自然微生物凝固熟化对SCR硫化特性的影响

利用天然胶乳自然微生物凝固熟化制备中国标准天然橡胶 (SCR) ,探讨自然微生物凝固熟化对SCR硫化特性的影响。结果表明 ,自然微生物凝固熟化对SCR的硫化特性影响显著 ,随着凝固熟化时间延长 ,SCR的ts1 ,ts2 和t90 明显缩短 ,最大转矩、转矩增大速率和硫化速率指数明显增大 ;粘度稳定剂盐酸羟胺对天然胶乳自然微生物凝固熟化有抑制作用。自然微生物凝固熟化制备的SCR成本低 ,强度高 ,性能稳定。

循环水养殖系统中自然微生物生物膜形成过程实验

进行了不同初始NH4-N浓度,在实验水温20～24℃条件下,利用微生态制剂辅助,循环水养殖系统中自然微生物生物膜形成过程的实验研究。结果表明:不同NH4-N浓度对自然微生物生物膜形成产生显著影响,5、10和20 mg/L高浓度NH4-N更易于微生物的扩繁生长和生物膜形成,其生物膜达到预期水质净化效果的形成周期,即生物挂膜成熟周期,约需要35～40 d。生物挂膜成功后,形成很好的硝化作用,实验生物滤池中的NH4-N、NO2-N浓度均保持低于0.05 mg/L,COD浓度低于3 mg/L,显示出对NH4-N、NO2-N和COD很高的去处效果,但对PO4-P处理效果不明显。而1和2 mg/L低浓度NH4-N不易于微生物的扩繁生长,难以形成具有较好水质净化效果的生物膜,即生物挂膜难以成功。

固定化微生物-曝气生物滤池（G-BAF）高效脱氮工艺

固定化微生物-曝气生物滤池（G-BAF）高效脱氮工艺是由北京大学环境工程研究所开发的生物脱氮新工艺。该工艺利用基因工程的手段，对自然微生物进行了强化与变异而产生的硝化菌、亚硝化菌和反硝化菌可适应各种水质，应用先进的微生物固定化技术，将高效微生物菌群固定在大孔网状载体，

食用菌

一、食用菌的营养价值食用菌是自然微生物食品,人工栽培的食用菌营养品位高于野生品种,但味感不如野生品种浓郁,原因是在于自然生态驯化有关,应尽快地掌握好人为自然驯化规律和管理措施。食用菌蛋白质一般含量15～40%,个别品种高达60%,享有"值物肉"之称,是低脂肪、高蛋白食品,一公斤蘑菇蛋白相当于二公斤瘦肉、三公斤鸡蛋、十二公斤牛奶。含有18种氨基酸,具备机体内不能合成而且必须的八种氨基酸。富含维生素 B、C、A、E、

Soil Biological Changes for a Natural Forest and Two Plantations in Subtropical China

Conversion of natural forests into pure plantation forests is a common management practice in subtropical China.To evaluate the effects of forest conversion on soil fertility, microbe numbers and enzyme activities in topsoils (0-10 cm)were quantified in two 33-year-old monoculture plantations of Castanopsis kawakamii Hayata (CK) and Cunninghamia lanceolata Lamb. (Chinese fir) (CF), and compared to a neighboring relict natural C. kawakamii forest (NF), in Sanming,Fujian. Five soil samples were collected once each in January, April, July, September and November in 2000 in each forest for laboratory analysis. Over the sampling year, there were significant differences for bacteria, fungi and actinomycetes between forests and between seasons (P ＜ 0.05). The largest bacteria and fungi populations were in NF, while CF contained the greatest number of actinomycetes. There were also significant differences (P ＜ 0.05) with microbial respiration for forests and seasons. Additionally, compared with NF, urease and acid phosphatase were significantly lower (P ＜ 0.05)in CK and CF. Also, the correlations of soil hydrolysable N and available P to soil microbial and enzymatic activities were highly significant (P ＜ 0.01). Thus, to alter the traditional Chinese fir monoculture so as to mimic the natural forest conditions, managing mixed stands of Chinese fir and broadleaf trees or conducting crop rotation of conifers and broadleaf trees as well as minimizing forest disturbances like clear-cutting, slash burning and soil preparing, could be utilized.

Bacterial Community Structure in a Mollisol Under Long-Term Natural Restoration, Cropping, and Bare Fallow History Estimated by PCR-DGGE

Soil microbial biomass and community structures are commonly used as indicators for soil quality and fertility. A investigation was performed to study the effects of long-term natural restoration, cropping, and bare fallow managements on the soil microbial biomass and bacterial community structures in depths of 0-10, 20 30, and 40-50 cm in a black soil （Mollisol）. Microbial biomass was estimated from chloroform fumigation-extraction, and bacterial community structures were determined by analysis of 16S rDNA using polymerase chain reaction-denaturing gradient gel electrophoresis （PCR- DGGE）. Experimental results showed that microbial biomass significantly declined with soil depth in the managements of restoration and cropping, but not in the bare fallow. DGGE profiles indicated that the band number in top 0-10 cm soils was less than that in depth of 20-30 or 40-50 cm. These suggested that the microbial population was high but the bacterial community structure was simple in the topsoil. Cluster and principle component analysis based on DGGE banding patterns showed that the bacterial community structure was affected by soil depth more primarily than by managements, and the succession of bacterial community as increase of soil depth has a similar tendency in the three managements. Fourteen predominating DGGE bands were excised and sequenced, in which 6 bands were identified as the taxa of Verrueomicrobia, 2 bands as Actinobacteria, 2 bands as α-Proteobacteria, and the other 4 bands as 8-Proteobacteria, Aeidobacteria, Nitrospira, and unclassified bacteria. In addition, the sequences of 11 DGGE bands were closely related to uncultured bacteria. Thus, the bacterial community structure in black soil was stable, and the predominating bacterial groups were uncultured.

