title: Simple and inexpensive DNA extraction  protocol for studying the bacterial composition of  sludges used in microbial fuel cells.
abstract: Bacteria oxidize organic matter and nutrients to  produce electric energy in microbial fuel cells (MFC) - a technology of  increasing importance because of its sustainability. To improve the performance  of MFCs, it is necessary not only to gain a better understanding of MFC  engineering designs, but also to improve the understanding of the composition  of the microbial communities in MFCs. Fast and efficient DNA extraction  protocols that are suitable for extracting diverse bacterial genomes are  necessary to identify the bacterial diversity present in MFCs and to further  monitor the dynamic changes of microbial communities. This study focused on  testing different direct cell lysis protocols to extract DNA from a microbial  sludge harvested from an MFC. The protocol that achieved the best results was  based on a previous study, but was modified by eliminating a chaotropic salt  and the special columns used for nucleic acid purification. The efficiency of  this less expensive and more straightforward protocol was confirmed by PCR  amplification of the 16S rRNA gene and denaturing gradient gel electrophoresis  analysis, which confirmed the extraction of multiple genomes. The sequences of  10 clones revealed the presence of phyla, Proteobacteria, Firmicutes and  Actinobacteria, comprising both Gram-negative and Gram-positive bacteria. Some  of these bacteria were identified at the genus level, e.g., Clostridium, Pseudoxanthomonas, Tistrella, and Enterobacter; these  genera have been described in active sludges from wastewater treatment,  supporting the congruency of our results. Therefore, this protocol is a useful  tool for analysis of the bacteria responsible for energy production in MFCs.
authors: Unidad de Biotecnología, Centro de Investigación Científica de Yucatán, Mérida, Yucatán, México. cantocanche@cicy.mx
authors: B
authors: B
authors: Canto-Canché
authors: M
authors: M
authors: Tzec-Simá
authors: J I
authors: JI
authors: Vázquez-Loría
authors: H
authors: H
authors: Espadas-Álvarez
authors: B H
authors: BH
authors: Chí-Manzanero
authors: R
authors: R
authors: Rojas-Herrera
authors: R
authors: R
authors: Valdez-Ojeda
authors: L
authors: L
authors: Alzate-Gaviria
mesh_terms: D001419:Bacteria / Q000737:chemistry*; D001674:Bioelectric Energy Sources / Q000382:microbiology*; D004269:DNA, Bacterial / Q000737:chemistry* / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction / Q000379:methods; D012722:Sewage / Q000382:microbiology*
chemical_list: D004269:DNA, Bacterial; D012722:Sewage