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1.
Rev Environ Contam Toxicol ; 249: 1-27, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-30725190

RESUMO

Metals are major abiotic stressors of many organisms, but their toxicity in plants is not as studied as in microorganisms and animals. Likewise, research in plant responses to metal contamination is sketchy. Candidate genes associated with metal resistance in plants have been recently discovered and characterized. Some mechanisms of plant adaptation to metal stressors have been now decrypted. New knowledge on microbial reaction to metal contamination and the relationship between bacterial, archaeal, and fungal resistance to metals has broadened our understanding of metal homeostasis in living organisms. Recent reviews on metal toxicity and resistance mechanisms focused only on the role of transcriptomics, proteomics, metabolomics, and ionomics. This review is a critical analysis of key findings on physiological and genetic processes in plants and microorganisms in responses to soil metal contaminations.


Assuntos
Adaptação Fisiológica/fisiologia , Ecossistema , Metais/toxicidade , Plantas , Microbiologia do Solo , Poluentes do Solo/toxicidade , Animais , Fungos , Metais Pesados , Solo
2.
J Agric Food Chem ; 67(38): 10577-10586, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31490682

RESUMO

Root and rhizosphere is important for phosphorus (P) uptake in rice plants. However, little is known about the detailed regulation of irrigation regimes, especially frequently alternate wetting and drying (FAWD), on P usage of rice plants. Here, we found that compared with normal water and P dose, FAWD with a reduced P dose maintained the grain yield in two rice varieties. Compared to rice variety Gaoshan1, rice variety WufengyouT025 displayed a higher grain yield, shoot P content, rhizosphere acid phosphatase activity, abundance of bacteria, and bacterial acid phosphatase gene of rhizosphere. Moreover, the FAWD regime may increase the abundance of bacteria with acid phosphatase activity to release available phosphorus in the rhizosphere, which is associated with rice varieties. Our results suggest that an optimized management of irrigation and phosphorous application can enhance both water and phosphorus use efficiency without sacrificing the yield, which may contribute significantly to sustainable agriculture production.


Assuntos
Irrigação Agrícola/métodos , Produção Agrícola/métodos , Oryza/crescimento & desenvolvimento , Fósforo/metabolismo , Microbiologia do Solo , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Produção Agrícola/instrumentação , Fertilizantes/análise , Microbiota , Oryza/classificação , Oryza/metabolismo , Oryza/microbiologia , Rizosfera , Água/metabolismo
3.
J Environ Sci (China) ; 85: 107-118, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31471017

RESUMO

Biochar (BC) and rhamnolipid (RL) is used in bioremediation of petroleum hydrocarbons, however, the combined effect of BC and RL in phytoremediation has not been studied until now. In this paper, the phytoremediation of petroleum hydrocarbon-contaminated soil using novel plant Spartina anglica was enhanced by the combination of biochar (BC) and rhamnolipid (RL). Samples of petroleum-contaminated soil (10, 30 and 50 g/kg) were amended by BC, BC+ RL and rhamnolipid modified biochar (RMB), respectively. After 60 day's cultivation, the removal rate of total petroleum hydrocarbons (TPHs) for unplanted soil (UP), planted soil (P), planted soil with BC addition (P-BC), planted soil with BC and RL addition (P-BC + RL) and planted soil with addition of RMB (P-RMB) were 8.6%, 19.1%, 27.7%, 32.4% and 35.1% in soil with TPHs concentration of 30 g/kg, respectively. Compared with UP, the plantation of Spartina anglica significantly decreased the concentration of C8-14 and tricyclic PAHs. Furthermore, the application of BC and RMB alleviated the toxicity of petroleum hydrocarbons to Spartina anglica via improving plant growth with increasing plant height, root vitality and total chlorophyll content. High-throughput sequencing result indicated that rhizosphere microbial community of Spartina anglica was regulated by the application of BC and RMB, with increase of bacteria and plant mycorrhizal symbiotic fungus in biochar and RMB amended soil.


