302
K. M. G. Mostofa et al.
the group contribution factors of S-, N-, or P-atom-containing functional groups
and the Taft constant, σ * , is observed (r = 0.99) (Fig. 2) (Karelson 2000). The
X Ri values for S-, N-, or P-atom-containing functional groups are greater than
those of the alkyl, oxygenated, and halogenated functional groups (Fig. 2).
This suggests that S-, N-, or P-atom-containing functional groups donate more
electrons toward the neighboring C–H bond(s), thereby enhancing the H-atom
abstraction by HO
• .
The GCM includes 66 group rate constants and 80 group contribution factors,
which characterize each HO
• reaction mechanism with steric effects of the chemical structure groups and impacts of the neighboring functional groups, respectively
(Minakata et al. 2009). The group contribution factors for H-atom abstraction and
HO
• addition to the aromatic compounds linearly correlate with the Taft constants,
σ * , and the electrophilic substituent parameters, σ + , respectively. The best calibrations for 83 % (257 rate constants) and predictions for 62 % (77 rate constants)
of the rate constants are within 0.5–2 times the experimental values. Literaturereported experimental HO
• rate constants for 310 and 124 compounds are used for
calibration and prediction, respectively.
Although there are a few tools available to determine aqueous phase hydroxyl radical reaction rate constants (Minakata et al. 2011; Herrmann 2003; Monod et al. 2005;
Minakata and Crittenden 2011; Herrmann et al. 2010), the GCM is quoted as “The
wide application range in combination with the user-friendliness makes it probably
the best currently available estimation tool for HO radical reactions in aqueous solution. Overall, the method of Minakata et al. (2009) is currently the most broadly usable
method for the prediction of HO radical reaction rates in aqueous solution (Herrmann
et al. 2010). The GCM peer-reviewed paper provided both MS Excel spread sheet and
compiled Fotran program as supportion information. Any users are able to access these
programs and determine the aqueous phase HO· reaction rate constants with inputs of
structural information of a compound of interest.
Table 2 Hydrogenotrophic homoacetogens and methanogens isolated from various environments
Microorganism
Growth temp
(ºC)
Optimum temp
(ºC)
References
Acetobacterium
bakiia
1–30
20
Sediments of a
polluted pond
Kotsyurbenko et al.
(1995)
Acetobacterium
paludosuma
1–30
20
Sediments of a fen Kotsyurbenko et al.
(1995)
Acetobacterium
fumetariuma
1–35
30
Manure digested at
low temp
Kotsyurbenko et al.
(1995)
Acetobacterium
tundraeb
1–30
20–25
Tundra wetlands
Simankova et al.
(2000)
Methanogenic
strain MSB
1–32
25–30
Sediments of a
polluted pond
Kotsyurbenko et al.
(2001)
Methanogenic
strain MSP
4–35
25–30
Sediments of a
polluted pond
Kotsyurbenko et al.
(2001)
Methanobacterium
strain MB4
5–30
25–30
Peat samples
Kotsyurbenko et al.
(2007)
K. M. G. Mostofa et al.
the group contribution factors of S-, N-, or P-atom-containing functional groups
and the Taft constant, σ * , is observed (r = 0.99) (Fig. 2) (Karelson 2000). The
X Ri values for S-, N-, or P-atom-containing functional groups are greater than
those of the alkyl, oxygenated, and halogenated functional groups (Fig. 2).
This suggests that S-, N-, or P-atom-containing functional groups donate more
electrons toward the neighboring C–H bond(s), thereby enhancing the H-atom
abstraction by HO
• .
The GCM includes 66 group rate constants and 80 group contribution factors,
which characterize each HO
• reaction mechanism with steric effects of the chemical structure groups and impacts of the neighboring functional groups, respectively
(Minakata et al. 2009). The group contribution factors for H-atom abstraction and
HO
• addition to the aromatic compounds linearly correlate with the Taft constants,
σ * , and the electrophilic substituent parameters, σ + , respectively. The best calibrations for 83 % (257 rate constants) and predictions for 62 % (77 rate constants)
of the rate constants are within 0.5–2 times the experimental values. Literaturereported experimental HO
• rate constants for 310 and 124 compounds are used for
calibration and prediction, respectively.
Although there are a few tools available to determine aqueous phase hydroxyl radical reaction rate constants (Minakata et al. 2011; Herrmann 2003; Monod et al. 2005;
Minakata and Crittenden 2011; Herrmann et al. 2010), the GCM is quoted as “The
wide application range in combination with the user-friendliness makes it probably
the best currently available estimation tool for HO radical reactions in aqueous solution. Overall, the method of Minakata et al. (2009) is currently the most broadly usable
method for the prediction of HO radical reaction rates in aqueous solution (Herrmann
et al. 2010). The GCM peer-reviewed paper provided both MS Excel spread sheet and
compiled Fotran program as supportion information. Any users are able to access these
programs and determine the aqueous phase HO· reaction rate constants with inputs of
structural information of a compound of interest.
Table 2 Hydrogenotrophic homoacetogens and methanogens isolated from various environments
Microorganism
Growth temp
(ºC)
Optimum temp
(ºC)
References
Acetobacterium
bakiia
1–30
20
Sediments of a
polluted pond
Kotsyurbenko et al.
(1995)
Acetobacterium
paludosuma
1–30
20
Sediments of a fen Kotsyurbenko et al.
(1995)
Acetobacterium
fumetariuma
1–35
30
Manure digested at
low temp
Kotsyurbenko et al.
(1995)
Acetobacterium
tundraeb
1–30
20–25
Tundra wetlands
Simankova et al.
(2000)
Methanogenic
strain MSB
1–32
25–30
Sediments of a
polluted pond
Kotsyurbenko et al.
(2001)
Methanogenic
strain MSP
4–35
25–30
Sediments of a
polluted pond
Kotsyurbenko et al.
(2001)
Methanobacterium
strain MB4
5–30
25–30
Peat samples
Kotsyurbenko et al.
(2007)