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1.
World J Microbiol Biotechnol ; 36(3): 51, 2020 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-32157408

RESUMO

Culture-independent molecular-based approaches can be used to identify genes of interest from environmental sources that have desirable properties such as thermo activity. For this study, a putative thermo stable endoglucanase gene was identified from a mixed culture resulting from the inoculation of Brock-CMcellulose (1%) broth with mudspring water from Mt. Makiling, Laguna, Philippines that had been incubated at 90 °C. Genomic DNA was extracted from the cellulose-enriched mixed culture and endo1949 forward and reverse primers were used to amplify the endoglucanase gene, which was cloned into pCR-script plasmid vector. Blastn alignment of the sequenced insert revealed 99.69% similarity to the glycosyl hydrolase, sso1354 (CelA1; Q97YG7) from Saccharolobus solfataricus. The endoglucanase gene (GenBank accession number MK984682) was determined to be 1,021 nucleotide bases in length, corresponding to 333 amino acids with a molecular mass of ~ 37 kDa. The endoglucanase gene was inserted into a pET21 vector and transformed in E. coli BL21 for expression. Partially purified recombinant Mt. Makiling endoglucanase (MM-Engl) showed a specific activity of 187.61 U/mg and demonstrated heat stability up to 80 °C. The thermo-acid stable endoglucanase can be used in a supplementary hydrolysis step to further hydrolyze the lignocellulosic materials that were previously treated under high temperature-dilute acid conditions, thereby enhancing the release of more glucose sugars for bioethanol production.


Assuntos
Celulase/genética , Celulase/metabolismo , Celulose/metabolismo , DNA , Genômica , Água/metabolismo , Sequência de Aminoácidos , Archaea/enzimologia , Archaea/genética , Bactérias/enzimologia , Bactérias/genética , Sequência de Bases , Clonagem Molecular , Estabilidade Enzimática , Escherichia coli/genética , Concentração de Íons de Hidrogênio , Peso Molecular , Filipinas , Proteínas Recombinantes , Alinhamento de Sequência , Sulfolobales/enzimologia , Sulfolobales/genética , Temperatura Ambiente , Microbiologia da Água
2.
J Agric Food Chem ; 68(9): 2696-2701, 2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32031789

RESUMO

All-cellulose composites are usually prepared by removing impurities and using a surface-selective dissolution approach, which detract significantly from their environment-friendly properties. In this paper, we report an environment-friendly approach to fabricate all-cellulose nanofiber composites from stack-up bacterial cellulose (BC) hydrogels via self-aggregation forces of the hydrogen bond by water-based processing. Structural and mechanical properties of BC-laminated composites have been investigated. The results indicated that BC composites possess the structure of all nanofibers, a tensile strength of 116 MPa, and a storage modulus of 25 GPa. Additionally, the interfacial shear strength and tensile strength of piece-hot-press BC demonstrate the strong self-aggregation forces of BC nanofibers. Thus, BC-laminated composites will be attractive in structural material.


Assuntos
Celulose/química , Gluconacetobacter xylinus/química , Hidrogéis/química , Nanofibras/química , Celulose/metabolismo , Gluconacetobacter xylinus/crescimento & desenvolvimento , Gluconacetobacter xylinus/metabolismo , Hidrogéis/metabolismo , Fenômenos Mecânicos , Resistência à Tração
3.
Plant Mol Biol ; 102(3): 239-252, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31832900

RESUMO

KEY MESSAGE: Lack of structural components results in inflorescence stem bending. Differentially expressed genes involved in lignin and hemicellulose biosynthesis are vital; genes involved in cellulose and glycan biosynthesis are also relevant. An erect inflorescence stem is essential for high-quality cut herbaceous peony flowers. To explore the factors underlying inflorescence stem bending, major cell walls contents were measured, and stem structure was observed in two herbaceous peony varieties with contrasting stem straightness traits ('Da Fugui', upright; 'Chui Touhong', bending). In addition, Illumina sequencing was performed and weighted correlation network analysis (WGCNA) was used to analyze the results. The results showed significant differences in lignin, hemicellulose and soluble sugar contents, sclerenchyma and xylem areas and thickening in cell walls in pith at stage S3, when bending begins. In addition, 44,182 significantly differentially expressed genes (DEGs) were found, and these DEGs were mainly enriched in 36 pathways. Among the DEGs, hub genes involved in lignin, cellulose, and xylan biosynthesis and transcription factors that regulated these process were identified by WGCNA. These results suggested that the contents of compounds that provided cell wall rigidity were vital factors affecting inflorescence stem straightness in herbaceous peony. Genes involved in or regulating the biosynthesis of these compounds are thus important; lignin and hemicellulose are of great interest, and cellulose and glycan should not be ignored. This paper lays a foundation for developing new herbaceous peony varieties suitable for cut flowers by molecular-assisted breeding.


