Enzymatic hydrolysis of barley straw for biofuel industry using a novel strain of Trametes villosa from Paranaense rainforest.

Agricultural practices generate lignocellulosic waste that can be bioconverted by fungi to generate value-added products such as biofuels. In this context, fungal enzymes are presented as an alternative for their use in the hydrolysis of cellulose to sugars that can be fermented to ethanol. The aim of this work was to characterize LBM 033 strain and to analyze its efficiency in the hydrolysis of cellulosic substrates, including barley straw. LBM 033 strain was identified as Trametes villosa by molecular techniques, through the use of the ITS and rbp2 markers and the construction of phylogenetic trees. The cell-free supernatant of T. villosa LBM 033 showed high titers of hydrolytic enzymatic activities, necessary for the hydrolysis of the holocellulosic substrates, hydrolyzing pure cellulose to cellobiose and glucose and also degraded the polysaccharides contained in barley straw to short soluble oligosaccharides. These results indicate that macro fungi from tropical soil environments, such as T. villosa LBM 033 can be a valuable resource for in-house, cost effective production of enzymes that can be applied in the hydrolysis stage, which could reduce the total cost of bioethanol production.

[Isolation of Aspergillus section Nigri strains in yerba mate in Posadas (Misiones, Argentina) and evaluation of their ochratoxigenic potential]. / Aislamiento de cepas de Aspergillus sección Nigri en la yerba mate comercializada en Posadas (Misiones, Argentina) y evaluación de su potencial ocratoxigénico.

The objectives of the present work were to investigate the isolation frequency of genus Aspergillus in canchada yerba mate (YMCH) and elaborated yerba mate (YME) (Ilex paraguariensis) and the proportion of section Nigri isolates, as well as to determine ochratoxin A production by Aspergillus species section Nigri. Three hundred twenty eight Aspergillus strains from 20 samples of YMCH and 1306 Aspergillus strains from 36 samples of YME were isolated; of the total, 279 from the first group of strains and 1215 from the latter group, belonged to section Nigri. For the detection of ochratoxin A production, the strains were cultivated on Czapeck yeast extract agar and the toxin was detected by thin layer chromatography under UV light. Uniserate species predominance was observed in the 1494 strains of Aspergillus section Nigri obtained (Aspergillus japonicus var. japonicus and Aspergillus japonicus var. aculeatus), whereas none of the strains analysed showed ochratoxin A production in vitro at the detection level of the methodology employed.

Aislamiento de cepas de Aspergillus sección Nigri en la yerba mate comercializada en Posadas (Misiones, Argentina) y evaluación de su potencial ocratoxigénico / [Isolation of Aspergillus section Nigri strains in yerba mate in Posadas (Misiones, Argentina) and evaluation of their ochratoxigenic potential].

The objectives of the present work were to investigate the isolation frequency of genus Aspergillus in canchada yerba mate (YMCH) and elaborated yerba mate (YME) (Ilex paraguariensis) and the proportion of section Nigri isolates, as well as to determine ochratoxin A production by Aspergillus species section Nigri. Three hundred twenty eight Aspergillus strains from 20 samples of YMCH and 1306 Aspergillus strains from 36 samples of YME were isolated; of the total, 279 from the first group of strains and 1215 from the latter group, belonged to section Nigri. For the detection of ochratoxin A production, the strains were cultivated on Czapeck yeast extract agar and the toxin was detected by thin layer chromatography under UV light. Uniserate species predominance was observed in the 1494 strains of Aspergillus section Nigri obtained (Aspergillus japonicus var. japonicus and Aspergillus japonicus var. aculeatus), whereas none of the strains analysed showed ochratoxin A production in vitro at the detection level of the methodology employed.

Aislamiento de cepas de Aspergillus sección Nigri en la yerba mate comercializada en Posadas (Misiones, Argentina) y evaluación de su potencial ocratoxigénico. / [Isolation of Aspergillus section Nigri strains in yerba mate in Posadas (Misiones, Argentina) and evaluation of their ochratoxigenic potential].

The objectives of the present work were to investigate the isolation frequency of genus Aspergillus in canchada yerba mate (YMCH) and elaborated yerba mate (YME) (Ilex paraguariensis) and the proportion of section Nigri isolates, as well as to determine ochratoxin A production by Aspergillus species section Nigri. Three hundred twenty eight Aspergillus strains from 20 samples of YMCH and 1306 Aspergillus strains from 36 samples of YME were isolated; of the total, 279 from the first group of strains and 1215 from the latter group, belonged to section Nigri. For the detection of ochratoxin A production, the strains were cultivated on Czapeck yeast extract agar and the toxin was detected by thin layer chromatography under UV light. Uniserate species predominance was observed in the 1494 strains of Aspergillus section Nigri obtained (Aspergillus japonicus var. japonicus and Aspergillus japonicus var. aculeatus), whereas none of the strains analysed showed ochratoxin A production in vitro at the detection level of the methodology employed.