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1.
J. venom. anim. toxins incl. trop. dis ; 27: e20200105, 2021. tab, graf
Article in English | ID: biblio-1180822

ABSTRACT

Amphibians inhabit the terrestrial environment, a conquest achieved after several evolutionary steps, which were still insufficient to make them completely independent of the aquatic environment. These processes gave rise to many morphological and physiological changes, making their skin (and cutaneous secretion) rich in bioactive molecules. Among the tree frogs, the secretion is composed mainly of peptides; but alkaloids, proteins and steroids can also be found depending on the species. The most known class of biologically active molecules is the antimicrobial peptides (AMPs) that act against bacteria, fungi and protozoans. Although these molecules are well-studied among the hylids, AMPs ontogeny remains unknown. Therefore, we performed peptidomic and proteomic analyses of Pithecopus nordestinus (formerly Phyllomedusa nordestina) in order to evaluate the peptide content in post-metamorphosed juveniles and adult individuals. Methods: Cutaneous secretion of both life stages of individuals was obtained and analyzed by LC-MS/MS after reduction and alkylation of disulfide bonds or reduction, alkylation and hydrolysis by trypsin. Results: Differences in the TIC profile of juveniles and adults in both treatments were observed. Moreover, the proteomic data revealed known proteins and peptides, with slight differences in the composition, according to the life stage and the treatment. AMPs were identified, and bradykinin-potentiating peptides were observed in trypsin-treated samples, which suggests a protein source of such peptide (cryptide). Conclusion: In general, skin secretion contents were similar between juveniles and adults, varying in quantity, indicating that the different stages of life are reflected in the number of molecules and not on their diversity.(AU)


Subject(s)
Animals , Female , Peptides , Trypsin , Proteomics , Amphibians , Bodily Secretions , Hydrolysis
2.
Chinese Journal of Biotechnology ; (12): 207-217, 2021.
Article in Chinese | WPRIM | ID: wpr-878555

ABSTRACT

Scleroglucan is a high-molecular water-soluble microbial exopolysaccharide and mainly applied in the fields of petroleum, food, medicine and cosmetics. The high molecular weight of scleroglucan produced by microbial fermentation leads to low solubility, high viscosity and poor dispersibility, thus bringing a series of difficulties to extraction, preservation and application. It is important to explore suitable degradation method to adjust the molecular weight of scleroglucan for expanding its industrial application. Taking Sclerotium rolfsii WSH-G01 as a model strain, in which functional annotations of the glucanase genes were conducted by whole genome sequencing. Based on design of culture system for culture system for differential expression of β-glucanase, endogenous β-glucanase genes in S. rolfsii WSH-G01 were excavated by transcriptomics analysis. Functions of these potential hydrolases were further verified. Finally, 14 potential endogenous hydrolase genes were obtained from S. rolfsii. After heterologous overexpression in Pichia pastoris, 10 soluble enzymes were obtained and 5 of them had the activity of laminarin hydrolysis by SDS-PAGE and enzyme activity analysis. Further investigation of the 5 endogenous hydrolases on scleroglucan degradation showed that enzyme GME9860 has positive hydrolysis effect. The obtained results provide references not only for obtaining low and medium molecular weight of scleroglucan with enzymatic hydrolysis, but also for producing different molecular weight of scleroglucan during S. rolfsii fermentation process with metabolic engineering.


Subject(s)
Basidiomycota/genetics , Glucans , Hydrolysis , Saccharomycetales
3.
Article in Chinese | WPRIM | ID: wpr-878539

ABSTRACT

Lignocellulose can be hydrolyzed by cellulase into fermentable sugars to produce hydrogen, ethanol, butanol and other biofuels with added value. Pretreatment is a critical step in biomass conversion, but also generates inhibitors with negative impacts on subsequent enzymatic hydrolysis and fermentation. Hence, pretreatment and detoxification methods are the basis of efficient biomass conversion. Commonly used pretreatment methods of lignocellulose are chemical and physic-chemical processes. Here, we introduce different inhibitors and their inhibitory mechanisms, and summarize various detoxification methods. Moreover, we propose research directions for detoxification of inhibitors generated during lignocellulose pretreatment.