Assuntos
Inflorescência/metabolismo , Paeonia/metabolismo , Transcriptoma , Metabolismo dos Carboidratos , Parede Celular , Celulose/metabolismo , Flores , Regulação da Expressão Gênica de Plantas , Genes de Plantas/genética , Lignina/metabolismo , Paeonia/genética , Caules de Planta/citologia , Caules de Planta/crescimento & desenvolvimento , Polissacarídeos
4.
Phytochemistry ; 170: 112219, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31794882

RESUMO

The habituation of cultured cells to cellulose biosynthesis inhibitors such as dichlobenil (dichlorobenzonitrile, DCB) has proven a valuable tool to elucidate the mechanisms involved in plant cell wall structural plasticity. Our group has demonstrated that maize cells cope with DCB through a modified cell wall in which cellulose is replaced by a more extensive network of highly cross-linked feruloylated arabinoxylans. In order to gain further insight into the contribution of phenolics to the early remodelling of cellulose-deficient cell walls, a comparative HPLC-PAD analysis was carried out of hydroxycinnamates esterified into nascent and cell wall polysaccharides obtained from non-habituated (NH) and habituated to low DCB concentrations (1.5 µM; H) maize suspension-cultured cells. Incipient DCB-habituated cell walls showed significantly higher levels of esterified ferulic acid and p-coumaric acid throughout the culture cycle. In terms of cell wall fortification, ferulic acid is associated to arabinoxylan crosslinking whereas the increase of p-coumaric suggests an early lignification response. As expected, the level of hydroxycinnamates esterified into nascent polysaccharides was also higher in DCB-habituated cells indicating an overexpression of phenylpropanoid pathway. Due to their key role in cell wall strengthening, special attention was paid into the dimerization pattern of ferulic acid. A quantitative comparison of diferulate dehydrodimers (DFAs) between cell lines and cell compartments revealed that an extra dimerization took place in H cells when both nascent and mature cell wall polysaccharides were analysed. In addition, qualitative differences in the ferulic acid coupling pattern were detected in H cells, allowing us to suggest that 8-O-4'-DFA and 8-5'-DFA featured the ferulic acid dimerization when it occurred in the protoplasmic and cell wall fractions respectively. Both qualitative and quantitative differences in the phenolic profile between NH and H cells point to a regioselectivity in the ferulate dehydrodimerization.


Assuntos
Parede Celular/metabolismo , Celulose/metabolismo , Fenóis/metabolismo , Compostos Fitoquímicos/metabolismo , Zea mays/química , Parede Celular/química , Celulose/química , Fenóis/química , Compostos Fitoquímicos/química , Zea mays/citologia , Zea mays/metabolismo
5.
Environ Pollut ; 256: 113265, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31733968

RESUMO

Recent studies have demonstrated the ability of mealworm (Tenebrio molitor) for plastic degradation. This study is focused on changes in microbiome structure depending on diets. Microbial community obtained from oat and cellulose diet formed similar group, two kinds of polyethylene formed another group, while polystyrene diet showed the highest dissimilarity. The highest relative abundance of bacteria colonizing gut was in PE-oxodegradable feeding, nevertheless all applied diets were higher in comparison to oat. Dominant phyla consisted of Proteobacteria, Bacteroides, Firmicutes and Actinobacteria, however after PS feeding frequency in Planctomycetes and Nitrospirae increased. The unique bacteria characteristic for cellulose diet belonged to Selenomonas, while Pantoea were characteristic for both polyethylene diets, Lactococcus and Elizabethkingia were unique for each plastic diet, and potential diazotropic bacteria were characteristic for polystyrene diet (Agrobacterium, Nitrosomonas, Nitrospira). Enzymatic similarity between oatmeal and cellulose diets, was shown. All three plastics diet resulted in different activity in both, digestive tract and bacteria. The enzymes with the highest activity were included phosphatases, esterases, leucine arylamidase, ß-galactosidase, ß-glucuronidase, α-glucosidase, ß-glucosidase, chitinase, α-mannosidase and α-fucosidase. The activity of digestive tract was stronger than cultured gut bacteria. In addition to known polyethylene degradation methods, larvae may degrade polyethylene with esterase, cellulose and oatmeal waste activity is related with the activity of sugar-degrading enzymes, degradation of polystyrene with anaerobic processes and diazotrophs.


