Characterization of a Lignocellulolytic Consortium and Methane Production from Untreated Wheat Straw: Dependence on Nitrogen and Phosphorous Content

Idania Valdez-Vazquez, Gabriela J. Torres-Aguirre, Carlos Molina, Graciela M. L. Ruiz-Aguilar


Impacts of microbial diversity and macronutrients levels (expressed as C:N and C:P ratios) on the methane production from an untreated lignocellulosic feedstock were assessed. Next-generation sequencing technology revealed the bacterial diversity of a lignocellulolytic inoculum. This inoculum comprised 75 bacterial species that were well distributed in 14 phyla, 67% of which belonged to Firmicutes and Bacteroidetes. The families Ruminococcaceae, Clostridiaceae, Bacteroidaceae, Bacillaceae, and Fibrobacteraceae comprised 46% of the identified families and were associated with hydrolytic members. Nutrient adjustment reduced 40% of the length of the lag phase and doubled methane production rate compared with a control. The highest methane production of 0.197 m3 per kg of total volatile solids observed at C:N of 31:1 and C:P of 428:1, peaked 20 days earlier than in previous studies using untreated lignocellulosic feedstock. Interestingly, the highest hydrolytic activities and solids removal rates were observed at high nitrogen contents; however, the conditions (pH > 8.0) inhibited methanogenesis.


Anaerobic digestion; Consortium; Pyrosequencing; Winter wheat (Triticum aestivum L.)

Full Text:


Welcome to BioResources! This online, peer-reviewed journal is devoted to the science and engineering of biomaterials and chemicals from lignocellulosic sources for new end uses and new capabilities. The editors of BioResources would be very happy to assist you during the process of submitting or reviewing articles. Please note that logging in is required in order to submit or review articles. Martin A. Hubbe, (919) 513-3022,; Lucian A. Lucia, (919) 515-7707, URLs:; ISSN: 1930-2126