[Objective] The aim was to identify the species diversity of Actinomycetes from Mangrove forest in Beihai,Guangxi Province. [Method] 10 strains of typical Actinomycetes were isolated from Mangrove forest soil,and the ...[Objective] The aim was to identify the species diversity of Actinomycetes from Mangrove forest in Beihai,Guangxi Province. [Method] 10 strains of typical Actinomycetes were isolated from Mangrove forest soil,and the Actinomycetes genomic DNA was successful extracted. 16S rDNA was amplified by PCR and sequenced by Sanger dideoxy sequencing method. [Result] All the sequences were blasted in genbank,eight strains belonged to the genus of Streptomyces (80%),and two strains belonged to the genus of Nocardiopsis (20%). [Conclusion] There are many different Actinomycetes species in Mangrove forest soil samples in Beihai,Guangxi Province.展开更多
Trichoderma/Hypocrea is a genus of soil-borne or wood-decaying fungi containing members important to mankind as producers of industrial enzymes and biocontrol agents against plant pathogens, but also as opportunistic ...Trichoderma/Hypocrea is a genus of soil-borne or wood-decaying fungi containing members important to mankind as producers of industrial enzymes and biocontrol agents against plant pathogens, but also as opportunistic pathogens of immunocompromised humans. Species identification, while essential in view of the controversial properties of taxa ofthis genus, has been problematic by traditional methods. Here we will present a critical survey of the various identification methods in use. In addition,we will present an update on the taxonomy and phylogeny of the 88 taxa (which occur as 14 holomorphs, 49 teleomorphs and 25 anamorphs in nature) of Trichoderma/Hypocrea that have been confirmed by a combination of morphological, physiological and genetic approaches.展开更多
In this work, sucrose utilizing microbes from soil were screened to evaluate their ability for accumulation of biopolymer of polyhydroxyalkanoate （PHA）. Among 72 isolates were transferred to mineral salt medium （MS...In this work, sucrose utilizing microbes from soil were screened to evaluate their ability for accumulation of biopolymer of polyhydroxyalkanoate （PHA）. Among 72 isolates were transferred to mineral salt medium （MSM）, 33 strains can be grown on sucrose agar medium. However, only one strain showed a strong black color for Sudan Black and gave positive result for Nile blue A. Identification by 16S rDNA nucleotide sequence homology of the isolate showed very closely to Hydrogenophaga sp. （99% identify）. To consider PHA production, the isolate was grown in the medium containing sucrose as a sole carbon under controlled conditions of 35 ℃ and at pH 7. Maximum dry cell weight （DCW） and PHA production were obtained at 3.61 g/L and 2.41 g/L after 36 and 42 h batch fermentation. Sucrose uptake measured in term of total organic carbon （TOC） showed at 14.73 g within 48 h. The highest PHA was 68.15% （gPHA/gDCW） giving maximum PHA yield （YP/s） of 0.17 （gPHA/gs ） and a productivity of 0.057 gPHA/L.h. This highlights the potential of microbial resources in soil environment and may be an exploitable application for the industrial production of PHA.展开更多
Soil oxalate degrading bacteria is an important source for removing of toxic oxalate compounds. Isolation, screening, characterization, identification and fingerprint of the soil oxalate degrading bacteria from Egypti...Soil oxalate degrading bacteria is an important source for removing of toxic oxalate compounds. Isolation, screening, characterization, identification and fingerprint of the soil oxalate degrading bacteria from Egyptian fertile soil was aimed in this work. Isolated bacteria were first characterized using API 20 NE system. Nine RAPD primers were used in genetic fingerprinting of the characterized bacteria using RAPD-PCR. The preliminary characterization and polyphasic taxonomy for mesophilic, aerobic oxalate-degrading bacteria isolated from Egyptian fertile soil including auxanography using API galleries confirmed that the isolate belonged to the genus Burkholderia cepacia, the percentage of identity was 99.8% for 5167777 profiles. Fingerprinting by RAPD-PCR showed a DNA fingerprint ranging from 0 to 9 bands, over a size range of 344 bp to 3,280 bp.展开更多
