Comparison of Different Strategies for Selection/Adaptation of Mixed Microbial Cultures Able to Ferment Crude Glycerol Derived from Second-Generation Biodiesel

Table 3

Metagenomic classification of the MMC at the genus level, for the anaerobic sludge enriched on hexane-pretreated crude glycerol in batch tests (HT) and with the untreated crude glycerol in fed-batch, expressed as fraction (%). T0–T11 = transfer numbers. ND = Not detected. Genera appearing at frequencies below 1% in all samples were omitted.

Genera	HT		FED-BATCH
	T0	T9	T11
	%	%	%
Blautia	0.24	0.04	50.8
Clostridium	30.1	46.6	16.2
Unclassified	31.5	6.45	9.89
Klebsiella	0.01	28.8	0.02
Escherichia	0.06	10.3	<0.01
Enterococcus	0.02	0.27	6.19
Alkaliphilus	5.64	0.06	0.88
Soehngenia	<0.01	ND	3.52
Serratia	0.01	2.67	0.04
Pedobacter	2.38	0.02	0.08
Enterobacter	0.02	2.21	0.01
Propionispora	1.99	0.01	0.03
Treponema	1.42	0.01	0.03
Peptoniphilus	0.07	0.02	1.35
Flavobacterium	1.33	0.03	0.54
Sedimentibacter	0.33	<0.01	1.26