the most reasonable control method allowing a quick search for the effective enzymatic biocatalysts. The influence of a wide range of mycotoxins and glucanases, which hydrolyze toxins with different chemical structures, on the analytical characteristics of luminescent photobacteria as a biosensing element has been studied. Different glucanases (ß-glucosidase and endoglucanase) were initially selected for reactions with 10 mycotoxins based on the results of molecular docking which was performed in silico with 20 mycotoxins. Finally, the biorecognizing luminescent cells were used to estimate the residual toxicity of reaction media with mycotoxins after their interaction with enzymes. The notable non-catalytic decrease in toxicity of media containing deoxynivalenol was revealed with luminous cells for both types of tested glucanases, whereas ß-glucosidase provided a significant catalytic detoxification of media with aflatoxin B2 and zearalenone at pH 6.0.


Assuntos
Celulases , Micotoxinas , Micotoxinas/análise , Biomarcadores Ambientais , Simulação de Acoplamento Molecular , Bactérias
11.
Environ Int ; 184: 108467, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38310815

RESUMO

Heavy metal (HM) enrichment is closely related to soil organic carbon (SOC) pools in terrestrial ecosystems, which are deeply intertwined with soil microbial processes. However, the influence of HMs on SOC remains contentious in terms of magnitude and direction. A global analysis of 155 publications was conducted to integrate the synergistic responses of SOC and microorganisms to HM enrichment. A significant increase of 13.6 % in SOC content was observed in soils exposed to HMs. The response of SOC to HMs primarily depends on soil properties and habitat conditions, particularly the initial SOC content, mean annual precipitation (MAP), initial soil pH, and mean annual temperature (MAT). The presence of HMs resulted in significant decreases in the activities of key soil enzymes, including 31.9 % for soil dehydrogenase, 24.8 % for ß-glucosidase, 35.8 % for invertase, and 24.3 % for cellulose. HMs also exerted inhibitory effects on microbial biomass carbon (MBC) (26.6 %), microbial respiration (MR) (19.7 %), and the bacterial Shannon index (3.13 %) but elevated the microbial metabolic quotient (qCO2) (20.6 %). The HM enrichment-induced changes in SOC exhibited positive correlations with the response of MBC (r = 0.70, p < 0.01) and qCO2 (r = 0.50, p < 0.01), while it was negatively associated with ß-glucosidase activity (r = 0.72, p < 0.01) and MR (r = 0.39, p < 0.01). These findings suggest that the increase in SOC storage is mainly attributable to the inhibition of soil enzymes and microorganisms under HM enrichment. Overall, this meta-analysis highlights the habitat-dependent responses of SOC to HM enrichment and provides a comprehensive evaluation of soil carbon dynamics in an HM-rich environment.


Assuntos
Celulases , Metais Pesados , Carbono/metabolismo , Solo/química , Ecossistema , Microbiologia do Solo , Metais Pesados/toxicidade , Metais Pesados/análise
12.
Microbiol Spectr ; 12(3): e0371023, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38294247

