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Global market of food enzymes is held by pectinases, mostly sourced from filamentous fungi via submerged fermentation. Given the one-time use nature of enzymes to clarify juices and wines, there is a crucial need to explore alternatives for enzyme immobilization, enabling their reuse in food applications. In this research, an isolated fungal strain (Penicillium crustosum OR889307) was evaluated as a new potential pectinase producer in submerged fermentation. Additionally, the enzyme was immobilized in magnetic core-shell nanostructures for juice clarification. Findings revealed that Penicillium crustosum exhibited enzymatic activities higher than other Penicillium species, and pectinase production was enhanced with lemon peel as a cosubstrate in submerged fermentation. The enzyme production (548.93 U/mL) was optimized by response surface methodology, determining the optimal conditions at 35 °C and pH 6.0. Subsequently, the enzyme was covalently immobilized on synthesized magnetic core-shell nanoparticles. The immobilized enzyme exhibited superior stability at higher temperatures (50 °C) and acidic conditions (pH 4.5). Finally, the immobilized pectinases decreased 30 % the orange juice turbidity and maintained 84 % of the enzymatic activity after five consecutive cycles. In conclusion, Penicillium crustosum is a proven pectinase producer and these enzymes immobilized on functionalized nanoparticles improve the stability and reusability of pectinase for juice clarification.

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This study investigated the impact of a support matrix and active group on the support to the nutritional properties of orange juice after juice clarification. Pectinase was immobilized on chitosan and aminated silica supports, activated with genipin or glutaraldehyde, and applied for juice clarification. The effects on various juice properties, including reducing sugars, total soluble solids, vitamin C, and phenolic compounds, juice color, and pH, were evaluated. The results revealed that the immobilization on chitosan activated using genipin resulted in the highest biocatalyst activity (1211.21 U·g-1). The juice treatments using the biocatalysts led to turbidity reduction in the juice (up to 90%), with the highest reductions observed in treatments involving immobilized enzyme on chitosan. Importantly, the enzymatic treatments preserved the natural sugar content, total soluble solids, and pH of the juice. Color differences between treated and raw juice samples were especially relevant for those treated using enzymes, with significant differences in L* and b*, showing loss of yellow vivid color. Analysis of phenolic compounds and vitamin C showed no significant alterations after the enzymatic treatment of the raw juice. According to our results, the clarification of orange juice using immobilized enzymes can be a compromise in turbidity reduction and color reduction to maintain juice quality.

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Aim: Obesity is a chronic pathology of epidemic proportions. Mature adipocytes from a 3T3-L1 cell line were used as in vitro obesity model to test different bioactive compounds. We aim to evaluate cassis (Ribes nigrum) extract antioxidant activity and its antiadipogenic effect on mature adipocytes. Results: We produced an extract by using enzyme that combines cellulase and pectinase; we obtained high yield of the bioactive compound anthocyanin. Extract showed high antioxidant capacity. We conducted in vitro assays by adding the extract to adipocytes culture medium. Extract reduced intracellular levels of triglyceride by 62% and cholesterol by 32%. Conclusion: Enzymatic extract's high antioxidant activity was likely attributable to its high concentration of anthocyanin. This extract inhibits lipid accumulation in adipocytes.

Obesity is a disease all over the world. By 2030, nearly 20% of adults are predicted to be obese. The consumption of processed foods is related to obesity in some countries such as Argentina. More natural food is needed. There are many different anti-obesity medicines but there is no good one to lose weight. We took extracts from cassis fruits and tested whether they could decrease fats like cholesterol within fat cells. We found that these extracts could successfully reduce the fat levels in the cells. Our results indicate that natural compounds like cassis fruit extract may be helpful in preventing future obesity epidemics.