Subject(s)
Biofuels , Biomass , Fermentation , Hydrolysis , Lignin/metabolism
4.
Acta amaz ; 50(4): 346-354, out. - dez. 2020.
Article in English | LILACS | ID: biblio-1146380

ABSTRACT

Fungos filamentosos tem sido alvo de estudos de bioprospecção devido à sua grande eficiencia em produzir enzimas extracelulares, as quais tem grande potencial para uso em bioindústrias. Neste estudo, fungos filamentosos foram isolados do intestino de larvas de insetos aquáticos da Amazônia, para avaliar sua atividade celulolítica. Foram coletadas 69 larvas de insetos aquáticos fragmentadores de três gêneros: Phylloicus (Trichoptera: Calamoceratidae), Triplectides (Trichoptera:Leptoceridae) e Stenochironomus (Diptera: Chironomidae) em dez igarapés de uma área protegida na Amazônia central brasileira. O crescimento dos fungos isolados foi feito em meio de cultura Ágar Batata Dextrose (BDA). Os isolados fúngicos foram transferidos para o meio sintético com Carboximetil celulose e utilizou-se vermelho Congo para determinar o índice enzimático. O halo de hidrólise, indicando a produção de celulases, foi observado em 175 isolados fúngicos (70% do total), dos quais 25 tiveram um índice enzimático ≥ 2,0 e pertencem a sete gêneros fúngicos. Os táxons fúngicos Cladosporium, Gliocephalotrichum, Penicillium, Pestalotiopsis, Talaromyces, Trichoderma e Umbelopsis foram isolados dos intestinos das larvas de Phylloicus, Triplectides e Stenochironomus e são tradicionalmente utilizados em aplicações biotecnológicas. Os resultados indicam um potencial celulolítco destes fungos associados ao intestino de insetos aquáticos amazônicos. (AU)


Subject(s)
Cellulase , Shredders , Amazonian Ecosystem , Hydrolysis
5.
Electron. j. biotechnol ; 48: 101-108, nov. 2020. tab, ilus
Article in English | LILACS | ID: biblio-1254920

ABSTRACT

BACKGROUND: Collagen is the most abundant protein in animals and can be obtained from residues of the food industry. Its hydrolysate has many desirable properties that make it suitable as an additive in foods and cosmetics, or as a component of scaffold materials to be used in biomedicine. RESULTS: We report here the characterization of type I collagen from five different sources, namely bovine, porcine, chicken, trout and salmon, as well as their hydrolysates by means of bioinformatics tools. As expected, the results showed that bovine and porcine collagen, as well as trout and salmon collagen, can be used interchangeably due to their high identity. This result is consistent with the evolution of proteins with highly identical sequences between related species. Also, 156 sequences were found as potential bioactive peptides, 126 from propeptide region and 30 from the central domain, according to the comparison with reported active sequences. CONCLUSIONS: Collagen analysis from a bioinformatic approach allowed us to classify collagen from 5 different animal sources, to establish its interchangeability as potential additive in diverse fields and also to determine the content of bioactive peptides from its in silico hydrolysis.


Subject(s)
Animals , Cattle , Peptides , Collagen/chemistry , Computational Biology , Protein Hydrolysates , Salmon , Swine , Cluster Analysis , Collagen Type I , Additives in Cosmetics , Food Additives , Hydrolysis
6.
Electron. j. biotechnol ; 46: 38-49, jul. 2020. ilus, graf
Article in English | LILACS | ID: biblio-1223238

