Actividades ligninolíticas y producción de basidiomas de Ganoderma lucidum en cultivo sólido suplementado con manganeso / Ligninolytic activities and production of Ganoderma lucidum basidiomes in solid culture supplemented with manganese

RESUMEN Ganoderma lucidum es un basidiomiceto de pudrición blanca estudiado especialmente por sus atributos medicinales. No obstante, la información sobre la suplementación de los medios de cultivo con metales como Zn, Li, Mn, Cu es escasa aun conociendo que la presencia de metales en los sustratos mejora las características de los basidiomas obtenidos e incrementa su productividad. El objetivo fue evaluar las actividades enzimáticas lacasa (Lc) y manganeso peroxidasa (MnP), la fructificación y eficiencia biológica (EB) de G. lucidum en cultivos sólidos formulados con residuos agroindustriales (aserrín de roble, cascarilla de café, salvado de maíz) suplementados con dos niveles de sal de manganeso II (0,05 % y 0,1 % p/p) y una formulación sin adición de la sal de manganeso. Las actividades enzimáticas se determinaron durante 98 días del ciclo productivo, con toma de muestras semanales. El tratamiento uno (0,05 % p/p de MnSO4H2O) suministró la mayor EB del cultivo con 25,90 ± 2,12 % y los mayores títulos de actividades ligninolíticas en el tiempo con 0,7299 UE/g s.s. de MnP a los 35 días de fermentación y 4,1 760 UE/g s.s para la actividad de Lc a los 42 días de proceso con relación a los tratamientos dos y control. Asimismo, hubo una disminución del ciclo de cultivo del hongo para los tratamientos uno (83 días) y dos (95 días) en comparación con el tratamiento control (117 días). Los resultados de este trabajo son promisorios para cultivadores industriales de G. lucidum, ya que la suplementación de los sustratos con Mn incrementa la productividad de los cultivos.

ABSTRACT Ganoderma lucidum is a white rot basidiomycete specially studied for its medicinal attributes. However, the information on the supplementation of the substrate with metals such as Zn, Li, Mn, Cu and others is scarce. Even knowing that the presence of metals in the substrates improves the characteristics of the basidiomes produced and increases their productivity. The objective was to evaluate the enzymatic activities laccase (Lc) and manganese peroxidase (MnP). The fructification and biological efficiency (BE) of G. lucidum in solid culture formulated with agroindustrial residues, (oak sawdust, coffee husk, bran corn) supplemented with two levels of manganese II salt, (0.05 % and 0.1 % w/ w) and a formulation without addition of manganese II salt. Enzymatic activities were determined during 98 days of the production cycle, with weekly sampling. Treatment one (0.05 % w/w MnSO4.H2O) provided the highest BE of the culture with 25.90 ± 0.54% and the highest titers of ligninolytic activities, in the time with 0.7299 EU/g d.s for MnP at 35 days of fermentation and 4.1760 EU/g d.s for Lc activity at 42 days of process, in relation to treatments two and control. Likewise, there was a decrease in the fungus culture cycle for treatments one (83 days) and two (95 days) compared to the control treatment (117 days). The results of this work are promising for industrial growers of G. lucidum, since the supplementation of the substrates with Mn increase the productivity of the cultures.

Produção de lacase de Pycnoporus sanguineus em meio de cultivo à base de melaço soja / Laccase production by Pycnoporus sanguineus in culture media with soybean molasses / Producción de lacasa de Pycnoporus sanguineus en medio de cultivo con melaza de soja

Lacases são polifenol oxidases que utilizam a capacidade redox de íons cobre para reduzir oxigênio a água e oxidar um substrato fenólico. A síntese e secreção de lacases de basidiomicetos dependem de vários fatores como os nutrientes presentes no meio de cultura. Visando à produção de lacase, Pycnoporus sanguineus foi cultivado em meio contendo melaço de soja como única fonte de carbono, ureia como fonte de nitrogênio suplementar em diferentes concentrações (0,6; 1,2; 2,4; 4,8 e 9,6 g/L de nitrogênio) e diferentes concentrações de CuSO4 (0, 150, 200, 250 e 300 µM). O extrato enzimático produzido nas melhores condições de cultivo foi utilizado para a descoloração dos corantes remazol azul brilhante R (antraquinona), amarelo 145, preto 5, vermelho 195 (azo) e verde malaquita (trifenilmetano). As concentrações de nitrogênio não afetaram a produção de lacase, exceto a maior concentração (9,6 g/L) que reduziu a atividade enzimática. A adição de cobre ao meio de cultivo (150 µM) aumentou a atividade de lacase em 112%. A maior atividade de lacase (~34300 U/L) promoveu a descoloração dos corantes remazol azul brilhante R (67,5%) e verde malaquita (28,3%) em 24h, sendo os corantes azo descoloridos apenas parcialmente. Concluiu-se que o melaço de soja é um resíduo agroindustrial adequado para produção de lacase de P. sanguineus com potencial para degradação de corantes.

