Table 2.

Microbial richness and diversity as determined by Chao1 estimator and Shannon index

Sample	Contamination	Chao1 estimate of OTU richness	95% CIa	Shannon index (H′)	No. of high-quality sequences
A1	Contaminated	3,127	2,804; 3,520	6.49	8,462
A2	Contaminated	3,259	2,994; 3,575	8.59	5,259
B1	Clean	13,024	11,963; 14,222	10.69	8,285
B2	Contaminated	4,493	4,183; 4,853	9.02	7,876
B3	Contaminated	8,348	7,599; 9,211	8.77	8,054
B4	Contaminated	6,431	5,847; 7,112	8.81	7,636
C1	Clean	11,783	10,891; 12,785	10.8	7,781
C2	Clean	9,226	8,499; 10,053	10.25	7,458
C3	Contaminated	5,315	4,848; 5,860	8.25	7,527
D1	Clean	6,794	6,235; 7,437	8.86	8,200
D2	Clean	7,811	7,184; 8,528	9.44	8,158
D3	Contaminated	4,227	3,783; 4,761	7.18	9,474
D4	Contaminated	3,849	3,472; 4,302	7.43	8,258
D5	Contaminated	4,587	4,155; 5,099	7.52	8,192
E1	Clean	6,948	6,346; 7,646	9.17	7,691
E2	Contaminated	6,529	5,983; 7,159	9.54	7,639
F1	Clean	14,683	13,506; 16,005	10.94	7,798
F2	Contaminated	5,439	4,932; 6,032	9.08	5,619
G1	Clean	9,820	8,941; 10,826	10.44	5,663
G2	Clean	11,929	11,075; 12,884	11.06	7,711
G3	Clean	14,447	13,512; 15,483	11.16	10,332
H1	Clean	12,824	11,878; 13,885	11.19	7,637
H2	Clean	12,637	11,767; 13,609	11.27	8,294
H3	Clean	7,716	7,227; 8,269	10.69	7,821
I1	Clean	4,382	3,987; 4,851	8.54	7,867
I2	Clean	521	463; 612	3.75	6,893

^aCI, confidence interval.