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Enhanced Mineralization of Amino Acids by Birnessite as Influenced by Pyrogallol
Author(s) -
Wang M. C.,
Lin ChingHo
Publication year - 1993
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1993.03615995005700010017x
Subject(s) - birnessite , chemistry , amino acid , methionine , cysteine , mineralization (soil science) , phenylalanine , decarboxylation , serine , biochemistry , organic chemistry , catalysis , nitrogen , manganese oxide , enzyme
The structural differences among amino acids influencing mineralization by soil minerals, and the role of phenols in this mineralization, is very important in C turnover and N and S transformations in soil. The objective of this study was thus to investigate the effect of birnessite and pyrogallol on the mineralization of amino acids. Using a specially designed reaction flask, amounts and distribution of CO 2 and NH 3 released were determined during 90‐h reaction periods. The results show that birnessite enhanced the decarboxylation of amino acids. The amount of CO 2 released with l ‐serine, l ‐phenylalanine, l ‐proline, dl ‐methionine, and l ‐cysteine without birnessite was not detectable, while with birnessite‐amino acid, losses were 109 ± 0, 162 ± 3, 145 ± 2, 95 ± 2, and 182 ± 3 µmol, respectively. Since L‐cysteine has the strongest reducing power among the amino acids examined, the amount of CO 2 released with birnessite‐ l ‐cysteine was greatest. Birnessite enhanced the deamination of amino acids. The amounts of NH 3 released with l ‐serine, l ‐phenylalanine, l ‐proline, dl ‐methionine, and l ‐cysteine without birnessite were not detectable, while those with birnessite‐amino acid were 140 ± 4, 145 ± 5, 66 ± 6, 83 ± 2, and 226 ± 8 µmol, respectively. Birnessite enhanced the mineralization of methionine and cysteine to release SO 2− 4 in the supernatants of the reaction systems. The amounts of SO 2− 4 released with dl ‐methionine and l ‐cysteine without birnessite were 0.1 ± 0.0 and 0.2 ± 0.0 µmol, respectively, while those with birnessite‐amino acid were 0.8 ± 0.0 and 112 ± 7 µmol, respectively. In conclusion, the enhancing effects of birnessite play an important role in C turnover and N and S transformations in soil.