ABSTRACT

BACKGROUND: Quizalofop-p-ethyl (QPE), a unitary R configuration aromatic oxyphenoxypropionic acid ester (AOPP) herbicide, was widely used and had led to detrimental environmental effects. For finding the QPEdegrading bacteria and promoting the biodegradation of QPE, a series of studies were carried out. RESULTS: A QPE-degrading bacterial strain YC-XJ1 was isolated from desert soil and identified as Methylobacterium populi, which could degrade QPE with methanol by cometabolism. Ninety-seven percent of QPE (50 mg/L) could be degraded within 72 h under optimum biodegradation condition of 35°C and pH 8.0. The maximum degradation rate of QPE was 1.4 mg/L/h, and the strain YC-XJ1 exhibited some certain salinity tolerance. Two novel metabolites, 2-hydroxy-6-chloroquinoxaline and quinoxaline, were found by high-performance liquid chromatography/mass spectroscopy analysis. The metabolic pathway of QPE was predicted. The catalytic efficiency of strain YC-XJ1 toward different AOPPs herbicides in descending order was as follows: haloxyfop-pmethyl ≈ diclofop-methyl ≈ fluazifop-p-butyl N clodinafop-propargyl N cyhalofop-butyl N quizalofop-p-ethyl N fenoxaprop-p-ethyl N propaquizafop N quizalofop-p-tefuryl. The genome of strain YC-XJ1 was sequenced using a combination of PacBio RS II and Illumina platforms. According to the annotation result, one α/ß hydrolase gene was selected and named qpeh1, for which QPE-degrading function has obtained validation. Based on the phylogenetic analysis and multiple sequence alignment with other QPE-degrading esterases reported previously, the QPEH1 was clustered with esterase family V. CONCLUSION: M. populi YC-XJ1 could degrade QPE with a novel pathway, and the qpeh1 gene was identified as one of QPE-degrading esterase gene.


Subject(s)
Propionates/metabolism , Quinoxalines/metabolism , Methylobacterium/metabolism , Soil Microbiology , Biodegradation, Environmental , Methylobacterium/enzymology , Methylobacterium/genetics , Sequence Analysis, Protein , Esterases/analysis , Esterases/metabolism , Herbicides , Hydrolases/analysis , Hydrolases/metabolism , Hydrolysis
7.
Electron. j. biotechnol ; 44: 60-68, Mar. 2020. tab, graf, ilus
Article in English | LILACS | ID: biblio-1087705

ABSTRACT

Background: Oleaginous yeasts can be grown on different carbon sources, including lignocellulosic hydrolysate containing a mixture of glucose and xylose. However, not all yeast strains can utilize both the sugars for lipogenesis. Therefore, in this study, efforts were made to isolate dual sugar-utilizing oleaginous yeasts from different sources. Results: A total of eleven isolates were obtained, which were screened for their ability to utilize various carbohydrates for lipogenesis. One promising yeast isolate Trichosporon mycotoxinivorans S2 was selected based on its capability to use a mixture of glucose and xylose and produce 44.86 ± 4.03% lipids, as well as its tolerance to fermentation inhibitors. In order to identify an inexpensive source of sugars, nondetoxified paddy straw hydrolysate (saccharified with cellulase), supplemented with 0.05% yeast extract, 0.18% peptone, and 0.04% MgSO4 was used for growth of the yeast, resulting in a yield of 5.17 g L−1 lipids with conversion productivity of 0.06 g L−1 h−1 . Optimization of the levels of yeast extract, peptone, and MgSO4 for maximizing lipid production using Box­Behnken design led to an increase in lipid yield by 41.59%. FAME analysis of single cell oil revealed oleic acid (30.84%), palmitic acid (18.28%), and stearic acid (17.64%) as the major fatty acids. Conclusion: The fatty acid profile illustrates the potential of T. mycotoxinivorans S2 to produce single cell oil as a feedstock for biodiesel. Therefore, the present study also indicated the potential of selected yeast to develop a zero-waste process for the complete valorization of paddy straw hydrolysate without detoxification


Subject(s)
Trichosporon/metabolism , Oryza , Xylose/isolation & purification , Trichosporon/chemistry , Oils/chemistry , Lipogenesis , Biofuels , Fermentation , Glucose/isolation & purification , Hydrolysis , Lignin/metabolism , Lipids/biosynthesis
8.
Chinese Journal of Biotechnology ; (12): 861-867, 2020.
Article in Chinese | WPRIM | ID: wpr-826890

ABSTRACT

Lignocellulose is a major biomass resource for the production of biofuel ethanol. Due to its abundance, environmental friendliness and renewability, the utilization of lignocellulose is promising to solve energy shortage. Surfactant can effectively promote the enzymatic hydrolysis of lignocellulose. By discussing the influence and mechanism of different surfactants on the enzymatic hydrolysis, we provide references for finding appropriate surfactants in enzymatic hydrolysis process.