Assuntos
Celulose/metabolismo , Microbioma Gastrointestinal/efeitos dos fármacos , Polietileno/metabolismo , Poliestirenos/metabolismo , Tenebrio/enzimologia , Ração Animal , Animais , Biodegradação Ambiental , Trato Gastrointestinal/metabolismo , Trato Gastrointestinal/microbiologia , Larva/metabolismo , Microbiota/efeitos dos fármacos , Tenebrio/efeitos dos fármacos , Tenebrio/microbiologia , beta-Glucosidase/metabolismo
6.
Carbohydr Polym ; 227: 115323, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31590841

RESUMO

Bacterial nanocellulose (BNC) has many advantages over plant cellulose, which make it widely used in many fields, especially in the food industry. In this study, three strains including BCA263, BCC529, and P1 were selected for characteristics analysis of BNCs under static and agitated culture conditions. The BNCs produced under static culture condition were in the shape of uniform membrane, while BNCs produced under agitated culture were in form of small agglomerates and fragments. BCA263 and BCC529 strains were more suitable for static culture, while P1 strain was more suitable for agitated culture. BNCs produced under static culture condition exhibited higher crystallinity, stronger tensile strength, denser network structure, higher temperature resistance and good flame retardancy; while BNCs produced under agitated culture condition exhibited larger porous and lower crystallinity. Furthermore, BNCs produced under agitated culture condition were more suitable as a stabilizer of coffee milk beverage.


Assuntos
Acetobacteraceae/metabolismo , Celulose/metabolismo , Nanopartículas/metabolismo , Polissacarídeos Bacterianos/metabolismo , Animais , Técnicas Bacteriológicas , Celulose/química , Café , Conservação de Alimentos , Microscopia Eletrônica de Varredura , Leite , Nanopartículas/química , Nanopartículas/ultraestrutura , Polissacarídeos Bacterianos/química
7.
Ecotoxicol Environ Saf ; 188: 109858, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31706236

RESUMO

Cultivar-dependent cadmium (Cd) accumulation was principal in developing Cd-pollution safe cultivars (PSCs). Proteins related to different Cd accumulations of the low-Cd-accumulating (SJ19) and high-Cd-accumulating (CX4) cultivars were investigated by iTRAQ analysis. Higher Cd bioaccumulation factors and translocation factor in CX4 than in SJ19 were consistent with the cultivar-dependent Cd accumulations. The Cd uptake was promoted in CX4 due to its higher expression of Cd-binding proteins and the lower expression of Cd-efflux proteins in roots. What's more, significantly elevated thiol groups (PC2 and PC3) in CX4 under Cd stress might contribute to the high Cd accumulation in roots and the root-to-shoot translocation of Cd-PC complex. Up-regulated proteins involved in cellulose biosynthesis and pectin de-esterification in SJ19 enhanced the Cd sequestration of root cell walls, which was considered as the predominant strategy for reducing Cd accumulation in shoots. The present study provided novel insights in the cultivar-dependent Cd accumulation in shoots of B. parachinensis.


Assuntos
Brassica/metabolismo , Cádmio/metabolismo , Proteínas de Plantas/metabolismo , Poluentes do Solo/metabolismo , Transporte Biológico , Brassica/genética , Celulose/metabolismo , Pectinas/metabolismo , Raízes de Plantas/metabolismo , Brotos de Planta/metabolismo , Proteômica , Reagentes de Sulfidrila/metabolismo
8.
Chemosphere ; 238: 124652, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31473524

RESUMO

This research aimed to find the best phenotype of the brown algae Fucus vesiculosus (kelp) which has the greater potential to become a sorption byproduct for Zn removal from contaminated waters. Thus, the Zn uptake capacity and sorption mechanisms of the kelp collected from the Baltic Sea shore was, for the first time, investigated under various conditions, and compared to the phenotype habiting on the Irish Sea shore. Sorption studies were performed investigating the effect of algal dosage, Zn sources as well as algal harvesting time of the year on Zn uptake capacity. The results suggested that the Baltic algae is a better bio-sorbent for Zn uptake. Sorption mechanisms were studied by employing various indirect and direct approaches, more importantly, including high resolution synchrotron X-Ray Fluorescence and X-Ray Absorption Spectroscopy (XAS) and molecular modelling (MM). The results revealed that alginate and cellulose are among the main polysaccharide bonding Zn at algal surface, via coordination with O atoms from carboxyl and hydroxyl groups. XAS results giving direct measurements of Zn bonding environment on algal surface are supported by MM outputs and suggested that Zn is surrounded by ca. 5 O atoms at interatomic distances varying from 1.94 to 2.02 Å. The results contribute to understanding sorption mechanisms which can further lead to finding the best eluent for Zn desorption from the used biomass, bio sorbent reconditioning and reuse in multiple sorption desorption cycles as well as process optimization before industrial scaling up.


