Please use this identifier to cite or link to this item: http://hdl.handle.net/1843/50584
Type: Artigo de Periódico
Title: Notable fibrolytic enzyme production by Aspergillus spp. isolates from the gastrointestinal tract of beef cattle fed in lignified pastures
Authors: Flávia Oliveira Abrão
Eduardo Robson Duarte
Moisés Sena Pessoa
Vera Lúcia dos Santos
Luiz Fernando de Freitas Júnior
Katharina de Oliveira Barros
Alice Ferreira da Silva Hughes
Thiago Dias Silva
Norberto Mário Rodriguez
Abstract: Fungi have the ability to degrade vegetal cell wall carbohydrates, and their presence in the digestive tract of ruminants can minimize the effects of lignified forage on ruminal fermentation. Here, we evaluated enzyme production by Aspergillus spp. isolates from the digestive tracts of cattle grazed in tropical pastures during the dry season. Filamentous fungi were isolated from rumen and feces by culture in cellulose-based medium. Ninety fungal strains were isolated and identified by rDNA sequence analysis, microculture, or both. Aspergillus terreus was the most frequently isolated species, followed by Aspergillus fumigatus. The isolates were characterized with respect to their cellulolytic, xylanolytic, and lignolytic activity through qualitative evaluation in culture medium containing a specific corresponding carbon source. Carboxymethyl cellulase (CMCase) activity was quantified by the reducing sugar method. In the avicel and xilan degradation test, the enzyme activity (EA) at 48 h was significantly higher other periods (P < 0.05). Intra- and inter-specific differences in EA were verified, and high levels of phenoloxidases, which are crucial for lignin degradation, were observed in 28.9% of the isolates. Aspergillus terreus showed significantly higher EA for avicelase (3.96 ±1.77) and xylanase (3.13 ±.091) than the other Aspergillus species at 48 h of incubation. Isolates AT13 and AF69 showed the highest CMCase specific activity (54.84 and 33.03 U mg-1 protein, respectively). Selected Aspergillus spp. isolates produced remarkable levels of enzymes involved in vegetal cell wall degradation, suggesting their potential as antimicrobial additives or probiotics in ruminant diets.
Subject: Bovino de corte
Ruminantes - Alimentação e rações
Fungos filamentosos
Aspergillus
Aspergillus fumigatus
Rúmen - Microbiologia
language: eng
metadata.dc.publisher.country: Brasil
Publisher: Universidade Federal de Minas Gerais
Publisher Initials: UFMG
metadata.dc.publisher.department: ICA - INSTITUTO DE CIÊNCIAS AGRÁRIAS
Rights: Acesso Aberto
metadata.dc.identifier.doi: https://doi.org/10.1371/journal.pone.0183628
URI: http://hdl.handle.net/1843/50584
Issue Date: 29-Aug-2017
metadata.dc.url.externa: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0183628
Appears in Collections:Artigo de Periódico



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