Table 3.

Effect sizes and explained variances of the main factors assessed by PERMANOVA analysis.

	Factors	Sums Of Sqs	Mean Sqs	F. Model	R2	P value
16S rRNA gene sequencing	Databases	1.91	0.38	2.67	0.40	0.00
	Microbial cell wall-breaking methods	0.84	0.42	2.45	0.18	0.01
	Classifiers	1.40	0.23	1.31	0.29	0.11
	DNA extraction kits	1.25	0.21	1.13	0.26	0.27
	Sequencers	0.78	0.19	1.02	0.16	0.44
	Primers (amplified regions)	0.81	0.16	0.81	0.17	0.79
Shotgun metagenomic sequencing	Classifiers	2.96	0.74	4.69	0.51	0.00
	Databases	0.78	0.78	3.28	0.13	0.00
	DNA ectraction kits	2.49	0.36	1.62	0.43	0.01
	Microbial cell wall-breaking methods	0.84	0.42	1.69	0.14	0.04
	Sequencers	1.81	0.30	1.21	0.31	0.17