Labeda D P, Liu K C, Casida L E
Appl Environ Microbiol. 1976 Apr;31(4):551-61. doi: 10.1128/aem.31.4.551-561.1976.
Arthrobacter globiformis and a Pseudomonas soil isolate were incubated separately and in combination in soil that had been presterilized by autoclaving. Growth and other responses of the cells in situ in this soil were monitored by plate counts and transmission electron microscopy examinations of cell sections. During the soil incubations, some of the samples were first allowed to dry and then were remoistened with water or with a dilute or a concentrated nutrient solution. Based on plate counts and ultrastructural analysis. Arthrobacter seemed to be in a non-multiplying coccoid-rod resting state and to be virtually immune to soil drying. Addition of a dilute nutrient solution helped maintain cell ultrastructure and prevent a low level of lysing that occurred in the absence of nutrient addition. Addition of a concentrated nutrient solution brought on cell multiplication as both coccoid-rods and long rods, but the ultimate form with further incubation was the coccoid-rod. The Pseudomonas strain suffered death and ultrastructural deterioration as water became less available. It responded by cell multiplication to an equal extent when either water or dilute nutrients were added, but possibly was able to give a growth response to nutritive amendment when a concentrated nutrient addition was made. The Arthrobacter was not affected by the presence of Pseudomonas in dual culture. The Pseudomonas, however, possibly suffered a nutritive deficiency under these conditions.
球形节杆菌和一种从土壤中分离出的假单胞菌分别进行培养，并在经过高压灭菌预先消毒的土壤中混合培养。通过平板计数和对细胞切片的透射电子显微镜检查，监测这些细胞在该土壤原位的生长及其他反应。在土壤培养期间，部分样品先使其干燥，然后用水或稀或浓的营养液重新湿润。基于平板计数和超微结构分析，节杆菌似乎处于非增殖的球状杆菌静止状态，并且实际上对土壤干燥具有免疫力。添加稀营养液有助于维持细胞超微结构，并防止在不添加营养物时发生的低水平细胞裂解。添加浓营养液会使球状杆菌和长杆菌都进行细胞增殖，但进一步培养后的最终形态是球状杆菌。随着水分供应减少，假单胞菌菌株会死亡且超微结构恶化。当添加水或稀营养物时，它通过细胞增殖做出同等程度的反应，但当添加浓营养物时，它可能能够对营养改良做出生长反应。在混合培养中，节杆菌不受假单胞菌存在的影响。然而，在这些条件下，假单胞菌可能会出现营养缺乏的情况。