Assuntos
Biodegradação Ambiental , Petróleo/análise , Poaceae/fisiologia , Poluentes do Solo/análise , Carvão Vegetal/química , Glicolipídeos/química , Petróleo/metabolismo , Hidrocarbonetos Policíclicos Aromáticos , Rizosfera , Microbiologia do Solo , Poluentes do Solo/metabolismo
4.
J Environ Sci (China) ; 85: 46-55, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31471030

RESUMO

Natural bacterial isolates from heavily contaminated sites may evolve diverse tolerance strategies, including biosorption, efflux mechanism, and intracellular precipitation under the continually increased stress of toxic lead (Pb) from anthropogenic activities. These strategies utilize a large variety of functional groups in biological macromolecules (e.g., exopolysaccharides (EPSs) and metalloproteins) and inorganic ligands, including carboxyl, phosphate and amide groups, for capturing Pb. The amount and type of binding sites carried by biologically originated materials essentially determines their performance and potential for Pb removal and remediation. Many factors, e.g., metal ion radius, electronegativity, the shape of the cell surface sheath, temperature and pH, are thought to exert significant influences on the abovementioned interactions with Pb. Conclusively, understanding the chemical basis of Pb-binding in these bacteria can allow for the development of effective microbial Pb remediation technologies and further elucidation of Pb cycling in the environment.


Assuntos
Chumbo , Microbiologia do Solo , Poluentes do Solo , Adaptação Fisiológica , Biodegradação Ambiental , Recuperação e Remediação Ambiental
5.
Ying Yong Sheng Tai Xue Bao ; 30(9): 2973-2982, 2019 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-31529872

RESUMO

Ant nesting can modify soil physicochemical conditions in the tropical forest, exerting a crucial effect on spatiotemporal variation in soil microbial biomass carbon and quotient. In this study, the chloroform fumigation method was used to measure the spatiotemporal dynamics of microbial biomass carbon and quotient in ant nests and the reference soils in Syzygium oblatum community of tropical Xishuangbanna. The results were as following: 1) Microbial biomass carbon and quotient were significantly higher in ant nests (1.95 g·kg-1, 6.8%) than in the reference soils (1.76 g·kg-1, 5.1%). The microbial biomass carbon in ant nests and the reference soils showed a signifi-cantly unimodal temporal variation, whereas the temporal dynamics of microbial biomass quotient presented a distribution pattern of "V" type. 2) The microbial biomass carbon and quotient showed significant vertical changes in ant nests and the reference soils. The microbial biomass carbon decreased, and microbial biomass quotient increased significantly along the soil layers. The vertical variations in microbial biomass carbon and quotient were more significant in ant nests than in refe-rence soils. 3) Ant nesting significantly changed the spatiotemporal distributions of soil water and temperature in ant nests, which in turn affected spatiotemporal dynamics of soil microbial biomass carbon and quotient. Soil water content could explain 66%-83% and 54%-69% of the variation of soil microbial biomass carbon and quotient, respectively. Soil temperature could explain 71%-86% and 67%-76% of the variation of soil microbial biomass carbon and quotient in ant nests and the reference soils, respectively. 4) Changes in soil physicochemical properties induced by ant nesting had significant effect on the soil microbial biomass carbon and quotient. There were positive correlations of soil microbial biomass carbon to soil organic carbon, soil temperature, total nitrogen and soil water content, and to bulk density, nitrate nitrogen and hydrolyzed nitrogen; whereas a negative correlation of them was observed with soil pH. Soil pH was positively and other soil physicochemical properties were negatively correlated with microbial biomass quotient. Total organic carbon, total nitrogen and soil temperature had greater contribution to microbial biomass carbon, while total organic carbon and total nitrogen had the least negative effect on microbial biomass quotient. Therefore, ant nesting could modify microhabitats (e.g., soil water and soil temperature) and soil physicochemical properties (e.g., total organic carbon and total nitrogen), thereby regulating the spatiotemporal variation in soil microbial biomass carbon and quotient in tropical forests.


Assuntos
Formigas , Florestas , Microbiologia do Solo , Solo , Animais , Biomassa , Carbono , China , Nitrogênio
6.
Ying Yong Sheng Tai Xue Bao ; 30(9): 2983-2991, 2019 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-31529873

RESUMO

To understand the relationship between soil fauna and microorganism in the detrital food chain during litter decomposition, leaf litters of poplar (Populus simonii) and fargesia (Fargesia spathacea) in a subalpine forest of western Sichuan were taken as study objects. Phospholipid fatty acid (PLFAs) biomarker method was used to determine the effects of soil fauna on the abundance, structure and diversity of microbial community during the decomposition of leaf litter of two species from April 2016 to April 2018 with in situ control experiment. The results showed that the presence of soil fauna significantly affected the microbial PLFAs content during the decomposition of both species, reducing the PLFAs content in the first 240 days and increasing the PLFAs content in the 360 to 480 days. Soil fauna participation reduced the ratio of fungi to bacteria in the decomposition of poplar litter, and increased the ratio of gram-positive bacteria (G+) to gram-negative bacteria (G-), which had the opposite effect on the ratio of fungi/bacteria and G+/G- in the decomposition of fargesia litter. Microbial diversity and evenness maintained a high level in 120th and 480th days of the decomposition, and decreased sharply in 360th and 720th days of decomposition. Soil fauna participation significantly affected microbial diversity and evenness of poplar litter, but it had no signifi-cant effect on fargesia litter. The effects of soil fauna on the changes of litter PLFAs content were different with the decomposition days and tree species. The interaction between soil fauna and microbial community during litter decomposition in subalpine forest varied with seasons and tree species.