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Immobilization of enzymes is one of the protein engineering methods used to improve their thermal and long-term stabilities. Immobilized pectinase has become an essential biocatalyst for optimization in the food processing industry. Herein, nanostructured magnetic nanoparticles were prepared in situ for use as supports to immobilize pectinase. The structural, morphological, optical and magnetic features and the chemical compositions of the nanoparticles were characterized. Nanoparticle agglomeration and low porosity were observed due to the synthetic conditions. These nanoparticles exhibited superparamagnetic behavior, which is desirable for biotechnological applications. The maximum retention rate for the enzyme was observed at pH 4.5 with a value of 1179.3 U/mgNP (units per milligram of nanoparticle), which was equivalent to a 65.6% efficiency. The free and immobilized pectinase were affected by the pH and temperature. The long-term instability caused 40% and 32% decreases in the specific activities of the free and immobilized pectinase, respectively. The effects of immobilization were analyzed with kinetic and thermodynamic studies. These results indicated a significant affinity for the substrate, a decreased reaction rate, and improved thermal stability of the immobilized pectinase. The reusability of the immobilized pectinase was preserved effectively during cycling, with only a 21.2% decrease in activity observed from the first to the last use. Therefore, alternative magnetic nanoparticles are presented for immobilizing and maintaining the thermostability of pectinase.

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HYPOTHESIS: The catalytic activity of enzymes immobilized in self-assembly systems as Langmuir-Blodgett (LB) films is influenced by molecular interactions dictated by the composition and viscoelasticity of the previous floating monolayers. We believe that the insertion of carbon nanotubes (CNT) in mixed polygalacturonase/lipid monolayers may influence intermolecular interactions and viscoelastic properties, being then possible to tune system stability and rheological properties, driving catalytic properties of the films for biosensing. EXPERIMENTS: The physicochemical properties of the monolayers were investigated by tensiometry, surface potential, Brewster angle microscopy, infrared spectroscopy, and dilatational rheology. The monolayers were transferred to solid supports LB films and characterized by atomic force microscopy, quartz crystal microbalance, and fluorescence spectroscopy. The catalytic activity of the LB films was verified by colorimetric assay. FINDINGS: The enzyme-CNT-lipid film had a catalytic activity at least twice as high as the pure enzyme owing to the synergy between the components, with the lipid acting as a protector matrix for the enzyme and the CNTs acting as an energy transfer facilitator. These results point to a proof-of-concept system, through which we can propose an alternative to achieve enhanced bio-inspired films with high control of the molecular architecture by using the LB approach.

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Aspergillus terreus can produce different holocellulose-degrading enzymes when grown in sugarcane bagasse, with predominant pectinase activity. Thus, pectinase was selected for purification and immobilization studies. Ion exchange and molecular exclusion chromatography studies were performed, after which it was possible to semipurify the enzyme with a yield of 80%. The crude extract pectinase (PECEB) and the partially purified enzyme (PEC2) were immobilized on monoamino-N-aminoethyl (MANAE)-agarose with pectinase activity yields of 66% and 98%, respectively. After immobilization in MANAE-agarose, the pectinase showed higher activity at acidic pH (pH 4.0) when compared to the nonimmobilized enzyme. It was also found that after the immobilization process, there was a threefold improvement in the enzyme's thermostability. Also, it was possible to reuse the immobilized enzyme for up to five cycles of hydrolysis with effective production of reducing sugars (0.196 mg/g of substrate). The industrial application test revealed a significant decrease in the viscosity of guava juice when the immobilized enzyme was used. PECEB, immobilized on MANAE-agarose, was the enzyme sample that generated the highest pulp viscosity reduction (approximately 47%). Although additional studies are needed for practical industrial application, the results obtained herein reveal the potential of application of immobilized pectinase in the industry.

