幾種環境因素對毛黴菌接合孢子形成與萌芽之影響

Abstract

本實驗研究幾種環境因素對毛黴菌(Mucor hiemalis)接合孢子形成與發芽之影響。發現在某些情況下（如相對濕度100％，培養基糖含量0.5％及1％乙醇蒸氣下之培養菌體），接合孢子雖能大量形成，但其發芽率卻大?降低，甚或完全消失（如30-31℃與黑暗下之培養菌體）。在24℃，12小時光照與黑暗輪替，pH5.8之環境下形成之接合孢子，其萌芽率達8－9％。前人發芽率試驗結果則低於1％。 推測形成具有萌芽能力之接合孢子之某些代謝過程，必對環境因素甚?敏感，於黑暗下形成之接合孢子不能萌芽，故光照對形成具有萌芽能力之接合孢子?一不可或缺之因素。 由交配試驗得知，接合孢子萌芽後，其(＋)(－)兩系之比率?一比二，即δ1個萌芽之接合孢子中，27個是(＋)系，54個是(－)系。 此外並發現毛黴菌(M. hiemalis)在二氧化碳堆積之環境下，能?生關結孢子(Arthrospores)及厚壁孢子(Chlamydospores)。

The reproduction of Mucor hiemalis was studied under various environmental conditions. It was observed that in CO2 accumulated plates, weak acidic and overheated medium, arthrospores were produced. It was concluded that arthrospore formation was mainly induced by CO2 accumulation, and its effect may be indirect. Chlamydospores were also produced in CO2 accumulated cultures as well as old cultures. Under certain conditions although zygospores were abundantly produced their potentiality for germination was greatly reduced or even suppressed. Some metabolic reactions involved in the development of zygospores were sensitive to environmental conditions such as light, temperature, relative humidity, ethyl alcohol and carbohydrate concentration of the cultural medium. Light was observed to be indispensable, while pH ranged at lease from 5.8-8.0 had given no influences. Zygospores produced under laboratory condition (24℃，medium pH 5.8) attained a germination rate of 8-9%, about 66% of the germination the cultures obtained reacted as (-) strains. Factors affecting the mating types of zygospore germination and the reasons why the zygospore germination rate was so low must await for further study.