Assuntos
Florestas , Microbiota , Populus , Animais , China , Folhas de Planta , Solo , Microbiologia do Solo
7.
Ying Yong Sheng Tai Xue Bao ; 30(9): 3010-3018, 2019 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-31529876

RESUMO

Frequent mowing and nitrogen enrichment can lead to the degradation of grassland ecosystem. It remains largely unknown that how the soil microbial characteristics, important bio-indicators of soil quality, respond to mowing and nitrogen enrichment. In this study, using a field experiment established in the meadow steppe in Hulunber, Inner Mongolia, we explored the responses of soil properties, microbial biomass, soil respiration, and soil enzyme activities to mowing and nitrogen addition during growing seasons. Mowing significantly reduced microbial biomass carbon, nitrogen and phosphorus, and soil respiration (basal respiration and substrate induced respiration), which might be caused by the moisture- and carbon-limitation. Mowing significantly reduced activities of the enzymes involved in nitrogen acquisition (N-acetyl-ß-D-glucosaminidase) and phosphorus acquisition (acidic phosphomonoesterases), which supports the resource allocation theory. Soil pH was significantly reduced by N addition. However, microbial biomass showed no significant response to nitrogen input, implying that soil acidification induced by nitrogen inputs was not profound enough to affect microbial biomass. Nitrogen addition did not affect soil respiration and microbial enzymatic activities, inconsistent with results from most of previous studies conducted in typical steppe. Combination of mowing and nitrogen addition reduced the activity of acidic phosphomonoesterases, which might be due to the increased phosphorus availability under the combined treatment. Combination of mowing and nitrogen addition reduced microbial biomass phosphorus, but increased soil available phosphorus, corresponding to the lowered activity of acidic phosphomonoesterases under the combined treatment. Microbial biomass carbon, nitrogen and phosphorus, and soil respiration peaked in July, which was associated with the high temperature and precipitation in summer. Soil enzymatic activities were higher in the spring and summer than in the late growing season. In summary, our results indicated that mowing would result in the imbalance of soil nutrients and intensify the risk of grassland degradation. In contrary, nitrogen addition exerted no effects on microbial biomass and activity.


Assuntos
Ecossistema , Nitrogênio , Microbiologia do Solo , Solo , Biomassa , Carbono , China , Poaceae
8.
Ying Yong Sheng Tai Xue Bao ; 30(9): 3057-3065, 2019 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-31529881

RESUMO

Vegetation patch is one of the most basic characteristics of natural grazing grassland. To explore the effects of vegetation patch on soil microbial community, the changes of soil microbial biomass and community structure under four different vegetation patches in Ningxia desert steppe were quantified using phospholipid fatty acid (PLFA) analysis. The results showed that: 1) Soil microbial groups were abundant in vegetation patches, with the highest bacterial content, low fungal and actinomycete content, and the Gram-positive bacteria content being higher than that of Gram-negative bacteria in the patches of the four plant communities; 2) The total soil microbial biomass of Glycyrrhiza uralensis patch was significantly higher than that of Artemisia scoparia, Sophora alopecuroides, and Astragalus melilotoides patches; 3) Total PLFAs, Gram-positive bacteria, Gram-negative bacteria, fungi, anaerobic bacteria and fungi/bacteria were significantly positively correlated with soil organic C, and significantly negatively correlated with soil pH, indicating that soil organic C and pH were important factors affecting the growth and development of soil microorganisms in desert steppe.