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ABSTRACT: The objective of this study was to produce vinegar from mangaba pulp using semi-solid alcoholic fermentation combined with the enzymatic activity of pectinase and to investigate the chemical composition and sensory characteristics of the final product. was evaluated for volatile acidity and the reduced dry extract was evaluated for ashes, alcohol content, sulfates, pH, total phenolic compounds, total carotenoids, color parameters, yield, productivity, and sensory analysis. Average and standard deviation was used for descriptive statistics. Principal component analysis (PCA) was applied to all variables except total carotenoid content. Physicochemical characterization of the raw and alcoholically fermented pulp was also carried out. The main results showed that, in the vinegar, the reduced dry extract, volatile acidity, pH, and ashes were 44.3±1.5 (g/L), 4.4±0.1 (% w/v), 3.1±0.0, and 3.0±0.41 (g/L), respectively. The total phenolic compound content and total carotenoid content for the mangaba vinegar were 19.2±8.20. mg/100 g and 2.6±0.6. mg/100 g, respectively. The conversion yield from ethanol to acetic acid was 90%. PCA showed that pH and volatile acidity had a strong influence on the product, and there was a strong positive correlation between color and aroma. The final product met all legal requirements, showing that it is possible to produce mangaba vinegar with antioxidant potential for consumers. In the sensory evaluation, it was favored by the tasters, demonstrating potential economic value in the Cerrado fruit.

RESUMO: Objetivou-se produzir vinagre, a partir da polpa de mangaba por fermentação alcoólica semi-sólida com ação enzimática através da pectinase, investigar a composição química e avaliação sensorial do produto final. O vinagre foi avaliado através da acidez volátil, extrato seco reduzido, cinzas, teor alcoólico, sulfatos, pH, compostos fenólicos totais, carotenoides totais, parâmetros de cor, rendimento, produtividade e análise sensorial. Os dados foram submetidos a estatística descritiva com média e desvio padrão. Foi aplicado a análise de componentes principais (ACP) para todas as variáveis, exceto para análise de carotenoides totais. Também foi realizada a caracterização físico-química da polpa e fermentado alcoólico. Os principais resultados mostraram que, no vinagre, extrato seco reduzido, acidez volátil, pH e cinzas foram, respectivamente, 44,3±1,5 (g/L), 4,4±0,1 (% m/v), 3,1±0,0, 3,0±0,41 (g/L). Os compostos fenólicos totais e carotenoides totais apresentaram valores de 19,2±8,20 (mg/100 g) e 2,6±0,6 (mg/100 g), respectivamente. O rendimento de conversão de etanol a ácido acético foi de 90%. ACP foi aplicada nas variáveis físico-químicas do vinagre no qual os parâmetros de cor, pH e acidez volátil apresentaram forte influência no produto e, para os atributos da análise sensorial, cor e aroma apresentaram uma forte correlação positiva entre si. O produto final atendeu a todos os quesitos legais, demonstrando ser possível a produção de vinagre de mangaba com potencial antioxidante. Na avaliação sensorial teve boa aceitação pelos provadores, valorizando o uso deste fruto do Cerrado.

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Abstract Alkaline pectinase is the utmost significant industrial enzyme of the bioscouring process. By considering bio scouring of cotton, 30 microbial isolates from fruit and vegetable waste rich dump soil of Solang Valley and Vasishta (Manali, Himachal Pradesh, India) were isolated and screened for the alkaline pectinase production in the current research work. Only four isolates P3, P16, P21, and P27 were capable to produce extracellular alkaline pectinase at pH 9. Further by applying submerged fermentation, the alkaline pectinase production was quantitatively screened. The most efficient isolate was P3 identified as Bacillus tropicus, based on morphological, biochemical, and molecular characterization. Molecular characteristics confirmed by 16S rDNA sequence analysis. The nucleotide sequence of the isolate was novel with a 97% similarity index and submitted to the GenBank with accession number MK332379. The Bacillus strain selected was active at broad pH range from 8-10.5 and a temperature range from 25-50 oC. Optimum pH and temperature observed were 9 and 37 oC respectively and can be suitably used for the bio scouring process for the pretreatment of the fabrics.