Assuntos
Biodegradação Ambiental , Fucus/metabolismo , Zinco/isolamento & purificação , Absorção Fisico-Química , Alginatos/metabolismo , Biomassa , Celulose/metabolismo , Fucus/química , Reciclagem/métodos , Zinco/farmacocinética
9.
J Sci Food Agric ; 100(2): 794-802, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31612484

RESUMO

BACKGROUND: Low-sodium sausages were manufactured using sodium substitution and biopolymer encapsulation. A diet comprising 10% treatment sausages (six treatment groups: C (100% NaCl), T1 (55% sodium substitute + 45% saltwort salt), T2 (55% sodium substitute + 45% saltwort salt with chitosan), T3 (55% sodium substitute + 45% saltwort salt with cellulose), T4 (55% sodium substitute + 45% saltwort salt with dextrin), and T5 (55% sodium substitute + 45% saltwort salt with pectin)) was added to a 90% commercial mouse diet for 4 weeks. RESULTS: Subacute toxicity, hematology, liver function, and organ weight tests in low-sodium sausage groups showed results similar to those of the control group, and all toxicity test levels were within normal ranges. CONCLUSIONS: All low-sodium sausage types tested are suggested to be safe in terms of subacute toxicity. Moreover, low-sodium sausages can be manufactured by biopolymer encapsulation of saltwort using pectin, chitosan, cellulose, and dextrin without toxicity. © 2019 Society of Chemical Industry.


Assuntos
Biopolímeros/análise , Aditivos Alimentares/análise , Manipulação de Alimentos/métodos , Produtos da Carne/análise , Salsola/química , Sódio/análise , Animais , Biopolímeros/metabolismo , Biopolímeros/toxicidade , Celulose/análise , Celulose/metabolismo , Celulose/toxicidade , Quitosana/análise , Quitosana/metabolismo , Quitosana/toxicidade , Feminino , Aditivos Alimentares/metabolismo , Aditivos Alimentares/toxicidade , Manipulação de Alimentos/instrumentação , Masculino , Produtos da Carne/toxicidade , Camundongos , Camundongos Endogâmicos ICR , Salsola/metabolismo , Salsola/toxicidade , Sódio/metabolismo , Sódio/toxicidade , Suínos
10.
World J Microbiol Biotechnol ; 36(1): 5, 2019 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-31832779

RESUMO

Stranded green macroalgae represents an important and renewable biomass that remains under valorized despite the numerous environmental problems generated by their accumulation in coastal regions. This work describes the isolation of a filamentous thermophile fungus identified as Aspergillus terreus JL1 that produces an efficient cellulolytic activity for green macroalgae saccharification. The characterization of the endoglucanase activity obtained after submerged fermentation showed a differential induction depending on the carbon source used with a unique isoform released when Ulva lactuca was used as inducer. The crude extract obtained hydrolyzed efficiently the untreated algal biomass (70.5%) compared to other cellulolytic extracts. The unique endoglucanase released was then purified to homogeneity (Yield: 49.6%; Specific activity: 30.1 U/mg; Purification fold: 4.36) and characterized biochemically. Its peptidic sequence was then determined and showed its belonging to the GH12. The described enzyme represents a promising biotechnological tool for algal biomass conversion.


