scholarly journals Effects of Bacillus thuringiensis HC-2 Combined with Biochar on the Growth and Cd and Pb Accumulation of Radish in a Heavy Metal-Contaminated Farmland under Field Conditions

2019 ◽  
Vol 16 (19) ◽  
pp. 3676 ◽  
Author(s):  
Zigang Li ◽  
Peng Wang ◽  
Xiaoyu Yue ◽  
Jingtao Wang ◽  
Baozeng Ren ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Bacillus Thuringiensis ◽  
Organic Matter Content ◽  
Dry Weight ◽  
Underlying Mechanism ◽  
Water Soluble ◽  
Field Conditions ◽  
Resistant Bacteria ◽  
Culture Solution ◽  
Rhizosphere Soils

The objective of this study was to explore the effect of heavy metal-resistant bacteria and biochar (BC) on reducing heavy metal accumulation in vegetables and the underlying mechanism. We tested Bacillus thuringiensis HC-2, BC, and BC+HC-2 for their ability to immobilize Cd and Pb in culture solution. We also studied the effects of these treatments on the dry weight and Cd and Pb uptake of radish in metal-contaminated soils under field conditions and the underlying mechanism. Treatment with HC-2, BC, and BC+HC-2 significantly reduced the water-soluble Cd (34–56%) and Pb (31–54%) concentrations and increased the pH and NH4+ concentration in solution compared with their vales in a control. These treatments significantly increased the dry weight of radish roots (18.4–22.8%) and leaves (37.8–39.9%) and decreased Cd (28–94%) and Pb (22–63%) content in the radish roots compared with the control. Treatment with HC-2, BC, and BC+HC-2 also significantly increased the pH, organic matter content, NH4+ content, and NH4+/NO3− ratio of rhizosphere soils, and decreased the DTPA-extractable Cd (37–58%) and Pb (26–42%) contents in rhizosphere soils of radish. Furthermore, BC+HC-2 had higher ability than the other two treatments to protect radish against Cd and Pb toxicity and increased radish biomass. Therefore, Bacillus thuringiensis HC-2 combined with biochar can ensure vegetable safety in situ for the bioremediation of heavy metal-polluted farmland.

scholarly journals Screening of Heavy Metal-Immobilizing Bacteria and Its Effect on Reducing Cd2+ and Pb2+ Concentrations in Water Spinach (Ipomoea aquatic Forsk.)

2020 ◽  
Vol 17 (9) ◽  
pp. 3122 ◽  
Author(s):  
Tiejun Wang ◽  
Xiaoyu Wang ◽  
Wei Tian ◽  
Lunguang Yao ◽  
Yadong Li ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Dry Weight ◽  
Water Spinach ◽  
Rhizosphere Soils ◽  
Microbial Resources ◽  
Heavy Pollution ◽  
Ipomoea Aquatic ◽  
Bacillus Thuringensis ◽  
Strong Ability

Microbial immobilization is considered as a novel and environmentally friendly technology that uses microbes to reduce heavy metals accumulation in plants. To explore microbial resources which are useful in these applications, three water spinach rhizosphere soils polluted by different levels of heavy metals (heavy pollution (CQ), medium pollution (JZ), and relative clean (NF)) were collected. The community composition of heavy metal-immobilizing bacteria in rhizosphere soils and its effects on reducing the Cd2+ and Pb2+ concentrations in water spinach were evaluated. Four hundred strains were isolated from the CQ (belonging to 3 phyla and 14 genera), JZ (belonging to 4 phyla and 25 genera) and NF (belonged to 6 phyla and 34 genera) samples, respectively. In the CQ sample, 137 strains showed a strong ability to immobilize Cd2+ and Pb2+, giving Cd2+ and Pb2+ removal rates of greater than 80% in solution; Brevundimonas, Serratia, and Pseudoarthrobacter were the main genera. In total, 62 strains showed a strong ability to immobilize Cd2+ and Pb2+ in the JZ sample and Bacillus and Serratia were the main genera. A total of 22 strains showed a strong ability to immobilize Cd2+ and Pb2+ in the NF sample, and Bacillus was the main genus. Compared to the control, Enterobacter bugandensis CQ-7, Bacillus thuringensis CQ-33, and Klebsiella michiganensis CQ-169 significantly increased the dry weight (17.16–148%) of water spinach and reduced the contents of Cd2+ (59.78–72.41%) and Pb2+ (43.36–74.21%) in water spinach. Moreover, the soluble protein and Vc contents in the shoots of water spinach were also significantly increased (72.1–193%) in the presence of strains CQ-7, CQ-33 and CQ-169 compared to the control. In addition, the contents of Cd and Pb in the shoots of water spinach meet the standard for limit of Cd2+ and Pb2+ in vegetables in the presence of strains CQ-7, CQ-33 and CQ-169. Thus, the results provide strains as resources and a theoretical basis for the remediation of Cd- and Pb-contaminated farmlands for the safe production of vegetables.

