生物炭复合青霉菌修复砷污染土壤对其微生物群落功能多样性的影响

真菌修复砷污染土壤是一种能够有效吸附固化环境中砷的重要措施.生物炭作为目前修复重金属的热点，其多空疏松的结构、较高的离子交换量、丰富的有机碳含量等都说明了其在土壤修复中的地位.为了探究生物炭与青霉菌在修复砷污染土壤的同时对土壤中微生物活性及其多样性的影响，在室内孵育条件下，运用Biolog法研究了3×3随机区组试验（3个生物炭梯度分别为0%、2%、4%，3个青霉菌梯度分别为0%、10%、20%）下土壤微生物对不同类型碳源的利用能力以及多种功能性指数的影响.结果表明:①添加青霉菌与生物炭后，土壤中有效砷含量较对照组显著下降，从而影响其微生物群落功能多样性.②砷污染土壤中微生物群落功能多样性、碳源利用丰富度随生物炭浓度梯度的升高呈先升后降的趋势.③高接菌量（20%）与低接菌量（10%）对砷污染土壤中微生物群落功能多样性的影响没有显著性差异.④2%生物炭与10%青霉菌处理土壤中微生物群落功能多样性、碳源利用丰度最高.⑤青霉菌对胺类及少部分酸类碳源的利用能力较弱（AWCD < 0.5，AWCD为Biolog微平板孔中溶液吸光值平均颜色变化率），对氨基酸类中大部分碳源以及脂类碳源的代谢能力较强（AWCD>1.0），对糖类、酚酸类的代谢能力稍弱（AWCD为0.3~1.0），青霉菌对D-半乳糖醛酸、L-天冬酰胺酸、L-丝氨酸、L-精氨酸、r-羟基丁酸这5种碳源的利用率最高（AWCD>1.2）.研究显示，低浓度生物炭可增加砷污染土壤中微生物群落多样性，生物炭含量的继续增加会对微生物产生抑制作用；青霉菌添加到砷污染土壤后，会显著提升砷污染土壤中微生物的群落功能多样性，改善砷污染土壤中微生的物群落结构；青霉菌的优势碳源大多为植物根系分泌物，可为后续青霉菌与超积累植物复合修复砷污染土壤提供参考. 

Effects of Biochar Composite Penicillium on Functional Diversity of Microbial Community in Arsenic-Contaminated Soil

Fungal remediation of arsenic-contaminated soil is considered to be an effective method to adsorb and solidify arsenic. The porous structure, high ion exchange capacity and abundant organic carbon content of biochar indicate its role in soil remediation. To explore the effects of biochar and penicillium on microbial activity and diversity of the contaminated soil, 3×3 randomized block experiments (biochar gradients was 0%, 2%, 4%, penicillium gradients was 0%, 10%, 20%) were conducted and the effects of soil microbes on different types of carbon sources and various functional indexes were studied using Biolog method under indoor incubation conditions. The results showed that the content of available arsenic in soil was significantly decreased after adding the penicillium and biochar, which further affected the functional diversity of microbial communities in soil. The functional diversity and the richness of carbon source utilization of microbial community in arsenic-contaminated soil showed a trend of first increasing and then decreasing with the increase of biochar concentration gradient. The effects of high inoculum (20%) and low inoculation (10%) on the functional diversity of microbial communities in arsenic-contaminated soils were not significantly different. The highest soil microbial community functional diversity, species richness, carbon source abundance and utilization capacity were observed in the treatment of 2% biochar and 10% of penicillium. Penicillium had a weak ability to utilize amines and a small number of acid carbon sources (AWCD<0.5) had high metabolism capacity for most carbon sources and lipid carbon sources in amino acids (AWCD>1.0) had slightly weaker metabolism capacity for sugars and phenolic acid (AWCD=0.3-1.0). Penicillium had the highest utilization rate of D-galacturonic acid, L-asparaginic acid, L-serine, L-arginine and R-hydroxybutyric acid (AWCD>1.2). The studies show that low concentration of biochar increased the metabolic activity and functional diversity of microorganisms in arsenic-contaminated soil. However, inhibition occurred when the biochar content increased. The addition of penicillium to arsenic-contaminated soil can significantly increase the functional diversity of microbial communities and improve the microbiota community structure in arsenic-contaminated soil. The dominant carbon source of penicillium is mostly the secretion of plant rhizosphere, which provides a reference for the remediation of arsenic-contaminated soil by the combination of penicillium and plants.