Assuntos
Aspergillus/enzimologia , Biomassa , Celulase/metabolismo , Alga Marinha/metabolismo , Aspergillus/classificação , Aspergillus/isolamento & purificação , Biodegradação Ambiental , Celulase/isolamento & purificação , Celulose/isolamento & purificação , Celulose/metabolismo , DNA Fúngico/isolamento & purificação , Estabilidade Enzimática , Fermentação , Genômica , Concentração de Íons de Hidrogênio , Hidrólise , Alga Marinha/efeitos dos fármacos , Análise de Sequência , Temperatura Ambiente , Ulva/efeitos dos fármacos , Ulva/metabolismo
11.
Biochem Soc Trans ; 47(6): 1781-1794, 2019 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-31845725

RESUMO

Conversion of cellulosic biomass (non-edible plant material) to products such as chemical feedstocks and liquid fuels is a major goal of industrial biotechnology and an essential component of plans to move from an economy based on fossil carbon to one based on renewable materials. Many microorganisms can effectively degrade cellulosic biomass, but attempts to engineer this ability into industrially useful strains have met with limited success, suggesting an incomplete understanding of the process. The recent discovery and continuing study of enzymes involved in oxidative depolymerisation, as well as more detailed study of natural cellulose degradation processes, may offer a way forward.


Assuntos
Biomassa , Celulose/metabolismo , Microbiologia Industrial , Bactérias/genética , Bioengenharia , Parede Celular/metabolismo , Hidrólise , Plantas/metabolismo , Leveduras/metabolismo
12.
Microb Cell Fact ; 18(1): 193, 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31699093

RESUMO

BACKGROUND: Biomass contains cellulose (C6-sugars), hemicellulose (C5-sugars) and lignin. Biomass ranks amongst the most abundant hydrocarbon resources on earth. However, biomass is recalcitrant to enzymatic digestion by cellulases. Physicochemical pretreatment methods make cellulose accessible but partially destroy hemicellulose, producing a C5-sugar-rich liquor. Typically, digestion of pretreated LCB is performed with commercial cellulase preparations, but C5-sugars could in principle be used for "on site" production of cellulases by genetically engineered microorganism, thereby reducing costs. RESULTS: Here we report a succession of genetic interventions in Aspergillus nidulans that redesign the natural regulatory circuitry of cellulase genes in such a way that recombinant strains use C5-sugar liquors (xylose) to grow a vegetative tissue and simultaneously accumulate large amounts of cellulases. Overexpression of XlnR showed that under xylose-induction conditions only xylanase C was produced. XlnR overexpression strains were constructed that use the xynCp promoter to drive the production of cellobiohydrolases, endoglucanases and ß-glucosidase. All five cellulases accumulated at high levels when grown on xylose. Production of cellulases in the presence of pretreated-biomass C5-sugar liquors was investigated, and cellulases accumulated to much higher enzyme titers than those obtained for traditional fungal cell factories with cellulase-inducing substrates. CONCLUSIONS: By replacing expensive substrates with a cheap by-product carbon source, the use of C5-sugar liquors directly derived from LCB pretreatment processes not only reduces enzyme production costs, but also lowers operational costs by eliminating the need for off-site enzyme production, purification, concentration, transport and dilution.


Assuntos
Aspergillus nidulans/metabolismo , Celulase/biossíntese , Celulose/metabolismo , Microrganismos Geneticamente Modificados/metabolismo , Xilose/metabolismo , Aspergillus nidulans/genética , Engenharia Genética
13.
J Anim Sci ; 97(11): 4519-4531, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31634399

RESUMO

Prebiotics and dietary fibers are nondigestible ingredients that may confer benefits to the host by selectively stimulating beneficial intestinal bacteria and microbial-derived metabolites that support gut and host health. This experiment evaluated the effects of a blend of prebiotics and dietary fibers on apparent total tract digestibility (ATTD) and fecal metabolites related to gastrointestinal health in adult dogs. Four diets containing either 5% cellulose (control; CT), 5% dietary fiber and prebiotic blend (FP), 0.02% saccharin and eugenol (SE), or 5% fiber blend plus 0.02% saccharin and eugenol (FSE) were formulated to meet or exceed the AAFCO (2017) nutritional requirements for adult dogs. Eight adult female beagles (mean age 4.2 ± 1.1 yr; mean BW = 10.8 ± 1.4 kg; mean BCS = 5.8 ± 0.6) were randomly assigned to 1 of the 4 dietary treatments using a replicated 4 × 4 Latin square design. Each experimental period consisted of 14 d (10 d of diet adaptation and 4 d of total and fresh fecal and total urine collection). All animals remained healthy throughout the study, with serum metabolites being within reference ranges for adult dogs. All diets were well accepted by the dogs, resulting in similar (P > 0.05) daily food intakes among treatments. Likewise, fecal output and scores did not differ (P > 0.05) among dietary treatments, with the latter being within the ideal range (2.5-2.9) in a 5-point scale. All diets were highly digestible and had similar (P > 0.05) ATTD of dry matter (81.6%-84.4%), organic matter (86.4%-87.3%), and crude protein (86.6%-87.3%). However, total dietary fiber (TDF) digestibility was greater for dogs fed the FSE diet (P < 0.05) in contrast with dogs fed the CT and SE diets, whereas dogs fed FP diets had intermediate TDF digestibility, but not different from all other treatments. Fecal acetate and propionate concentrations were greater (P < 0.05) for dogs fed FP and FSE diets. Fecal concentrations of isobutyrate and isovalerate were greater for dogs fed CT (P < 0.05) compared with dogs fed the other three treatments. No shifts in fecal microbial richness and diversity were observed among dietary treatments. Overall, the data suggest that dietary supplementation of fiber and prebiotic blend was well tolerated by dogs, did not cause detrimental effects on fecal quality or nutrient digestibility, and resulted in beneficial shifts in fecal metabolites that may support gut health.


