ABSTRACT
Analyses of microbial
properties in soil and manure had always included the problem that there was no
available standard method to evaluate microbial property. The one of the major problems
was the vast diversity and the enormous population of soil microorganisms [1],
the other was an existence of numerically dominant unculturable microorganisms
which comprise 99% of soil habitat [2]. We evaluated whether our newly
developed method, by which taxonomies and their number of each bacterial groups
were estimated, could be used as evaluation method of microbial properties of
soils and manures. In the forest soil, β-Proteobacteria,
which included Burkholderia sp., Ralstonia sp., and Alcaligenes sp., was numerically dominant bacteria (3.64 × 106 MPN g-1 dry soil), followed by γ-Proteobacteria
(1.32 × 106 MPN), δ-Proteobacteria
(0.006 × 106 MPN), and the other gram negative bacteria (0.006 × 106 MPN). In the commercial manure, Actinobacteria, which included Streptoverticillium salmonis, Mycrococcus sp., Streptomyces bikiniensis, and Microbacterium ulmi, was numerically
dominant bacterial group (30.8 × 106 MPN), followed by α-Proteobacteria (26.0 × 106 MPN), β-Proteobacteria (17.1 × 106 MPN), δ-Proteobacteria (11.2 × 106 MPN), the other Firmicutes (1.71 × 106 MPN), γ-Proteobacteria (0.5 × 106 MPN), and the other gram
negative bacteria (0.05 × 106 MPN). In the upland field, the other
Firmicutes, which included Paenibacillus sp., was numerically dominant bacteria (4.41 × 106 MPN), followed by
Actinobacteria (2.14 × 106 MPN), Bacillus sp. (2.14 × 106 MPN), and γ-Proteobacteria
(0.35 × 106 MPN). Although the precision of the affiliations became
lower because of higher diversity of samples and the number of some
Antinobacteria and Firmicutes might be underestimated by the used PCR
condition, the method was found suitable as a candidate of a new evaluation system
of soil and manure.