黄河三角洲土壤真菌群落结构对盐生植被演替的响应

采用高通量测序技术,探究了黄河三角洲光板地和4种盐生植被(翅碱蓬、獐茅、白茅和罗布麻)下土壤真菌群落结构组成及分布特征,揭示其与盐生植被演替的关系.结果表明,随盐生植被正向演替,土壤质量有不断改善的趋势.轻度耐盐群落(罗布麻群落、白茅群落)土壤中真菌丰富度相对较高,其Shannon多样性指数分别为5.21、5.84;在重度耐盐群落(翅碱蓬、獐茅)土壤中真菌丰富度较低,其Shannon多样性指数分别为4.64、4.66.在不同演替阶段时,土壤真菌群落结构差别相对较大(Unifrac Metric值为0.48~0.67).土壤中全氮含量是影响真菌OTU数、ACE指数和Shannon指数的主要因素.5个土壤样本共获得60174条有效序列,可归到子囊菌门(Ascomycota)、担子菌门(Basidiomycota)、壶菌门(Chytridiomycota)、球囊菌门(Glomeromycota)、毛霉亚门(Mucoromycotina)5个真菌门;其中,子囊菌门在重度耐盐植物群落(翅碱蓬、獐茅)中相对丰度较高(2.69%、69.97%),担子菌门在轻度耐盐群落(罗布麻群落、白茅群落)中相对丰度较高(9.43%、6.64%).     

生物表面活性剂逆胶束中漆酶催化性能的研究

对一种新型生物表面活性剂逆胶束中漆酶的催化性能进行了研究.以鼠李糖脂(RL,阴离子生物表面活性剂)为表面活性剂,异辛烷和正己醇为溶剂和助表面活性剂,构建逆胶束,分别考察了有机相组成、RL浓度、逆胶束体系含水率W0、缓冲溶液酸碱度及盐浓度等因素对该逆胶束体系中漆酶催化性能的影响.结果表明,当逆胶束有机相正己醇/异辛烷体积比为1:1.8,RL浓度为13mmol/L,体系含水率W0为42,缓冲溶液pH5.0,KCl浓度为10mmol/L时,该体系中漆酶具有较好的活性及稳定性.对比试验显示,与化学表面活性剂AOT逆胶束相比,RL逆胶束能使漆酶表现出较高的活性及稳定性,说明与传统化学表面活性剂相比生物表面活性剂在构建逆胶束酶体系上的具有一定的优越性.     

土地利用方式对会仙岩溶湿地土壤真菌群落和功能类群的影响

研究土地利用对会仙湿地土壤真菌群落及其功能类群特性的影响,可以为湿地的保护提供理论依据.以芦苇湿地(PCW)、华科拉莎草湿地(CCW)、稻田撂荒地(APF)、稻田(PF)和玉米地(CF)为研究样地,采用高通量测序法对不同土地利用土壤真菌群落结构进行分析,利用FUNGuild数据库对真菌的功能类群进行预测.结果表明,PF和CF的Simpson指数和Shannon指数显著高于PCW和CCW;在门水平上,子囊菌门(Ascomycota)为5种土地利用的最优势菌,丰度为70.60%～87.02%,隐真菌门(Rozellomycota)为PCW的次优势菌,丰度为7.14%;担子菌门(Basidiomycota)为CCW、 APF、 PF和CF的次优势菌,丰度分别为9.70%、 5.19%、 8.13%和7.50%.在目水平上,PCW中最优势菌为格孢菌目(Pleosporales),丰度为16.47%; CCW、 APF、 PF和CF的最优势菌均为肉座菌目(Hypocreales),丰度分别为22.52%、 23.50%、 17.60和23.80%.在属水平上,PCW和CCW中的最优势菌分别为粪盘...     

基于磁性纳米粒子固定技术的漆酶传感器用于垃圾堆肥中邻苯二酚的检测

以邻苯二酚为检测目标,研究了一种基于核/壳磁性纳米粒子固定漆酶的邻苯二酚生物传感器制备方法及其在城市生活垃圾堆肥中的应用.制备Fe₃O₄磁性纳米颗粒,使用正硅酸乙酯（TEOS）和氨丙基三甲氧基硅烷（APTMS）将其功能化并利用戊二醛将漆酶共价固定,借助磁场吸附在磁性碳糊电极上,检测邻苯二酚.固定在电极表面的漆酶保持了很好的活性.该生物传感器的检测线性范围为7.5×10^-7～2.75×10^-4 mol/L,检测下限达到7.5×10^-7 mol/L,达到稳态电流95%所需时间大概为70 s.将该传感器检测堆肥浸出液中酚的含量的结果与高效液相色谱法对比,两者非常接近.     

