[Dynamic Changes in Antibiotic Resistance Genes During Biological Fermentation of Chicken Manure and Pig Manure].

Livestock manure is a major carrier that stores and transmits antibiotic resistance genes (ARGs). The aim of this study was to identify the crucial environmental factors that result in the change in relative abundance of ARGs and MGEs to explore effective methods to reduce the occurrence of ARGs. The abundance of ten ARGs and five MGEs were measured using real-time quantitative PCR with 0, 3, 7, 10, 14, 21, 28, 45, 60, and 75 d in CM and PM aerobic composting.

[Effects of salinity on soil bacterial diversity and assembly processes in coastal soils.].

Coastal saline soil is an important reserve resource of agricultural land. Soil microorganisms play a key role in soil nutrient cycling. However, it is still far from clear about the effects of salinity on soil microbial community.

Active Soil Nitrifying Communities Revealed by Transcriptomics and Microcosm-Based Stable-Isotope Probing.

Long-term nitrogen field fertilization often results in significant changes in nitrifying communities that catalyze a key step in the global N cycle. However, whether microcosm studies are able to inform the dynamic changes in communities of ammonia-oxidizing bacteria (AOB) and archaea (AOA) under field conditions remains poorly understood. This study aimed to evaluate the transcriptional activities of nitrifying communities under conditions, and we found that they were largely similar to those of C-labeled nitrifying communities in the urea-amended microcosms of soils that had received different N fertilization regimens for 22 years.

Bacillus fengqiuensis sp. nov., isolated from a typical sandy loam soil under long-term fertilization.

A Gram-staining-positive, endospore-forming, moderately alkaliphilic bacterium, strain NPK15(T), was isolated from a typical sandy loam soil under long-term NPK fertilization in northern China and was subjected to a polyphasic taxonomic study. The diamino acid of the cell-wall peptidoglycan of strain NPK15(T) was found to be meso-diaminopimelic acid and the cell-wall sugars were xylose, glucose and traces of mannose. The only respiratory quinone found in strain NPK15(T) was menaquinone 7 (MK-7).

[Response of soil microbial community to the bioremediation of soil contaminated with PAHs].

The diversity of bacterial community in soil contaminated with polycyclic aromatic hydrocarbons (PAHs) was investigated during the plant-microbe remediation enhanced by biosurfactant rhamnolips (RH), using the polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) method. The results showed that Shannon-Weaver diversity index was only 3.17 before bioremediation, and increased to 3.

[Construction of Hg(2+)-induced luminescent reporter gene system and its application to detect mercury in red soil].

A luminescent reporter gene system was constructed by fusing the mercury-inducible promoter, P(merT), and its regulatory gene, merR with a promoterless reporter gene EGFP. A stable whole-cell reporter was created by mini-Tn5 and introducing the merR-egfp system cassette into the chromosome of Pseudomonas putida strain, then applied it for mercury detection in the red soil of Jiangxi province, the fluorescence density of the sensor strain was confirmed in soil extraction and fluorescence intensity was quantified by flow cytometry. The results showed positive correlation with the mercury pollutant in the concentration range of 0.

[Interactive effect of spent mushroom compost and rhamnolipids to enhance the efficiency of alfalfa remediation of aged PAHs contaminated soil].

Polycyclic aromatic hydrocarbons (PAHs) are a group of the most widespread organic pollutants, which distributed widely in soil and sediment. Pot experiment was conducted to improve efficiency of phytoremediation using alfalfa (Medicago sativa L.) in aged PAHs contaminated soil by introducing spent mushroom compost and rhamnolipids.

[Interaction of biosurfactant-microorganism to enhance phytoremediation of aged polycyclic aromatic hydrocarbons (PAHS) contaminated soils with alfalfa (Medicago sativa L.)].

A pot experiment in greenhouse was carried out to investigate the interactive effect of rhamnolipids (RH) addition and PAHs-specific degrading bacteria (DB) inoculation on the phytoremediation efficiency for removal polycyclic aromatic hydrocarbons (PAHs) from agricultural soils. Results indicated that RH addition and DB inoculation promoted alfalfa (Medicago sativa L. ) growth and PAHs degradation in the soil.

A chromosomally based luminescent bioassay for mercury detection in red soil of China.

A luminescent reporter gene system was constructed by fusing the mercury-inducible promoter, P ( merT ), and its regulatory gene, merR, with a promoterless reporter gene EGFP. A stable and nonantibiotic whole-cell reporter (BMB-ME) was created by introducing the system cassette into the chromosome of Pseudomonas putida strain and then applied it for mercury detection in the red soil of China. Spiked with 10 and 100 microg g(-1) Hg(2+) and after 15 and 30 days incubation, soil samples were extracted and evaluated water soluble, bioavailable, organic matter bound, and residual fractions of mercury by both BMB-ME and chemical way.