Assuntos
Fibras na Dieta/administração & dosagem , Suplementos Nutricionais/análise , Cães/fisiologia , Eugenol/administração & dosagem , Microbioma Gastrointestinal , Prebióticos/administração & dosagem , Ração Animal/análise , Animais , Celulose/metabolismo , Dieta/veterinária , Digestão/efeitos dos fármacos , Fezes/química , Fezes/microbiologia , Feminino , Trato Gastrointestinal/metabolismo , Trato Gastrointestinal/microbiologia , Nutrientes/administração & dosagem , Distribuição Aleatória , Sacarina/administração & dosagem
14.
Carbohydr Polym ; 226: 115243, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31582059

RESUMO

Nonsense mutation in the bcsC gene occurred in the ethanol-adapted strain of Komagataeibacter oboediens MSKU 3, E3 strain, resulting in the loss of the function to produce BNC. In this study, we tried to restore the BNC-producing ability of E3 strain by the following adaptive mutation through repetitive static culture, and obtained four BNC-producing revertant strains, of which the bcsC gene had InDel mutations near the frameshift mutation region in E3 strain, resulting in several amino acid alterations compared with the BcsC of MSKU 3. Each revertant produced BNCs with different productivity on the static culture. Interestingly, one of the revertants, R37-9, produced BNC with a finer structure and narrower range of fibrils width, compared to others. The genome of R37-9 strain revealed only one amino acid substitution in the bcsC gene. Thus, we concluded that N713D mutation occurred in the bcsC gene is responsible for the finer fibrils structure.


Assuntos
Acetobacteraceae , Celulose/metabolismo , Glucosiltransferases , Acetobacteraceae/genética , Acetobacteraceae/metabolismo , Glucosiltransferases/genética , Glucosiltransferases/metabolismo , Mutação
15.
BMC Genomics ; 20(1): 758, 2019 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-31640549

RESUMO

BACKGROUND: The mesocotyl connects the coleoptilar node and the basal part of the seminal root of maize (Zea mays) seedling. The mesocotyl pushes the shoot of the seedling out of the soil during seed germination; thus, its growth is highly related to deep-sowing tolerance. Although many studies on the maize mesocotyl have been carried out at physiological and molecular levels, the proteomic changes associated with cellular and physiological activities during mesocotyl growth are still unknown. RESULTS: In the present study, the maize hybrid Zhengdan 958 was used to study mesocotyl growth and accompanying protein changes. The dark-grown etiolated mesocotyls exhibited a slow-fast-slow feature, with significant changes in the levels of indole-3-acetic acid (IAA) and cellulose and the activity of peroxidase (POD). In particular, POD activity increased with mesocotyl growth, showing higher activity at the mature (lower) end of the mesocotyl. For the proteomic analysis, soluble proteins were extracted from etiolated mesocotyls dark-grown for 48 h, 84 h, and 132 h, corresponding to the initial, rapid, and slow growth periods, respectively, and subjected to separation by two-dimensional gel electrophoresis (2-DE). As a result, 88 differentially abundant proteins (DAPs) were identified using MALDI-TOF-TOF analysis. At 48 h, most DAPs were stress proteins, heat shock proteins and storage proteins; at 84 h, oxidation/reduction proteins, carbohydrate biogenesis-related proteins and cytoskeleton-related proteins were highly accumulated; at 132 h, the most striking DAPs were those involved in the synthesis and modification of the cell wall and the biogenesis of carbohydrates. Gene ontology (GO) analysis showed that changes in the abundance and proportion of DAPs were consistent with cellular and physiological activities and biological processes during mesocotyl growth. The accumulation of nine DAPs of interest was verified by immunoblotting and RT-qPCR. CONCLUSIONS: The present study revealed that the protein patterns in 2-D gels differed greatly with mesocotyl growth. At different growth periods, a specific set of DAPs participate in various biological processes and underlie the cellular and physiological activities of the mesocotyl. These results contributed to the understanding of mesocotyl growth and the cultivation of maize lines with deep-sowing tolerance.


