Chapter 11
A Subsystem Microcosm Verification
of the Microcosm N-System
Yuhei Inamori, Ryuhei Inamori, and Kazuhito Murakami
Abstract Various impact assessments are enabled using the microcosm N-system
as described in the previous chapters, and the consistency of the microcosm with the
natural ecosystem was demonstrated experimentally. However, analysis of the
structural parameter (abundance) becomes particularly complicated in comparison
with the single-species test prescribed by the OECD. Therefore, a microcosm
subsystem was constructed, which combines one species each of microorganisms
as a producer, consumer, and decomposer. Together, these were investigated for the
possibility of using this subsystem for impact assessment (i.e., it was inspected with
respect to its superiority relative to the N-system).
11.1 Outline of the Microcosm Subsystem
11.1.1 Species Composition
The microcosm subsystem was constructed with the bacterium Pseudomonas putida
as a decomposer, the protozoan Cyclidium glaucoma as a consumer, and the
chlorophyte Chlorella vulgaris as a producer. Pseudomonas putida and Cyclidium
glaucoma were isolated from the microcosm N-system, and Chlorella vulgaris was
isolated from the Microorganisms Culture Center of the NIES, Japan. Another
microcosm subsystem composed of the euglenid Euglena gracilis as a producer,
the ciliate Tetrahymena thermophila as a consumer, and the bacterium Escherichia
coli as a decomposer was also constructed from a pure strain culture. All microorganisms in these microcosm subsystems can be observed ordinally in natural
ecosystems. Each simplified system exhibited high reproducibility and stability,
similar to the microcosm N-system.
Y. Inamori (*) · R. Inamori
Foundation for Advancement of International Science, Tsukuba, Ibaraki, Japan
e-mail: y_inamori@fais.or.jp; r_inamori@fais.or.jp
K. Murakami
Chiba Institute of Technology, Narashino, Chiba, Japan
e-mail: kazuhito.murakami@p.chibakoudai.jp
© Springer Nature Singapore Pte Ltd. 2020
Y. Inamori (ed.), Microcosm Manual for Environmental Impact Risk Assessment,
https://doi.org/10.1007/978-981-13-6798-4_11
195
A Subsystem Microcosm Verification
of the Microcosm N-System
Yuhei Inamori, Ryuhei Inamori, and Kazuhito Murakami
Abstract Various impact assessments are enabled using the microcosm N-system
as described in the previous chapters, and the consistency of the microcosm with the
natural ecosystem was demonstrated experimentally. However, analysis of the
structural parameter (abundance) becomes particularly complicated in comparison
with the single-species test prescribed by the OECD. Therefore, a microcosm
subsystem was constructed, which combines one species each of microorganisms
as a producer, consumer, and decomposer. Together, these were investigated for the
possibility of using this subsystem for impact assessment (i.e., it was inspected with
respect to its superiority relative to the N-system).
11.1 Outline of the Microcosm Subsystem
11.1.1 Species Composition
The microcosm subsystem was constructed with the bacterium Pseudomonas putida
as a decomposer, the protozoan Cyclidium glaucoma as a consumer, and the
chlorophyte Chlorella vulgaris as a producer. Pseudomonas putida and Cyclidium
glaucoma were isolated from the microcosm N-system, and Chlorella vulgaris was
isolated from the Microorganisms Culture Center of the NIES, Japan. Another
microcosm subsystem composed of the euglenid Euglena gracilis as a producer,
the ciliate Tetrahymena thermophila as a consumer, and the bacterium Escherichia
coli as a decomposer was also constructed from a pure strain culture. All microorganisms in these microcosm subsystems can be observed ordinally in natural
ecosystems. Each simplified system exhibited high reproducibility and stability,
similar to the microcosm N-system.
Y. Inamori (*) · R. Inamori
Foundation for Advancement of International Science, Tsukuba, Ibaraki, Japan
e-mail: y_inamori@fais.or.jp; r_inamori@fais.or.jp
K. Murakami
Chiba Institute of Technology, Narashino, Chiba, Japan
e-mail: kazuhito.murakami@p.chibakoudai.jp
© Springer Nature Singapore Pte Ltd. 2020
Y. Inamori (ed.), Microcosm Manual for Environmental Impact Risk Assessment,
https://doi.org/10.1007/978-981-13-6798-4_11
195