不同菌株培养顺序对添加铁铝锰氧化物白浆土腐殖质组成的影响

Effects of different microbial culture sequences on the humic composition of Albic soil amended with Fe,Al,Mn oxide minerals

文章旨在探索巨大芽孢杆菌(Bacillus megaterium)、黑曲霉(Aspergillus niger)和灰色链霉菌(Streptomyces griseus)3种菌株、6种培养顺序在添加铁、铝、锰氧化物情况下对混有木质素白浆土腐殖质组成的差异影响.采用室内培养法,在针铁矿、三羟铝石和δ-MnO_2参与条件下,通过6种菌株培养顺序的设置,探讨其对木质素白浆土混料腐殖质组成的影响.结果表明:基于针铁矿添加条件,在以巨大芽孢杆菌为Ⅰ期培养菌株时更有利于白浆土腐殖化系数(CHA/CFA)的促进.而在针铁矿和δ-MnO_2添加条件下,A.niger→S.griseus→B.megaterium的培养顺序更有利于白浆土胡敏酸(HA)向富里酸(FA)的转化.基于三羟铝石添加条件,灰色链霉菌为Ⅰ期培养菌株时更有利于白浆土CHA/CFA的促进,而以巨大芽孢杆菌为Ⅰ期培养菌株时可使CHA/CFA降低;除S.griseus→A.niger→B.megaterium外的5种菌株培养顺序,δ-MnO_2均能有效促进白浆土HA的降解、使其分子结构更加简单;无论哪一菌株培养顺序,针铁矿均有利于微生物对混料胡敏素(Hu)的矿化,δ-MnO_2可使混料总有机碳(TOC)发生较大程度矿化;与对照相比,δ-MnO_2亦可促进微生物对混料水溶性物质(WSS)的消耗,且对可提取腐殖酸(HE)的形成有促进作用.

The effects of six microbial culture sequences of three strains, containing Bacillus megaterium, Aspergillus niger and Streptomyces griseus, on the humic composition in Albic soil amended with lignin were systematically studied in this study based on the additions of Fe, A1, Mn oxide, such as goethite, bayerite and 3-MnO2. The results show that ： the goethite could increase the humification coefficient （ CHA/CFA ratio） of Albic soil to the highest degree when the B. megaterium served as inoculated in the period I. The culture sequence of A. niger→S, griseus→B, megaterium was more beneficial for the transformation of humic acid （HA） into fulvic acid （FA） in Albic soil added with δ-MnO2 and goethite. Under the existence of bayerite, the S. griseus was more beneficial to the improvement of CHA/CFA in Albic soil especially in the period I. However, the CHA/CFA ratio decreased in case that B. megaterium was inoculated in the period I. Based on the five microbial culture sequences except for S. griseus→A, niger→B, megaterium, the ＆MnO2 could effectively promote the degradation of HA extracted from the Albic soil and make their molecular structures tend to be much simpler. No matter which strain culture sequence, the goethite was beneficial to the microbial mineralization of Hu extracted from the mixture. The addition of δ-MnO2 could enhance the mineralization of total organic C （TOC） content of mixture to the greatest extent. Compared with the control treatment, the δ-MnO2 could also greatlypromote the microbial consumption of water soluble substance （WSS） and the formation of humic-extracted acid （HE） extracted from the mixture.