Iunusova L S, Drugova N A
Kosm Biol Aviakosm Med. 1977 May-Jun;11(3):71-4.
The purpose of the present investigation was to study variations in the population density of microorganisms, their qualitative and quantitative composition during substrate-free cultivation of beats. The results obtained show that the microbial number in the nutrient solution increased by the time of intensive growth of beats and decreased by the time of harvesting. The number of root microorganisms was much greater than the total number of microorganisms in the nutrient solution. Oligonitrophils and nitrogen fixing bacteria were found in the solution. This may be associated with a transient decrease of nitrogen in the solution. The number of ammonifiers and denitrifiers in the solution increased significantly by the end of plant vegetation; the amount of denitrifiers inhabiting the roots decreased during vegetation and that of ammonifiers increased. In the middle of vegetation cellulose decomposing aerobes appeared; this might occur since root hairs began to die off. By the end of vegetation an insignificant amount of fungi was also found. Nitrifying and spore-forming microorganisms were not detected. The identification of predominant microbial species showed them to be bacteria of the genera Pseudomonas and Mycobacterium. Besides, microorganisms of the genera Bacterium, Micrococcus, Mycococcus, Chromobacterium and Pseudobacterium also occurred.
本研究的目的是研究甜菜在无底物培养过程中微生物种群密度的变化、其定性和定量组成。所得结果表明，营养液中的微生物数量在甜菜生长旺盛期增加，在收获期减少。根际微生物的数量远大于营养液中微生物的总数。在溶液中发现了寡养硝化菌和固氮菌。这可能与溶液中氮的短暂减少有关。在植物生长末期，溶液中氨化菌和反硝化菌的数量显著增加；在生长过程中，根际反硝化菌的数量减少，氨化菌的数量增加。在生长中期出现了分解纤维素的需氧菌；这可能是由于根毛开始死亡所致。在生长末期还发现了少量真菌。未检测到硝化和产芽孢微生物。对优势微生物种类的鉴定表明它们是假单胞菌属和分枝杆菌属的细菌。此外，还出现了芽孢杆菌属、微球菌属、分枝微球菌属、色杆菌属和假细菌属的微生物。
