In this study, Aspergillus niger 1107 was isolated and identified as an efficient phosphate-solubilizing fungus （PSF）. This strain generated 689 mg soluble P L-1 NBRIP medium after 10 d of culture. To produce an aff...In this study, Aspergillus niger 1107 was isolated and identified as an efficient phosphate-solubilizing fungus （PSF）. This strain generated 689 mg soluble P L-1 NBRIP medium after 10 d of culture. To produce an affordable biofertilizer using A. niger 1107, the potential of widely available carrier materials for growth and maintenance of this strain were evaluated. The effects of sterilization procedures （autoclaving and gamma-ray irradiation） on the suitability of these carriers to maintain growth of the fungus were also investigated. The carrier materials were peat, corn cobs with 20% （w/w） perlite （CCP）, wheat husks with 20% （w/w） perlite （WHP）, and composted cattle manure with 20% （w/w） perlite （CCMP）. In the first 5-6 mon of storage, the carriers sterilized by gamma-ray irradiation maintained higher inoculum loads than those in carriers sterilized by autoclaving. However, this effect was not detectable after 7 mon of storage. For the P-biofertilizer on WHP, more than 2.0× 10^7 viable spores of A. niger g-1 inoculant survived after 7 mon of storage. When this biofertilizer was applied to Chinese cabbage in a pot experiment, there were 5.6×10^6 spores of A. niger g-1 soil before plant harvesting. In the pot experiment, Chinese cabbage plants grown in soil treated with peat- and WHP-based P-biofertilizers showed significantly greater growth （P〈0.05） than that of plants grown in soil treated with free-cell biofertilizer or the CCMP-based biofertilizer. Also, the peat- and WHP-based P-biofertilizers increased the available P content in soil.展开更多
Rare earth element(REE)mining has wrought severe ecosystem destruction,particularly in the loss of carbon(C),nitrogen(N),and phosphorus(P).Furthermore,its effects on nutrient recovery characteristics and associated mi...Rare earth element(REE)mining has wrought severe ecosystem destruction,particularly in the loss of carbon(C),nitrogen(N),and phosphorus(P).Furthermore,its effects on nutrient recovery characteristics and associated microbial abundance are still poorly understood.In this study,an investigation was conducted to determine C,N,and P recovery patterns and microbial communities in abandoned REE mining tailings with different abandoned durations of 1.5(1.5-Y),7(7-Y),10(10-Y),and 14(14-Y)years and at an unmined site(the control group)in Jiangxi Province,China.Longitudinal tailing delamination at each site was investigated in 0–15(layer 1)and 15–30(layer 2)cm tailing layers.During the abandoned duration of REE tailings,C and P in layer 1 continued to recover from 1.62 to 8.51 g kg^(-1) and from 0.71 to 1.94 g kg^(-1),respectively;N losses of 0.60 and 0.22 g kg^(-1) occurred at the 1.5-Y and 10-Y sites,while N in layer 1 slightly increased at the 14-Y site.Mesorhizobium,Methylosinus,Bradyrhizobium,Pseudomonas,and Azospirillum were dominant bacteria at the 14-Y site and in the control.The relative abundances of N-fixing bacteria Mesorhizobium(32.94%),Sinorhizobium(0.24%),Frankia(0.71%),and Burkholderia(2.38%)at the 14-Y site were 1.33–3.97 times those in the control(24.19%,0.18%,0.32%and 0.60%,respectively),which was helpful for tailing N recovery.At the 14-Y site,Tylospora(50.24%),Luellia(11.02%),Tomentella(6.94%),and Chaetomium(4.34%)were the dominant fungal genera,while Tylospora(56.93%),Suillus(11.45%),and Penicillium(6.78%)predominated in the control.The relative abundance of the P-dissolving fungus Aspergillus at the 14-Y site(0.42%)was 4.2 times that in the control(0.1%),which may lead to the improved tailing P solubility.At the 14-Y site,woody plants such as Pinus massoniana and native pioneering herbs and ferns such as Dicranopteris dichotoma and Nephrolepis auriculata probably invaded from adjacent areas.This study unraveled the natural restoration of plant and microbial communities along with soil nutrient changes in abandoned REE tailings,thus providing a novel insight into ecological recovery and restoration after mining.展开更多
