Low-Temperature (10°C) Anaerobic Digestion of Dilute Dairy Wastewater in an EGSB Bioreactor: Microbial Community Structure, Population Dynamics, and Kinetics of Methanogenic Populations

Table 2

Specific methanogenic activity (SMA) profiles against direct and indirect methanogenic substrates expressed as mL CH₄ g VSS⁻¹ day⁻¹ and the absolute quantification of 16S rRNA gene copy concentration expressed in copies/mL, of day 0 and day 335 biomass.

	𝑇 (°C)	Specific methanogenic activity (mL CH4 g VSS^−1 day^−1)					Absolute quantification by qPCR
		SMA Substrate					16S rRNA gene copy concentration (copies/mL)
		Acetate	H2/CO2	Ethanol	Propionate	Butyrate	Mst	MBT + MMB
Biomass day 0	37	366±26	422±21	336±27	203±20	293±19 *	4.2×10^6	7.1×10^5
	15	87±10	91±4	85±3	59±7	59±2	4.2×10^6	7.1×10^5
Biomass day 335	37	257±6	774±42	425±21 *	140±4	222±13	5.4×10^6	3.6×10^5
	10	38±4	37±4	29±5	7±0	22±3	5.4×10^6	3.6×10^5

All SMA values are the mean of triplicates (std. error; 𝑛=3), except *where values are the mean of duplicates (std. error; 𝑛=2). Absolute quantification of 16S rRNA gene copy concentration of the groups: Mst (Methanosaetaceae), MBT (Methanobacteriales) and MMB (Methanomicrobiales).