[Effects of Exogenous Plant Hormone Spraying on the Phytoremediation by Bidens pilosa L. in Cadmium-contaminated Soil].

To explore the effect of exogenous plant hormone spraying on the absorption of heavy metals by hyperaccumulated plants, Bidens pilosa L. was selected as the tested plant owing to the large biomass, short growth cycle, and high accumulation efficiency. Here, the effect of foliar spraying 6-benzylaminopurine (6-BA), salicylic acid (SA), and 24-epi-brassinosteroid (24-EBR) on the remediation of cadmium (Cd)-contaminated soil by B. pilosa L. was examined. The results showed:① the efficiency of the remediation in Cd-contaminated soil by B. pilosa L. was effectively enhanced after the spraying of all three kinds of exogenous plant hormones with appropriate concentrations. The spraying of the three exogenous plant hormones could promote the cadmium concentration in the leaves of B. pilosa L. to increase by 4.21%, 31.79%, and 14.89%; promote the translocation factor (TF) to increase by 9.67%, 18.83%, and 17.85%; promote the phytoextraction rates (PR) to increase by 15.36%, 32.33%, and 64.38%, respectively. ② The growth of B. pilosa L. was significantly promoted after the spraying of the three kinds of exogenous plant hormones with appropriate concentrations. The spraying of the three exogenous plant hormones could promote plant growth under cadmium stress, and the dry weight of the plant root, stem, and leaf was increased by 37.53%, 74.50%, and 104.02%, respectively. ③ The photosynthesis of B. pilosa L. was significantly enhanced after the spraying of the three kinds of exogenous plant hormones with appropriate concentrations. The chlorophyll concentration of the plant was significantly increased after foliar spraying with plant hormones, and the concentration of chlorophyll a was increased by 79.31%, 92.27%, and 51.12%; the photochemical quenching coefficient (qP) was increased by 11.32%, 89.16%, and 78.43%; and the non-photochemical quenching coefficient (NPQ) was increased by 51.71%, 241.12%, and 27.85%, respectively, after foliar spraying with appropriate concentrations of 6-BA, SA, and 24-EBR. ④ The antioxidant capacity of B. pilosa L. was significantly strengthened after the spraying of the three kinds of exogenous plant hormones with appropriate concentrations. The malondialdehyde (MDA) concentration of the plant was reduced by 62.41%, 68.67%, and 46.76% after the application of 6-BA, SA, and 24-EBR, respectively. Meanwhile, superoxide dismutase (SOD) was increased by 68.33%, 10.28%, and 6.17%, and catalase (CAT) was increased by 31.43%, 37.87%, and 37.31%, respectively. Generally, the spraying of exogenous 6-BA, SA, and 24-EBR with the appropriate concentration under Cd stress could significantly increase the biomass of B. pilosa L. and promote the accumulation of heavy metals in the plant, improve the photosynthetic ability of the plant, reduce the oxidative damage of the plant under heavy metal stress, enhance the antioxidant capacity, and improve the absorption and tolerance of plants to Cd. It also could promote the transfer of Cd from roots to shoots, improve the phytoextraction rates of Cd from the plant, and effectively strengthen the phytoremediation efficiency. Among them, 30 mg·L-1 SA foliar spraying had the best effect.

[Role and Mechanism of Low Molecular-Weight-Organic Acids in Enhanced Phytoremediation of Heavy Metal Contaminated Soil].

Phytoremediation is an environmentally friendly technology to remove heavy metals from polluted soil by using the physical and chemical roles of plants. This can effectively reduce the production of secondary pollutants and is economically feasible. Low molecular-weight-organic acids (LMWOAs) are biodegradable and environmentally friendly and have strong application potential in the phytoremediation of heavy metal-contaminated soils. The role and mechanism of LMWOAs in phytoremediation was elaborated on in this study with the aim to:① regulate the development of roots, stems, and leaves; increase plant biomass; and enhance plant enrichment of heavy metals; ② improve photosynthesis, enhance plant resistance, and promote tolerance to heavy metals; ③ change the properties of rhizosphere soil, improve rhizosphere microbial activity, and promote the absorption of heavy metals; and ④ change the form of heavy metals, reduce the toxicity of heavy metals, and improve transport efficiency. Moreover, the advantages, disadvantages, and application of LMWOAs in enhanced phytoremediation of heavy metal-contaminated soil were explored in this study. Finally, the research direction of LMWOAs in the phytoremediation of heavy metal-contaminated soils was proposed, which will have practical scientific significance for the research and application of LMWOAs in future phytoremediation.

