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

Table 2

Metagenomic classification of the MMC at the genus level. Results of batch transfers, during the enrichment of activated sludge, expressed as fraction (%). MM-KC = Minimal Medium with Kinetic Control (21 h); MM-EF = Minimal Medium with End of Fermentation (72 h); BA-KC = Basal Medium with Kinetic Control (21 h); BA-EF = Basal Medium with End of Fermentation (72 h). T0–T20 = transfer numbers. ND = Not detected. Genera appearing at frequencies below 1% in all samples were omitted.

GENERA	MM-KC							MM-EF							BA-KC				BA-EF
	T1	T3	T7	T10	T13	T18		T0	T6	T7	T8	T15	T20		T1	T12	T18		T0	T7	T11	T15	T20
	%	%	%	%	%	%		%	%	%	%	%	%		%	%	%		%	%	%	%	%
Clostridium	51.3	80.8	37.0	12.4	28.8	18.1		28.4	1.42	1.21	40.1	43.2	83.9		86.4	67.4	7.92		67.9	60.3	73.7	32.0	45.4
Klebsiella	0.74	0.42	47.4	28.9	19.1	65.4		28.0	0.13	66.7	0.15	0.07	0.03		0.30	9.12	9.18		0.02	0.03	0.19	6.61	0.03
Escherichia	0.54	8.46	0.60	33.5	28.7	1.05		0.99	54.2	7.05	31.0	31.6	0.05		0.74	5.16	34.4		0.05	0.11	0.84	30.9	42.8
Unclassified	6.47	2.83	8.31	8.14	11.5	8.88		13.8	18.4	10.5	13.5	10.9	1.23		2.91	6.56	14.2		18.3	3.41	5.93	5.72	4.03
Lactobacillus	29.7	0.07	0.11	0.01	0.02	0.01		0.39	3.53	0.78	0.79	4.74	14.3		6.05	4.72	13.3		0.01	16.8	14.8	21.8	4.12
Slackia	0.07	<0.01	<0.01	<0.01	0.01	<0.01		0.01	7.04	1.21	5.16	0.41	0.03		<0.01	3.61	0.55		1.05	18.1	2.61	0.21	1.01
Serratia	0.01	2.06	0.45	9.97	5.72	0.59		0.64	8.02	2.68	4.36	4.35	0.01		0.28	1.05	10.3		0.01	0.01	0.14	1.73	1.35
Enterobacter	0.01	1.58	0.93	3.86	3.72	1.39		0.66	3.67	1.78	2.27	2.50	<0.01		0.08	0.55	2.61		<0.01	<0.01	0.07	0.74	0.25
Alkaliphilus	0.29	0.01	0.02	<0.01	<0.01	0.01		3.66	0.01	<0.01	0.01	0.01	<0.01		0.14	<0.01	0.01		0.65	<0.01	0.02	ND	ND
Tolumonas	0.01	0.22	1.74	1.19	0.70	2.73		1.43	0.04	2.66	0.03	0.03	ND		0.06	0.48	0.63		<0.01	<0.01	0.01	0.01	<0.01
Negativicoccus	0.02	<0.01	0.01	<0.01	<0.01	<0.01		0.01	<0.01	0.00	<0.01	<0.01	<0.01		0.01	0.14	2.56		0.06	0.02	0.04	<0.01	ND
Blautia	0.20	0.05	0.57	0.04	0.01	0.04		0.92	0.07	0.02	0.01	0.01	<0.01		0.10	0.01	0.29		0.03	0.01	0.01	ND	ND
Ruminococcus	ND	ND	ND	<0.01	ND	ND		0.02	0.13	2.17	0.14	0.13	ND		<0.01	<0.01	<0.01		0.05	0.24	ND	ND	ND
Erwinia	<0.01	2.11	0.06	0.10	0.06	0.07		0.03	0.05	0.46	0.03	0.04	ND		<0.01	0.04	0.25		ND	<0.01	<0.01	0.05	<0.01
Methylotenera	0.91	0.05	<0.01	<0.01	ND	<0.01		0.89	ND	<0.01	ND	ND	<0.01		0.10	ND	<0.01		1.97	ND	ND	ND	ND
Geobacillus	0.14	0.02	0.05	0.03	<0.01	0.05		1.44	<0.01	0.02	<0.01	<0.01	<0.01		0.05	<0.01	0.03		0.03	<0.01	<0.01	ND	ND
Pseudomonas	0.73	0.12	0.06	0.18	0.04	0.01		1.16	0.04	0.02	0.04	0.03	0.01		0.02	0.01	0.01		0.01	<0.01	0.02	0.01	0.27
Weissella	1.08	0.02	<0.01	<0.01	<0.01	<0.01		0.55	<0.01	<0.01	<0.01	<0.01	ND		0.21	<0.01	0.01		0.41	<0.01	0.01	ND	ND