Subject(s)
Biofuels , Biomass , Hydrolysis , Lignin , Metabolism , Sugars , Metabolism , Surface-Active Agents , Pharmacology
9.
Chinese Journal of Biotechnology ; (12): 868-878, 2020.
Article in Chinese | WPRIM | ID: wpr-826889

ABSTRACT

2-Haloacid dehalogenases (EC 3.8.1.X) catalyze the hydrolytic dehalogenation of 2-haloacids, releasing halogen ions and producing corresponding 2-hydroxyacids. The enzymes not only degrade xenobiotic halogenated pollutants, but also show wide substrate profile and astonishing efficiency for enantiomer resolution, making them valuable in environmental protection and the green synthesis of optically pure chiral compounds. A variety of 2-haloacid dehalogenases have been biochemically characterized so far. Further studies have been made in protein crystal structures and catalytic mechanisms. Here, we review the recent progresses of 2-haloacid dehalogenases in their source, protein structures, reaction mechanisms, catalytic properties and application. We also suggest further research directions for 2-haloacid dehalogenase.


Subject(s)
Catalysis , Halogenation , Hydrolases , Chemistry , Metabolism , Hydrolysis , Research , Substrate Specificity
10.
Braz. arch. biol. technol ; 63: e20190151, 2020. tab, graf
Article in English | LILACS | ID: biblio-1132269

ABSTRACT

Abstract A comprehensive comparison of the main fermentation parameters, productivity, yield and final L-lactic acid concentration, obtained through batch, fed-batch and continuous cultivations using Lactobacillus casei CCDM 198 and a model cultivation medium was carried out. Using this data, a pulse-feed fed-batch process was established for testing chicken feather hydrolysate as a replacement for all complex nitrogen sources (yeast and beef extracts and peptone) in the medium. As comparably high values of productivity (about 4.0 g/L/h) and yield (about 98 %) were reached under all cultivation conditions, the maximum final L-lactic acid concentration (116.5 g/L), as achieved through pulse-feed fed-batch fermentation, was chosen as the most important criterion for process selection. Fed-batch cultivation with chicken feather hydrolysate as both a complex nitrogen source and a neutralizing agent for maintaining constant culture pH yielded half the concentration of L-lactic acid compared to the model medium. We demonstrate here that chicken feather hydrolysate has potential for use in the production of L-lactic acid but its utilization requires further optimization


Subject(s)
Animals , Lactic Acid/metabolism , Fermentation , Lactobacillus casei/growth & development , Biotechnology/methods , Chromatography, High Pressure Liquid , Biomass , Bioreactors , Hydrolysis
11.
Electron. j. biotechnol ; 41: 1-8, sept. 2019. tab, ilus, graf
Article in English | LILACS | ID: biblio-1053552

ABSTRACT

Background: The bioethanol produced from biomass is a promising alternative fuel. The lignocellulose from marginal areas or wasteland could be a promising raw material for bioethanol production because it is present in large quantities, is cheap, renewable and has favorable environmental properties. Despite these advantages, lignocellulosic biomass is much more difficult to process than cereal grains, due to the need for intensive pretreatment and relatively large amounts of cellulases for efficient hydrolysis. Therefore, there is a need to develop an efficient and cost-effective method for the degradation and fermentation of lignocellulosic biomass to ethanol. Results: The usefulness of lignocellulosic biomass from wasteland for the production of bioethanol using pretreatment with the aid of ionic liquids of 1-ethyl-3-methylimidazolium acetate and 1-ethyl-3-methylimidazolium chloride was evaluated in this study. The pretreatment process, enzymatic hydrolysis and alcoholic fermentation lasted a total of 10 d. The largest amounts of bioethanol were obtained from biomass originating from agricultural wasteland, in which the dominant plant was fireweed (Chamaenerion angustifolium) and from the field where the common broom (Cytisus scoparius) was the dominant. Conclusions: The plants such as fireweed, common broom, hay and goldenrod may be useful for the production of liquid biofuels and it would be necessary in the further stage of research to establish and optimize the conditions for the technology of ethyl alcohol producing from these plant species. Enzymatic hydrolysis of biomass from agricultural wastelands results in a large increase in fermentable sugars, comparable to the enzymatic hydrolysis of rye, wheat, rice or maize straw.