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The objective of this study was to produce vinegar from mangaba pulp using semi-solid alcoholic fermentation combined with the enzymatic activity of pectinase and to investigate the chemical composition and sensory characteristics of the final product. was evaluated for volatile acidity and the reduced dry extract was evaluated for ashes, alcohol content, sulfates, pH, total phenolic compounds, total carotenoids, color parameters, yield, productivity, and sensory analysis. Average and standard deviation was used for descriptive statistics. Principal component analysis (PCA) was applied to all variables except total carotenoid content. Physicochemical characterization of the raw and alcoholically fermented pulp was also carried out. The main results showed that, in the vinegar, the reduced dry extract, volatile acidity, pH, and ashes were 44.3±1.5 (g/L), 4.4±0.1 (% w/v), 3.1±0.0, and 3.0±0.41 (g/L), respectively. The total phenolic compound content and total carotenoid content for the mangaba vinegar were 19.2±8.20. mg/100 g and 2.6±0.6. mg/100 g, respectively. The conversion yield from ethanol to acetic acid was 90%. PCA showed that pH and volatile acidity had a strong influence on the product, and there was a strong positive correlation between color and aroma. The final product met all legal requirements, showing that it is possible to produce mangaba vinegar with antioxidant potential for consumers. In the sensory evaluation, it was favored by the tasters, demonstrating potential economic value in the Cerrado fruit.(AU)

Objetivou-se produzir vinagre, a partir da polpa de mangaba por fermentação alcoólica semi-sólida com ação enzimática através da pectinase, investigar a composição química e avaliação sensorial do produto final. O vinagre foi avaliado através da acidez volátil, extrato seco reduzido, cinzas, teor alcoólico, sulfatos, pH, compostos fenólicos totais, carotenoides totais, parâmetros de cor, rendimento, produtividade e análise sensorial. Os dados foram submetidos a estatística descritiva com média e desvio padrão. Foi aplicado a análise de componentes principais (ACP) para todas as variáveis, exceto para análise de carotenoides totais. Também foi realizada a caracterização físico-química da polpa e fermentado alcoólico. Os principais resultados mostraram que, no vinagre, extrato seco reduzido, acidez volátil, pH e cinzas foram, respectivamente, 44,3±1,5 (g/L), 4,4±0,1 (% m/v), 3,1±0,0, 3,0±0,41 (g/L). Os compostos fenólicos totais e carotenoides totais apresentaram valores de 19,2±8,20 (mg/100 g) e 2,6±0,6 (mg/100 g), respectivamente. O rendimento de conversão de etanol a ácido acético foi de 90%. ACP foi aplicada nas variáveis físico-químicas do vinagre no qual os parâmetros de cor, pH e acidez volátil apresentaram forte influência no produto e, para os atributos da análise sensorial, cor e aroma apresentaram uma forte correlação positiva entre si. O produto final atendeu a todos os quesitos legais, demonstrando ser possível a produção de vinagre de mangaba com potencial antioxidante. Na avaliação sensorial teve boa aceitação pelos provadores, valorizando o uso deste fruto do Cerrado.(AU)

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The objective of this study was to produce vinegar from mangaba pulp using semi-solid alcoholic fermentation combined with the enzymatic activity of pectinase and to investigate the chemical composition and sensory characteristics of the final product. was evaluated for volatile acidity and the reduced dry extract was evaluated for ashes, alcohol content, sulfates, pH, total phenolic compounds, total carotenoids, color parameters, yield, productivity, and sensory analysis. Average and standard deviation was used for descriptive statistics. Principal component analysis (PCA) was applied to all variables except total carotenoid content. Physicochemical characterization of the raw and alcoholically fermented pulp was also carried out. The main results showed that, in the vinegar, the reduced dry extract, volatile acidity, pH, and ashes were 44.3±1.5 (g/L), 4.4±0.1 (% w/v), 3.1±0.0, and 3.0±0.41 (g/L), respectively. The total phenolic compound content and total carotenoid content for the mangaba vinegar were 19.2±8.20. mg/100 g and 2.6±0.6. mg/100 g, respectively. The conversion yield from ethanol to acetic acid was 90%. PCA showed that pH and volatile acidity had a strong influence on the product, and there was a strong positive correlation between color and aroma. The final product met all legal requirements, showing that it is possible to produce mangaba vinegar with antioxidant potential for consumers. In the sensory evaluation, it was favored by the tasters, demonstrating potential economic value in the Cerrado fruit.