RESUMO

Hot springs are potential sources of diverse arrays of microbes and their thermostable hydrolytic enzymes. Water and sediment samples were collected from three hot springs of Ethiopia and enriched on nutrient and thermus agar media to isolate pure cultures of potential microbes. A total of 252 bacterial isolates were screened and evaluated for the production of amylase, protease, cellulase, and lipase. About 95.23%, 84.12%, 76.58%, and 65.07% of the isolates displayed promising amylase, proteases, cellulase, and lipase activities, respectively. Based on the diameter of the clear zone formed, 45 isolates were further screened and identified to species level using matrix-assisted laser desorption/ionization time-of-flight-mass spectrometry analysis and 16S rRNA gene sequencing. Five of the 45 isolates showed significantly high (P < 0.05) clear zone ratios as compared to others. The identified isolates were categorized under five bacterial species, namely, Bacillus licheniformis, Bacillus cereus, Paenibacillus thiaminolyticus, Paenibacillus dendritiformis, and Brevibacillus borstelensis. The most dominant species (66.7%) was B. licheniformis. It could be concluded that hot springs of Ethiopia are potential sources of thermostable extracellular hydrolytic enzymes for various industrial applications. Further optimization of the growth conditions and evaluation for better productivity of the desired products is recommended before attempting for large-scale production of the hydrolytic enzymes. IMPORTANCE: Thermostable microbial enzymes play an important role in industries due to their stability under harsh environmental conditions, including extreme temperatures. Despite their huge application in different industries, however, the thermostable enzymes of thermophilic microorganism origin have not yet been fully explored in Ethiopia. Here, we explored thermophilic bacteria and their enzymes from selected hot spring water and sediment samples. Accordingly, thermophilic bacteria were isolated and screened for the production of extracellular hydrolytic enzymes. Promising numbers of isolates were found as producers of the enzymes. The potent enzyme producers were further identified using matrix-assisted laser desorption/ionization time-of-flight-mass spectrometry analysis and 16S rRNA gene sequencing. The findings revealed the presence of potential hydrolytic enzyme-producing thermophilic bacteria in hot springs of Ethiopia and necessitate further comprehensive study involving other extreme environments. Our findings also revealed the potential of Ethiopian hot springs in the production of thermostable enzymes of significant application in different industries, including food industries.


Assuntos
Celulases , Fontes Termais , Fontes Termais/microbiologia , RNA Ribossômico 16S/genética , Etiópia , Lipase , Peptídeo Hidrolases , Endopeptidases , Amilases , Água
13.
Sci Total Environ ; 918: 170295, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38278240

RESUMO

Microbial anabolism and catabolism regulate the accumulation and dynamics of soil organic carbon (SOC). However, very little attention has been paid to the role of microbial functional traits in the accumulation and dynamics of SOC in forest soils. In this study, nine forest soils were selected at three altitudes (600 m, 1200 m, and 1500 m) and three soil depths (0-15 cm, 15-30 cm, and 30-45 cm) located in Jiugong Mountain. Vertical traits of functional genes encoding microbial carbohydrate-active enzymes (CAZymes) were observed using metagenomic sequencing. Soil amino sugars were used as biomarkers to indicate microbial residue carbon (MRC). The results showed that GH1 (ß-glucosidase: 147.49 TPM) and GH3 (ß-glucosidase: 109.09 TPM) were the dominant genes for plant residue decomposition, and their abundance increased with soil depth and peaked in the deep soil at 600 m (GH1: 147.89 TPM; GH3: 109.59 TPM). The highest abundance of CAZymes for fungal and bacterial residue decomposition were GH18 (chitinase: 30.81 TPM) and GH23 (lysozyme: 58.02 TPM), respectively. The abundance of GH18 increased with soil depth, while GH23 showed the opposite trend. Moreover, MRC accumulation was significantly positively correlated with CAZymes involved in the degradation of hemicellulose (r = 0.577, p = 0.002). Compared with the soil before incubation, MRC in the topsoil at the low and middle altitudes after incubation increased by 4 % and 8 %, respectively, while MRC in the soils at 1500 m tended to decrease (p > 0.05). The mineralization capacity of SOC at 1500 m was significantly higher than that at 1200 m and 600 m (p < 0.05). Our results suggested that microbial function for degrading plant residue components, especially hemicellulose and lignin, contributed greatly to SOC accumulation and dynamics. These results were vital for understanding the roles of microbial functional traits in C cycling in forest.