A few soil microorganisms can convert insoluble forms of phosphorus （P） to an accessible form to increase plant yields The objectives of this study were to isolate, screen and identify the phosphobacteria, i.e., pho...A few soil microorganisms can convert insoluble forms of phosphorus （P） to an accessible form to increase plant yields The objectives of this study were to isolate, screen and identify the phosphobacteria, i.e., phosphate-solubilizing bacteria （PSB） and phosphate-mineralizing bacteria （PMB）, in some poplar plantations and to select potential microbial inoculants that could increase the P uptake by plants. Seventy four PSB strains and 138 PMB strains were preliminarily screened from 797＂colonies isolated from the rhizosphere soil of poplar by the visible decolorization in the National Botanical Research Institute＇s phosphate growth medium （NBRIP） containing a pH indicator of bromophenol and by the clear/halo zone on yeast malt agar plate, respectively. Then, based on the solubilization of Ca3（PO4）2 in liquid NBRIP medium and the mineralization of lecithin in liquid Menkina medium, 15 PS1R strains and 7 PMB strains were further determined for their abilities to solubilize Ca3（PO4）2 and to mineralize lecithin. The results showed that the 15 PSB strains exhibited inorganic P-solubilizing abilities ranging between 376.62 and 669.56 mg L-1 and the 7 PMB strains exhibited organic P-mineralizing abilities vaxying from 0.32 to 1.56 mg L-1 three days after incubation. Three of PSB strains with the highest P-solubilizing ability, named JW-JS1, JW-JS2 and JW-SX2, were all preliminarily identified as Pseudomonas ftuorescens, while two of PMB strains with the highest P-mineralizing ability, named JYZ-SD1 and JYT-JS2, were preliminarily identified as Bacillus cereus and Bacillus subtilis, respectively. All the efficient PSB and PMB strains should be further studied under both pot culture and field conditions to test their beneficial effects on poplar.展开更多
Polycyclic aromatic hydrocarbons （PAHs） are mainly produced by combustion processes and consist of a number of toxic com- pounds. They are always emitted as a mixture and have become a major type of pollutants in ur...Polycyclic aromatic hydrocarbons （PAHs） are mainly produced by combustion processes and consist of a number of toxic com- pounds. They are always emitted as a mixture and have become a major type of pollutants in urban areas. The degree of soil contamination by PAHs is of special concern in areas immediately in proximity to cities with heavy traffic, factories, older buildings, and infrastructure. The accumulation of soil PAHs is also affected by non-anthropogenie factors, such as climate, vegetation, and soil property. This paper reviews three typical source identification techniques, including diagnostic ratios, positive matrix factorization, and principle components analysis. The advantages or disadvantages of these techniques are analyzed. It is recommended that multiple identification techniques be used to determine the sources in order to minimize the weaknesses inherent in each method and thereby to strengthen the conclusions for PAH source identification.展开更多
基金Supported by Science Foundation of Guangxi Province (0899006)South China Agricultural University Principal Foundation ( 5100-k05099)~~
文摘[Objective] The aim was to identify the species diversity of Actinomycetes from Mangrove forest in Beihai,Guangxi Province. [Method] 10 strains of typical Actinomycetes were isolated from Mangrove forest soil,and the Actinomycetes genomic DNA was successful extracted. 16S rDNA was amplified by PCR and sequenced by Sanger dideoxy sequencing method. [Result] All the sequences were blasted in genbank,eight strains belonged to the genus of Streptomyces (80%),and two strains belonged to the genus of Nocardiopsis (20%). [Conclusion] There are many different Actinomycetes species in Mangrove forest soil samples in Beihai,Guangxi Province.
文摘Trichoderma/Hypocrea is a genus of soil-borne or wood-decaying fungi containing members important to mankind as producers of industrial enzymes and biocontrol agents against plant pathogens, but also as opportunistic pathogens of immunocompromised humans. Species identification, while essential in view of the controversial properties of taxa ofthis genus, has been problematic by traditional methods. Here we will present a critical survey of the various identification methods in use. In addition,we will present an update on the taxonomy and phylogeny of the 88 taxa (which occur as 14 holomorphs, 49 teleomorphs and 25 anamorphs in nature) of Trichoderma/Hypocrea that have been confirmed by a combination of morphological, physiological and genetic approaches.
