RESUMO

Laccases (E.C. 1.10.3.2) are glycoproteins widely distributed in nature. Their structural conformation includes three copper sites in their catalytic center, which are responsible for facilitating substrate oxidation, leading to the generation of H2O instead of H2O2. The measurement of laccase activity (UL-1) results may vary depending on the type of laccase, buffer, redox mediators, and substrates employed. The aim was to select the best conditions for rGILCC 1 and rPOXA 1B laccases activity assay. After sequential statistical assays, the molecular dynamics proved to support this process, and we aimed to accumulate valuable insights into the potential application of these enzymes for the degradation of novel substrates with negative environmental implications. Citrate buffer treatment T2 (CB T2) (pH 3.0 ± 0.2; λ420nm, 2 mM ABTS) had the most favorable results, with 7.315 ± 0.131 UL-1 for rGILCC 1 and 5291.665 ± 45.83 UL-1 for rPOXA 1B. The use of citrate buffer increased the enzyme affinity for ABTS since lower Km values occurred for both enzymes (1.49 × 10-2 mM for rGILCC 1 and 3.72 × 10-2 mM for rPOXA 1B) compared to those obtained in acetate buffer (5.36 × 10-2 mM for rGILCC 1 and 1.72 mM for rPOXA 1B). The molecular dynamics of GILCC 1-ABTS and POXA 1B-ABTS showed stable behavior, with root mean square deviation (RMSD) values not exceeding 2.0 Å. Enzyme activities (rGILCC 1 and rPOXA 1B) and 3D model-ABTS interactions (GILCC 1-ABTS and POXA 1B-ABTS) were under the strong influence of pH, wavelength, ions, and ABTS concentration, supported by computational studies identifying the stabilizing residues and interactions. Integration of the experimental and computational approaches yielded a comprehensive understanding of enzyme-substrate interactions, offering potential applications in environmental substrate treatments.

Assuntos

RESUMO

The first traces of Tetracycline (TE) were detected in human skeletons from Sudan and Egypt, finding that it may be related to the diet of the time, the use of some dyes, and the use of soils loaded with microorganisms, such as Streptomyces spp., among other microorganisms capable of producing antibiotics. However, most people only recognise authors dating between 1904 and 1940, such as Ehrlich, Domagk, and Fleming. Antibiotics are the therapeutic option for countless infections treatment; unfortunately, they are the second most common group of drugs in wastewaters worldwide due to failures in industrial waste treatments (pharmaceutics, hospitals, senior residences) and their irrational use in humans and animals. The main antibiotics problem lies in delivered and non-prescribed human use, use in livestock as growth promoters, and crop cultivation as biocides (regulated activities that have not complied in some places). This practice has led to the toxicity of the environment as antibiotics generate eutrophication, water pollution, nutrient imbalance, and press antibiotic resistance. In addition, the removal of antibiotics is not a required process in global wastewater treatment standards. This review aims to raise awareness of the negative impact of antibiotics as residues and physical, chemical, and biological treatments for their degradation. We discuss the high cost of physical and chemical treatments, the risk of using chemicals that worsen the situation, and the fact that each antibiotic class can be transformed differently with each of these treatments and generate new compounds that could be more toxic than the original ones; also, we discuss the use of enzymes for antibiotic degradation, with emphasis on laccases.

Assuntos

RESUMO

The history of colour is fascinating from a social and artistic viewpoint because it shows the way; use; and importance acquired. The use of colours date back to the Stone Age (the first news of cave paintings); colour has contributed to the social and symbolic development of civilizations. Colour has been associated with hierarchy; power and leadership in some of them. The advent of synthetic dyes has revolutionized the colour industry; and due to their low cost; their use has spread to different industrial sectors. Although the percentage of coloured wastewater discharged by the textile; food; pharmaceutical; cosmetic; and paper industries; among other productive areas; are unknown; the toxic effect and ecological implications of this discharged into water bodies are harmful. This review briefly shows the social and artistic history surrounding the discovery and use of natural and synthetic dyes. We summarise the environmental impact caused by the discharge of untreated or poorly treated coloured wastewater to water bodies; which has led to physical; chemical and biological treatments to reduce the colour units so as important physicochemical parameters. We also focus on laccase utility (EC 1.10.3.2), for discolouration enzymatic treatment of coloured wastewater, before its discharge into water bodies. Laccases (p-diphenol: oxidoreductase dioxide) are multicopper oxidoreductase enzymes widely distributed in plants, insects, bacteria, and fungi. Fungal laccases have employed for wastewater colour removal due to their high redox potential. This review includes an analysis of the stability of laccases, the factors that influence production at high scales to achieve discolouration of high volumes of contaminated wastewater, the biotechnological impact of laccases, and the degradation routes that some dyes may follow when using the laccase for colour removal.