Assuntos
Carbono , Celulases , Carbono/química , Solo/química , Microbiologia do Solo , Florestas , Carboidratos
14.
Ecotoxicol Environ Saf ; 271: 115968, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38218107

RESUMO

The physicochemical properties, chemical fractions of six metals (Cu, Zn, Pb, Cd, Cr, and Mn), and microbial communities of soil around a typical sanitary landfill were analyzed. The results indicate that soils around the landfill were from neutral to weak alkalinity. The contents of organic matter (OM), total nitrogen (TN), total phosphorous (TP), and activities of catalase, cellulase, and urease were significantly higher in landfill soils than those in background soils. Negative correlations were found between pH and metals. Cr was the dominant metal. Cu, Pb, Cr, and Mn were accumulated in the nearby farmland soils. Cd had the highest percentage of exchangeable fraction (33.7%-51.8%) in landfill and farmland soils, suggesting a high bioavailability to the soil environment affected by the landfill. Pb, Cr, and Mn existed mostly in oxidable fraction, and Cu and Zn were dominant in residual fraction. There was a low risk of soil metals around the landfill based on the RI values, while according to RAC classification, Cd had high to very high environmental risk. The MisSeq sequencing results showed that Actinobacteria, Proteobacteria, Chloroflexi, and Acidobacteria were the dominant phyla of bacteria, and the most abundant phylum of fungi was Ascomycota. The NMDS analysis revealed that the landfill could influence soil fungal communities more intensely than bacterial communities. TN, cellulase, and bioavailable metals (Pb-Bio and Cr-Bio) were identified to have main influences on microbial communities. Pb-Bio was the most dominant driving factor for bacterial community structures. For fungi, Pb-Bio was significantly negatively related to Olpidiomycota and Cr-Bio had a significantly negative correlation with Ascomycota. It manifests that bioavailable metals play important roles in assessing environmental risks and microbial community structures of soil around landfill.


Assuntos
Celulases , Metais Pesados , Microbiota , Poluentes do Solo , Solo/química , Metais Pesados/toxicidade , Metais Pesados/análise , Cádmio/análise , Chumbo/análise , Poluentes do Solo/toxicidade , Poluentes do Solo/análise , Bactérias/genética , Fungos , Instalações de Eliminação de Resíduos , Medição de Risco , China , Monitoramento Ambiental
15.
Adv Protein Chem Struct Biol ; 138: 211-231, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38220425

RESUMO

The cellulases are among the most used enzyme in industries for various purposes. They add up to the green economy perspective and cost-effective production of enterprises. Biorefineries, paper industries, and textile industries are foremost in their usage. The production of endoglucanases from microorganisms is a valuable resource and can be exploited with the help of biotechnology. The present review provides some insight into the uses of endoglucanases in different industries and the potent fungal source of these enzymes. The advances in the enzyme technology has helped towards understanding some pathways to increase the production of industrial enzymes from microorganisms. The proteomics analysis and systems biology tools also help to identify these pathways for the enhanced production of such enzymes. This review deciphers the use of proteomics tools to analyze the potent microorganisms and identify suitable culture conditions to increase the output of endoglucanases. The review also includes the role of quantitative proteomics which is a powerful technique to get results faster and more timely. The role of metatranscriptomic approaches are also described which are helpful in the enzyme engineering for their efficient use under industrial conditions. Conclusively, this review helps to understand the challenges faced in the industrial use of endoglucanases and their further improvement.


Assuntos
Celulase , Celulases , Celulase/metabolismo , Proteômica , Celulases/metabolismo , Biotecnologia
16.
J Phys Chem B ; 128(3): 635-647, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38227769

RESUMO

Enzymatic degradation of cellulosic biomass is a well-established route for the sustainable production of biofuels, chemicals, and materials. A strategy employed by nature and industry to achieve an efficient degradation of cellulose is that cellobiohydrolases (or exocellulases), such as Cel7A, work synergistically with endoglucanases, such as Cel7B, to achieve the complete degradation of cellulose. However, a complete mechanistic understanding of this exo-endo synergy is still lacking. Here, we used single-molecule fluorescence microscopy to quantify the binding kinetics of Cel7A on cellulose when it is acting alone on the cellulose fibrils and in the presence of its synergy partner, the endoglucanase Cel7B. To this end, we used a fluorescently tagged Cel7A and studied its binding in the presence of the unlabeled Cel7B. This provided the single-molecule data necessary for the estimation of the rate constants of association kON and dissociation kOFF of Cel7A for the substrate. We show that the presence of Cel7B does not impact the dissociation rate constant, kOFF. But, the association rate of Cel7A decreases by a factor of 2 when Cel7B is present at a molar proportion of 10:1. This ratio has previously been shown to lead to synergy. This decrease in association rate is observed in a wide range of total enzyme concentrations, from sub nM to µM concentrations. This decrease in kON is consistent with the formation of cellulase clusters recently observed by others using atomic force microscopy.