[Effect of Porous Fillers Properties on Biofilm Growth].

As an important part of biological aerated filters (BAFs), porous fillers are key to the effectiveness of BAF wastewater treatment. At present, there are many types of fillers, but the influence of the surface physical and chemical properties on biofilm formation is unclear, and how to compare and select the best biological filler remains a difficult problem in BAF engineering applications. In this study, the physical and chemical characteristics of several porous biological fillers that are commonly used in BAFs were studied, and the correlation between their physical/chemical properties and the biofilm attachment and enzyme activity of the biofilm on the filler was investigated. The results showed that the sponge filler could easily absorb sludge, but also clogged easily and the overall biofilm activity was not high. The three-dimensional hollow filler had a low surface-adsorbed biomass, but the specific surface area was large and the surface attachment growth biofilm activity was relatively strong. Ceramsite had a good hydrophilicity and high surface roughness, and the zeta potential was the most positive. Moreover, microorganisms easily attached and grew, it had the strongest sludge adhesion performance, and the best biofilm activity. According to a redundancy analysis (RDA), the main factor affecting the biomass on the surface of the fillers was the zeta potential, whereas the main factors affecting the surface sludge activity of the fillers was the clearance rate. According to the removal load of NH4+-N by six groups of reactors, the removal load of NH4+-N by ceramsite was the largest [68 g·(m3·d)-1], and was followed by volcanic rocks [67 g·(m3·d)-1]. Combined with the above factors, ceramsite was determined to be the most suitable filler for BAF.

The Phytophthora infestans AVR2 Effector Escapes R2 Recognition Through Effector Disordering.

Intrinsic disorder is a common structural characteristic of proteins and a central player in the biochemical processes of species. However, the role of intrinsic disorder in the evolution of plant-pathogen interactions is rarely investigated. Here, we explored the role of intrinsic disorder in the development of the pathogenicity in the RXLR AVR2 effector of Phytophthora infestans. We found AVR2 exhibited high nucleotide diversity generated by point mutation, early-termination, altered start codon, deletion/insertion, and intragenic recombination and is predicted to be an intrinsically disordered protein. AVR2 amino acid sequences conferring a virulent phenotype had a higher disorder tendency in both the N- and C-terminal regions compared with sequences conferring an avirulent phenotype. In addition, we also found virulent AVR2 mutants gained one or two short linear interaction motifs, the critical components of disordered proteins required for protein-protein interactions. Furthermore, virulent AVR2 mutants were predicted to be unstable and have a short protein half-life. Taken together, these results support the notion that intrinsic disorder is important for the effector function of pathogens and demonstrate that SLiM-mediated protein-protein interaction in the C-terminal effector domain might contribute greatly to the evasion of resistance-protein detection in P. infestans.

Evidence for intragenic recombination and selective sweep in an effector gene of Phytophthora infestans.

Effectors, a group of small proteins secreted by pathogens, play a critical role in the antagonistic interaction between plant hosts and pathogens through their dual functions in regulating host immune systems and pathogen infection capability. In this study, evolution in effector genes was investigated through population genetic analysis of Avr3a sequences generated from 96 Phytophthora infestans isolates collected from six locations representing a range of thermal variation and cropping systems in China. We found high genetic variation in the Avr3a gene resulting from diverse mechanisms extending beyond point mutations, frameshift, and defeated start and stop codons to intragenic recombination. A total of 51 nucleotide haplotypes encoding 38 amino acid isoforms were detected in the 96 full sequences with nucleotide diversity in the pathogen populations ranging from 0.007 to 0.023 (mean = 0.017). Although haplotype and nucleotide diversity were high, the effector gene was dominated by only three haplotypes. Evidence for a selective sweep was provided by (i) the population genetic differentiation (GST) of haplotypes being lower than the population differentiation (FST) of SSR marker loci; and (ii) negative values of Tajima's D and Fu's FS. Annual mean temperature in the collection sites was negatively correlated with the frequency of the virulent form (Avr3aEM), indicating Avr3a may be regulated by temperature. These results suggest that elevated air temperature due to global warming may hamper the development of pathogenicity traits in P. infestans and further study under confined thermal regimes may be required to confirm the hypothesis.

