Chemical fractions of organic nitrogen in acid hydrolysates given from microbial cells and their cell wall substances and characterization of decomposable soil organic nitrogen due to drying

Creators Marumoto Takuya

Creators Kai Hideaki

Creators Yoshida Takashi

Creators Harada Togoro

1) The major part of organic nitrogen fractions in acid hydrolysate which is mineralized through the decomposition process of cells of B. subtilis in sand for 2 weeks was the form of amino acid N, but the form of amino sugar N was hardly mineralized. Their cytoplasmic substances were mineralized quickly, but their cell wall substances comparatively slowly. When the latter, however, was pretreated with ultrasonic or oven-drying treatment, their mineralization was accelerated. The mineralization rate of the form of amino sugar N was remarkably high. 2) The major part of the decomposable organic nitrogen fractions due to the ultrasonicating or oven-drying effects in acid hydrolysates given from microbial cells and their cell wall substances was the forms of amino acid N and amino sugar N. The accelerating effect of oven-drying pretreatment on the mineralization of the form of amino sugar N was larger than that of ultrasonicating pretreatment under this experimental conditions. 3) The amino acid composition of the amino acid N fraction in acid hydrolysates given from cells of B. subtilis and their cell wall substances which become decomposable due to the ultrasonicating or oven-drying effects almost equalled that of the mucopeptides in cell wall substances, and the quantity of mineralization was proportional to the contents of individual amino acids in cell wall substances. Namely, they were in the following order : Ala, Glu>Asp, Gly, Lys, Val>Ileu, Leu, Ser, Thr, Arg. 4) These results might complementarily prove that microbial cells, especially their cell wall substances, contribute considerably to a source of the decomposable soil organic matter, which was described in the previous paper (7).

[ISSN]0038-0768

[NCID]AA00844314

[isVersionOf] [NAID]http://ci.nii.ac.jp/naid/110001719218/

[isVersionOf] [URI]http://www.blackwellpublishing.com/journal.asp?ref=0038-0768&site=1