HEAVY METAL SPECIATION IN BOTTOM SEDIMENTS OF THE VYSHNEVOLOTSKY RESERVOIR

2018 ◽  
pp. 46-54
Author(s):  
O. A. Lipatnikova
Keyword(s):  
Heavy Metal ◽  
Organic Matter ◽  
Bottom Sediments ◽  
Metal Speciation ◽  
Organic Matter Content ◽  
Water Reservoir ◽  
Matter Content ◽  
Heavy Metal Speciation ◽  
Mobile Forms ◽  
Manganese Hydroxides

The study of heavy metal speciation in bottom sediments of the Vyshnevolotsky water reservoir is presented in this paper. Sequential selective procedure was used to determine the heavy metal speciation in bottom sediments and thermodynamic calculation — to determine ones in interstitial water. It has been shown that Mn are mainly presented in exchangeable and carbonate forms; for Fe, Zn, Pb и Co the forms are related to iron and manganese hydroxides is played an important role; and Cu and Ni are mainly associated with organic matter. In interstitial waters the main forms of heavy metal speciation are free ions for Zn, Ni, Co and Cd, carbonate complexes for Pb, fulvate complexes for Cu. Effects of particle size and organic matter content in sediments on distribution of mobile and potentially mobile forms of toxic elements have been revealed.

Species Density and Lead (Pb) Pollution in Mangrove Ecosystem, South Kalimantan

2020 ◽  
Vol 5 (1) ◽  
pp. 70-81
Author(s):  
Anang Kadarsah ◽  
Dafiuddin Salim ◽  
Sadang Husain ◽  
Marta Dinata
Keyword(s):  
Heavy Metal ◽  
Oil Palm ◽  
Ph Value ◽  
Coal Mines ◽  
Organic Matter Content ◽  
Mangrove Ecosystem ◽  
Organic Content ◽  
Species Density ◽  
Pb Pollution ◽  
Mangrove Ecosystems

Its crucial to get information about lead (Pb) heavy metal pollution from mining and oil palm plantation on species density in mangrove ecosystem, to anticipate its impacts. This study aimed is to compare the types and densities of vegetation in mangrove ecosystems allegedly due to mining in Setarap village, Tanah Bumbu Regency and oil palm plantations in Kuala Tambangan Village, Tanah Laut Regency. We also analysis the condition of waters (TDS, pH and DO) and organic content in sediments to acquire data from the South Kalimantan mangrove ecosystems. The results showed there were four species of true mangroves (Avicennia alba, Acanthus ebracteatus, Nypa fruticans and Rhizophora apiculate) could live well in the environment affected by mining or oil palm plantations. The species density for trees was low (933 ind/ha) for mangroves affected by coal mines, while those affected by oil palm plantations had higher densities (1,067 ind/ha). pH value of waters in affected area by coal mining showed more acidic value (pH 5.76) especially at the back, while those by palm oil plantations are more acidic (pH 6) in the estuary. Organic matter content in sediments affected by coal mines was in the range of 0.61-6.59%, while those affected by oil palm plantations showed higher values (0.12-2.19%). Lead heavy metal content (Pb) in waters affected by coal mines was 0.031-0.056 mg/L, while the area affected by oil palm plantations was of higher value (0.110-0.128 mg/L). Lead (Pb) levels in sediments indicate higher values than waters, which reach 3.512-6.046 mg/Kg (affected by coal mines), and in areas affected by oil palm plantations reaching 6.658-6.66 mg/Kg. The general conclusion is that vegetation densities in areas affected by coal mines are lower than oil palm plantations. The level of lead  (Pb) pollution in the sediments is higher than in the waters.