Increased frequency of self-fertile isolates in Phytophthora infestans may attribute to their higher fitness relative to the A1 isolates.

Knowledge of population dynamics of mating types is important for better understanding pathogen's evolutionary potential and sustainable management of natural and chemical resources such as host resistances and fungicides. In this study, 2250 Phytophthora infestans isolates sampled from 61 fields across China were assayed for spatiotemporal dynamics of mating type frequency. Self-fertile isolates dominated in ~50% of populations and all but one cropping region with an average frequency of 0.64 while no A2 isolates were detected. Analyses of 140 genotypes consisting of 82 self-fertile and 58 A1 isolates indicated that on average self-fertile isolates grew faster, demonstrated higher aggressiveness and were more tolerant to fungicides than A1 isolates; Furthermore, pattern of association between virulence complexity (defined as the number of differential cultivars on which an isolate can induce disease) and frequency was different in the two mating types. In A1 isolates, virulence complexity was negatively correlated (r = -0.515, p = 0.043) with frequency but this correlation was positive (r = 0.532, p = 0.037) in self-fertile isolates. Our results indicate a quick increase of self-fertile isolates possibly attributable to their higher fitness relative to A1 mating type counterpart in the field populations of P. infestans in China.

[Carbon metabolic characteristics of airborne microbes in Hangzhou].

Carbon metabolic characteristics in four sampling sites including Yan'an Road Business Street (YRBS), Tianmushan Jiaogong Cross Road (TJCR), Zhejiang Gongshang University Jiaogong Campus (ZJGSUJC) and Breeze-ruffled Lotus at Quyuan Garden (BLQG) in Hangzhou were analyzed using Biolog technology in this study. Results showed that average well color development (AWCD) values were at stationary phase after 240 h cultivation in all four selected sampling sites. Significant differences in sole carbon utilization characterized as AWCD value were found among the four sampling sites, and the highest carbon utilization capacity was observed at YRBS, followed by TJCR and ZJGSUJC, and the lowest at BLQG. The species abundance and diversity of airborne microbes deceased in the order of YRBS, TJCR, ZJGSUJC, and BLQG. In addition, sugar and amino acid utilization capacity of airborne microbes was significantly higher that other carbons sources in all four sampling sites. Significant differences in different sole carbon utilization of airborne microbes in the same sampling site were found. The sugar utilization capacity was the highest, and polymer utilization capacity was the lowest at YRBS. At BLQG, highest sugar and lowest amine utilization capacity was detected. Principal component analysis showed that the contribution of PC1 and PC2 was 43.8% and 23.4%, respectively, in different sampling sites. Significant differences in carbon metabolic characteristics of microbial community in the air were found among YRBS, BLQG and TJCR, and no differences were observed between TJCR and ZJGSUJC.

[Effects of light quality on the growth characteristics and biochemical component of Chlorella pyrenoidosa].

Effect of light quality, including red light, blue light, white light, red and blue mixing light with ratios of 8: 1, 8:2 and 8 : 3, on the growth characteristics and biochenmical composition of Chlorella pyrenoidosa was investigated based on light emitting diode (LED). Results showed that Chlorella pyrenoidosa grew best under blue light, and the optical density, specific growth rate and biomass of Chlorella pyrenoidosa was about 2.4, 0.10 d(-1) and 0.64 g x L(-1), respectively, while the optical density of Chlorella pyrenoidosa was between 1.0 and 1.7, the specific growth rate was between 0.07-0.10 d(-1) and the biomass was between 0.27 and 0.38 g x L(-1) under other light quality after 30 days of cultivation. Under blue light, the optical density, specific growth rate and biomass of Chlorella pyrenoidosa was approximately 2.05 times, 1.33 times and 2.06 times higher than red light, respectively. Moreover, red and blue mixing light was conducive to the synthesis of chlorophyll a and ß-carotene of Chlorella pyrenoidosa, and blue light could promote the synthesis of chlorophyll b. Chlorophyll a and carotenoids content of Chlorella pyrenoidosa was 13.5 mg xg(-1) and 5.8 mg x g(-1) respectively under red and blue mixing light with a ratio of 8:1, while it was 8.4 mg x g(-1) and 3.6 mg x g(-1) respectively under blue light. Red and blue mixing light was more conducive to protein and total lipid content per dry cell of Chlorella pyrenoidosa. Protein and total lipid content was 489.3 mg x g(-1) and 311.2 mg x g(-1) under red and blue mixing light with a ratio of 8 : 3, while it was 400.9 mg x g(-1) and 231.9 mg x g(-1) respectively under blue light.

