A. Katayama et al., Long-term changes in microbial community structure in soils subjected to different fertilizing practices revealed by quinone profile analysis, SOIL SCI PL, 44(4), 1998, pp. 559-569
Quinone profile analysis of stored air-dried soils gave an approximation of
the long-term changes in the microbial community structure in four soils;
subjected to different types of fertilizer application from 1987 to 1997: u
nfertilized soil (NF-soil), soil amended with chemical fertilizers (CF-soil
), soil amended with chemical fertilizers and 40 t ha(-1) y(-1) of farmyard
manure (CF+FYM-soil), and soil amended with 400 t ha(-1) y(-1) of farmyard
manure (FYM-soil). The carbon content increased, and the soil pH remained
higher in the soils receiving farmyard manure. Principal component analysis
of the quinone profiles of the soils indicated that the microbial communit
y structure showed a high similarity among the four soils before the onset
of cultivation and changed to a different community structure specific to t
he respective fertilizing practices except for the NF-soil. The specific qu
inone profile became stable after two cropping seasons in the FYM-soil, aft
er 10 cropping seasons in the CF+FYM-soil and after 15 cropping seasons in
the CF-soil, respectively. The quinone profile of the NF-soil did not becom
e stable, and no specific profile was developed. The specific quinone profi
les in the FYM- and CF+FYM-soils were both characterized by large mole frac
tions of menaquinone with seven isoprenoid units (MK-7). Farmyard manure it
self contained a large mole fraction of MK-7. It was suggested that the amo
unt of MK-7 increased due to the application of farmyard manure. MK-7 indic
ates the presence of Gram-positive bacteria with low guanine plus cytosine
contents such as Bacillus and Gram-negative bacteria of the Cytophaga-Flavo
bacterium complex. The specific quinone profile in the CF-soil was characte
rized by the presence of menaquinone with seven isoprenoid units dihydrated
(MK-7(H-2)) and MK-7(H-4). Although Brevibacterium and Kocuria contain MK-
7(H-2), no microorganisms are known to have MK-7(H-4) as major quinone. The
common major quinones were MK-8, MK-10(H-4) and a mixture of MK-8(H-4) and
MK-9, suggesting the predominance of Grampositive bacteria in all the soil
s. Mole fractions of ubiquinone with 8 isoprenoid units (Q-8) and Q-10 incr
eased at various times in all the soils, indicating the sporadic growth of
Gram-negative bacteria.