Standardization and bacteria inhibitory test of purified extract of mahogany (Swietenia mahagoni (L.) Jacq) seeds and leaves

2019 ◽  
Vol 10 (3) ◽  
pp. 2132-2138
Author(s):  
Virsa Handayani ◽  
Rezki Amriati Syarif ◽  
Ahmad Najib ◽  
Aktsar Roskiana Ahmad ◽  
Abdullah Mahmud ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Heavy Metal ◽  
Bitter Taste ◽  
Drying Shrinkage ◽  
Ash Content ◽  
Water Soluble ◽  
Lead Contamination ◽  
Specific Parameter ◽  
Chemical Content ◽  
Swietenia Mahagoni

Mahogany (Swietenia mahagoni (L.) Jacq) is one of the plants that is often used by the community as traditional medicine. One of them is antifungal, antibacterial, antidiabetic, and eczema. This study aims to obtain standardized extracts from mahogany seeds and leaves. Standardization of purified extract of mahogany has been carried out according to the monographs of extract standardization guidelines, which include testing of specific and non-specific parameters. The results of the specific parameter testing showed that the purified extract of mahogany seeds is a thick extract, brown to reddish, smells distinctive and has a bitter taste. While the purified extract of mahogany leaves is a thick extract, greenish-brown in color, distinctive smell and has a bitter taste. The chemical content of purified extract of mahogany seeds and leaves showed the presence of flavonoids, alkaloids, terpenoids and saponins. Water-soluble essence levels in mahogany seeds and leaves was 14.84% and 10.28%. While the ethanol-soluble essence levels in mahogany seeds and leaves were 15.38% and 12.43%. Testing of non-specific parameters on mahogany seeds and leaves showed the results of drying shrinkage levels of 0.22% and 8.84%, moisture content of 2.60% and 4.04%, total ash content of 1.71% and 1.93%, levels acidic insoluble ash 0.38% and 0.32%, Total Plate Number (ALT) of mahogany seed bacteria 1x102 colonies/g, Number of mahogany mold seeds 4x10 colonies/g, heavy metal lead contamination and cadmium in mahogany seeds 0.0607µg/g and<0.003µg/g. The inhibitory diameter of each concentration of seeds against Escherichia coli, 3%, 5%, 7%, and 9%, is 12,67; 13,67; 17,67; and 19,67 mm, respectively. The inhibitory diameter of each concentration of leaves against Escherichia coli, 3%, 5%, 7%, and 9%, is 10,27; 10,90; 13,46; and 15,68 mm, respectively.

scholarly journals Effects of exogenous silicon on maize seed germination and seedling growth

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yankun Sun ◽  
Jiaqi Xu ◽  
Xiangyang Miao ◽  
Xuesong Lin ◽  
Wanzhen Liu ◽  
...  
Keyword(s):  
Seed Germination ◽  
Seedling Growth ◽  
Crop Yields ◽  
Dry Weight ◽  
Membrane System ◽  
Water Soluble ◽  
Current Status ◽  
Antioxidant Enzyme Activities ◽  
Chlorophyll Contents ◽  
Antioxidant Defence System

AbstractAs the global population continues to increase, global food production needs to double by 2050 to meet the demand. Given the current status of the not expansion of cultivated land area, agronomic seedlings are complete, well-formed and strong, which is the basis of high crop yields. The aim of this experiment was to study the effects of seed germination and seedling growth in response to silicon (from water-soluble Si fertilizer). The effects of Si on the maize germination, seedling growth, chlorophyll contents, osmoprotectant contents, antioxidant enzyme activities, non-enzymatic antioxidant contents and stomatal characteristics were studied by soaking Xianyu 335 in solutions of different concentrations of Si (0, 5, 10, 15, 20, and 25 g·L−1). In this study, Si treatments significantly increased the seed germination and per-plant dry weight of seedlings (P < 0.05), and the optimal concentration was 15 g·L−1. As a result of the Si treatment of the seeds, the chlorophyll content, osmotic material accumulation and antioxidant defence system activity increased, reducing membrane system damage, reactive oxygen species contents, and stomatal aperture. The results suggested that 15 g·L−1 Si significantly stimulated seed germination and promoted the growth of maize seedlings, laying a solid foundation for subsequent maize growth.

scholarly journals Resistance of bacteria isolated from leachate to heavy metals and the removal of Hg by Pseudomonas aeruginosa strain FZ-2 at different salinity levels in a batch biosorption system

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Muhammad Fauzul Imron ◽  
Setyo Budi Kurniawan ◽  
Siti Rozaimah Sheikh Abdullah
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Pseudomonas Aeruginosa ◽  
Fresh Water ◽  
Landfill Leachate ◽  
Saline Water ◽  
Resistant Bacteria ◽  
Sanitary Landfill ◽  
Salinity Levels ◽  
Sanitary Landfill Leachate