Laccases are multicopper oxidases using the redox ability from copper ions to reduce oxygen to water, while oxidizing a phenolic substrate. Laccase synthesis and secretion in basidiomycetes depend on the conditions provided and on the nutrients present in the culture medium. Pycnoporus sanguineus was cultivated in medium containing soybean molasses as the sole carbon source, with urea as the source of supplemental nitrogen at different concentrations (0.6, 1.2, 2.4, 4.8 and 9.6 g/L nitrogen), and different CuSO4 concentrations (0, 150, 200, 250 and 300 µM). The enzymatic extract produced under the best cultivation conditions was used for the depigmentation of remazole brilliant blue R (anthraquinone), yellow 145, black 5, red 195 (azo) and malachite green (triphenylmethane). Nitrogen concentrations did not affect laccase production, except for the higher concentration (9.6 g/L) reducing enzymatic activity. The addition of copper to the culture medium (150 µM) increased laccase activity by 112%. The highest laccase activity (~34300 U/L) promoted the depigmentation of remazol brilliant blue R (67.5%) and malachite green (28.3%) dyes in 24 hours. Azo dyes were only partially discolored. Therefore, it can be considered that soybean molasses is an agro-industrial byproduct suitable for the production of P. sanguineus laccase with potential for dye degradation.

Lacasas son polifenoles oxidasas que utilizan la capacidad redox de iones de cobre para reducir el oxígeno del agua y oxidar un sustrato fenólico. La síntesis y secreción de lacasas de basidiomicetos dependen de las condiciones como los nutrientes presentes en el medio de cultura. Buscando la producción de lacasa, se cultivó Pycnoporus sanguineus en medio que contenía melaza de soja como única fuente de carbono, urea como fuente de nitrógeno suplementar a diferentes concentraciones (0,6, 1,2, 2,4, 4,8 y 9,6 g/L de nitrógeno) y diferentes concentraciones de CuSO4 (0, 150, 200, 250 y 300 µM). El extrato enzimático producido en mejores condiciones de cultivo ha sido utilizado para la decoloración de los colorantes remazol azul brillante R (antraquinona), amarillo 145, negro 5, rojo 195 (azoico) y verde malaquita (trifenilmetano). Las concentraciones de nitrógeno no afectaron la producción de lacasa, excepto la mayor concentración (9,6 g/L) que redujo la actividad enzimática. La adición de cobre al medio de cultivo (150 µM) aumentó la actividad de la lacasa en un 112%. La mayor actividad de lacasa (~34300 U/L) promovió la decoloración de los colorantes remazol azul brillante R (67,5%) y verde malaquita (28,3%) en 24h, siendo que los colorantes azoicos fueran parcialmente decolorados. Se concluye que la melaza de soja es un desecho agroindustrial adecuado para la producción de lacasa de P. sanguineus con potencial para degradación de colorantes.

Halotolerance, ligninase production and herbicide degradation ability of basidiomycetes strains

Fungi have been recently recognized as organisms able to grow in presence of high salt concentration with halophilic and halotolerance properties and their ligninolytic enzyme complex have an unspecific action enabling their use to degradation of a number of xenobiotic compounds. In this work, both the effect of salt and polyols on growth of the basidiomycetes strains, on their ability to produce ligninolytic enzyme and diuron degradation were evaluated. Results showed that the presence of NaCl in the culture medium affected fungal specimens in different ways. Seven out of ten tested strains had growth inhibited by salt while Dacryopinax elegans SXS323, Polyporus sp MCA128 and Datronia stereoides MCA167 fungi exhibited higher biomass production in medium containing 0.5 and 0.6 mol.L-1 of NaCl, suggesting to be halotolerant. Polyols such as glycerol and mannitol added into the culture media improved the biomass and ligninases production by D. elegans but the fungus did not reveal consumption of these polyols from media. This fungus degraded diuron in medium control, in presence of NaCl as well as polyols, produced MnP, LiP and laccase.

Ethanol production from spent substrate of pleurotus eous.

Spent substrate, the residual material of mushroom cultivation, causes disposal problems for cultivators. Currently the spent substrate of different mushrooms is used mainly for composting. Edible mushrooms of Pleurotus sp. can grow on a wide range of lignocellulosic substrates. In the present study, Pleurotus eous was grown on paddy straw and the spent substrate was used for the production of ethanol. Lignocellulosic biomass cannot be saccharified by enzymes to high yield of ethanol without pretreatment. The root cause for the recalcitrance of lignocellulosic biomass such as paddy straw is the presence of lignin and hemicelluloses on the surface of cellulose. They form a barrier and prevent cellulase from accessing the cellulose in the substrate. In the untreated paddy straw, the amount of hemicelluloses and lignin (in % dry weight) were 20.30 and 20.34 respectively and the total reducing sugar was estimated to be 5.40 mg/g. Extracellular xylanase and ligninases of P. eous could reduce the amount of hemicelluloses and lignin to 16 and 11(% dry weight) respectively, by 21st day of cultivation. Growth of mushroom brought a seven fold increase in the total reducing sugar yield (39.20 mg/g) and six fold increase in the production of ethanol (6.48 g/L) after 48hrs of fermentation, when compared to untreated paddy straw.