Subject(s)
Soil/chemistry , Biomass , Ethanol/metabolism , Biodegradation, Environmental , Cellulases/analysis , Enzymes/metabolism , Ionic Liquids , Biofuels , Hydrolysis , Lignin/analysis
12.
Electron. j. biotechnol ; 41: 95-99, sept. 2019. graf, tab, ilus
Article in English | LILACS | ID: biblio-1087252

ABSTRACT

Background: Pretreatment is the critically important step for the production of ethanol from lignocelluloses. In this study, hardwood birch (Betula pendula) and softwood spruce (Norway spruce) woods were pretreated with a newly synthesized morpholinium ionic liquid, 1-H-3-methylmorpholinium chloride ([HMMorph][Cl]), followed by enzymatic hydrolysis and fermentation to ethanol. Results: [HMMorph][Cl] was synthesized using inexpensive raw materials, i.e., hydrochloric acid and N-methyl morpholine, following a simple process. The influence of pretreatment time (2, 3, 5, and 8 h) and temperature (120 and 140°C) in terms of hydrolysis efficiency was investigated. Glucose yields from enzymatic hydrolysis were improved from 13.7% to 45.7% and 12.9% to 51.8% after pretreatment of birch and spruce woods, respectively, under optimum pretreatment conditions (i.e., at 140°C for 3 h) as compared to those from pristine woods. Moreover, the yields of ethanol production from birch and spruce were increased to 34.8% and 44.2%, respectively, while the yields were negligible for untreated woods. Conclusions: This study demonstrated the ability of [HMMorph][Cl] as an inexpensive agent to pretreat both softwood and hardwood.


Subject(s)
Betula/metabolism , Ethanol/metabolism , Ethanol/chemical synthesis , Lignin/metabolism , Cellulose/metabolism , Pretreatment , Chlorides/chemistry , Abies , Biofuels , Fermentation , Hydrolysis
13.
Electron. j. biotechnol ; 40: 78-83, July. 2019. tab, graf, ilus
Article in English | LILACS | ID: biblio-1053493

ABSTRACT

Background: Mathematical modeling is useful in the analysis, prediction, and optimization of an enzymatic process. Unlike the conventional modeling methods, Monte Carlo method has special advantages in providing representations of the molecule's spatial distribution. However, thus far, Monte Carlo modeling of enzymatic system is namely based on unimolecular basis, not suitable for practical applications. In this research, Monte Carlo modeling is performed for enzymatic hydrolysis of lactose for the purpose of real-time applications. Results: The enzyme hydrolysis of lactose, which is conformed to Michaelis­Menten kinetics, is modeled using the Monte Carlo modeling method, and the simulation results prove that the model predicts the reaction kinetics very well. Conclusions: Monte Carlo modeling method can be used to model enzymatic reactions in a simple way for real-time applications.


Subject(s)
Monte Carlo Method , Enzymes/metabolism , Hydrolysis , Lactose/metabolism , Time Factors , Kinetics , beta-Galactosidase/metabolism , Enzymes, Immobilized , Galactose/metabolism
14.
Electron. j. biotechnol ; 39: 52-60, may. 2019. ilus, tab, graf
Article in English | LILACS | ID: biblio-1052027