Assuntos
Proteínas de Plantas/metabolismo , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Zea mays , Agricultura , Celulose/metabolismo , Eletroforese em Gel Bidimensional , Estiolamento , Ácidos Indolacéticos/metabolismo , Peroxidases/metabolismo , Proteínas de Plantas/genética , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Proteômica , RNA Mensageiro/metabolismo , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
16.
Int J Mol Sci ; 20(20)2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31600952

RESUMO

Biotransformation via solid state fermentation (SSF) mediated by microorganisms is a promising approach to produce useful products from agricultural biomass. Lactic acid bacteria (LAB) that are commonly found in fermented foods have been shown to exhibit extracellular proteolytic, ß-glucosidase, ß-mannosidase, and ß-mannanase activities. Therefore, extracellular proteolytic, cellulolytic, and hemicellulolytic enzyme activities of seven Lactobacillus plantarum strains (a prominent species of LAB) isolated from Malaysian foods were compared in this study. The biotransformation of palm kernel cake (PKC) biomass mediated by selected L. plantarum strains was subsequently conducted. The results obtained in this study exhibited the studied L. plantarum strains produced versatile multi extracellular hydrolytic enzyme activities that were active from acidic to alkaline pH conditions. The highest total score of extracellular hydrolytic enzyme activities were recorded by L. plantarum RI11, L. plantarum RG11, and L. plantarum RG14. Therefore, they were selected for the subsequent biotransformation of PKC biomass via SSF. The hydrolytic enzyme activities of treated PKC extract were compared for each sampling interval. The scanning electron microscopy analyses revealed the formation of extracellular matrices around L. plantarum strains attached to the surface of PKC biomass during SSF, inferring that the investigated L. plantarum strains have the capability to grow on PKC biomass and perform synergistic secretions of various extracellular proteolytic, cellulolytic, and hemicellulolytic enzymes that were essential for the effective biodegradation of PKC. The substantial growth of selected L. plamtraum strains on PKC during SSF revealed the promising application of selected L. plantarum strains as a biotransformation agent for cellulosic biomass.


Assuntos
Biomassa , Biotransformação , Celulose/metabolismo , Microbiologia de Alimentos , Lactobacillales/metabolismo , Phoeniceae/química , Biodegradação Ambiental , Celulose/química , Espaço Extracelular/metabolismo , Fermentação , Hidrólise , Lactobacillales/isolamento & purificação , Proteólise
17.
Phys Rev E ; 100(3-1): 032409, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31640020

RESUMO

Plants transport water against the risk of cavitation inside xylem vessels, called "embolism." As one of their hydraulic strategies, pit membranes composed of cellulose fibers have been known as safety valves that prevent the spreading of embolism towards adjacent xylem vessels. However, detailed observation of embolism spreading through a pit membrane is still lacking. Here, we hypothesized that the pit membranes normally remain to be wetted in xylem vessels and noticed in particular the hydraulic role of water film on air spreading that has been overlooked previously. For the hydrodynamic study of the embolism spreading through a wetted pit membrane, we investigated the penetration and spreading dynamics of air plugs through the wetted cellulose membrane in a channel flow. Air spreading exhibits two types of dynamics: continuous and discrete spreading. We elucidated the correlation of dynamic characteristics of air flow and pressure variations according to membrane thickness. Our study speculates that the thickness of pit membranes affects the behaviors of water film captured by cellulose fibers, and it is a crucial criterion for the reversible gating of further spreading of embolism throughout xylem networks.


