Biological and chemical characteristics of the aged microcosm and its ecological significance.

衰老微观世界的生物化学特征及其生态意义。

• 批准号: 62480004
• 负责人: KURIHARA Yasushi
• 金额: $ 2.56万
• 依托单位: TOHOKU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1987
• 资助国家: 日本
• 起止时间: 1987 至 1988
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-62480004/
• 关键词: Microcosm; Closed system; Community metabolism activity; Bacteria; Serial transfer; 形質変化; 種間競争; 低濃度培地; 過老令化; 開放系; 閉鎖系; 群集維持; 構成種の単離

We have made observation on closed microcosms (medium:air = 2:1), which did not exchange gas with the atmosphere, when flasks were stoppered with rubber plugs at 25 d of cultivation. The population densities and the diural changes of dissolved oxygen in the closed microcosms were same as those in the control microcosm, which exchanged gas with atmosphere. The concentration of gaseous oxygen were almost constant in the closed microcosms. Thus, the population densities and the level of community metabolism activity could be maintained after microcosms were totally closed at mature stage.In an attempt to clarify the significance of characteristics of bacterial populations in aged microcosms, the growth rates of bacteria were investigated. Bacteriafrom the microcosms were subjected to serial transfer at 3 d intervals in both single and two-species culture. Selection in single species populations under serial transfer favored an increased growth rate. When selection was applied to mixed populations, the growth rates of both species did not change or were sometimes reduced from that of parental strain. These results can be viewed as evidence for a trade-off between interspecitic competitive ability and growth rate.Selection was applied to adapting bacterial populations in two ways: in high nutrient (Bac-H) and low nutrient (Bac-L) medium. The growth rate of Bac-L was higher than that of Bac-H in low nutrient medium and the growth rate of Bac-L was lower than that of Bac-H in high nutrient condition.

我们对封闭的微观世界（培养基：空气=2：1）进行了观察，培养25天时，用橡皮塞塞住烧瓶，不与大气进行气体交换。封闭微观世界中的种群密度和溶解氧的日变化与与大气进行气体交换的对照微观世界相同。在封闭的微观世界中，气态氧的浓度几乎恒定。因此，在成熟阶段微观世界完全封闭后，种群密度和群落代谢活性水平仍能得以维持。为了阐明老化微观世界中细菌种群特征的意义，对细菌的生长速率进行了研究。来自微观世界的细菌在单菌种和双菌种培养物中以 3 d 的间隔进行连续转移。连续转移下单一物种种群的选择有利于生长速率的提高。当选择应用于混合群体时，两个物种的生长速率没有变化，或者有时比亲本品系的生长速率有所降低。这些结果可以被视为种间竞争能力和生长率之间权衡的证据。选择以两种方式应用于适应细菌种群：在高营养（Bac-H）和低营养（Bac-L）培养基中。在低营养培养基中Bac-L的生长速率高于Bac-H，在高营养条件下Bac-L的生长速率低于Bac-H。

项目成果

S. Shikano; Y. Kurihara: "Analysis of factors controlling responses of an aquatic microcosm to organic loading." Hydrobiologia. 169. 251-257 (1988)

S.鹿野；

S.Shikano;Y.Kurihara: Yydrobiologia. (1988)

S.Shikano；Y.Kurihara：Yydrobiology。

S.Shikano: Hydrobiologia. 169. 251-257 (1988)

S.Shikano：水生生物学。