STUDIES ON THE ORIGIN OF THE BACTERIAL COMMUNITY IN THE RIVER

1995 Fiscal Year Final Research Report Summary

• Project/Area Number: 05680443
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: Environmental dynamic analysis
• Research Institution: TOKYO UNIVERSITY OF AGRICULTURE AND TECHNOLOGY
• Principal Investigator: MORIKAWA Kazuko TOKYO UNIV.of AGRICULTURE and TECHNOLOGY,ASSOCIATE PROFESSOR, 農学部, 助教授 (50015046)
• Project Period (FY): 1993 – 1995
• Keywords: River water / Bacterial community / Origin of river bacteria / Soil bacteria / Spring bacteria / Counting methods / Gram reaction / Spore formation

Research Abstract

The origin of the bacterial community in river water were discussed making a comparison between bacterial community in river water, in spring and in soil particles. Because the bacterial community in the river water thught to be originated from the spring at the upper part of the stream, and from the rain or surrounded riverbed at the course of the river flow. Generic composition of the bacterial community in the river water had been revealed previously at Unazawa in the upper part of the Tamagawa River. In the bacterial community at Unazawa, many aquatic bacterial strains were observed ; that is Flavobacterium, Pseudomonas, Aeromonas, Acinetobacter and Moraxlla. It is said generally that bacterial community in the soil had contained many Bacillus, Arthrobacter, and Actinomycetes etc. The bacterial community in the spring investigated at Masugata-no-ike showed that many bacterial strains had gram positive reaction and spore forming ability. Therefore, the bacterial community in this spring seems to be resembled to the bacterial community in the soil. However, there are many probrems to be clarified of understanding the soil bacterial community. For example, bacterial counting methods were not fixed and dispersion conditions from the soil micro particles were not yet established. So in this study, the counting methods of soil bacteria were studied prior to the comparison to the spring bacterial communtiy and the bacterial communtiy in river water. Then the bacterial community in the soil was devided by washing out method using several repeated hand treatments. The bacterial community in the compartment of soil particle were distinguished from the flowing water compartment.