[Studies on the size distribution of airborne microbes at home in Beijing].

The effect of airborne microbes on human health not only depends on their compositions (genera and species), but also on their concentrations and sizes. Moreover, there are different mechanisms of airborne microbes of different sizes with different effects on human health. The size distributions and median diameters were investigated in detail with imitated six-stage Andersen sampler in 31 selected family homes with children in Beijing. Results showed that there was similar distribution characteristics of airborne microbes in different home environment, different season, different child's sex, and different apartment's architecture, but different distribution characteristics between airborne bacteria and fungi were observed in family homes in Beijing. In general, although airborne bacteria and fungi were plotted with normal logarithmic distribution, the particle percentage of airborne bacteria increased gradually from stage 1 (> 8.2 microm) to stage 5 (1.0-2.0 microm), and then decreased dramatically in stage 6 (< 1.0 microm), the percentage of airborne fungi increased gradually from stage 1 to stage 4 (2.0-3.5 microm), and then decreased dramatically from stage 4 to stage 6. The size distributions of dominant fungi were different in different fungal genera. Cladosporium, Penicillium and Aspergillus were recorded with normal logarithmic distribution, with the highest percentage detected in stage 4, and Alternaria were observed with skew distribution, with the highest percentage detected in stage 2 (5.0-10.4 microm). Finally, the median diameters of airborne bacteria were larger than those of airborne fungi, and the lowest median diameter of airborne bacteria and fungi was found in winter, while there were no significant variations of airborne bacterial and fungal median diameters in spring, summer and autumn in a year in this study.

[Airborne fungal community composition in indoor environments in Beijing].

Indoor environmental quality has significant effects on human health. It is reported that adults in China spent about 80%-90% of their time in indoor environments, and a number of physically handicapped people such as the elderly and infants stayed in the room even up to 95% of their total time. Moreover, air conditioner in indoor environments becomes more and more important in modern life, and a closed circulatory system can be formed among human body, room and air conditioner in indoor environments with an air conditioner, which can make the microbes such as bacteria, viruses and mold indoors propagate rapidly or abundantly. Therefore, studies on the microbial pollution in the air at places such as mall, classroom, office, and family home have been the research hotspots recently. In the present study, the community composition and concentration variation pattern of airborne fungi were investigated from Nov 2009 to Oct 2010 in 31 family homes with children in Beijing. Results showed that 24 generas of airborne fungi in family homes were identified from 225 isolates. The most common fungi were Penicillium, Cladosporium, Aspergillus, Alternaria and Phoma. The frequency of Penicillium, Cladosporium, Aspergillus, Alternaria and Monilia was much higher than those of other fungal genera in family home, and the frequency of Penicillium was more than 90%. As for the concentration percentage, airborne fungi with most high concentrations were Penicillium, Cladosporium, Aspergillus, No-sporing, and Alternaria, and totally accounted for more than 65.0%. Penicillium contributed to 32.2% of the total airborne fungi in family homes. In the 31 family homes selected, the fungal concentration in the air ranged from 62-3 498 CFU x m(-3), and the mean concentration was 837 CFU x m(-3). Seasonal variation pattern of total fungi, and Cladosporium, Aspergillus, Alternaria concentration was consistent, and the highest fungal concentration was observed in summer, followed by spring and autumn, and the lowest in winter. Concerning the Penicillium concentration, the seasonal variation pattern was different, and higher concentration was observed in spring than summer, autumn and winter. Finally, we also found that higher fungal concentration was detected in families with boys than those with girls, and negative correlation was found between airborne fungal concentration and living area per capita.

[Study on the Chlorella pyrenoidosa cultivation technology based on the excess sludge utilization].

