Al-resistance mechanism of Al-resistant microorganisms from strongly acid soils

近年来，由于酸雨和土壤供能因素的影响，世界范围内土壤酸度呈上升趋势，主要集中在工业化国家。当大量的H+被吸附时。铝在土壤中释放，土壤中活化的铝造成作物危害和森林死亡，特别是在酸性土壤中，铝导致侧根伸长和丛生的减少。为了缓解这些限制，最近已经尝试了选择耐铝作物和生产转基因植物。为了获得产生转基因植物的基因来源，虽然可以利用抗铝微生物，但对抗铝微生物和基因的研究仅在根瘤菌中进行。首先，为了研究土壤中的抗铝微生物，我尝试在强酸条件下制备含铝琼脂平板。要电离所有添加的铝，pH值必须低于3.5，但在这样的pH条件下，琼脂不会固化。接下来，我尝试在酸性条件下(pH 3.0)制备含Al的琼脂平板(真菌为100 mm，酵母菌为250 mm)以分离耐铝微生物，将培养液(pH 3.0)、Al2(S04)3溶液(pH 3.0)和琼脂溶液分别高压灭菌后混合，即可使琼脂固化。8株Emericellopsis、EP.、淡紫拟青霉、兰花拟青霉。从茶园土壤中鉴定出角孢霉、膨胀芽孢杆菌、光肩青霉、金龟子绿僵菌、伊氏毛孢霉和烟曲霉等6种抗铝真菌。从茶园土壤(高腐植酸土)中分离到两株耐铝酵母菌，经鉴定为耐铝酵母菌。

Recently, due to acid rain and offer factors, soil acidity has tended to increase worldwide mainly in the industrialized countries. When a large quantity of H+ is adsorbed. Al is released in soil and activated Al of soil causes crop damage and forest dieback.In acid soils, Al leads to the decrease of root elongation and clustering of lateral roots, especially. To alleviate these constraints selection of crops and production of transgenic plants that are Al-tolerant have been attempted recently. For the source of genes to produce transgenic plants, although Al-resistant microorganisms could be used, studies on Al-resistant microorganisms and gene have been carried out only in Rhizobia.At, first, to study the Al-resistant microorganisms of soils, I tried to prepare agar plates containing aluminum under strongly acid conditions. in order to ionize all added Al, pH value has to be below 3.5, but under such pH conditions, agar dose not solidify. Next, I attempted to prepare an agar plate containing Al (100mM for fungi, Al : 250mM for yeast) under the acid conditions (pH3.0) to isolate Al-resistant microorganisms.Agar could be solidified when the culture medium solution (pH3.0), Al2(S04)3 solution (pH3.0), and agar solution were mixed after autoclaving separately. Eight strains Emericellopsis, ep., Paecilomyces lilacinus , Moritierella ramanniana var. angulispora, Sprothrix inflata, Penicillium glabrum, Metarhizum anisopliae, Chaetosphria inaeqalis, and Aspergillus fumiatus were identifeid as Al-resistant fungi from the tea garden soils. Tow strains Rhodotoru la mucilaginosa and Cryptococcus laurentii were identified as Al-resistant yeast from the tea garden soil (High-humic Andosols).