Field Evidence for Intrinsic Aerobic Chlorinated Ethene Cometabolism by Methanotrophs Expressing Soluble Methane Monooxygenase

Figures & data

FIGURE 1 Test Area North TCE plume showing wells sampled.

TABLE 1 Analytes and Analytical Methods

Parameter	Analytical method and laboratory
Chlorinated ethenes	EPA SW-846 8260B, Fixed Laboratory
Dissolved gases (CH4, H2, CO, and C2H6)	GC/FID (Reduced Gas Analysis), Fixed Laboratory
Chloride	Hach Field Test Kit Method 8207, Field Laboratory
Nitrate (as nitrogen)	Hach Field Test Kit Method 8171, Field Laboratory
Sulfate	Hach Field Test Kit Method 8051, Field Laboratory
Iron	Hach Field Test Kit Method 8146, Field Laboratory
Carbon dioxide	Hach Field Test Kit Method 8205, Field Laboratory
Alkalinity	Hach Field Test Kit Method 8203, Field Laboratory
Dissolved organic carbon	EPA Method 415.1, Fixed Laboratory
Metals (Al, Ca, Mg, K, Na, and Cu)	SW-846 Methods 3010A and 6010B, Fixed Laboratory
Tritium	Liquid Scintillation Counting, Fixed Laboratory
Ammonia (as nitrogen)	Hach Field Test Kit Method 10023, Field Laboratory
Phosphate	Hach Field Test Kit Method 8048, Field Laboratory
Temperature/pH/conductivity/DO/ oxidation reduction potential	Flow-through cell during groundwater sampling (Hydrolab MiniSonde 4a)

FIGURE 2 TCE and tritium profiles from TAN-51 and TAN-55.

TABLE 2 Results of Groundwater Analysis for the Enzyme Probe Coumarin, Naphthalene, and Controls

					Controls
Year	Well	TCE (μg/L)	Sample depth below ground surface (m)	Coumarin (I/min) ^a	Naphthalene (color change)	Formate (I/min) ^a	PA ^b (I/min) ^a
2002	7	< 5	91	19.0 + 0.3	ND	28.1 + 1.3	ND
		< 5	91	17.5 + 0.2	ND	24.0 + 0.6	ND
		< 5	91	14.0 + 0.1	ND	21.4 + 0.8	ND
	55	150	97	19.0 + 0.0	+	30.5 + 0.9	0 + 0.2
		120	123	DNA	+	25.0 + 1.4	0.4 + 0.1
		76	141	20.3 + 0.4	+	34.0 + 0.9	0.0 + 0.4
	52	47	81	DNA	+	27.0 + 0.8	1.0 + 0.1
		51	114	18.5 + 0.2	+	29.5 + 0.6	0.4 + 0.3
		40	139	19.0 + 0.0	+	32.2 + 1.0	1.6 + 0.4
	51	96	78	21.0 + 0.0	+	32.0 + 1.0	0.7 + 0.6
		45	104	18.5 + 0.0	+	33.2 + 1.2	0.6 + 0.3
		190	141	17.2 + 0.2	+	29.0 + 0.3	0.0 + 0.2
2003	58	0.9	90	10.6 + 0.2	+	19.1 + 1.5	0.1 + 0.2
	56	1	74	21.3 + 0.2	+	33.5 + 1.4	0.7 + 0.5
	57	2.2	70	12.0 + 0.0	+	22.4 + 1.3	0.6 + 0.2
		2.6	80	7.2 + 0.1	+	18.0 + 1.4	1.5 + 0.6
		3.8	134	10.1 + 0.1	+	19.7 + 0.9	0.0 + 0.5
	16	41.8	94	23.0 + 0.2	+	31.0 + 0.8	0.0 + 0.7
	52	48.8	74	6.0 + 0.2	+	13.0 + 0.7	0.0 + 0.6
		47.6	110	9.5 + 0.34	+	14 + 0.44	0.5 + 0.38
		37	134	8.0 + 0.21	+	15.2 + 0.79	0.3 + 0.13
	51	41.5	73	8.0 + 0.07	+	13.2 + 0.49	0.5 + 0.29
		45.2	98	4.0 + 0.03	+	11.0 + 0.64	0.0 + 0.44
		131	126	9.0 + 0.04	+	21.0 + 0.46	0.4 + 0.71
2003			Pseudomonas putida F1	0.0 + 0.0	−	ND	ND
2003			Burkholderia cepacia G4	0.0 + 0.0	−	ND	ND
DNA = filtered groundwater was used for DNA analysis, but not enzyme probe exposure.
ND = No data. + denotes a positive color change.

TABLE 3 Fluorescent Signals in Response to the Methane Reversible Inhibitor Control Study

Year	Well	Depth below ground surface (m)	Initial Result (I/min) ^a	Methane (I/min) ^a	Atmosphere (I/min) ^a
2002	52	81	14.75	1.95	13.23
	52	114	15.93	2.01	15.32
	52	139	16.72	2.02	16.17
	51	78	4.3	0.1	3.4
	51	104	3.9	0.1	3.2
	51	141	3.6	0.1	3.1
2003	58	90	10.22	0	9.833
	56	74	11.78	0.208	7.865
	57	70	6.04	0	10.81
	57	80	5.784	0.2	6.421
	57	134	11.98	0.4	11.27
	16	94	21.84	0.1	21.69
	52	74	9.15	1.5	8.825
	52	110	7.9	0.7	8.876
	52	134	8.12	0	8.825
	51	73	8.06	0.9	7.24
	51	98	10.57	0	10.33
	51	126	12.4	0.6	13.9
Values are a result of exposing groundwater to coumarin (initial result) as described above, competitively inhibiting the response of the cells in the same sample by the presence of methane (methane), and then reexposing the sample to coumarin in the absence of methane (atmosphere).

FIGURE 3 Application of the tracer-corrected method (Sorenson et al., 2000) for TCE (a) and c-DCE (b).

Sorenson , K. S. 2000 . Intrinsic and enhanced in situ biodegradation of trichloroethene in a deep, fractured basalt aquifer , PhD Dissertation University of Idaho .

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