镧与钕对红假单胞菌的生长、类胡萝卜素生成及固氮活性的影响

本文报道了不同浓度的La^(3+)和Nd^(3+)对红假单胞菌(Rhodopseudomonas sp.)的细胞形态、生长、类胡萝卜素生成和固氮活性的影响。LaCl_3在25和50mg/L时对红假单胞菌的细胞生长有轻微刺激作用;当浓度高于75mg/L时有抑制作用,随浓度的提高而抑制作用增强,细胞缩小;NdCl_3在25和50mg/L时对该菌细胞生长有轻微抑制作用,高于75mg/L时抑制作用明显增强,细胞缩小。两种稀土元素在25和50mg/L时对该菌类胡萝卜素的生成有刺激作用,高于75mg/L时则有抑制作用。La^(3+)在0～100mg/L,Nd^(3+)在0～75mg/L时对固氮酶活性有刺激作用,La^(3+)和Nd^(3+)分别高于100mg/L和75mg/L时则有抑制作用,并随浓度的增高,抑制作用明显增强。

EFFECTS OF La~3 AND Nd~3 ON THE GROWTH, CAROTENE CONTENT AND NITROGENASE ACTIVITY OF RHODOPSEUDOMONAS SP.

The effects of La3 and Nd3 on the growth, carotene content and nitrogen fixation of Rhodopseudomonas sp. were studied. The experimental data showed that lower concentrations (<50mg/L) of both LaCl3 and NdCl3 barely slightly sti-munlated cell growth and its carotene content of Rhodopseudomonas sp., and higher concentrations (>75 mg/L) inhibited the growth and carotene content. The nitro-genase activity of Rhodopseudomonas sp. was increased distinctly when the concentration of both LaCl3 and NdCl3 at 75 mg/L, and decreased as the concentration incre-ased.