Assuntos
Ecossistema , Microbiologia do Solo , Solo , Bactérias , China , Clima Desértico , Fungos , Pradaria
9.
Ying Yong Sheng Tai Xue Bao ; 30(9): 3145-3154, 2019 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-31529890

RESUMO

The combination of field trial and indoor incubation experiment were conducted to examine the long-term effects of one-time application of bio-organic fertilizer on soil organic carbon (C) components, organic C mineralization, and enzyme activity in cucumber continuous cropping. Compared with CK, bio-organic fertilizer application significantly increased the content of soil organic C, activated C pool, slow-release C pool and inert C pool during four continuous cucumber planting seasons. With the increases of the number of consecutive crops, the proportion of soil inert carbon gradually increased. After four continuous seasons of cucumber planting, the cumulative and daily mineralization rate of soil organic C in the bio-organic fertilizer treatment increased by 17.3%-31.0% and 7.8%-43.0%, respectively. In the stage of cucumber ripening, bio-organic fertilizer application increased the activities of continuous soil urease, catalase, sucrose and neutral phosphatase by 10.5%-62.1%, 4.8%-25.5%, 3.9%-21.4% and 4.6%-66.4%. The activities of those four enzymes increased with the increases of the application amount of organic fertilizer. Results from the correlation and path analysis showed that the activity of the four enzymes were significantly correlated with the dynamics of organic carbon components in soil cucumber continuous cropping process. Soil urease and invertase activities significantly affected organic carbon mineralization during the continuous cropping process of cucumber. Application of bio-organic fertilizer could increase soil organic carbon content and enzyme activity, improve inert carbon ratio of soil organic carbon pools, cumulative and mineralization rate of organic carbon in continuous cropping process, thereby enhance soil carbon sequestration capacity.


Assuntos
Agricultura/métodos , Cucumis sativus/crescimento & desenvolvimento , Fertilizantes , Carbono , Solo , Microbiologia do Solo
10.
Ying Yong Sheng Tai Xue Bao ; 30(9): 3183-3194, 2019 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-31529894

RESUMO

Soil organic carbon is essential for maintaining terrestrial ecosystem function and mitigating soil degradation. Soil microorganisms participate in soil carbon cycling. They are affected by tillage methods and straw returning. A split-plot design was adopted in this experiment. The whole-plot treatment had two tillage methods, subsoil tillage (ST) and rotary tillage (RT). The split-plot treatment included full straw returning (F) and no straw returning (0). The microbial community structure and carbon sequestration genes were assessed by Illumina sequencing technique. Soil organic carbon contents were measured during 2012-2017. The results showed that 1) subsoil tillage and straw returning significantly increased pH, microbial biomass carbon, total nitrogen, silt content, and clay content, while significantly decreased sand content; 2) during the test period (2012-2017), soil organic carbon (SOC) content under all treatments showed an increasing trend, but the increment for average SOC content under straw returning and subsoiling treatments was significantly higher than that of no straw returning and rotary tillage by 33.2 % and 30.6%, respectively; 3) Proteobacteria was the most abundant type of bacteria in the soil, followed by Acidobacteria and Gemmatadanetes; 4) STF treatment maintained high microbial diversity; 5) Excepted for soil sand content, soil pH, microbial biomass carbon, total nitrogen, silt content and clay content all caused the variation of soil microbial community structure under the STF treatment in the direction of SOC accumulation; 6) in addition to the gene abundance in the di- and oligosaccharides metabolic pathway, the gene abundance in the metabolic pathways for CO2 fixation, central carbohydrate metabolism, fermentation, one-carbon metabolism, organic acids, sugar alcohols and glycoside hydrolases showed that subsoil tillage was significantly higher than rotary tillage, with posi-tively correlation with soil organic carbon content. Therefore, the combination of subsoil tillage and straw returning could improve basic soil properties, affect soil microbial community structure, and increase the capacity of soil carbon fixation, thus providing a realistic basis for solving soil degradation.


Assuntos
Agricultura , Microbiota , Microbiologia do Solo , Solo , Carbono/análise , Triticum
11.
Int J Syst Evol Microbiol ; 69(10): 3128-3134, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31364963

RESUMO

A novel Gram-stain-positive actinobacterial strain, designated C9-28T, was isolated from soil sampled in a natural cave on Jeju Island, Republic of Korea. Strain C9-28T morphologically exhibited a rod-coccus life cycle and grew at 10-37 °C (optimum, 30 °C), pH 6-9 (optimum, pH 7) and 0-3 % (optimum, absence of NaCl). In the maximum-likelihood tree based on 16S rRNA gene sequences, strain C9-28T formed a sublineage between a Rhodococcus equi-Rhodococcus soli-Rhodococcus agglutinans clade and the type strain of Rhodococcus defluvii. The closest relatives of strain C9-28T were the type strains of R. defluvii (98.88 % 16S rRNA gene sequence similarity), R. equi (98.88 %) and R. soli (98.60 %). The phylogenomic tree based on whole genome sequences supported the distinct position of the novel strain within the genus Rhodococcus. The following chemotaxonomic characteristics also supported the assignment to the genus: meso-diaminopimelic acid; arabinose and galactose in whole-cell hydrolysates; the predominant menaquinone of MK-8(H2); and polar lipids including diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside, three unidentified glycolipids and two unidentified lipids. The predominant cellular fatty acids were C16 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C18 : 1ω9c and C14 : 0. Based on the values of average nucleotide identity and digital DNA-DNA hybridization from whole genome sequences, and in vitro DNA-DNA hybridization between the isolate and the closest relatives, strain C9-28T (=KACC 19823T=DSM 107559T) represents a novel species of the genus Rhodococcus, for which the name Rhodococcussubtropicus sp. nov. is proposed.