Relationship Between Microbial Community and Soil Properties During Natural Succession of Abandoned Agricultural Land

The changes of microbial biomass carbon (MBC) and nitrogen (MBN) and microbial community in the topsoil of the abandoned agricultural land on the semi-arid Loess Plateau in China during the natural succession were evaluated to understand the relationship between microbial community and soil properties. MBC and MBN were measured using fumigation extraction, and microbial community was analyzed by the method of fatty acid methyl ester (FAME). The contents of organic C, total N, MBC, MBN, total FAME, fungal FAME, bacterial FAME and Gram-negative bacterial FAME at the natural succession sites were higher than those of the agricultural land, but lower than those of the natural vegetation sites. The MBC, MBN and total FAME were closely correlated with organic C and total N. Furthermore, organic C and total N were found to be positively correlated with fungal FAME, bacterial FAME, fungal/bacterial and Gram-negative bacterial FAME. Natural succession would be useful for improving soil microbial properties and might be an important alternative for sustaining soil quality on the semi-arid Loess Plateau in China.

A preliminary study on air microorganism in a wood mill

The air microbial species and quantities in a wood mill in Harbin, China weremeasured using sedimentation plate method. Results showed that the microbial quantity in the air atthe workshop without depurator (54939 cfu·m^(-3)) was 2.1 times that of the workshop withdepu-rator (25768 cfu·m^(-3)). The depurator could purify air microorganisms at the workshop, witha purifying rate of 53.1%, but it did not reach the standards of clean air. Comparatively thedepurator is effective in reducing the quantity of air actinomyces, and some kinds of airactinomyces, such as Scabies, Cinereas and Hygroscopicas, can be clean out, but it is not veryeffective to bacteria and fungi. It is suggested that more effective and feasible methods should bedeveloped for purifying air microorganisms at the workshop in the future.

新型防护口罩和防护服在上海面世

经过东华大学科研人员十个昼夜的研究、攻关和测试,由纺织界著名专家、中国工程院周翔院士领衔研制的针对不同防护群体的多种新型防护口罩和防护服今日在沪正式面世并即将投入批量生产。据介绍,此次研制成功的新型防护口罩共有两类,一类为高效吸附口罩,其结构分为三层。

Genomics,metagenomics,and microbial oceanography—A sea of opportunities

Microbial oceanography is an emerging discipline resulted from the interaction,cross-fertilization and integration of life science and ocean science.Microbial oceanography integrates the principles of marine microbiology,microbial ecology and oceanography to study the role of microorganisms in the biogeochemical dynamics of natural marine ecosystems.The application of genomics tools to study marine microbes is resulting in rapid advancements in microbial oceanography that has important implications in global carbon cycle,climate change,and ecosystem function.Here we review the application of genomics and metagenomics in microbial oceanography and suggest future directions in microbial oceanography research.

Soil Microbial Activities in Beech Forests Under Natural Incubation Conditions as Affected by Global Warming

Microbial activity in soil is known to be controlled by various factors. However, the operating mechanisms have not yet been clearly identified, particularly under climate change conditions, although they are crucial for understanding carbon dynamics in terrestrial ecosystems. In this study, a natural incubation experiment was carried out using intact soil cores transferred from high altitude(1 500 m) to low(900 m) altitude to mimic climate change scenarios in a typical cold-temperate mountainous area in Japan. Soil microbial activities, indicated by substrate-induced respiration(SIR) and metabolic quotient(q CO2), together with soil physicalchemical properties(abiotic factors) and soil functional enzyme and microbial properties(biotic factors), were investigated throughout the growing season in 2013. Results of principal component analysis(PCA) indicated that soil microbial biomass carbon(MBC) andβ-glucosidase activity were the most important factors characterizing the responses of soil microbes to global warming. Although there was a statistical difference of 2.82 ℃ between the two altitudes, such variations in soil physical-chemical properties did not show any remarkable effect on soil microbial activities, suggesting that they might indirectly impact carbon dynamics through biotic factors such as soil functional enzymes. It was also found that the biotic factors mainly controlled soil microbial activities at elevated temperature,which might trigger the inner soil dynamics to respond to the changing environment. Future studies should hence take more biotic variables into account for accurately projecting the responses of soil metabolic activities to climate change.

A review on promoting structure research of polysaccharide from natural resources

Polysaccharides widely exist in plants,animals and microorganisms,and have important impacts on the diet and health of humans.However,the research on polysaccharide has progressed much slower than that of protein,due to the complexity of polysaccharide structures,limitations on structural theory,and poor understanding of the mechanism of the bioactivities.In order to promote related research fields,this review provided recommendations to solve the critical issues in the research of polysaccharide structure.The followings are recommended:correct understanding structure types of polysaccharide,improving the preparation efficiency of polysaccharide to ensure reproducibility, and improving characterization of fine structures utilizing "partial degradation-methylation-NMR".Importantly,the theories and research ideas for protein research should not be indiscriminately applied to polysaccharide research.Proper theories and research methods for polysaccharide should be established to promote the field.