Objetivou-se produzir vinagre, a partir da polpa de mangaba por fermentação alcoólica semi-sólida com ação enzimática através da pectinase, investigar a composição química e avaliação sensorial do produto final. O vinagre foi avaliado através da acidez volátil, extrato seco reduzido, cinzas, teor alcoólico, sulfatos, pH, compostos fenólicos totais, carotenoides totais, parâmetros de cor, rendimento, produtividade e análise sensorial. Os dados foram submetidos a estatística descritiva com média e desvio padrão. Foi aplicado a análise de componentes principais (ACP) para todas as variáveis, exceto para análise de carotenoides totais. Também foi realizada a caracterização físico-química da polpa e fermentado alcoólico. Os principais resultados mostraram que, no vinagre, extrato seco reduzido, acidez volátil, pH e cinzas foram, respectivamente, 44,3±1,5 (g/L), 4,4±0,1 (% m/v), 3,1±0,0, 3,0±0,41 (g/L). Os compostos fenólicos totais e carotenoides totais apresentaram valores de 19,2±8,20 (mg/100 g) e 2,6±0,6 (mg/100 g), respectivamente. O rendimento de conversão de etanol a ácido acético foi de 90%. ACP foi aplicada nas variáveis físico-químicas do vinagre no qual os parâmetros de cor, pH e acidez volátil apresentaram forte influência no produto e, para os atributos da análise sensorial, cor e aroma apresentaram uma forte correlação positiva entre si. O produto final atendeu a todos os quesitos legais, demonstrando ser possível a produção de vinagre de mangaba com potencial antioxidante. Na avaliação sensorial teve boa aceitação pelos provadores, valorizando o uso deste fruto do Cerrado.

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Cannabaceae is a known family because of the production of cannabinoids in laticifers and glandular trichomes of Cannabis sativa. Laticifers are latex-secreting structures, which in Cannabaceae were identified only in C. sativa and Humulus lupulus. This study aimed to expand the knowledge of laticifers in Cannabaceae by checking their structural type and distribution, and the main classes of substances in the latex of Celtis pubescens, Pteroceltis tatarinowii, and Trema micrantha. Such information is also updated for C. sativa. Samples of shoot apices, stems, leaves, and flowers were processed for anatomical, histochemical, ultrastructural, and cytochemical analyses. Laticifers are articulated unbranched in all species instead of non-articulated as previously described for the family. They occur in all sampled organs. They are thick-walled, multinucleate, with a large vacuole and a peripheral cytoplasm. The cytoplasm is rich in mitochondria, endoplasmic reticulum, dictyosomes, ribosomes, and plastids containing starch grains and oil drops. Pectinase and cellulase activities were detected in the laticifer wall and vacuole, confirming its articulated origin, described by first time in the family. These enzymes promote the complete dissolution of the laticifer terminal walls. The latex contains proteins, lipids, and polysaccharides in addition to phenolics (C. sativa) and terpenes (C. pubescens, T. micrantha). The presence of laticifers with similar distribution and morphology supports the recent insertion of Celtis, Pteroceltis, and Trema in Cannabaceae. The articulated type of laticifer found in Cannabaceae, Moraceae, and Urticaceae indicates that the separation of these families by having distinct laticifer types should be reviewed.

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Magnetic-chitosan particles were prepared following three different protocols enabling the preparation of particles with different sizes - nano (Nano-CMag, Micro (Micro-CMag) and Macro (Macro-CMag) - and used for pectinase immobilization and clarification of grape, apple and orange juices. The particle size had a great effect in the kinetic parameters, Nano-CMag biocatalyst presented the highest Vmax value (78.95 mg. min-1), followed by Micro-CMag and Macro-CMag, with Vmax of 57.20 mg.min-1 and 46.03 mg.min-1, respectively. However, the highest thermal stability was achieved using Macro-CMag, that was 8 and 3-times more stable than Nano-CMag and Micro-CMag biocatalysts, respectively. Pectinase immobilized on Macro-CMag kept 85% of its initial activity after 25 batch cycles in orange juice clarification. These results suggested that the chitosan magnetic biocatalysts presented great potential application as clarifying catalysts for the fruit juice industry and the great importance of the chitosan particles preparation on the final biocatalyst properties.