Microalgae cultivation based on the waste water or other reused waste can not only make rational use of the waste, but also provide cheap materials for microalgae production. In the present study, Chlorella pyrenoidosa was used to develop a new way for microalgae cultivation based on the mix culture media with different ratio of sludge extracts and SE (selenite enrichment). Results showed that after 14 d cultivation under the same cultivating condition, the absorbency of C. pyrenoidosa at 680 nm was 0. 858 and 0. 845, respectively, when the ratio between culture medium of SE and sludge extracts was 1:9 and 2:8, and the absorbency at 680 nm was 0.247 and 0.571, respectively, when the ratio between culture medium of SE and sludge extracts was 0:10 and 10:0. Our results also demonstrated that highest content of chlororphyll, beta-carotene and protein was achieved in C. pyrenoidosa cultivated in the mix medium between SE and sludge extracts with the ratio of 2: 8. Therefore, sludge extracts can be used as a good medium to cultivate C. pyrenoidosa, and the C. pyrenoidosa grew much better in this mix medium than in SE medium. In this study, the best condition for C. pyrenoidosa cultivation was achieved in the mix medium with 80% sludge extracts, and C. pyrenoidosa grew very well and the content of chlororphyll and protein was also high in the microalgae cell in this mixture medium.

[Toxicity effects of Rac- and S-metolachlor on two algaes].

The enantioselective toxicity of the chiral herbicides Rac- and S-metolachlor to Scenedesmus obliquus and Chlorella vulgaris was determined, and the effect of humic acid was studied by using acute toxicity testing method. The results indicated that the toxicity of Rac- and S-metolachlor increased with increasing concentration and exposure time. The EC(50, 96 h) ratio of Rac-metolachlor to S-metolachlor was 2.25 for C. vulgaris and 1.81 for S. obliquus, indicating that S-metolachlor had higher effect on two algaes, and S. obliquus was more sensitive to Rac- and S-metolachlor. Linear correlation between toxicity on S. obliquus and C. vulgaris was observed. The toxicity of Rac- and S-metolachlor changed with humic acid, with more significant change was observed in S-metolachlor (P<0.05).

[Cellulose degradation and ethanol production of different Clostridium strain].

Cellulose degradation and ethanol production of two types of cellulosic materials with different concentration were evaluated in batch system of mono-cultures of cellulolytic ethanol producing strains (Clostridium thermocellum strain LQRI and Clostridium thermocellum strain VPI), and co-cultures of LQRI or VPI in combination with one of the non-cellulolytic ethanol producing strains (Thermoanaerobacter ethanolicus strains X514 or Thermoanaerobacter ethanolicus 39E). Results demonstrated that higher cellulose degradation abilities about 1.2 times were detected in LQRI mono-culture than in VPI mono-culture, while no significant difference of ethanol yields was found between the two mono-cultures. Abilities of cellulose degradation and ethanol production decreased significantly with the increasing of substrate cellulose concentration (1%, 2%, 5%). In the co-culture system, cellulose degradation abilities of LQRI were also significantly higher than VPI, the former is 1.28-1.58 times of the latter. Cellulose degradation rate of LQRI + Thermoanaerobacter and VPI + Thermoanaerobacter decreased gradually with the increasing of substrate cellulose concentration, while the absolute value of cellulose degradation was also affected by the partner Thermoanaerobacter strain. Additionally, the ethanol yields in the co-cultures of LQRI + Thermoanaerobacter were significantly higher than that in the co-cultures of VPI + Thermoanaerobacter with same Thermoanaerobaeter partner, the former is 1.27-1.77 times of the latter. However, ethanol yields in the co-cultures have not significantly declined with the increasing of substrate cellulose concentration.

[Enhanced role of the co-culture of thermophilic anaerobic bacteria on cellulosic ethanol].