文摘In this work, sucrose utilizing microbes from soil were screened to evaluate their ability for accumulation of biopolymer of polyhydroxyalkanoate （PHA）. Among 72 isolates were transferred to mineral salt medium （MSM）, 33 strains can be grown on sucrose agar medium. However, only one strain showed a strong black color for Sudan Black and gave positive result for Nile blue A. Identification by 16S rDNA nucleotide sequence homology of the isolate showed very closely to Hydrogenophaga sp. （99% identify）. To consider PHA production, the isolate was grown in the medium containing sucrose as a sole carbon under controlled conditions of 35 ℃ and at pH 7. Maximum dry cell weight （DCW） and PHA production were obtained at 3.61 g/L and 2.41 g/L after 36 and 42 h batch fermentation. Sucrose uptake measured in term of total organic carbon （TOC） showed at 14.73 g within 48 h. The highest PHA was 68.15% （gPHA/gDCW） giving maximum PHA yield （YP/s） of 0.17 （gPHA/gs ） and a productivity of 0.057 gPHA/L.h. This highlights the potential of microbial resources in soil environment and may be an exploitable application for the industrial production of PHA.
文摘Soil oxalate degrading bacteria is an important source for removing of toxic oxalate compounds. Isolation, screening, characterization, identification and fingerprint of the soil oxalate degrading bacteria from Egyptian fertile soil was aimed in this work. Isolated bacteria were first characterized using API 20 NE system. Nine RAPD primers were used in genetic fingerprinting of the characterized bacteria using RAPD-PCR. The preliminary characterization and polyphasic taxonomy for mesophilic, aerobic oxalate-degrading bacteria isolated from Egyptian fertile soil including auxanography using API galleries confirmed that the isolate belonged to the genus Burkholderia cepacia, the percentage of identity was 99.8% for 5167777 profiles. Fingerprinting by RAPD-PCR showed a DNA fingerprint ranging from 0 to 9 bands, over a size range of 344 bp to 3,280 bp.
基金Supported by the Program for Science and Technology Development of Jiangsu Province,China (No. BE2008393)the InnovationPlan for Graduate Students of Jiangsu Province,China (No. CX08B 028Z)the Public Welfare Scientific Special of State ForestryAdministration in China (No. 201004061)
文摘A few soil microorganisms can convert insoluble forms of phosphorus （P） to an accessible form to increase plant yields The objectives of this study were to isolate, screen and identify the phosphobacteria, i.e., phosphate-solubilizing bacteria （PSB） and phosphate-mineralizing bacteria （PMB）, in some poplar plantations and to select potential microbial inoculants that could increase the P uptake by plants. Seventy four PSB strains and 138 PMB strains were preliminarily screened from 797＂colonies isolated from the rhizosphere soil of poplar by the visible decolorization in the National Botanical Research Institute＇s phosphate growth medium （NBRIP） containing a pH indicator of bromophenol and by the clear/halo zone on yeast malt agar plate, respectively. Then, based on the solubilization of Ca3（PO4）2 in liquid NBRIP medium and the mineralization of lecithin in liquid Menkina medium, 15 PS1R strains and 7 PMB strains were further determined for their abilities to solubilize Ca3（PO4）2 and to mineralize lecithin. The results showed that the 15 PSB strains exhibited inorganic P-solubilizing abilities ranging between 376.62 and 669.56 mg L-1 and the 7 PMB strains exhibited organic P-mineralizing abilities vaxying from 0.32 to 1.56 mg L-1 three days after incubation. Three of PSB strains with the highest P-solubilizing ability, named JW-JS1, JW-JS2 and JW-SX2, were all preliminarily identified as Pseudomonas ftuorescens, while two of PMB strains with the highest P-mineralizing ability, named JYZ-SD1 and JYT-JS2, were preliminarily identified as Bacillus cereus and Bacillus subtilis, respectively. All the efficient PSB and PMB strains should be further studied under both pot culture and field conditions to test their beneficial effects on poplar.
基金the financial support from the National Natural Science Foundation of China(No.41671085)
文摘Polycyclic aromatic hydrocarbons （PAHs） are mainly produced by combustion processes and consist of a number of toxic com- pounds. They are always emitted as a mixture and have become a major type of pollutants in urban areas. The degree of soil contamination by PAHs is of special concern in areas immediately in proximity to cities with heavy traffic, factories, older buildings, and infrastructure. The accumulation of soil PAHs is also affected by non-anthropogenie factors, such as climate, vegetation, and soil property. This paper reviews three typical source identification techniques, including diagnostic ratios, positive matrix factorization, and principle components analysis. The advantages or disadvantages of these techniques are analyzed. It is recommended that multiple identification techniques be used to determine the sources in order to minimize the weaknesses inherent in each method and thereby to strengthen the conclusions for PAH source identification.