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The present work had the objective of producing liqueurs from mango peels (varieties "Haden" and "Tommy Atkins") by processes of alcoholic maceration and maceration with pectinase, as well as to evaluate bioactive compounds by reversed-phase high-performance liquid chromatography coupled to diode array detection and fluorescence-detection (RP-HPLC/DAD/FD) and in vitro antioxidant activity (AOX), for by-product potential reuse. Alcoholic maceration in wine ethanol (65% v/v) produced liqueurs with higher phytochemical and AOX content. Maceration with pectinase resulted in liqueurs with higher quercetin-3-O-glucopyranoside content. In relation to mango varieties, Haden liqueurs presented higher bioactive content than Tommy Atkins liqueurs. The liqueurs presented high antioxidant activity. The main bioactive compounds found were flavanols (epicatechin-gallate, epigallocatechin-gallate), flavonols (quercetin-3-O-glucopyranoside and rutin), and phenolic acids (gallic acid, o-coumaric acid, and syringic acid). The present study showed that the production of liqueur enabled the recovering of an important part of the bioactive content of mango peels, suggesting an alternative for the recovery of antioxidant substances from this by-product.

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Pectinase is a general term for a class of enzymes that decompose pectin. To obtain a fungal strain with high-activity pectinase of potential commercial importance, we screened microorganisms from the soil of vineyards, performed mutation breeding by ultraviolet (UV) and nitrosoguanidine (NTG) mutagenesis, and performed comparisons to commercially available pectinases. We found that the derived pectinase-producing strain Rn14-88A had the highest pectinase activity of 8363.215 U/mL, and identified it using internal transcribed spacer sequence analysis as Aspergillus tubingensis. Rn14-88A was the original strain for UV mutagenesis, from which mutant strain R-7-2-4 had the highest pectinase enzyme activity (9198.68 U/mL), which was a 9.99% increase compared to that of Rn14-88A. Following NTG mutagenesis of R-7-2-4, mutant strain Y1-3-2-6 had a pectinase enzyme activity of 9843.34 U/mL, which reflects a 6.36% increase compared to the pectinase activity of R-7-2-4. Subsequently, another round of NTG mutagenesis was performed on Y1-3-2-6, and the mutagenic strain Y2-6-3-4 exhibited an improved enzyme activity of 21,864.34 U/mL, which was 161.44% higher than that of Rn14-88A. Through liquid fermentation experiments of A. tubingensis Y2-6-3-4, it was determined that pectinase activity was the highest at a fermentation time of 20 h. Therefore, we conclude that A. tubingensis Y2-6-3-4 has potential for use in commercial production.

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Pectinases are important enzymes not only for their potential applications in different industries such animal feed, agricultural, textile, beverage, food processing, oil extraction, etc. Ten fungal species were isolated from the soil and screened for production of pectinase enzyme by using the pectin agar medium. Pectinolytic enzymes synthesis were attained at a temperature of 30 °C and activities were determined after a seven-days culture of Aspergillus sp. 391 and Aspergillus sp. 031, in a basic medium containing 2% citrus pectin and as the sole carbon source. The extract enzymatic showed an optimum activity for exo-polygalacturonase (PG) and pectin lyase (PNL) against galacturonic acid and pectin at pH 4.5 and 5.5, respectively. There were variations in PG and PNL enzymes levels produced in culture filtrates obtained of Aspergillus sp. 391 with addition of citrus waste (2.0 and 4.0 % w/v) to the medium. Maximum activity for PNL activity was observed in the medium containing 5% pectin or 4% citrus waste, as sole carbon source, after 7 days of growth. The results showed that the isolate Aspergillus sp. 391 is a promising for pectinolytic enzymes production at the industrial level.(AU)

