Bacteroides mutants were generated by deletion or replacement of the target gene with an inactive version by counter selectable allelic exchange using the pExchange-tdk plasmid. The full method is described in34 (link). Mutants generated in this study are distinguished by the locus tag of the gene deleted/inactivated (Δbtxxx or ΔBACOVAxxxxx).
Bacteroides spp. were routinely cultured under anaerobic conditions at 37 °C using an anaerobic cabinet (Whitley A35 Workstation; Don Whitley) in culture volumes of 0.2, 2 or 5 ml) of TYG (tryptone-yeast extract-glucose medium) or minimal medium (MM) containing 0.5-1% of an appropriate carbon source and 1.2 mg ml−1 porcine haematin (Sigma-Aldrich) as previously described9 (link). The growth of the cultures were routinely monitored at OD600 nm using a Biochrom WPA cell density meter for the 5 ml cultures or a Gen5 v2.0 Microplate Reader (Biotek) for the 0.2 and 2 ml cultures.
Bacteroides spp. were routinely cultured under anaerobic conditions at 37 °C using an anaerobic cabinet (Whitley A35 Workstation; Don Whitley) in culture volumes of 0.2, 2 or 5 ml) of TYG (tryptone-yeast extract-glucose medium) or minimal medium (MM) containing 0.5-1% of an appropriate carbon source and 1.2 mg ml−1 porcine haematin (Sigma-Aldrich) as previously described9 (link). The growth of the cultures were routinely monitored at OD600 nm using a Biochrom WPA cell density meter for the 5 ml cultures or a Gen5 v2.0 Microplate Reader (Biotek) for the 0.2 and 2 ml cultures.