Fermentation of the type of cellulosic materials to ethanol was evaluated in batch system of mono-cultures of cellulolytic ethanol producing strains (Clostridium thermocellum strain LQRI), and co-cultures of LQRI in combination with one of the non-cellulolytic ethanol producing strains (Thermoanaerobacter pseudoethanolicus strains X514 or Thermoanaerobacter ethanolicus 39E). Results showed that ethanol yields and cellulose degradation abilities were significantly improved by the establishment of co-cultures consisting of LQRI and Thermoanaerobacter ethanolicus partner. A factorial experimental comparison revealed that the co-culture of LQRI + X514 provided the higher ethanol yield than the co-culture of LQRI + 39E, but no significant difference on cellulose degradation by LQRI was found in these co-cultures. In the absence of yeast extract, the highest ethanol concentrations in the co-cultures of LQRI + X514 and LQRI + 39E were about 71 mmol/L and 36.5 mmol/L, which were approximately 5-11 and 3-5 times higher than that of the mono-culture LQRI under the same concentration substrate, respectively. In the presence of 0.6% yeast extract, the highest ethanol concentrations in the co-cultures of LQRI + X514 and LQRI + 39E were rapidly improved and reached 263.5 mmol/L and 143.5 mmol/L, which were approximately 8-22 and 8-12 times higher than that of the mono-culture LQRI under the same concentrations substrate, respectively. The maximum ethanol concentration reached about 263.5 mmol/L (1.2%) in the co-culture of LQRI + X514 grown on 5% Solka Floc in the presence of 0.6% yeast extract, while the maximum ethanol concentration reached 143.5 mmol/L (1.2%) in the co-culture of LQRI + 39E grown on 2% Solka Floc in the presence of 0.6% yeast extract.

[Effects of C/P on the competition between PAOs and GAOs and PHAs metabolism in EBPR system].

Based on accumulating enrich phosphorus accumulating organisms (PAOs) in activated sludge and by fluorescence in situ hybridization (FISH) technique, the effects of C/P (25: 1, 20: 1, 15: 1 and 10: 1) on flora changes and polyhydroxyalkanoates (PHAs) metabolism in enhanced biological phosphorus removal (EBPR) system were systematically studied. The results show that after 10 days treatment (acetate as carbon source), the systems with C/P of 25: 1, 20: 1 and 15: 1 have good phosphate removal rate (> 88%); while for C/P of 10: 1 system, the phosphate removal rate was 0%. FISH results showed that the content of PAOs decreased from( 76.42 +/- 1.24) % to (10.40 +/- 0.97) % with C/P decreasing from 25: 1 to 10: 1, while glycogen accumulating organisms (GAOs) increased from (16.36 +/- 3.41)% to (34.25 +/- 2.59)%. In various C/P systems in the anaerobic, the production kinetic coefficients of PHB and PHV were K25: 1 > K20: 1 > K15: 1 > K10: 1 and K15: 1 > K20: 1 > K25: 1 > K10: 1, respectively. The PHB production in the proportion of PHAs decreased from 85% to 24%, while PHV increased from 15% to 76% with C/P decreasing from 25: 1 to 10: 1. For various C/P systems in the aerobic phase, their consumption kinetic coefficients of both PHB and PHV were K:20: 1 > K25: 1 > K15: 1 > K10: 1. PHB (the proportion of PHAs is 71% -75%) was the main consumption component in C/P of the 25: 1, 20: 1 and 15: 1 systems; while PHV(the proportion of PHAs is 71%) was the main consumption component in C/P of 10: 1 system. It is suggested that an increases of GAOs and decreases of PAOs in the EBPR system lead to the decreasing of PHB production and consumption, and to the increasing of PHV.

[Utilization of different carbon sources types in biolog-GN microplates by soil microbial communities from four forest types].

Utilization of different carbon source type in Biolog-GN microplates by soil microbial communities under different forest restoration types was studied. The results shows that metabolic capacity of soil microbial commuinty under natural secondary forest are higher than those of three plantations. Carbohydrates, carboxylic acids and amino acids are the main carbon sources possessing higher utilization efficiency or utilization intensity. At the same time, the three carbon source types contributed to the differentiation of soil microbial communities from four forest restoration types. And the three types of carbon sources were sensitive to change of soil microbial communities. These results possessed important referenced significance for substrate selection during the study on soil microbial communities and their functional diversity with incubating methods.

[Effects of Arbuscular Mycorrhizae on growth and essential oil of Atractylodes lancea].