Assuntos

RESUMO

BACKGROUND: Laccases (EC 1.10.3.2) are multi-copper oxidoreductases with great biotechnological importance due to their high oxidative potential and utility for removing synthetic dyes, oxidizing phenolic compounds, and degrading pesticides, among others. METHODS: A real-time stability study (RTS) was conducted for a year, by using enzyme concentrates from 3 batches (L1, L3, and L4). For which, five temperatures 243.15, 277.15, 298.15, 303.15, 308.15, and 313.15 K were assayed. Using RTS data and the Arrhenius equation, we calculated the rPOXA 1B accelerated stability (AS). Molecular dynamics (MD) computational study results were very close to those obtained experimentally at four different temperatures 241, 278, 298, and 314 K. RESULTS: In the RTS, 101.16, 115.81, 75.23, 46.09, 5.81, and 4.83% of the relative enzyme activity were recovered, at respective assayed temperatures. AS study, showed that rPOXA 1B is stable at 240.98 ± 5.38, 277.40 ± 1.32 or 297.53 ± 3.88 K; with t1/2 values of 230.8, 46.2, and 12.6 months, respectively. Kinetic and thermodynamic parameters supported the high stability of rPOXA 1B, with an Ed value of 41.40 KJ mol- 1, a low variation of KM and Vmax, at 240.98 ± 5.38, and 297.53 ± 3.88 K, and ∆G values showing deactivation reaction does not occur. The MD indicates that fluctuations in loop, coils or loops with hydrophilic or intermediate polarity amino acids as well as in some residues of POXA 1B 3D structure, increases with temperature; changing from three fluctuating residues at 278 K to six residues at 298 K, and nine residues at 314 K. CONCLUSIONS: Laccase rPOXA 1B demonstrated experimentally and computationally to be a stable enzyme, with t1/2 of 230.8, 46.2 or 12.6 months, if it is preserved impure without preservatives at temperatures of 240.98 ± 5.38, 277.40 ± 1.32 or 297.53 ± 3.88 K respectively; this study could be of great utility for large scale producers.

Assuntos

RESUMO

Laccases (E.C. 1.10.3.2) are multicopper oxidases of great importance in the industry due to their non-specificity and high oxidative potential. Laccases are useful to bleach synthetic dyes, oxidize phenolic compounds and degrade pesticides, among others. Hence, the objective of this work was to optimize low cost culture media for recombinant (rPOXA 1B) laccase production from Pleurotus ostreatus in Pichia pastoris. To this end, low cost nitrogen sources were studied, such as malt extract, isolated soy protein and milk serum. Following, two central composite designs (CCD) were performed. In CCD-1 different concentrations of glucose USP (0-13.35 gL-1), protein isolated soy protein (5-25 gL-1), malt extract (3.5-17.5 gL-1) and (NH4)2SO4 (1.3-6.5 gL-1) were evaluated. In CCD-2 only different concentrations of glucose USP (7.9-22 gL-1) and isolated soy protein (15.9-44.9 gL-1) were evaluated. CCD-2 results led to a One Factor Experimental design (OFED) to evaluate higher isolated soy protein (20-80 gL-1) concentrations. In all designs, (CCD-1, CCD-2 and OFED) CuSO4 (0.16 gL-1) and chloramphenicol (0.1 gL-1) concentrations remained unchanged. For the OFED after sequential statistical optimization, an enzyme activity of 12,877.3 ± 481.2 UL-1 at 168 h was observed. rPOXA 1B activity increased 30.54 % in comparison with CCD-2 results. Final composition of optimized media was: 20 gL-1 glucose USP, 50 gL-1 isolated soy protein 90 % (w/w), 11.74 gL-1 malt extract, and 4.91 gL-1 (NH4)2SO4. With this culture media, it was possible to reduce culture media costs by 89.84 % in comparison with improved culture media previously described by our group.

RESUMO

The objective of this study was to evaluate the potential of eight fungal isolates obtained from soils in rice crops for straw degradation in situ. From the initial eight isolates, Pleurotus ostreatus T1.1 and Penicillium sp. HC1 were selected for further characterization based on qualitative cellulolytic enzyme production and capacity to use rice straw as a sole carbon source. Subsequently, cellulolytic, xylanolytic, and lignolytic (Pleurotus ostreatus) activity on carboxymethyl cellulose, oat xylan, and rice straw with different nitrogen sources was evaluated. From the results obtained it was concluded both isolates are capable to produce enzymes necessary for rice straw degradation. However, their production is dependent upon carbon and nitrogen source. Last, it was established that Pleurotus ostreatus T1.1 and Penicillium sp. HC1 capability to colonize and mineralize rice straw, in mono-and co-culture, without affecting nitrogen soil content.

