不同类型林分土壤微生物生理类群分析

本研究就三种不同处理林分土壤微生物生理类群的初步分析,表明杉木马尾松混交后有利于固氮微生物的生长,固氮微生物数量的增加,促进了混交林分生长;有利于氨化细菌的生长,氨化细菌数量的增加,又利于提高含氮有机物的分解和转化速率,从而提高混交林地土壤肥力;同时促进了纤维素分解菌的生长,利于有机物的转化和加快碳素循环速率,从而为植物生长提供更多的碳素和能源。因此,在混交林中杉木的平均胸径比对照提高24%,平均树高比对照提高21%;马尾松平均胸径比对照提高20%,平均树高比对照提高19%,可见营造杉、马混交林比纯林更具发展潜力,可实现树高、胸径积累的双赢。     

双免耕覆盖对旱地土壤微生物、酶活性和冬小麦干物质转运的影响

为了解双免耕覆盖下旱地土壤微生物数量、土壤酶活性及冬小麦干物质转运特征，研究了双免耕覆盖下麦田土壤中细菌、真菌、放线菌的数量、土壤蛋白酶和脲酶的活性、冬小麦花前和花后干物质向籽粒的转运量与传统耕作（对照）的差异。结果表明，与对照相比，双免耕覆盖下土壤中微生物的数量和酶活性在冬小麦不同生育时期和不同土层均显著（P<0.05）或极显著（P<0.01）高于对照；在0～60 cm土壤中，双免耕覆盖下微生物总量平均较对照高68.2%，差异达极显著水平；土壤中蛋白酶和脲酶活性平均较对照高 27.3%和32.7%。双免耕覆盖下冬小麦花后干物质积累量对籽粒产量的贡献率为44.2%，较对照增加了 61.7%；产量较对照提高18.4%，二者差异达极显著水平。     

Advances in Biodegradation of Aflatoxins

Aflatoxins are secondary metabolites of fungi such as Aspergillus flavus and Aspergillus parasiticus. They are one of the contaminants most common in food and feed, with high toxicity and carcinogenicity. Aflatoxins usually enter animal body together with feed and then enter human body by food chain, thereby seriously threatening human health. In recent years, the degradation of aflatoxins has become a hot research topic. This study overviewed the characteristics and detoxification ways of aflatoxins, specifically for the advances in biodegradation and degradation products of aflatoxins.     

Effect of rifaximin on gut-lung axis in mice infected with influenza A virus

Gut-lung axis injury is a common finding in patients with respiratory diseases as well as in animal model of influenza virus infection. Influenza virus damages the intestinal microecology while affecting the lungs. Rifaximin, a non-absorbable derivative of rifamycin, is an effective antibiotic that acts by inhibiting bacterial RNA synthesis. This study aimed to determine whether rifaximin-perturbation of the intestinal microbiome leads to protective effects against influenza infection, via the gut-lung axis. Our results showed that influenza virus infection caused inflammation of and damage to the lungs. The expression of tight junction proteins in the lung and colon of H1N1 infected mice decreased significantly, attesting that the barrier structure of the lung and colon was damaged. Due to this perturbation in the gut-lung axis, the intestinal microbiota became imbalanced as Escherichia coli bacteria replicated opportunistically, causing intestinal injury. When influenza infection was treated with rifamixin, qPCR results from the gut showed significant increases in Lactobacillus and Bifidobacterium populations, while Escherichia coli populations markedly decreased. Furthermore, pathology sections and western blotting results illustrated that rifaximin treatment strengthened the physical barriers of the lung-gut axis through increased expression of tight junction protein in the colon and lungs. These results indicated that rifaximin ameliorated lung and intestine injury induced by influenza virus infection. The mechanisms identified were the regulation of gut flora balance and intestinal and lung permeability, which might be related to the regulation of the gut-lung axis. Rifaximin might be useful as a co-treatment drug for the prevention of influenza virus infection.     

土壤锗污染对土壤微生物的生态毒理效应

着重讨论土壤添加Ge对土壤微生物的生态效应及土壤Ge污染临界含量。盆栽试验表明,在土壤Ge含量2～2 0 0mgkg-1范围,低浓度Ge对土壤细菌、真菌、放线菌有刺激作用,随着浓度增高,而交替出现抑制和刺激作用。土壤Ge浓度与明亮发光杆菌T3发光度之间有极显著的负相关性,按照T3发光度80 %和10 0 %为临界值,计算得土壤Ge临界浓度分别为5 0 2mgkg-1和5 8mgkg-1。     

恶唑菌酮土壤降解影响因子研究

探讨了土壤环境中的主要因素:土壤微生物、温度、含水量、pH值以及施用有机肥对恶唑菌酮降解的影响。结果表明:土壤微生物对恶唑菌酮在土壤中的降解起着重要作用,相同条件下灭菌土壤的降解半衰期是非灭菌土壤的27.6倍。环境温度、土壤含水量等对恶唑菌酮降解也有影响,在15℃～40℃的试验条件下,随着温度升高,恶唑菌酮的降解速率加快,特别是15℃～25℃温度范围内降解速率上升较快;过高和过低的土壤含水量都不利于土壤中恶唑菌酮的降解,土壤含水量为50?～100?时适宜恶唑菌酮的降解;此外施用有机肥会加速恶唑菌酮的降解;而土壤pH值对降解的影响不显著。     

杨树刺槐混交林及纯林根际微生物数量及其生化强度的季节性动态研究

测定了杨树、刺槐混交林及纯林根际土壤微生物数量及其生化强度的季节性动态变化。结果表明 ,混交后根际土壤微生物数量和生化强度高于纯林 ,其中硝化细菌数量及硝化强度、解无机磷微生物数量及磷转化强度尤为显著 ,幅度达 1～ 2倍。说明混交后更有利于氮、磷养分的有效化。并且在生长旺季根际微生物的数量和生化活性最高 ,有利于树木的旺盛生长。     

微生物在污染环境生物修复中的应用

生物修复是一项利用生物特别是微生物治理污染的技术。与理化修复方法相比具有投资少、对环境影响小的优点。本文重点分析了影响微生物修复的关键因素,包括生物因素、营养因素、O2和电子受体、表面活性剂和共代谢物等,并介绍了微生物在生物修复中成功应用的实例,讨论了生物修复所具有的优势和存在的不足及今后研究重点。     

黑茶加工中微生物作用的研究

六堡茶、普洱茶、茯砖茶等同属黑茶类，传统加工过程中的渥堆发酵是形成黑茶品质特征的关键，上述过程需要微生物参与才使其具有独特品质。本文就黑茶生产过程中的主要微生物种类、微生物分泌的胞外酶及其对黑茶品质形成所起的作用、微生物的安全性进行综述。     

几株食用菌对初烤烟叶品质的影响

选取7株可食用真菌,接种于B3F级初烤烟叶,温度30℃,湿度（70±2）%培养50 d。通过测试烟叶的还原糖、烟碱、总氮、糖碱比、蛋白含量和样品感官评吸,对发酵后烟叶品质做理化和感官上的综合评价,以筛选出对烟叶品质有明显改善作用的菌株用于烟草的醇化研究。结果发现几株真菌对烟叶品质改善明显,特别是食用菌Z-7（Pleurotusostreatus）对烟叶品质改善显著。