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Biological degumming is an eco-friendly, efficient, high-quality and low-cost method that has become the leading bast fiber degumming technology. However, bacterial strains with short degumming cycles, high gum removal rates and small fiber damage are few. To screen high quality microbial resources with bast-fiber biological degumming function, soil samples were collected from a continuously cultivated banana plantation and then used to be enriched by ramie and kenaf materials in turn. A selective pectin-degrading medium was used to screen for excellent bacteria. A dominant bacterial strain was identified by phenotypic and genotypic characteristics, and its biological degumming effects on ramie and kenaf were verified by a comprehensive evaluation system. Results showed that seven bacterial strains secreting pectinase were obtained and the largest hydrolysis circle with a diameter ratio H/C of 2.4 was produced by the bacterial strain hn1-1, which was preliminarily identified as the Bacillus cereus by colony morphological characteristics and 16S rDNA sequence (GenBank accession number: KX013542) cluster analysis. The fiber production of ramie and kenaf degummed by B. cereus hn1-1 for 10 h were 72 % and 76 %, the residual gum rates were 4 % and 5 %, respectively. These values satisfied the textile industry requirement of < 6 % residual gum rate. Therefore, an effective biological degumming bacterium, B. cereus, was identified using a pectin-hydrolysis selective medium through a simple, economical, and time-saving method. Furthermore, the biological degumming technology by B. cereus for ramie and kenaf had a short cycle, ideal removal gum rate, and high-quality and productive fiber output.

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Biological degumming is an eco-friendly, efficient, high-quality and low-cost method that has become the leading bast fiber degumming technology. However, bacterial strains with short degumming cycles, high gum removal rates and small fiber damage are few. To screen high quality microbial resources with bast-fiber biological degumming function, soil samples were collected from a continuously cultivated banana plantation and then used to be enriched by ramie and kenaf materials in turn. A selective pectin-degrading medium was used to screen for excellent bacteria. A dominant bacterial strain was identified by phenotypic and genotypic characteristics, and its biological degumming effects on ramie and kenaf were verified by a comprehensive evaluation system. Results showed that seven bacterial strains secreting pectinase were obtained and the largest hydrolysis circle with a diameter ratio H/C of 2.4 was produced by the bacterial strain hn1-1, which was preliminarily identified as the Bacillus cereus by colony morphological characteristics and 16S rDNA sequence (GenBank accession number: KX013542) cluster analysis. The fiber production of ramie and kenaf degummed by B. cereus hn1-1 for 10 h were 72 % and 76 %, the residual gum rates were 4 % and 5 %, respectively. These values satisfied the textile industry requirement of < 6 % residual gum rate. Therefore, an effective biological degumming bacterium, B. cereus, was identified using a pectin-hydrolysis selective medium through a simple, economical, and time-saving method. Furthermore, the biological degumming technology by B. cereus for ramie and kenaf had a short cycle, ideal removal gum rate, and high-quality and productive fiber output.(AU)

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The present study deals with the isolation screening and optimization of fungal strain for pectinase production. The fungal strains were isolated from different sources, including soil, fruits etc. Qualitative screening was performed on the basis of the pectin hydrolysis zone. While, quantitative screening was carried out employing submerged fermentation. Among all the strains the strains showing highest pectinolytic potential were selected identified and assigned the code Aspergillus niger ABT-5.The influence of different fermentation media on pectinase production was evaluated. The M5 medium containing 10g wheat bran, nutrient medium containing (g/l) of (NH4)2SO4 6.0, K2HPO4 6.0, KH2PO4 6.0, MgSO4.7H2O 0.1 gave the highest pectinase production. The other important physico chemical parameters including incubation period, temperature, and volume of media, size of inoculum, carbon and nitrogen sources were also optimized for pectinase production. The highest pectinase production (15.5U/ml) was obtained at 72h of incubation, pH 6, temperature 30°C, volume of media 50ml. Fructose and urea were designated as best carbon and nitrogen sources subsequently.

