1. Tubes centrifuged at room temperature for 10,000 rpm for 10 mins (to precipitate bacterial cells) (Control) E.coli (24h old culture) a loopful /tube was suspended in Eppendorf tubes containing 0.5mL sterile water Tubes centrifuged in a hi speed centrifuge at 18,000 rpm for 20 mins at 4 ℃ One set (triplicates) used as samples for Physical extraction of EPS Two set s(triplicates) used as samples for Chemical extraction of EPS 2% EDTA was added to supernatant and precipitate respectively in 1:1 and 1:2 ratio (sample:EDTA) and incubated for 3h at 4 ℃ 36.5% Formaldehyde was added to supernatant and precipitate respectively in 1:1 and 1:2 ratio (sample:formaldehyde) and incubated for 1h at 4 ℃ Tubes centrifuged in a hi speed centrifuge at 18,000 rpm for 20 mins at 4 ℃ Extracted EPS in the supernatant analyzed using ESI-MS Supernatant and precipitate separated and both were used for chemical extraction of EPS Fig S1

2. Fig S2 (a)(b) (c) (d)

3. Fig S3 (a) (b) (c) (d)

4. (a) Absolute Abundance (b) (a) Absolute Abundance (b) Fig S4A Fig S4B

5. (a) Absolute Abundance (b) Fig S5

6. (a) Absolute Abundance (b) Fig S6