Assuntos
Cavernas/microbiologia , Filogenia , Rhodococcus/classificação , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , República da Coreia , Rhodococcus/isolamento & purificação , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
12.
Ecotoxicol Environ Saf ; 182: 109456, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31398779

RESUMO

The seasonal flooding and drainage process affect the paddy soils, the existence of the iron state either Fe(III) or Fe(II) is the main redox system of paddy soil. Its morphological transformation affects the redox nature of paddy soils, which also affects the distribution of bacterial community diversity. This study based on molecular biological methods (qPCR, Illumina MiSeq sequencing technique) to investigate the effect of Fe(II) and environmental factors on cbbM genes containing carbon fixing microbes. Both Eh5 and pH were reduced with Fe(II) concentrations. The Fe(II) addition significantly affects the cbbM gene copy number in both texture soils. In loamy soil, cbbM gene copy number increased with high addition of Fe(II), while both low and high concentrations significantly reduced the cbbM gene copy number in sandy soil. Chemotrophic bacterial abundance significantly increased by 79.7% and 54.8% with high and low Fe(II) addition in loamy soil while in sandy soil its abundance decreased by 53% and 54% with the low and high Fe(II) accumulation. The phototrophic microbial community increased by 37.8% with low Fe(II) concentration and decreased by 16.2% with a high concentration in loamy soil, while in sandy soil increased by 21% and 14.3% in sandy soil with low and high Fe(II) addition. Chemoheterotrophic carbon fixing bacterial abundance decreased with the Fe(II) accumulation in both soil textures in loamy soil its abundance decreased by 5.8% and 24.8%, while in sand soil 15.7% and 12.8% with low and high Fe(II) concentrations. The Fe(II) concentration and soil textures maybe two of the major factors to shape the bacterial community structure in paddy soils. These results provide a scientific basis for management of paddy soil fertility and it can be beneficial to take measures to ease the greenhouse gases effect.


Assuntos
Ferro/química , Microbiologia do Solo , Bactérias , Carbono , Compostos Férricos/química , Compostos Ferrosos , Inundações , Microbiota , Oryza/química , Oxirredução , Solo/química , Poluentes do Solo/análise
13.
World J Microbiol Biotechnol ; 35(8): 126, 2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-31363938

RESUMO

Isolation and identification of temperature tolerant phosphate solubilizing bacteria (TTPSB) and their use as microbial fertilizers was the main goal of the study. In this study, TTPSB were isolated from soil samples treated for 16 h at 55 °C. Their phosphate solubilizing activity was either evaluated in solid media by forming a clear zone (halo) or in liquid media by quantification of the soluble phosphate in the growth medium. Five colonies (RPS4, RPS6, RPS7, RPS8 and RPS9) were identified to be able to form a halo and two of the isolates (RPS9 and RPS7) tolerated a temperature of 55 °C. With tricalcium phosphate (TCP) as the sole P-source, the phosphate solubilizing capacity of RPS9 and RPS7 was determined to be 563.8 and 324.1 mg P L-1 in liquid Sperber medium, respectively. Both bacterial isolates were identified as Pantoea agglomerans by molecular and biochemical characterization. To be used as a microbial fertilizer a carrier system for the temperature tolerant bacteria consisting of rock phosphate, sulfur and bagasse was used. It could be established that the bacterial cell counts of the microbial fertilizers were acceptable for application after storage for 4 months at 28 °C. In a greenhouse experiment using pot cultures, inoculation of maize (S.C.704) with the microbial fertilizers in an autoclaved soil resulted in a significant effect on total fresh and dry weight of the plant root and shoot as well as on the P content of the root and shoot. The effects observed with RPS9 as a component of the microbial fertilizer on plant growth and P nutrition was comparable with the addition of 50% of recommended triple superphosphate (TSP) dose. Using temperature tolerant bacteria in microbial fertilizers will overcome limitations in production and storage of the microbial fertilizers and contribute to a environmentally-friendly agriculture. The temperature tolerant P. agglomerans strain RPS9 was shown to be effective as part of a microbial fertilizer in supporting the growth and P uptake in maize.