Assuntos
Ar , Membrana Celular/metabolismo , Celulose/metabolismo , Modelos Biológicos , Plantas/metabolismo , Transporte Biológico , Hidrodinâmica , Pressão , Segurança , Água/metabolismo
18.
Biochimie ; 165: 275-284, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31472178

RESUMO

Glycoside hydrolase (GH) family 45 is one of the smallest and poorly studied endoglucanase family with a broad biotechnological application ranging from treatment of textiles to conversion of complex cell wall polysaccharides into simple oligo- and monosaccharides. In a present study, GH45 cellulase from Neurospora crassa OR74A (NcCel45A) was characterized both biochemically and structurally. HPLC analysis of the hydrolytic products confirmed the endo-ß(1,4) mode of action of the enzyme. Moreover, such pattern revealed that NcCel45A cannot hydrolyze efficiently oligosaccharides with a degree of polymerization smaller than six. The crystal structure of NcCel45A catalytic domain in the apo-form was determined at 1.9 Šresolution and the structure of the enzyme bound to cellobiose was solved and refined to 1.8 Šresolution. Comparative structural analyses and molecular dynamics simulations show that the enzyme dynamics is affected by substrate binding. Taken together, MD simulations and statistical coupling analysis revealed previously unknown correlation of a loop 6 with the breakdown of cellulose substrates by GH45.


Assuntos
Celulase/química , Celulose/metabolismo , Neurospora crassa/enzimologia , Domínio Catalítico , Cristalografia por Raios X , Hidrólise , Simulação de Dinâmica Molecular , Conformação Proteica , Especificidade por Substrato
19.
J Anim Sci ; 97(11): 4532-4539, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31560750

RESUMO

Dietary fibers can influence a dog's overall health, but high concentrations of soluble dietary fibers can cause soft stools. An in vitro model could be useful to predict the rate fibers are fermented once they reach the colon. Pet food companies are constantly searching for new ingredients to differentiate their products from competitors. Miscanthus grass (MG), pea fiber (PF), and sorghum bran (SB) are novel fiber sources that could be alternatives to standards like cellulose (CE) and beet pulp (BP). The objectives of the study were to determine the effects of fiber source on organic matter disappearance (OMD), estimated organic matter disappearance (EOMD), and fermentation end-product concentrations using an in vitro fermentation procedure and dog fecal inoculum. Total dietary fiber (TDF) residues from MG, CE, BP, PF, and SB were fermented in vitro with buffered dog feces. Fecal samples were collected and maintained in anaerobic conditions until the dilution and inoculation. Test tubes containing the fibrous substrates were incubated for 4, 8, and 12 h at 39 °C. Short-chain fatty acids (SCFA), branched-chain fatty acids (BCFA), OMD, and EOMD were determined for each fiber source and time point. Beet pulp had the highest OMD, EOMD, and SCFA production of all tested fiber sources (38.6% OMD, 26.2% EOMD, 2.72 mmol SCFA/g of substrate). Sorghum bran led to greater concentrations of BCFA (59.86 µmol/g of substrate) and intermediate OMD and EOMD compared to the other tested fibers. Cellulose and MG were poorly fermented with the lowest OMD, EOMD, SCFA, and BCFA compared to other fibers. In conclusion, MG could be used as an insoluble minimally fermentable replacement fiber for CE in dog foods.


Assuntos
Ração Animal/análise , Fibras na Dieta/análise , Cães/fisiologia , Ácidos Graxos Voláteis/análise , Poaceae , Animais , Beta vulgaris , Celulose/metabolismo , Fibras na Dieta/metabolismo , Digestão , Ácidos Graxos Voláteis/metabolismo , Fezes/química , Fezes/microbiologia , Feminino , Fermentação , Masculino , Distribuição Aleatória
20.
Nat Commun ; 10(1): 3548, 2019 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-31391460

RESUMO

Microbial fermentation of lignocellulosic biomass to produce industrial chemicals is exacerbated by the recalcitrant network of lignin, cellulose and hemicelluloses comprising the plant secondary cell wall. In this study, we show that transgenic poplar (Populus trichocarpa) lines can be solubilized without any pretreatment by the extreme thermophile Caldicellulosiruptor bescii that has been metabolically engineered to shift its fermentation products away from inhibitory organic acids to ethanol. Carbohydrate solubilization and conversion of unpretreated milled biomass is nearly 90% for two transgenic lines, compared to only 25% for wild-type poplar. Unexpectedly, unpretreated intact poplar stems achieved nearly 70% of the fermentation production observed with milled poplar as the substrate. The nearly quantitative microbial conversion of the carbohydrate content of unpretreated transgenic lignocellulosic biomass bodes well for full utilization of renewable biomass feedstocks.


Assuntos
Clostridiales/metabolismo , Fermentação , Microbiologia Industrial , Engenharia Metabólica , Populus/metabolismo , Biomassa , Celulose/metabolismo , Clostridiales/genética , Etanol/metabolismo , Lignina/metabolismo , Plantas Geneticamente Modificadas/química , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Polissacarídeos/metabolismo , Populus/química , Populus/genética
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