Petroleum hydrocarbon rich oil refinery sludge of North-East India harbours anaerobic, fermentative, sulfate-reducing, syntrophic and methanogenic microbial populations

Table 2 Read and OTU distribution of the samples obtained through next generation sequencing (Illumina), diversity indices (calculated using QIIME workflow) and taxonomical distribution

	GR1	GR3	DB2
Parameters
Number of reads	627,638	435,940	472,180
OTUs (97% identity)	7837	12,774	10,617
Estimated total OTUs (Chao1)	15,448.14	32,314.94	25,135.21
Shannon diversity index	6.148	4.443	6.369
Simpson index	0.9452	0.7081	0.95
Equitability	0.475	0.326	0.476
Goods coverage	0.9933	0.9819	0.9863
Archaeal taxa (% Reads)	0.03	0.0002	0.02
Bacterial taxa (% Reads)	95.41	99.14	97.07
Unclassified (% Reads)	4.56	0.86	2.91
Number of Archeal taxa detected
Phylum	2	1	2
Class	3	1	5
Family	2	1	3
Genus	2	1	3
Genus ^e	2	2	2
Genus common in 3 samples	1
Number of Bacterial taxa detected
Phylum	49	46	49
Class	118	96	116
Family	213	186	215
Genus	280	244	285
Genus common in 3 samples	139

ISSN: 1471-2180