Table 2.

Cluster assignments for a subset of ROIs (n = 777) using isotope and elemental ratios resulting from 1, 2, or 3 stable isotope labeled substrates.

Ratios used	FISH identification	Distribution of ROIs per cluster
		a	b	c	d	e
13C/12C	Gamma	416	142	77	52	38
	Delta	13	27	12	1	0
15N/14N	Gamma	385	125	96	120	32
	Delta	13	2	6	5	27
33S/32S	Gamma	579	81	24	33	7
	Delta	18	5	1	17	12
13C/12C, 15N/14N, C/CN	Gamma	309	77	207	82	51
	Delta	16	1	4	0	32
13C/12C, 33S/32S, C/S	Gamma	483	100	29	84	29
	Delta	10	21	2	1	19
15N/14N, 33S/32S, S/CN	Gamma	428	226	35	27	8
	Delta	14	8	2	16	13
13C/12C, 15N/14N, 33S/32S, C/CN, C/SN	Gamma	427	134	101	30	32
	Delta	16	2	5	2	28

Gamma, Gammaproteobacteria; Delta, Deltaproteobacteria.