Assuntos
Celulase , Celulases , Trichoderma , Hidrólise , Celulose/química , Celulases/química , Celulase/metabolismo , Celulose 1,4-beta-Celobiosidase/metabolismo
17.
Prep Biochem Biotechnol ; 54(1): 19-38, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37149786

RESUMO

Fifty percent of the overall operational expenses of biorefineries are incurred during enzymatic-saccharification processes. Cellulases have a global-market value of $1621 USD. Dearth of conventional lignocelluloses have led to the exploration of their waste stream-based, unconventional sources. Native fungus-employing cellulase-production batches fail to yield sustained enzyme titers. It could be attributed to variations in the enzyme-production broth's quasi-dilatant behavior, its fluid and flow properties; heat and oxygen transfer regimes; kinetics of fungal growth; and nutrient utilization. The current investigation presents one of the first-time usages of a substrate mixture, majorly comprising disposed COVID-19 personal protective-equipment (PPE). To devise a sustainable and scalable cellulase-production process, various variable-regulated, continuous-culture auxostats were performed. The glucose concentration-maintaining auxostat recorded consistent endoglucanase titers throughout its feeding-cum-harvest cycles; furthermore, it enhanced oxygen transfer, heat transfer co-efficient, and mass transfer co-efficient by 91.5, 36, and 77%, respectively. Substrate-characterization revealed that an unintended, autoclave-based organsolv pretreatment caused unanticipated increases in endoglucanase titers. The cumulative lab-scale cellulase-production cost was found to be $16.3. The proposed approach is economical, and it offers a pollution-free waste management process, thereby generating carbon credits.


Assuntos
COVID-19 , Celulase , Celulases , Humanos , Celulase/química , COVID-19/prevenção & controle , Celulases/química , Temperatura Alta , Oxigênio
18.
Pest Manag Sci ; 80(3): 1314-1324, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37903714

RESUMO

BACKGROUND: Pesticide formulations based on nanotechnology can effectively improve the efficiency of pesticide utilization and reduce pesticide residues in the environment. In this study, mesoporous silica nanoparticles containing disulfide bonds were synthesized by the sol-gel method, carboxylated and adsorbed with lufenuron, and grafted with cellulose to obtain a lufenuron-loaded nano-controlled release formulation (Luf@MSNs-ss-cellulose). RESULTS: The structure and properties of Luf@MSNs-ss-cellulose were characterized. The results showed that Luf@MSNs-ss-cellulose exhibits a regular spherical shape with 12.41% pesticide loading. The highest cumulative release rate (73.46%) of this pesticide-loaded nanoparticle was observed at 7 days in the environment of glutathione and cellulase, which shows redox-enzyme dual-responsive performance. As a result of cellulose grafting, Luf@MSNs-ss-cellulose had a small contact angle and high adhesion work on corn leaves, indicating good wetting and adhesion properties. After 14 days of spraying with 20 mg L-1 formulations in the long-term control efficacy experiment, the mortality of Luf@MSNs-ss-cellulose against Ostrinia furnacalis larvae (56.67%) was significantly higher than that of commercial Luf@EW (36.67%). Luf@MSNs-ss-cellulose is safer for earthworms and L02 cells. CONCLUSION: The nano-controlled release formulation obtained in this study achieved intelligent pesticide delivery in time and space under the environmental stimulation of glutathione and cellulase, providing an effective method for the development of novel pesticide delivery systems. © 2023 Society of Chemical Industry.