生物炭对西瓜连作土壤真菌群落结构和功能类群的影响

为明确生物炭施入后对西瓜连作土壤真菌群落结构及功能类群的长期影响,以西瓜成熟期根区土壤为研究对象,借助Illumina NovaSeq高通量测序技术和 FUNGuild平台,探究不同用量（7.5、15.0和30.0 t·hm^-2）生物炭施用3 a后西瓜连作土壤真菌群落组成、多样性及功能的差异,并分析土壤环境因子与真菌群落结构间的关联性.结果表明,添加生物炭3 a后提高了土壤pH、有效磷、速效钾、全氮、有机质和阳离子交换量,降低了土壤碱解氮含量.生物炭的施用改变了西瓜连作土壤真菌群落结构,提高了土壤真菌的丰富度和多样性.所有土壤样本共获得922个OTU,子囊菌门、担子菌门、被孢菌门、壶菌门和球囊菌门为优势真菌类群,占土壤真菌群落的85.70 %~92.45 %,生物炭的施入降低了子囊菌门和担子菌门的相对丰度,增加了被孢菌门和球囊菌门的相对丰度;属水平上,随着生物炭的施用,被孢霉属和囊根壶菌属的相对丰度增加,而镰刀菌属相对丰度降低.Mantel检验分析发现,速效钾、碱解氮、有机质和pH是影响土壤真菌群落结构的主要环境因子.真菌主要营养类型为腐生营养型、病理营养型和共生营养型,中、高剂量生物炭处理显著降低了土壤中病理营养型真菌的相对丰度,显著增加了共生营养型真菌的相对丰度.综上,生物炭施用3 a后可改变西瓜连作土壤理化性质,促进土壤真菌群落结构和功能类群向健康有益方向发展.     

酸改性壳聚糖载体对漆酶的固定化

利用有机酸改性壳聚糖和交联法制备酸化壳聚糖载体,然后用改性壳聚糖载体固定漆酶。结果表明,甲酸、酒石酸改性壳聚糖的最适条件是壳聚糖与酸的量比分别为100/1(g/mol)、100/0.5(g/mol),戊二醛的浓度分别为1%、2%,缓冲溶液的pH分别为4.4、3.6,反应时间分别为3h、4.5h。两种酸改性的壳聚糖用于漆酶的固定,其酶活都有所提高,尤其用酒石酸改性的壳聚糖载体的效果最好,其酶活提高了57%。     

Phospholipid fatty acid patterns of microbial communities in paddy soil under different fertilizer treatments

The microbial communities under irrigated rice cropping with different fertilizer treatments, including control （CK）, PK, NK, NP, NPK fertilization, were investigated using phospholipid fatty acid （PLFA） profile method. The results of this study revealed that the fertilizer practice had an impact on the community structure of specific microbial groups. The principal components analysis （PCA） showed that proportion of the actinomycete PLFAs （10Me 18：0 and 10Me 16：0） were the lowest in the PK treatment and the highest in the NPK treatment, which means that soil nitrogen status affected the diversity of actinomycetes, whereas nitrogen cycling was related to the actinomycets. Under CK treatment, the ratio of Gram-positive to Gram-negative bacteria was lower compared with that in fertilizer addition treatments, indicating that fertilizer application stimulated Gram-positive bacterial population in paddy soil. The fatty acid 18：2to6,9, which is considered to be predominantly of fungal origin, was at low level in all the treatments. The ratio of cyl9：0 to 18：1 to7, which has been proposed as an indicator of stress conditions, decreased in PK treatment. Changes of soil microbial community under different fertilizer treatments of paddy soil were detected in this study; however, the causes that lead to changes in the microbial community still needs further study.     

蚕豆根尖微核技术监测环境污染物的诱变活性

应用蚕豆根尖微核技术对10份矿尘样品、黄曲霉毒素B_1(AFB_1)和15份真菌提取物进行诱变性研究,结果有10份矿尘、AFB_1和5种真菌提取物能明显诱发蚕豆根尖细胞微核率的增高;对其中5~#矿尘、AFB_1和杂色曲霉提取物进行剂量效应测定,显示了良好的剂量效应关系,提示具有诱变活性,这对当地的肿瘤发病率可能起重要作用。说明蚕豆根尖微核技术对研究环境诱变剂不失为一种有效的手段。     

大孔树脂共价固定化漆酶及其对孔雀石绿的脱色研究

以大孔树脂为固定化载体,戊二醛为表面活化剂,采用共价结合法固定漆酶。以ABTS为漆酶底物,通过对固定化漆酶活性的测定,确定大孔树脂固定漆酶的最佳固定条件为：戊二醛浓度=2%、pH=6、活化时间=2 h、固定时间=10 h。在此条件下制备的固定化漆酶能够保持79%的初始活性,获得的固定化漆酶活力能够达到1．94 U·g-1。在酸性条件(pH=3)下,游离漆酶的活性在3 h内丧失71%,而固定化漆酶仅丧失37%,显示出固定化漆酶良好的环境稳定性。固定化漆酶对孔雀石绿染料的脱色率在5h内可达到96%。     

Enhanced oxidation of benzo[a]pyrene by crude enzyme extracts produced during interspecific fungal interaction of Trametes versicolor and Phanerochaete chrysosporium

The effects of interspecific fungal interactions between Trametes versicolor and Phanerochaete chrysosporium on laccase activity and enzymatic oxidation of polycyclic aromatic hydrocarbons (PAHs) were investigated. A deadlock between the two mycelia rather than replacement of one fungus by another was observed on an agar medium. The laccase activity in crude enzyme extracts from interaction zones reached a maximum after a 5-day incubation, which was significantly higher than that from regions of T. versicolor or P. chrysosporium alone. The enhanced induction of laccase activity lasted longer in half nutrition than in normal nutrition. A higher potential to oxidize benzo[a]pyrene by a crude enzyme preparation extracted from the interaction zones was demonstrated. After a 48 hr incubation period, the oxidation of benzo[a]pyrene by crude enzyme extracts from interaction zones reached 26.2%, while only 9.5% of benzo[a]pyrene was oxidized by crude extracts from T. versicolor. The oxidation was promoted by the co-oxidant 2,2'-azinobis-3-ethylbenzthiazoline-6-sulphonate diammonium salt (ABTS). These findings indicate that the application of co-culturing of white-rot fungi in bioremediation is a potential ameliorating technique for the restoration of PAH-contaminated soil.