Assuntos
Agricultura/métodos , Fosfatos de Cálcio/metabolismo , Pantoea/isolamento & purificação , Pantoea/metabolismo , Microbiologia do Solo , Zea mays/crescimento & desenvolvimento , Técnicas Bacteriológicas , Biotransformação , Fosfatos de Cálcio/química , Meios de Cultura/química , Temperatura Alta , Pantoea/classificação , Pantoea/efeitos da radiação , Solubilidade , Zea mays/microbiologia
14.
Ying Yong Sheng Tai Xue Bao ; 30(7): 2338-2344, 2019 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-31418237

RESUMO

To obtain salt-alkali tolerant strains which could be potenially used to improve the quality of saline-alkali soil, soil samples collected from Dongying, Shandong Province were diluted and spread to modified Gibbson medium with pH 9 and salt concentration of 100 g·L-1. A total of 18 bacteria strains were obtained. By increasing salt concentration and pH, an extremely salt-alkali tole-rant strain N14 was screened which could grow at pH 12 and salt concentration of 20%. We analyzed the morphological, physiological and biochemical characters and 16S rDNA sequence of N14. The strain N14 was identified as Bacillus marmarensis. N14 bacterial fertilizer significantly increased the biomass of wheat, improved shoot height, fresh weight and dry weight by 21.8%, 57.9% and 41.7%, respectively. The addition of N14 bacterial fertilizer significantly increased the chlorophyll a, chlorophyll b and total chlorophyll in wheat by 36.4%, 20.0% and 31.7%, respectively. It significantly increased the activities of invertase, urease and alkaline phosphatase in saline-alkali soil by 23.2%, 68.8% and 106.5%, respectively. It also significantly increased the activities of superoxide dismutase, peroxidase and catalase in roots by 109.6%, 17.8% and 50%, respectively. The concentration of malondialdehyde in wheat roots was significantly reduced by 39.8%. This study provided an idea for the application of extreme salt-alkali tolerant bacteria and a way for improvement of saline-alkali soil.


Assuntos
Fertilizantes , Plantas Tolerantes a Sal/fisiologia , Triticum/fisiologia , Agricultura , Álcalis , Clorofila A , Solo , Microbiologia do Solo
15.
Ying Yong Sheng Tai Xue Bao ; 30(7): 2345-2351, 2019 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-31418238

RESUMO

Clubroot, caused by the soil-borne obligate pathogen Plasmodiophora brassicae, is one of the most severe disease in cruciferous crops. Previous studies showed that when oilseed rape was planted after soybean (namely soybean-oilseed rotation), the incidence and severity of clubroot of oilseed rape could be significantly reduced, compared with that with oilseed rape-oilseed rape conti-nuous cropping. Therefore, the soybean-oilseed rape rotation is a good way to suppress clubroot of oilseed rape. In this study, we compared the rhizosphere microbiome of soybean and oilseed rape rhizosphere soil collected from the field by 16S rRNA (for identification of prokaryotes) and the internal transcribed spacer (ITS) (for identification of fungi) sequencing. The results showed that both soybean and oilseed rape rhizosphere soils had Proteobacteria, Bacteroidetes, Acidobacteria, Actinobacteria, Ascomycota, Zygomycota, Basidiomycota and Chytridiomycota. Many microbial genera (e.g., Flavobacterium, Sphingomonas, Bacillus, Streptomyces, Pseudomonas, Trichoderma and Coniothyrium) with activities of biological control and plant growth promotion were more abundant in soybean rhizosphere soil than in the oilseed rape rhizosphere soil. The abundance of plant pathogenic bacteria and fungi was higher in the oilseed rape rhizosphere soil than in the soybean rhizosphere soil. Moreover, the soybean rhizosphere soil was enriched with Rhizobium, Bradyrhizobium (both for nitrogen fixation), and arbuscular mycorrhizal fungus (Glomus). These results indicated that soybean rhizosphere soil could promote the growth and proliferation of beneficial microorga-nisms, but inhibit that of plant pathogens. Our results provide evidence for explanation of the effectiveness of soybean-oilseed rape rotation to control clubroot of oilseed rape and provide potential bio-control resources for clubroot prevention.


