Table 1.

Summary of the distribution of alpha diversity indices for the investigated factors potentially influencing the bacterial community of washing machines. Factors that had a significant influence are highlighted in grey. Displayed are mean values, minimum and maximum value as well as standard deviation of each diversity index.

Influencing Factor	Levels	n	Observed				Chao1				Shannon				Simpson
			Mean	SD	Min	Max	Mean	SD	Min	Max	Mean	SD	Min	Max	Mean	SD	Min	Max
Site	Door seal	13	44.54	15.50	22.00	77.00	85.44	46.88	25.00	189.80	2.57	0.63	1.88	3.59	0.83	0.09	0.70	0.96
	Detergent drawer	13	73.77	18.49	46.00	103.00	141.64	51.03	48.15	246.00	3.56	0.46	2.87	4.24	0.94	0.03	0.89	0.98
	Sump	12	53.08	16.47	25.00	74.00	90.37	33.98	34.17	154.09	2.89	0.66	1.77	3.59	0.87	0.09	0.71	0.95
	Fibres (washing solution)	12	66.08	14.08	44.00	83.00	129.83	48.74	60.62	216.00	3.22	0.50	2.08	3.81	0.90	0.07	0.73	0.96
Age	0 - 10 years	34	58.85	20.96	22.00	103.00	113.79	55.82	25.00	246.00	3.03	0.73	1.83	4.24	0.88	0.09	0.70	0.98
	11 -20 years	16	60.44	16.74	25.00	97.00	107.85	39.38	34.17	171.88	3.14	0.53	1.77	4.07	0.90	0.06	0.71	0.97
Smell	Yes	10	62.44	20.70	28.00	97.00	123.02	54.57	32.00	216.00	3.11	0.72	1.83	4.24	0.89	0.08	0.72	0.98
	No	40	58.80	17.31	32.00	97.00	105.52	40.28	49.50	156.91	3.13	0.58	1.97	4.07	0.90	0.08	0.70	0.97
Standard wash cycles per month ≥60 °C	1 - 5 cycles	18	51.56	18.10	22.00	83.00	93.69	50.01	25.00	216.00	2.77	0.61	1.83	3.69	0.85	0.08	0.70	0.94
	6 -10 cycles	32	63.75	19.21	25.00	103.00	122.13	49.07	34.17	246.00	3.23	0.65	1.77	4.24	0.90	0.08	0.71	0.98
Regular Cleaning	Yes	20	62.95	20.69	25.00	97.00	118.60	49.36	32.00	216.00	3.14	0.70	1.77	4.24	0.89	0.08	0.71	0.98
	No	30	56.97	18.72	22.00	103.00	107.41	52.09	25.00	246.00	3.01	0.65	1.97	4.10	0.88	0.08	0.70	0.97
Softener	Yes	16	62.44	20.70	28.00	97.00	123.02	54.57	32.00	216.00	3.11	0.72	1.83	4.24	0.89	0.08	0.72	0.98
	No	34	57.91	19.12	22.00	103.00	106.65	48.89	25.00	246.00	3.04	0.65	1.77	4.10	0.88	0.08	0.70	0.97
Detergent	Liquid	18	57.78	13.61	32.00	85.00	109.06	37.93	49.50	171.88	3.03	0.54	1.97	4.03	0.89	0.08	0.70	0.97
	Powder	32	60.25	22.36	22.00	103.00	113.48	57.30	25.00	246.00	3.08	0.74	1.77	4.24	0.88	0.09	0.71	0.98