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.     

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。     

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.     

胃肠道褪黑素的合成及其对消化道微生物群体影响的研究进展

胃肠道褪黑素主要是由肠嗜铬细胞分泌,具有一定昼夜节律性。褪黑素通过调控细胞因子或NF-κB等调控肠道微生物及其代谢,进而影响动物肠道微生物群体结构以及某些细菌的昼夜节律。本文主要对近几年胃肠道褪黑素的合成分泌及其生理功能、肠道微生物节律性以及褪黑素对肠道微生物的调控作用等研究进行综述,以期为胃肠道褪黑素与菌群之间调控关系的研究提供一定参考。     

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。     

微生物在秸秆饲料中的应用

大力开发秸秆资源、发展秸秆饲料是高效发展畜牧业的良好前景，但许多加工秸秆的方法不能有效地解决秸秆消化率低和可利用营养物少的问题。本文推荐3种利用微生物处理农作物秸秆的方法，事实证明饲喂效果非常理想，据此提出了未来微生物处理秸秆的主攻方向。     

纤维体及其在瘤胃微生物中的研究进展

纤维体是指某些厌氧细菌和真菌产生的降解纤维素的多酶复合体,它能够将纤维素和微生物细胞连接起来,进而实现对纤维素的高效降解。纤维体首先是在嗜热纤维梭菌上发现并被提出。目前,纤维体的研究已成为瘤胃微生物研究领域的热点问题。本文对纤维体概念的提出过程、纤维体存在的证据、纤维体作用的分子基础和功能以及瘤胃微生物纤维体类似物的研究进行了综述。     

生物饲料饲喂奶牛试验效果及分析

研究采用专用微生物发酵制剂生产的生物饲料对奶牛产奶性能的影响。将20头产奶牛随机分成试验组和对照组，以生物发酵料和全价混合精料分别作试验组和对照组奶牛日粮精料，青、粗饲料以及饲养管理条件试验组与对照组相同。结果表明：试验组奶牛头日平均产奶量比对照组多2．61kg,增加11．57％，（p〈0．05），每头增收27．38元。与对照组相比，用生物饲料饲喂奶牛可提高产奶量，经济效益明显。     

微生物与重金属作用机理研究

以微生物与重金属相互作用为对象,结合近年来国内外研究,系统地说明了5种主要分子作用机理,分别为细胞表面吸附、主动运输、细胞内隔绝、胞外沉淀及酶的解毒作用。对重金属产生抗性的基因位于微生物的染色体、质粒和转座子上。最后介绍了多种抗性菌株,并就研究和应用前景进行了分析。     

竹醋液对黄瓜育苗基质和苗期根圈微生物的影响

以黄瓜为试材,研究竹醋液处理黄瓜育苗基质对基质微生物和苗期根圈微生物的影响。结果表明,竹醋液处理育苗基质会增加基质中细菌的数量,减少真菌的数量,而放线菌数量以0.5%处理的最多。所以,0.5%竹醋液灌根,有利于黄瓜根圈细菌、放线菌和真菌的繁殖。