Assuntos
Microbiota , Rizosfera , Microbiologia do Solo , Brassica rapa/crescimento & desenvolvimento , Brassica rapa/microbiologia , Sequenciamento de Nucleotídeos em Larga Escala , RNA Ribossômico 16S , Soja/crescimento & desenvolvimento , Soja/microbiologia
16.
Ying Yong Sheng Tai Xue Bao ; 30(7): 2384-2392, 2019 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-31418242

RESUMO

A phosphate solubilizing fungus was isolated from the rhizosphere of tomato in greenhouse in Liaozhong County, Liaoning Province, Northeast China. The strain was identified as a new strain of Penicillium oxalicum by morphological characteristics and ITS rDNA sequence comparison, and then was named PSF1. Strain PSF1 could utilize various carbon sources such as glucose, sucrose, lactose, galactose, soluble starch and nitrogen sources such as ammonium sulfate, ammonium chloride, ammonium nitrate, potassium nitrate, urea for growth and metabolism, with an efficient phosphate solubilizing capacity. It grew well and had a high ability of phosphate solubilization under the conditions of C/N 10:1-60:1 and initial pH 7-8. Strain PSF1 had strong acid production ability, with the pH of culture mediums decreasing from 7.00-7.50 to 2.06-4.87 during the culture process. The highest phosphate solubilizing capacity in four phosphorus sources mediums was tricalcium phosphate (869.62 mg·L-1) > phosphate rock power (233.56 mg·L-1) > aluminum phosphate (44.77 mg·L-1) > iron phosphate (28.42 mg·L-1). Results from Pearson correlation analysis showed that there were significant negative correlations between the changes of phosphate solubili-zing capacity and pH in tricalcium phosphate, phosphate rock power and iron phosphate mediums, but no significant correlation in aluminum phosphate medium. Strain PSF1 had strong phosphate solu-bilizing capacity and wide growing conditions, thus would have strong phosphate solubilizing capacity in soil.


Assuntos
Fungos/metabolismo , Fosfatos/metabolismo , Microbiologia do Solo , China , Rizosfera , Solubilidade
17.
Ying Yong Sheng Tai Xue Bao ; 30(8): 2691-2698, 2019 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-31418194

RESUMO

Using an approach of spatial sequence instead of temporal succession, we investigated the variation and driving factors of soil microbial biomass and microbial entropy in desert grasslands across four different desertification stages (grassland, fixed dune, semi-fixed dune and mobile dune) in Yanchi County, Ningxia, China. The results showed that soil microbial biomass carbon, nitrogen and phosphorus reduced by 46.1%, 80.8% and 30.0% from grassland to mobile dunes, respectively. The soil microbial entropy (qMBC, qMBN, and qMBP) decreased but soil-microbial stoichiometry imbalance (C:Nimb, C:Pimb and N:Pimb) generally increased with the development of desertification. There were significantly positive relationship between soil microbial biomass nitrogen and C:Nimb, soil microbial biomass phosphorus and C:Pimb, while negative relationship between soil microbial biomass nitrogen and N:Pimb. The RDA result showed that soil ecological stoichiometry (C:N, C:P) had the strongest negative effect on soil microbial entropy carbon (qMBC). Soil microbial biomass and microbial entropy were significantly affected by desertification in desert grassland.


Assuntos
Pradaria , Microbiologia do Solo , Solo , Biomassa , Carbono , China , Conservação dos Recursos Naturais , Clima Desértico , Entropia , Nitrogênio
18.
Ying Yong Sheng Tai Xue Bao ; 30(8): 2699-2706, 2019 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-31418195

RESUMO

Biological soil crusts (biocrusts) play an important role in soil nutrient accumulation and cycling. We examined the relationship between soil nutrient characters and biocrusts types, with six typical types of biocrusts in the hilly Loess Plateau region, including light cyanobacterial crust, dark cyanobacterial crust, cyanobacterial with moss crust (mixed crusts), moss crust, Diploschistes spp. crust, and Nostoc commune crust. The variations of soil carbon (C), nitrogen (N), phospho-rus (P) concentrations and stoichiometric ratios of biocrustal layer and the subsoil under different types of biocrusts were investigated. The results showed that there were significant differences in C, N, P concentrations and stoichiometric ratio among different biocrusts types. The concentrations and stoichiometric ratios of C, N, P in the biocrustal layer were significantly higher than those of 0-10 cm soil beneath biocrusts. The concentrations of C and N significantly decreased with the increases of soil depth across all the biocrusts types. P content showed no variation between soil layers. The concentrations and stoichiometric ratios of C, N, P of moss crust were significantly higher than those of other biocrusts,with C, N, and P content of 27.07, 2.42 and 0.67 g·kg-1. In soil layer of 0-2 cm, the concentrations and stoichiometric ratios of C, N, P under N. commune crust were significantly higher than those of other biocrusts.