O presente estudo trata da triagem de isolamento e otimização da cepa fúngica para produção de pectinase. As cepas fúngicas foram isoladas de diferentes fontes, incluindo solo, frutas, etc. A triagem qualitativa foi realizada com base na zona de hidrólise da pectina. Enquanto, a triagem quantitativa foi realizada utilizando fermentação submersa. Entre todas as cepas, as cepas que apresentaram maior potencial pectinolítico foram selecionadas e atribuídas ao código Aspergillus niger ABT-5. Avaliou-se a influência de diferentes meios de fermentação na produção de pectinase. O meio M5 contendo 10g de farelo de trigo, meio nutriente contendo (g / l) de (NH4)2SO4 6.0, K2HPO4 6.0, KH2PO4 6.0, MgSO4.7H2O 0.1, proporcionou a maior produção de pectinase. Os outros parâmetros físico-químicos importantes, incluindo período de incubação, temperatura e volume dos meios, tamanho do inóculo, fontes de carbono e nitrogênio também foram otimizados para a produção de pectinase. A maior produção de pectinase (15,5U / ml) foi obtida às 72h de incubação, pH 6, temperatura 30 ºC, volume dos meios 50ml. A frutose e a ureia foram designadas como melhores fontes de carbono e nitrogênio posteriormente.

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RESUMO

The kinetics and thermodynamics of Aspergillus aculeatus pectinase, either free or immobilized in alginate beads, were investigated. Pectinase immobilization ensured an enzyme immobilization yield of 59.71%. The irreversible denaturation of pectinase in both preparations was evaluated at temperatures ranging from 30 to 60 °C. When temperature was raised, the first-order thermal denaturation constant increased from 0.0011 to 0.0231 min-1 for the free enzyme and from 0.0017 to 0.0700 min-1 for the immobilized one, respectively. The results of residual activity tests enabled us to estimate, for denaturation of both free and immobilized pectinase, the activation energy (E⁎d = 85.1 and 101.6 kJ·mol-1), enthalpy (82.59 ≤ ΔH⁎d ≤ 82.34 kJ·mol-1 and 99.11 ≤ ΔH⁎d ≤ 98.86 kJ·mol-1), entropy (-63.26 ≤ ΔS⁎d ≤ -63.85 J·mol-1·K-1 and -5.50 ≤ ΔS⁎d ≤ -5.23 J·mol-1·K-1) and Gibbs free energy (101.8 ≤ ΔG⁎d ≤ 104.7 kJ·mol-1 and 100.6 ≤ ΔG⁎d ≤ 102.0 kJ·mol-1). The integral activity of a continuous system using the free and immobilized enzyme was also predicted, whose results indicated a satisfactory enzyme long-term thermostability in both preparations at temperatures commonly used to clarify juice. These results suggest that both free and immobilized pectinase from A. aculeatus may be profitably exploited in future food industrial applications, with special concern to the immobilized enzyme because of its reusability.

Assuntos

RESUMO

In the present study, we prepared two different magnetic biocatalysts of pectinase and cellulase: carrier-free magnetic CLEAs (CLEA-MP*) and immobilization on glutaraldehyde-activated magnetite (Enz-Glu-MP*). The biocatalysts were compared to their magnetic properties, immobilization parameters, stability and grape juice clarification. Enz-Glu-MP* presented higher magnetic properties than CLEA-MP*, whereas this presented higher surface area and pore volume. The KM of the enzyme immobilized on Enz-Glu-MP* was 25.65mM, lower in comparison to the CLEA-MP* (33.83mM). On the other hand, CLEA-MP* was the most active and stable biocatalyst, presenting higher recovered activity (33.4% of cellulase), higher thermal stability (2.39 stabilization factor) and improved reusability (8cycles). The integration of magnetic technology with enzymatic immobilization emerges as a possibility to increase the recover and reuse of biocatalysts for application in juice technology.

Assuntos