ABSTRACT

BACKGROUND: Biologically active peptides produced from fish wastes are gaining attention because their health benefits. Proteases produced by halophilic microorganisms are considered as a source of active enzymes in high salt systems like fish residues. Hence, the aim of this study was the bioprospection of halophilic microorganisms for the production of proteases to prove their application for peptide production. RESULTS: Halophilic microorganisms were isolated from saline soils of Mexico and Bolivia. An enzymatic screening was carried out for the detection of lipases, esterases, pHB depolymerases, chitinases, and proteases. Most of the strains were able to produce lipases, esterases, and proteases, and larger hydrolysis halos were detected for protease activity. Halobacillus andaensis was selected to be studied for proteolytic activity production; the microorganism was able to grow on gelatin, yeast extract, skim milk, casein, peptone, fish muscle (Cyprinus carpio), and soy flour as protein sources, and among these sources, fish muscle protein was the best inducer of proteolytic activity, achieving a protease production of 571 U/mL. The extracellular protease was active at 50°C, pH 8, and 1.4 M NaCl and was inhibited by phenylmethylsulfonyl fluoride. The proteolytic activity of H. andaensis was used to hydrolyze fish muscle protein for peptide production. The peptides obtained showed a MW of 5.3 kDa and a radical scavenging ability of 10 to 30% on 2,2-diphenyl-1-picrylhydrazyl and 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) and a ferric reducing ability of plasma. Conclusion: The use of noncommercial extracellular protease produced by H. andaensis for biologically active peptide production using fish muscle as the protein source presents a great opportunity for high-value peptide production.


Subject(s)
Peptide Hydrolases/metabolism , Peptides/metabolism , Fish Proteins/metabolism , Halobacillus/enzymology , Soil , Bacteria/isolation & purification , Bolivia , Esterases , Salinity , Hydrolysis , Lipase , Mexico , Muscle Proteins , Antioxidants
15.
Biosci. j. (Online) ; 35(1): 277-288, jan./fev. 2019. tab, ilus, graf
Article in English | LILACS | ID: biblio-1048581

ABSTRACT

The international standards for top glucomannan flour require a minimum of 70% glucomannan. The glucomannan content of Amorphophallus oncophyllus flour was approximately 60%, with starch as the major impurity. Elimination of starch was expected to increase the purity of glucomannan. The purpose of this research was to study starch hydrolysis of the flour using α-amylase. Temperature (35.5-84.5oC), time (0.4-3.6 h) and pH (2.2-8.8) of hydrolysis were selected as independent variables. A central composite design of response surface methodology (RSM) was performed to obtain the optimum condition. This approach was a novelty of this enzymatic purification of A. oncophyllus. Glucomannan content, starch content, and solubility were chosen as the response variables. The models were reliable for predicting the responses (R2≥ 0.771). It was predicted that the highest glucomannan content (93.0%) obtained at the lowest starch content (1.14%), which hydrolysed at pH 6.17, 84.5oC and 3.6 h. Prior the verification of the optimum hydrolysed condition from the model, the glucomannan and starch content was 81.59% and 2.27%, respectively. After purification, the absorbance of the ß-1,4 glycosidic bond increased as a sign of higher glucomannan purity. A less rough surface and irregular shape of the grain morphology was observed after purification.


Os padrões internacionais para a farinha de alta calidade de glucomanan requerem um mínimo de 70% de glucomanan. O conteúdo de glucomanano da farinha de Amorphophallus oncophyllus foi de aproximadamente 60%, com o amido como a maior impureza. Esperava-se que a eliminação do amido aumentasse a pureza do glucomanan. O objetivo desta pesquisa foi estudar a hidrólise do amido da farinha usando α-amilase. A temperature (35,5-84,5oC), o tempo (0,4-3,6 h) e o pH (2,2-8,8) da hidrólise foram selecionados como variáveis independentes. Um desenho central composto pertencente á metodologia da superfície de resposta (MSR) foi realizado para obter a condição ótima. Esta abordagem foi uma novidade desta purificação enzimática de A. oncophyllus. O conteúdo de glucomanan, conteúdo de amido e solubilidade foram escolhidos como as respostas. Os modelos foram confiáveis para predizer as respostas (R2≥ 0,771). Os modelos indicaram que o maior conteúdo de glucomanan (93,0%) foram obtidos no menor conteúdo de amido (1,14%),que hidrolisou a um pH 6,17, 84,5ºC e 3,6 h. Antes da verificação da condição hidrolisada ótima do modelo, o conteúdo de glucomanan e amido foi de 81,59% e 2,27%, respectivamente. Após a purificação, a absorbância da ligação ß-1,4 glicosídica aumentou com um sinal de maior pureza de glucomanan. Uma superfície mais lisa e forma irregular da morfologia do grão foi observada após a purificação.