Assuntos

RESUMO

Cellulase is a family of at least three groups of enzymes that participate in the sequential hydrolysis of cellulose. Recombinant expression of cellulases might allow reducing their production times and increasing the low proteins concentrations obtained with filamentous fungi. In this study, we describe the production of Trichoderma reesei cellobiohydrolase II (CBHII) in a native strain of Wickerhamomyces anomalus. Recombinant CBHII was expressed in W. anomalus 54-A reaching enzyme activity values of up to 14.5 U L-1. The enzyme extract showed optimum pH and temperature of 5.0-6.0 and 40°C, respectively. Enzyme kinetic parameters (KM of 2.73 mM and Vmax of 23.1 µM min-1) were between the ranges of values reported for other CBHII enzymes. Finally, the results showed that an enzymatic extract of W. anomalus 54-A carrying the recombinant T. reesei CBHII allows production of reducing sugars similar to that of a crude extract from cellulolytic fungi. These results show the first report on the use of W. anomalus as a host to produce recombinant proteins. In addition, recombinant T. reesei CBHII enzyme could potentially be used in the degradation of lignocellulosic residues to produce bioethanol, based on its pH and temperature activity profile.

RESUMO

Floriculture is a vital agro-industrial sector in the Colombian economy; the export of flowers positively impacts employment and the balance of trade. However, this industry could negatively impact the environment if its waste products are not handled properly. These flower residues, rich in lignin, hemicellulose and cellulose, could be a cost-effective raw material to produce enzymes. Here, we evaluate the production of lignocellulolytic enzymes by degradation of Chrysanthemum and Rosa residues using Pleurotus ostreatus, and manganese sulfate and copper sulfate as inductors. From the two residues, we obtained laccase, manganese peroxidase, endoglucanase, exoglucanase, and (3-glucosidase. The use of inductors, favored all enzyme activities except for (3-glucosidase. The enzymes that displayed the highest activity were laccase (4,693.4 U/L and 2,640 U/L from the residues of Chrysanthemum and Rosa, respectively) and (3-glucosidase (9,513 U/L and 6,811.9 U/L). The enzyme that showed the lowest activity was endoglucanase (11.5 U/L and 15.4 U/L). Under the conditions evaluated, the best substrate for enzyme production is Chrysanthemum wastes; the extracts obtained had higher enzymatic activity than the extracts from Rosa residues.

En Colombia la floricultura es un sector agro-industrial importante, con impactos positivos en el empleo y la balanza comercial. Sin embargo, tiene impacto negativo en el medio ambiente porque genera alto volumen de residuos. Estos residuos, ricos en lignina, hemicelulosa y celulosa, podrían ser una materia prima de bajo costo para la producción de enzimas. En este trabajo se estudió en la producción de enzimas lignocelulíticas por la degradación con Pleurotus ostreatus de residuos de Chrysanthemum y Rosa, usando como inductores sulfato de manganeso y de cobre. A partir de ambos residuos se obtuvieron lacasa, manganeso peroxidasa, endoglucanasa, exoglucanasa y p-glucosidasa. Los inductores favorecieron todas las actividades enzimáticas, excepto para p-glucosidasa. Las enzimas que tuvieron mayores actividades fueron lacasa (4,693.4 U/L y 2,640 U/L a partir del residuo de Chrysanthemum y Rosa, respectivamente) y p-glucosidasa (9,513 U/L y 6,811.9 U/L). La enzima que tuvo menor actividad fue endoglucanasa (11.5 U/L y 15.4 U/L). Bajo las condiciones evaluadas, el mejor residuo para producción de enzimas fue Chrysanthemum, porque los extractos tuvieron mayor actividad enzimática que los producidos a partir de Rosa.

Na Colombia, a floricultura è um importante setor da indùstria agrícola, com impactos positivos sobre o sector laboral na balança comercial. Além disto, tem impacto negativo sobre o meio ambiente, pois gera grandes volumes de resíduos. Estes resíduos, com altos conteùdos em lignina, hemicelulose e celulose, podem ser uma matèria-prima de baixo custo para a produçâo de enzimas. Neste traballio foi estudada a produçâo da enzimas lignoceluliticas pela degradaçâo com Pleurotus ostreatus de residuos de Chrysanthemum e Rosa, utilizando como indutores sulfatos de cobre e manganês. A partir destes resíduos foram obtidos lacase, manganês peroxidase, endoglucanase, exoglucanase e β-glicosidase. O uso de indutores favoreceu as atividades enzimáticas, exceto β-glicosidase. As enzimas que apresentaram atividades mais elevadas foram lacase (4,693.4 U/L e 2,640 U/L a partir do Chrysanthemum e Rosa, respetivamente) e β-glicosidase (9,513 U/L e 6,81.9 U/L). A enzima que apresentou menor atividade foi a endoglucanase (11.5 U/L e 15.4 U/L). Nas condiçôes testadas, o melhor resíduo para a produçâo da enzima foi Chrysanthemum, porque os extratos tinham uma atividade enzimática mais elevada que aqueles produzidos a partir de Rosa.