OBJECTIVE: To study the effects of Arbuscular Mycorrhizae on cultivated Atractylodes lancea. METHOD: Pot experiment of A. lancea, with (code as AM) or without (code as CK) Glomus mosseae (GM) was conducted 5 times respectively, then the biomass, essential oil, and soil nutrition, soil organism, soil microbial were detected after A. lancea were harvested. RESULT: (1) Mycorrhizal dependency of A. lancea was 245%, and height of individuals, numbers of leaves, leaf area, biomass of A. lancea were all higher in AM than in CK (P < 0.05). (2) GC-MS analysis with cluster analysis and principal components analysis showed that there were no differences in essential oil of A. lancea between AM and CK. (T3) Total N, available N, available P and available K in AM soil were all lower than in CK soil. (4) GC-MS analysis showed organic matters changed differenly in AM soil and CK soil, components 5,6 in AM soil were higher than that in CK soil, but component 9, 10, 11 were lower in AM soil than that in CK soil. (5) Biolog detect showed AWCD of AM soil microbe were higher than that of CK soil throughout the incubation, and AWCD of the former was 0.66, and the later was 0.46 after 192 h incubation. and t-test showed, Shannon seven indices and McIntosh'seven indices were same both at 72 h and 192 h, and diversity indices of Shannon and McIntosh were also same at 72 h, but AM soil microbe were higher than CK soil microbe at 168 h (P < 0.05). CONCLUSION: AM could promote nutrition uptake, improve the function diversity and activity of microbe in rhizosphere of A. lancea, influence the composition of the organic matter, that lead the growth of A. lancea, but not to the quality.

[Community composition and dynamics of airborne bacteria in Beijing].

Airborne bacteria are important biological components of the aerosol. They have a close relation with human health. The much higher concentrations can result in kinds of microbial disease. Using BIOLOG identification technology, the study on the community structure and dynamics of airborne bacteria was carried out in three typical functional areas in Beijing by systemic site sampling. Results show that the gram positive bacteria contributing 80%-85% were much more than the gram negative bacteria. Amongst 47 genera of bacteria including 31 Gram positive bacteria and 16 Gram negative bacteria, Micrococcus, Staphylococcus, Bacillus, Corynebacterium, and Pseudomonas were dominant, and Micrococcus contributing 20%-30% was the most dominant genus. The concentration of airborne bacteria was significant lower in GGR than in CER and MTL. In a year, the bacterial concentrations of summer and autumn were much more than those of winter and spring in CER and MTL, and there were no significant variations of bacterial concentrations in GGR. In different periods, the lower concentration of airborne bacteria was exhibited at 13:00.

[Ecological distributions of airborne fungi in outdoor environments in Beijing, China].

An investigation on fungal types, concentrations, and their dynamic variation in outdoor environments was carried out in three different functional areas around one year in Beijing. Results show that the fungal concentrations varied widely and the average was (1164.8 +/- 73.2) CFU x m(-3), ranging from 23.6CFU x m(-3) to 13 959.5 CFU x m(-3). The most common culturable airborne fungi in all seasons and all functional areas were Cladosporium , nonsporulating fungi, Alternaria, Penicillium and Aspergillus. The most dominant fungus was Cladosporium, which contributed to more than 1/3 of the total. The fungal levels in culture and education region (CER) and garden green region (GGR) were highest in the fall and summer, and lowest in the winter and spring, while the seasonal variation in main traffic line (MTL) was not significant. The fungal concentrations in CER and GGR were significantly higher than in MTL (p <0.05). No statistically significant difference exists between CER and GGR.

[Granularity distribution of airborne microbes in summer in Beijing].

A study on granularity distribution of airborne microbes was conducted in details in summer, and the fluctuation regular was analyzed in Beijing. Results show that the distribution characteristics which are not changed with the different functional regions and periods are very different among airborne bacteria, fungi and actinomycete. Airborne bacteria appear skew distribution, the particles larger than 2.0 microm account for 80.0% of the total while smaller than 1.0 microm contribute 9.0% approximately. Airborne fungi are recorded with normal logarithm distribution, the particles between 1.0 microm and 6.0 microm account for 70.0% while smaller than 1.0 microm contribute 5.0% approximately. The distribution of airborne actinomycete are completely opposite to fungi, the particles larger than 8.2 microm and smaller than 1.0 microm account for 60.0% while between 3.0 microm and 6.0 microm contribute 10.0% approximately. Moreover, the granularity distribution of dominant fungi is consistent in different functional regions. But Cladosporium, Penicillium and Aspergillus are most collected in F3, F4 and F5 grades (1.0-6.0 microm) while Alternaria and nonsporing most in former four grades (>2.0 microm) of FA-I sampler, contributing 85.0%, 85.0%, 85.0%, 90.0% and 75.0% of the total respectively. The granularity of former presents normal logarithm distribution and latter skew distribution. In the past ten years, it is no change on the trend of microbial granularity distribution in Beijing, but the peak value declines from 3.0-6.0 microm to 2.0-3.0 microm.