Cultivation-independent methods applied to the microbial prospection of oil and gas in soil from a sedimentary basin in Brazil

AMB Express

Table 3 Richness and diversity estimates for bacterial and archaeal 16S rRNA and SDIMO gene clone libraries from both P and Np Soil samples (sequence classification based on the cutoff value determined by DOTUR).

Gene (n^a)	Richness^b	Distance^c	Chao^d	Ace^e	Shannon^f
Bacterial 16S rDNA library (145)	105	0.03	331.8	391.4	4.49
Archaeal 16S rDNA library (53)	12	0.03	17	18.3	2.05
SDIMO Gene (68 - P Soil)	7	0.17	7	7.3	1.09
SDIMO Gene (70 - Np Soil)	2	0.17	2	0	0.44

^an, Number of gene sequences analyzed.
^b 97% identity was estimated as the species-level distance (D = 0.03) for Bacteria and Archaea, and 83% identity for SDIMO genes.
^cRichness is based on observed unique OTUs.
^dNonparametric statistical prediction of total richness of different OTUs and OPFs based on distribution of abundant (10) and rare (10) OTUs.
^eNonparametric statistical predictions of total richness of OTUs and OPFs based on distribution of singletons and doubletons.
^fShannon diversity index. A higher number represents more diversity.