Subject(s)
Amorphophallus , alpha-Amylases , Flour , Hydrolysis
16.
Article in English | WPRIM | ID: wpr-764043

ABSTRACT

In the present study, rutile phase titanium dioxide nanoparticles (R-TiO₂ NPs) were prepared by hydrolysis of titanium tetrachloride in an aqueous solution followed by calcination at 900℃. The composition of R-TiO₂ NPs was determined by the analysis of X-ray diffraction data, and the characteristic features of R-TiO₂ NPs such as the surface functional group, particle size, shape, surface topography, and morphological behavior were analyzed by Fourier-transform infrared spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy, transmission electron microscopy, dynamic light scattering, and zeta potential measurements. The average size of the prepared R-TiO₂ NPs was 76 nm, the surface area was 19 m²/g, zeta potential was −20.8 mV, and average hydrodynamic diameter in dimethyl sulfoxide (DMSO)–H₂O solution was 550 nm. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and morphological observations revealed that R-TiO₂ NPs were cytocompatible with oral cancer cells, with no inhibition of cell growth and proliferation. This suggests the efficacy of R-TiO₂ NPs for the aesthetic white pigmentation of teeth.


Subject(s)
Dimethyl Sulfoxide , Dynamic Light Scattering , Hydrodynamics , Hydrolysis , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , Mouth Neoplasms , Nanoparticles , Particle Size , Pigmentation , Spectrometry, X-Ray Emission , Spectrum Analysis , Titanium , Tooth , X-Ray Diffraction
17.
Chinese Journal of Biotechnology ; (12): 244-253, 2019.
Article in Chinese | WPRIM | ID: wpr-771382

ABSTRACT

Natural lignocellulosic materials contain cellulose, hemicellulose, and lignin. Cellulose hydrolysis to glucose requires a series of lignocellulases. Recently, the research on the synergistic effect of lignocellulases has become a new research focus. Here, four lignocellulase genes encoding β-glucosidase, endo-1,4-β-glucanase, xylanase and laccase from termite and their endosymbionts were cloned into pETDuet-1 and pRSFDuet-1 and expressed in Escherichia coli. After SDS-PAGE analysis, the corresponding protein bands consistent with the theoretical values were observed and all the proteins showed enzyme activities. We used phosphoric acid swollen cellulose (PASC) as substrate to measure the synergistic effect of crude extracts of co-expressing enzymes and the mixture of single enzyme. The co-expressed enzymes increased the degradation efficiency of PASC by 44% compared with the single enzyme mixture; while the degradation rate increased by 34% and 20%, respectively when using filter paper and corn cob pretreated with phosphoric acid as substrates. The degradation efficiency of the co-expressed enzymes was higher than the total efficiency of the single enzyme mixture.


Subject(s)
Animals , Cellulase , Cellulose , Hydrolysis , Isoptera , Lignin , Symbiosis , beta-Glucosidase
18.
Braz. arch. biol. technol ; 62: e19160816, 2019. tab, graf
Article in English | LILACS | ID: biblio-1011524

ABSTRACT

Abstract The development of new technologies which increase the production of biofuel without directly compete with food production is required. Microalgal biomass has recently been in the highlight. The role of this biomass is here discussed within the concept of biorefinery and industrial sustainability of bioethanol production. The process of cultivation in order to accumulate around 50% of carbohydrates in the biomass (dry weight) and the importance of water and nutrient recycling are reviewed. Saccharification of biomass using enzymes or acids and alternative processes such as hydrothermal liquefaction and flash hydrolysis are addressed. Since the main monosaccharide in microalgal biomass is glucose, high rates of hydrolysis and fermentation were, generally, achieved (more than 80% of the efficiency as a sum of these two processes). Anaerobic digestion to treat vinasse and the recycling of CO2 from the ethanolic fermentation and biogas could increase the process sustainability. Alternative techniques for the concentration of bioethanol from fermentation broth and for the optimization of fuel transportation are mentioned. Finally, the advantage of using microalgae rather than other sources is estimated with reference to the production rate, even though the cultivation costs are still high.


