Airtight Condition Research Articles

Survival of Entomophthora spp.in Laboratory Cultures

The prolong survival of cultures of Entomophthora coronata (COST.) KEVORK. 〔=Conidiobolus coronatus (COST.) TYRRELL. and MACLEOD〕, E.virulenta HALL and DUNN, E. thaxteriana(PETCH) HALL and BELL, and E. sphaerosperma FRES. under air-tight condition appeared to be dependent on the hyphae, some of which were knobby and might become chlamydo-spores. The conidia were very short lived, and the resting spores produced by E. virulenta also did not survive for long periods. The conidia survived longer at 5°C than at room temperatures.Under air-tight condition, the metabolic activity of the fungus was reduced as indicated by the production of only a few small conidia and narrow hyphae. As air became available more conidia were produced, the hyphae increased in size, became vacuolated, fragmented, and then collapsed and disintegrated.

Cultivation of M. lepraemurium on the 1% Ogawa yolk medium and animal inoculation with cultivated M. lepraemurium (author's transl)

A follow experiment of the Ogawa's method was began at April 1971 and identification of cultivated M. lepraemurium passaged 11 generations was carried out by a method of injection to mouse, rat, hamster, rabbit, guinea pig and quail and by a diffusion chamber method.Efficiency of isolation culture was better in cases of a subcutaneous leproma treated with alkali and using air loose stopper than in cases of no treatment and using air tight stopper. When the cultivation was carried out under 33°C for long time, several microcolonies of M. lepraemurium were seen after one year. As M. lepraemurium grows very slowly, it takes so long time that primary isolation should be kept low temperature to avoid a degradation of medium composition. The isolation of M. lepraemurium succeeded in 83% out of all test tube media on the case of air loose condition, while succeeded in only 50% on the case of air tight condition. Moreover, piled up and big colonies were seen in air loose condition. Some of these colonies were able to passagedon new 1% Ogawa yolk media but not on 1% Ogawa whole egg media.A 3 months old culture of M. lepraemurium passaged 11 generations was donated from Dr. Ogawa and then its bacterial suspension was inoculated to back subcutaneous tissue of ddO white mouse. After 5 months a small leproma was palpable in the local place injected more than 1.8×104 bacilli. At the same time, the bacterial suspension was mixed with mouse peritoneal cells and enclosed into the millipore diffusion chamber, which was inoculated in abdominal cavity of mouse. After 5 months many globi were seen in peritoneal cells mixed with 0.9×103 bacilli. When the bacterial suspension grown in the diffusion chamber was inoculated to abdominal subcutaneous tissue of ddO white mouse, 5 bacilli was able to form a palpable subcutaneous leproma after 5 months. The second passage of the leproma which was grown on the back of ddO mouse by an injection with the cultivated M. lepraemurium, was carried out in C3H mice. After 8 to 13 months, big leproma was formed in the injected site of all mice.At the present, for definition as a M. lepraemurium the organism must form a leproma contained globi of acid fast bacilli to mouse, rat and hamster and must not form a leproma to guinea pig, rabbit and bird, and the organism does not grow on the culture media for M. tuberculosis. Therefore the cultivated M. lepraemurium was injected into rat, hamster, guinea pig, rabbit and quail. After 6 to 10 months thinly developed leproma was seen in the injected local of rat and hamster, but was not seen in guinea pig, rabbit and quail.From these results, the acid fast bacillus isolated on 1% Ogawa yolk medium by Dr. Ogawa can identify as M. lepraemurium.

The influence of environmental conditions on the artificial germination and vitality of pollen in <i>Allium ordorum</i> L.

The paper deals with the results of an investigation of the best conditions for the artificial germination and vitality of pollen in Allium ardorum L. About 25°C is the optimum temperature for the germination and the number of burst pollen in the medium increases in the higher temperature. The low temperature such as under 8°C and low humidity such as 40% are both effective to the preservation of pollen-vitality. The air-tight condition is also good for it. The light has no influence upon the germination and vitality.

On the Relations between the Moisture Content and the Physio-Chemical Changes in Rice Grains Stored in the Air-Tight Condition

On the Relations between the Moisture Content and the Physio-Chemical Changes in Rice Grains Stored in the Air-Tight Condition