Assuntos
Benzamidas , Celulases , Fluorocarbonos , Nanopartículas , Praguicidas , Preparações de Ação Retardada , Nanopartículas/química , Glutationa/metabolismo , Oxirredução , Celulose , Dióxido de Silício/química , Porosidade , Portadores de Fármacos/química , Compostos Orgânicos
19.
Tree Physiol ; 44(1)2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-37930230

RESUMO

Rhododendron species provide excellent ornamental use worldwide, yet heat stress (HS) is one of the major threats to their cultivation. However, the intricate mechanisms underlying the photochemical and transcriptional regulations associated with the heat stress response in Rhododendron remain relatively unexplored. In this study, the analyses of morphological characteristics and chlorophyll fluorescence (ChlF) kinetics showed that HS (40 °C/35 °C) had a notable impact on both the donor's and acceptor's sides of photosystem II (PSII), resulting in reduced PSII activity and electron transfer capacity. The gradual recovery of plants observed following a 5-day period of culture under normal conditions indicates the reversible nature of the HS impact on Rhododendron × pulchrum. Analysis of transcriptome data unveiled noteworthy trends: four genes associated with photosynthesis-antenna protein synthesis (LHCb1, LHCb2 and LHCb3) and the antioxidant system (glutamate-cysteine ligase) experienced significant down-regulation in the leaves of R. × pulchrum during HS. Conversely, aseorbate peroxidase and glutathione S-transferase TAU 8 demonstrated an up-regulated pattern. Furthermore, six down-regulated genes (phos-phoenolpyruvate carboxylase 4, sedoheptulose-bisphosphatase, ribose-5-phosphate isomerase 2, high cyclic electron flow 1, beta glucosidase 32 and starch synthase 2) and two up-regulated genes (beta glucosidase 2 and UDP-glucose pyrophosphorylase 2) implicated in photosynthetic carbon fixation and starch/sucrose metabolism were identified during the recovery process. To augment these insights, a weighted gene co-expression network analysis yielded a co-expression network, pinpointing the hub genes correlated with ChlF dynamics' variation trends. The cumulative results showed that HS inhibited the synthesis of photosynthesis-antenna proteins in R. × pulchrum leaves. This disruption subsequently led to diminished photochemical activities in both PSII and PSI, albeit with PSI exhibiting heightened thermostability. Depending on the regulation of the reactive oxygen species scavenging system and heat dissipation, photoprotection sustained the recoverability of R. × pulchrum to HS.


Assuntos
Celulases , Rhododendron , Rhododendron/genética , Rhododendron/metabolismo , Clorofila/metabolismo , Transcriptoma , Fotossíntese/fisiologia , Folhas de Planta/fisiologia , Resposta ao Choque Térmico , Complexo de Proteína do Fotossistema II , Celulases/genética , Celulases/metabolismo
20.
Crit Rev Biotechnol ; 44(2): 191-201, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36592990

RESUMO

Protein glycosylation is the most complex posttranslational modification process. Most cellulases from filamentous fungi contain N-glycosylation and O-glycosylation. Here, we discuss the potential roles of glycosylation on the characteristics and function of cellulases. The use of certain cultivation, inducer, and alteration of engineering glycosylation pathway can enable the rational control of cellulase glycosylation. Glycosylation does not occur arbitrarily and may tend to modify the 3D structure of cellulases by using specially distributed glycans. Therefore, glycoengineering should be considered comprehensively along with the spatial structure of cellulases. Cellulase glycosylation may be an evolution phenomenon, which has been considered as an economical way for providing different functions from identical proteins. In addition to gene and transcription regulations, glycosylation may be another regulation on the protein expression level. Enhanced understanding of the potential regulatory role of cellulase glycosylation will enable synthetic biology approaches for the development of commercial cellulase.


Assuntos
Celulase , Celulases , Celulase/química , Celulase/genética , Celulase/metabolismo , Glicosilação , Celulases/química , Celulases/genética , Celulases/metabolismo , Fungos/metabolismo
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