Shawky B T
Zentralbl Mikrobiol. 1983;138(1):9-15.
Study of the behaviour of representative aerobic freeliving dinitrogen-fixers, other than azotobacters, with respect to different carbon sources, showed that a broad range of compounds is accessible to them. This group of nitrogen-fixers can assimilate molecular nitrogen as a result of utilization of carbohydrates, alcohols, and organic acid salts. The highest nitrogen-fixation productivity, reaching 20.6-27.3 mg of nitrogen per g of carbon utilized, was observed on medium containing glucose as the carbon and energy source. Supplementary growth factors added to the N-deficient medium in the form of small amounts of yeast extract stimulated their growth and fixation of atmospheric nitrogen. This stimulation is particularly evident in mixed cultures. The nature of the mutual influences of micro-organisms in these cultures remains fairly obscure and further inquiry is necessary to elucidate this problem. A medium containing 1% glucose and Difco yeast extract to produce a bound nitrogen concentration of 10 ppm appeared to be the most favourable for the cultivation and N2-fixation of this group of microorganisms.
对除固氮菌外具有代表性的好氧自生固氮菌在不同碳源条件下的行为研究表明，它们能够利用多种化合物。这类固氮菌可通过利用碳水化合物、醇类和有机酸盐来同化分子态氮。在以葡萄糖作为碳源和能源的培养基上，观察到最高的固氮生产力，每利用1克碳可固定20.6 - 27.3毫克氮。以少量酵母提取物形式添加到缺氮培养基中的补充生长因子刺激了它们的生长和大气氮的固定。这种刺激在混合培养物中尤为明显。这些培养物中微生物相互影响的性质仍相当模糊，需要进一步研究来阐明这个问题。含有1%葡萄糖和Difco酵母提取物、能产生10 ppm结合态氮浓度的培养基似乎最有利于这类微生物的培养和固氮。