RESUMO

Ethanol production derived from Saccharomyces cerevisiae fermentation of a hydrolysate from floriculture waste degradation was studied. The hydrolysate was produced from Chrysanthemum (Dendranthema grandiflora) waste degradation by Pleurotus ostreatus and characterized to determine the presence of compounds that may inhibit fermentation. The products of hydrolysis confirmed by HPLC were cellobiose, glucose, xylose and mannose. The hydrolysate was fermented by S. cerevisiae, and concentrations of biomass, ethanol, and glucose were determined as a function of time. Results were compared to YGC modified medium (yeast extract, glucose and chloramphenicol) fermentation. Ethanol yield was 0.45 g g(-1), 88 % of the maximal theoretical value. Crysanthemum waste hydrolysate was suitable for ethanol production, containing glucose and mannose with adequate nutrients for S. cerevisiae fermentation and low fermentation inhibitor levels.

Assuntos

RESUMO

Objetivo. Determinar actividades amilolíticas, celulolíticas, lipolíticas, pectinolíticas y proteolíticas en 32 aislamientos de Fusarium spp. de origen humano, animal y vegetal. Materiales y métodos. Las actividades enzimáticas se determinaron a nivel cualitativo, por medio de la medición de halos de hidrólisis en placas de agar con el respectivo sustrato, y a nivel cuantitativo se realizó un cultivo líquido para determinar la degradación del respectivo sustrato por medio de técnicas colorimétricas. Resultados. Todos los aislamientos presentaron actividades enzimáticas a nivel cualitativo, excepto las amilolíticas y lipolíticas. La determinación a nivel cuantitativo fue posible para las enzimas evaluadas, a excepción de las lipasas. Conclusión. La determinación de los perfiles enzimáticos amilolíticos, celulolíticos, pectinolíticos y proteolíticos de cada uno de los aislamientos evaluados pertenecientes al género Fusarium sugirió su capacidad, indistintamente de su procedencia, de degradar estos sustratos...

Assessment of enzymatic characterization of Fusarium spp. isolated from human, animal, and plant wounds. Objective. To determine amylolytic, cellulolytic, lipolytic, pectinolytic and proteolytic activities in 32 Fusarium spp. isolates from humans, animals and plants. Materials and methods. Qualitative determination of enzymatic activities was done by measuring hydrolysis halos in agar plates with their corresponding substrate. Quantitative determination was done by colorimetric techniques, using liquid culture supernatants to determine the respective substrate degradation. Results. All isolates showed enzymatic activities from a qualitative point of view, except amylolytic and lipolytic. Quantitative determination was possible for all the evaluated enzymes except lipases. Conclusion. The determination of amylolytic, cellulolytic, pectinolytic and proteolytic enzymatic profiles of each of the Fusarium isolates assessed suggests their capacity to degrade these substrates, irrespectively of their origin...

Avaliação das atividades enzimáticas de Fusarium spp. Isolados a partir de lesões em humanos, animais e plantas. Objetivo. Determinar as atividades amilolíticas, celulolíticas, lipolítica, pectinolíticas e proteolíticas em 32 isolamentos de Fusarium spp. de origem humana, animal e vegetal. Materiais e métodos. As atividades enzimáticas foram determinadas a nível qualitativo medindo os halos de hidrólise em placas de agar com o substrato respectivo e a nível quantitativo realizou-se uma cultura líquida para determinar a degradação do substrato respectivos por meio de técnicas colorimétricas. Resultados. Todos os isolados apresentaram uma atividade enzimática a nível qualitativo, exceto as amilolíticas e lipolíticas. A determinação a nível quantitativo foi possível para as enzimas testadas, exceto para as lipases. Conclusão. A determinação de perfis enzimáticos amilolíticos, celulolíticos, pectinolíticos e proteolíticos de cada um dos isolados testados pertencentes ao gênero Fusarium, sugeriu sua capacidade, independentemente da sua origem, para degradar estes substratos...

Assuntos