基金financially supported by the Special Fund for Agro-Scientific Research in the Public Interest, China (201003014)the Central Public-Interest ScientificInstitution Basal Research Fund, China (202-27)
文摘In this study, Aspergillus niger 1107 was isolated and identified as an efficient phosphate-solubilizing fungus （PSF）. This strain generated 689 mg soluble P L-1 NBRIP medium after 10 d of culture. To produce an affordable biofertilizer using A. niger 1107, the potential of widely available carrier materials for growth and maintenance of this strain were evaluated. The effects of sterilization procedures （autoclaving and gamma-ray irradiation） on the suitability of these carriers to maintain growth of the fungus were also investigated. The carrier materials were peat, corn cobs with 20% （w/w） perlite （CCP）, wheat husks with 20% （w/w） perlite （WHP）, and composted cattle manure with 20% （w/w） perlite （CCMP）. In the first 5-6 mon of storage, the carriers sterilized by gamma-ray irradiation maintained higher inoculum loads than those in carriers sterilized by autoclaving. However, this effect was not detectable after 7 mon of storage. For the P-biofertilizer on WHP, more than 2.0× 10^7 viable spores of A. niger g-1 inoculant survived after 7 mon of storage. When this biofertilizer was applied to Chinese cabbage in a pot experiment, there were 5.6×10^6 spores of A. niger g-1 soil before plant harvesting. In the pot experiment, Chinese cabbage plants grown in soil treated with peat- and WHP-based P-biofertilizers showed significantly greater growth （P〈0.05） than that of plants grown in soil treated with free-cell biofertilizer or the CCMP-based biofertilizer. Also, the peat- and WHP-based P-biofertilizers increased the available P content in soil.
基金supported by the National Natural Science Foundation of China(Nos.42293350,42293354,42293355,and 21707177).
文摘Rare earth element(REE)mining has wrought severe ecosystem destruction,particularly in the loss of carbon(C),nitrogen(N),and phosphorus(P).Furthermore,its effects on nutrient recovery characteristics and associated microbial abundance are still poorly understood.In this study,an investigation was conducted to determine C,N,and P recovery patterns and microbial communities in abandoned REE mining tailings with different abandoned durations of 1.5(1.5-Y),7(7-Y),10(10-Y),and 14(14-Y)years and at an unmined site(the control group)in Jiangxi Province,China.Longitudinal tailing delamination at each site was investigated in 0–15(layer 1)and 15–30(layer 2)cm tailing layers.During the abandoned duration of REE tailings,C and P in layer 1 continued to recover from 1.62 to 8.51 g kg^(-1) and from 0.71 to 1.94 g kg^(-1),respectively;N losses of 0.60 and 0.22 g kg^(-1) occurred at the 1.5-Y and 10-Y sites,while N in layer 1 slightly increased at the 14-Y site.Mesorhizobium,Methylosinus,Bradyrhizobium,Pseudomonas,and Azospirillum were dominant bacteria at the 14-Y site and in the control.The relative abundances of N-fixing bacteria Mesorhizobium(32.94%),Sinorhizobium(0.24%),Frankia(0.71%),and Burkholderia(2.38%)at the 14-Y site were 1.33–3.97 times those in the control(24.19%,0.18%,0.32%and 0.60%,respectively),which was helpful for tailing N recovery.At the 14-Y site,Tylospora(50.24%),Luellia(11.02%),Tomentella(6.94%),and Chaetomium(4.34%)were the dominant fungal genera,while Tylospora(56.93%),Suillus(11.45%),and Penicillium(6.78%)predominated in the control.The relative abundance of the P-dissolving fungus Aspergillus at the 14-Y site(0.42%)was 4.2 times that in the control(0.1%),which may lead to the improved tailing P solubility.At the 14-Y site,woody plants such as Pinus massoniana and native pioneering herbs and ferns such as Dicranopteris dichotoma and Nephrolepis auriculata probably invaded from adjacent areas.This study unraveled the natural restoration of plant and microbial communities along with soil nutrient changes in abandoned REE tailings,thus providing a novel insight into ecological recovery and restoration after mining.