Subject(s)
Biomass , Ethanol/economics , Microalgae , Recycling/methods , Hydrolysis
19.
Rev. chil. nutr ; 45(4): 316-322, dic. 2018. tab
Article in Spanish | LILACS | ID: biblio-978092

ABSTRACT

RESUMEN Se evaluó el efecto de adición de lactasa (β-galactosidasa) y sacarosa (como edulcorante) en una bebida isotónica a partir del lactosuero dulce. Se estableció dos factores en estudio: factor "A" dosis de lactasa 5200 NLU (0,5; 1,1 y 3,0 mL) y factor "B" porcentajes de sacarosa (7 y 8%). La unidad experimental fue de 18.18 kg de lactosuero dulce, distribuidos en seis tratamientos con tres réplicas, formulándose combinaciones: T1 (0,5:7), T2 (0,5:8), T3 (1,1:7), T4 (1,1:8), T5 (3:7) y T6 (3:8). Se evaluó la energia y carbohidratos. Los resultados mostraron diferencias significativas para la variable carbohidratos sobre los tratamientos, y diferencias significativas para el factor "B" sobre la variable carbohidratos. Se determinó al T2 como el mejor tratamiento en base a una prueba afectiva. Los análisis de electrolitos de sodio y potasio realizados al mismo T2 demostraron que el sodio fue el único que cumple con los valores establecidos. La adición de varias dosis de lactasa no incidió en los parámetros sustanciales de una bebida isotónica, mientras que los porcentajes de sacarosa incidieron significativamente sobre las variables respuesta, aumentando los carbohidratos y calorias por encima del valor normado.


ABSTRACT The effect of adding lactase (β-galactosidase) and sucrose (as a sweetener) to an isotonic drink from sweet whey was evaluated. Two factors were studied: factor "A" lactase dose 5200 NLU (0.5, 1.1 and 3 mL) and factor "B" percentages of sucrose (7 and 8%). The experimental unit was 18.18 kg of sweet whey, distributed in six treatments with three replications, creating the following combinations: T1 (0.5: 7), T2 (0.5: 8), T3 (1.1: 7), T4 (1.1: 8), T5 (3: 7) and T6 (3: 8). Energy and carbohydrates were evaluated. The results showed significant differences for the carbohydrate variable over the treatments, and significant differences for the "B" factor over the carbohydrate variable. T2 was determined as the best treatment based on a test of affect. The sodium and potassium electrolyte analyses performed on the same T2 show that sodium was the only one that complied with established values. The addition of several doses of lactase did not affect the substantial parameters of an isotonic drink, while the percentages of sucrose significantly affected the response variables, increasing carbohydrates and calories above normal values.


Subject(s)
Carbohydrates , Electrolytes , Energy Drinks , Hydrolysis , Sucrose , Lactase
20.
Braz. j. microbiol ; 49(4): 879-884, Oct.-Dec. 2018. tab, graf
Article in English | LILACS | ID: biblio-1039268

ABSTRACT

ABSTRACT The multi-enzyme complex (crude extract) of white rot fungi Pleurotus ostreatus, Pleurotus eryngii, Trametes versicolor, Pycnosporus sanguineus and Phanerochaete chrysosporium were characterized, evaluated in the hydrolysis of pretreated pulps of sorghum straw and compared efficiency with commercial enzyme. Most fungi complexes had better hydrolysis rates compared with purified commercial enzyme.


Subject(s)
Fungal Proteins/chemistry , Sorghum/chemistry , Cellulases/chemistry , Fungi/enzymology , Lignin/chemistry , Fungal Proteins/metabolism , Plant Stems/microbiology , Plant Stems/chemistry , Sorghum/microbiology , Cellulases/metabolism , Biocatalysis , Fungi/chemistry , Hydrolysis , Lignin/metabolism
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