Assuntos
Ecossistema , Microbiologia do Solo , Solo , China , Ecologia
19.
Ying Yong Sheng Tai Xue Bao ; 30(8): 2746-2756, 2019 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-31418200

RESUMO

To understand the effects of agricultural management activities on soil arbuscular mycorrhizal (AM) fungi diversity, the high-throughput sequencing based on Illumina MiSeq platform, and the fatty acids fingerprints were used to examine the effects of maize straw returning on soil arbuscular mycorrhizal fungi. The relationships between AM fungal community composition, AM fungal biomass and soil factors after maize straw returning were examined for four continuous years. A total of 2430 operational taxonomic units (OTUs) of AM fungi were classified into 10 genera and 143 species, respectively, which belonged to 1 phylum, 3 classes, 4 orders, 8 families. There was no significant difference in AM fungal community richness (Chaoles index and ACE index) and diversity (Shannon, Simpson diversity indices) in different treatments. Paraglomus and Glomus were dominant genera among all AM fungal communities. With the increase of the maize straw returned amounts, the abundance of Glomus reduced. Under the treatments of 3000 and 9000 kg·hm-2 straw returned, the abundance of Glomus and Acaulospora had significant differences with the control (0 kg·hm-2). Compared with the control, there were significant differences between Archaeospora, Paraglomus and Glomus in the treatment of 3000 kg·hm-2 straw returned. Results from non-metric multi-dimensional scale (NMDS) analysis showed that under 9000 and 12000 kg·hm-2 straw returning treatments, the difference between the ß diversity of soil AM fungi and the spatial distance of controls was farther apart than the other treatments. The effect of straw returning on the ß diversity of AM fungi was significant. The multivariate analysis results revealed the relationship of the spatial variation between the soil physicochemical properties and AM fungi richness and diversity could be explained at 82.8% cumulative variables. The total nitrogen and available nitrogen were the most important factors driving soil microbial communities biomass marked by PLFAs and AM fungal biomass (NLFAs). The continuous maize straw returning to the field changed the genera composition of AM fungi. With the increases of straw returning amounts, the specific species of AM fungi decreased and the similarity between AM fungi community composition decreased. Straw returning increased soil AM fungi biomass and its contribution to soil total microbial biomass.


Assuntos
Micobioma , Micorrizas , Microbiologia do Solo , Solo/química , Zea mays
20.
Ying Yong Sheng Tai Xue Bao ; 30(8): 2757-2766, 2019 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-31418201

RESUMO

Soil microbial community dynamics during the spring freezing-thawing period could affect carbon and nutrient cycling in the subsequent growing season. During spring soil freezing-thawing period, we monitored temporal dynamics of soil microbial community in different soil substrates for Larix gmelinii forest using phospholipid fatty acids (PLFAs) as biomarkers every 3-7 days. The results were as followed: 1) the total PLFAs content, the PLFAs content and relative abundance of each soil microbial group, the ratio of Gram-positive bacteria to Gram-negative bacteria (G+/G-), the ratio of saturated PLFAs to unsaturated PLFAs (S/NS) and the ratio of bacteria to total fungi (fungi + arbuscular mycorrhizal fungi) (B/F) all varied among sampling times; 2) soil total organic carbon (TOC) and nitrogen (TN) were the main factors affecting soil microbial community in the early stage of soil freezing-thawing period; soil moisture, TOC and TN were the main driving factors in the middle stage of soil freezing-thawing period; soil microbes were affected by soil tempera-ture, moisture, TOC, TN and C/N in the late stage of soil freezing-thawing period; 3) the total PLFAs content, the PLFAs content and relative abundance of each soil microbial group (except the relative abundance of bacteria), B/F, G+/G- and S/NS all showed significant difference between soil substrates, and soil TOC, TN and C/N were the key determination factors. Soil temperature, moisture, and nutrient availability were the main factors affecting soil microbial community during the spring soil freezing-thawing period, but the degree of influence varied with the freezing-thawing stages and microbial groups.


Assuntos
Larix , Microbiologia do Solo , Solo/química , Florestas , Congelamento , Nitrogênio , Estações do Ano
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