[Arbuscular mycorrhizal fungal effects on wheat growth in response to elevated tropospheric O3 concentration].

A FACE (Free-air component enrichment) system in a rice/wheat rotation field was used to investigate the effects of arbuscular mycorrhizal fungal (AMF) inoculation on wheat growth and soil microbial biomass under elevated tropospheric O3 concentration. The elevated O3 concentration tended to increase AM colonization of wheat seedling and bate plant growth during the booting period, then significantly (p < 0.05) reduced aerial biomass, individual yield and kernel weight by 22%, 29% and 9%, respectively, and decreased soil microbial biomass N by 37% after wheat harvesting.

[Spatiotemporal evolvement of soil microbiological characteristics in upland fields with different utilization duration in Cixi, Zhejiang Province].

The microbial number, microbial biomass, and enzymatic activities in five upland soils under agricultural utilization for 50-700 years were determined, with the correlations between soil microbiological characteristics and agricultural utilization duration analyzed. In the meantime, the functional diversity of microbes in soils having been utilized for 50, 100, and 700 years were investigated. The results showed that at the early stage (< 100 years) of agricultural utilization, the number of soil fungi (F) had a slight increase, while the bacterial number (B), B/F ratio, microbial biomass C (C(mic)), microbial biomass N (N(mic)), and the activities of catalase, invertase and urease all decreased markedly.

Effect of arbuscular mycorrhizal fungal inoculation on heavy metal accumulation of maize grown in a naturally contaminated soil.

A pot culture experiment was carried out to study heavy metal (HM) phytoaccumulation from soil contaminated with Cu, Zn, Pb, and Cd by maize (Zea mays L.) inoculated with arbuscular mycorrhizal (AM) fungi (AMF). Two AM fungal inocula--MI containing only one AM fungal strain (Glomus caledonium 90036) and MII consisting of Gigaspora margarita ZJ37, Gigaspora decipens ZJ38, Scutellospora gilmori ZJ39, Acaulospora spp.

[Effects of earthworm (Eisennia foetida ) on As, P uptake by maize and As, P fractional transformation in the rhizosphere].

A pot experiment was conducted to examine the roles of earthworm in As uptake from original As-polluted soil by maize (Zea mays L.), and their effects on As, P fractions in the rhizosphere. The As-polluted soils with three As levels were collected from the arable soil near As mine.

Halomonas shengliensis sp. nov., a moderately halophilic, denitrifying, crude-oil-utilizing bacterium.

A moderately halophilic bacterium, designated strain SL014B-85(T), was isolated from a crude-oil-contaminated saline soil from Shengli oilfield, Shandong Province, China. Cells were Gram-negative, aerobic, short rods with lateral flagella. Growth occurred at NaCl concentrations of 0-15 % (optimum 5-15 %), at 10-42 degrees C (optimum 30 degrees C) and at pH 8.

Role of microbial inoculation and chitosan in phytoextraction of Cu, Zn, Pb and Cd by Elsholtzia splendens--a field case.

A field experiment was carried out to study the effect of microbial inoculation on heavy metal phytoextraction by Elsholtzia splendens and whether chitosan could have a synergistic effect with the microbial inocula. The microbial inocula consisted of a consortium of arbuscular mycorrhizal fungi and two Penicillium fungi. Three treatments were included: the control, inoculation with microbial inocula, and the inoculation combined with chitosan.

[Influence of arbuscular Mycorrhizal fungi on growth and cu uptake of Elsholtzia splendens].

A pot culture experiment was carried out to study the influence of arbuscular mycorrhizal (AM) fungi on the growth and Cu uptake of E. splendens. Five levels of Cu (0, 50, 100, 200, 400mg x kg(-1)) and two AM fungal inocula, Glomus caledonium 90036 (36) and Acaulospora mellea ZZ (ZZ), and one nonmycorrhizal inoculum (CK), were applied to the soil under sterilized conditions.

Effect of inoculation with arbuscular mycorrhizal fungi on the degradation of DEHP in soil.

The effect of inoculation with arbuscular mycorrhizal (AM) fungi (Acaulospora lavis) on the degradation of di(2-ethylhexyl) phthalate (DEHP) in soil was studies. Cowpea plants (Pigna sinensis) were used as host plants and grown in a specially designed rhizobox. The experimental results indicated that, both in sterile and non-sterile soil, mycorrhizal colonization rates were much higher in the mycorrhizal plants than in the non-mycorrhizal plants.

Arbuscular mycorrhizal status of wild plants in saline-alkaline soils of the Yellow River Delta.

A survey was made of the arbuscular mycorrhizal (AM) status of five dominant wild plants Tamarix chinensis, Phragmites communis, Suaeda glauca, Aeluropus littoralis var. sinensis and Cirsium setosum in saline-alkaline soils of the Yellow River Delta that show low plant diversity. All of the species were colonized and showed typical AM structures (arbuscules, vesicles).