Resumen

DONAIRE FIGUEROA, KAREM et al. Establishment and evaluation of two methods of pre-treatment of soil samples for the extraction of DNA for the study of bacterial diversity. Rev.Cs.Farm. y Bioq. [online]. 2017, vol.5, n.1, pp. 27-38. ISSN 2310-0265.

Abstract The knowledge about biochemical and physiological mechanisms by micro-organisms in soils are required for a complete description of microbial diversity, lately different molecular techniques have been developed to study this feature (qPCR, DGGE, T- RFLP, RAPD). DNA extraction techniques ensure the description of the microbial diversity success, according the soil samples characteristics. Generally, DNA extraction protocols used for separation of microorganism of matrix soil before DNA extraction by physical and chemical lysis. Other protocol is direct extraction of microbial DNA from soil samples, humic acids and phenolic substances affect the quality of DNA, which affect the development of subsequent molecular studies. The purpose of this study was to establish pretreatment procedures for different kind of soil samples (frank, sandy and clayey) in order to describe richness and bacterial diversity by PCR DGGE. In this sense, we determined the addition of CaCO3 in frank soils samples allows the identification of greater diversity and bacterial richness (10 bands) than the other method. Besides, PVPP pretreatment is no only useful to obtain bacterial diversity in sandy soil (8 bands), butalso in clayey soils (3 bands) soils by PCR-DGGE method. This indicates that the pretreatment procedures with CaCO3 and PVPP are specific for soil microbial community's isolation.

Palabras llave : Bacterial diversity; PCR DGGE; DNA extraction; pretreatment of soils.