AbstractLeachate is produced from sanitary landfills containing various pollutants, including heavy metals. This study aimed to determine the resistance of bacteria isolated from non-active sanitary landfill leachate to various heavy metals and the effect of salinity levels on the removal of Hg by the isolated bacterium. Four dominant bacteria from approximately 33 × 1017 colony-forming units per mL identified as Vibrio damsela, Pseudomonas aeruginosa, Pseudomonas stutzeri, and Pseudomonas fluorescens were isolated from non-active sanitary landfill leachate. Heavy metal resistance test was conducted for Hg, Cd, Pb, Mg, Zn, Fe, Mn, and Cu (0–20 mg L− 1). The removal of the most toxic heavy metals by the most resistant bacteria was also determined at different salinity levels, i.e., fresh water (0‰), marginal water (10‰), brackish water (20‰), and saline water (30‰). Results showed that the growth of these bacteria is promoted by Fe, Mn, and Cu, but inhibited by Hg, Cd, Pb, Mg, and Zn. The minimum inhibitory concentration (MIC) of all the bacteria in Fe, Mn, and Cu was > 20 mg L− 1. The MIC of V. damsela was 5 mg L− 1 for Hg and >  20 mg L− 1 for Cd, Pb, Mg, and Zn. For P. aeruginosa, MIC was > 20 mg L− 1 for Cd, Pb, Mg, and Zn and 10 mg L− 1 for Hg. Meanwhile, the MIC of P. stutzeri was > 20 mg L− 1 for Pb, Mg, and Zn and 5 mg L− 1 for Hg and Cd. The MIC of P. fluorescens for Hg, Pb, Mg, and Zn was 5, 5, 15, and 20 mg L− 1, respectively, and that for Cd was > 20 mg L− 1. From the MIC results, Hg is the most toxic heavy metal. In marginal water (10‰), P. aeruginosa FZ-2 removed up to 99.7% Hg compared with that in fresh water (0‰), where it removed only 54% for 72 h. Hence, P. aeruginosa FZ-2 is the most resistant to heavy metals, and saline condition exerts a positive effect on bacteria in removing Hg.

scholarly journals Incorporation of alternative amino acids into cyanophycin by different cyanophycin synthetases heterologously expressed in Corynebacterium glutamicum

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ramona Wördemann ◽  
Lars Wiefel ◽  
Volker F. Wendisch ◽  
Alexander Steinbüchel
Keyword(s):  
Amino Acids ◽  
Dry Weight ◽  
Growth Conditions ◽  
Amino Acid Biosynthesis ◽  
Water Soluble ◽  
Lysine Content ◽  
Polyaspartic Acid ◽  
Acid Biosynthesis ◽  
Cyanophycin Synthetase ◽  
Potential Precursor

AbstractCyanophycin (multi-l-arginyl-poly-l-aspartic acid; also known as cyanophycin grana peptide [CGP]) is a biopolymer that could be used in various fields, for example, as a potential precursor for the synthesis of polyaspartic acid or for the production of CGP-derived dipeptides. To extend the applications of this polymer, it is therefore of interest to synthesize CGP with different compositions. A recent re-evaluation of the CGP synthesis in C. glutamicum has shown that C. glutamicum is a potentially interesting microorganism for CGP synthesis with a high content of alternative amino acids. This study shows that the amount of alternative amino acids can be increased by using mutants of C. glutamicum with altered amino acid biosynthesis. With the DM1729 mutant, the lysine content in the polymer could be increased up to 33.5 mol%. Furthermore, an ornithine content of up to 12.6 mol% was achieved with ORN2(Pgdh4). How much water-soluble or insoluble CGP is synthesized is strongly related to the used cyanophycin synthetase. CphADh synthesizes soluble CGP exclusively. However, soluble CGP could also be isolated from cells expressing CphA6308Δ1 or CphA6308Δ1_C595S in addition to insoluble CGP in all examined strains. The point mutation in CphA6308Δ1_C595S partially resulted in a higher lysine content. In addition, the CGP content could be increased to 36% of the cell dry weight under optimizing growth conditions in C. glutamicum ATCC13032. All known alternative major amino acids for CGP synthesis (lysine, ornithine, citrulline, and glutamic acid) could be incorporated into CGP in C. glutamicum.

scholarly journals Erratum to: Antibacterial Effects of Amino Acids-grafted Water-soluble Chitosan against Drug-resistant Bacteria

2021 ◽  
Vol 26 (3) ◽  
pp. 501-501
Author(s):  
Jun-Ho Kim ◽  
Nam-Hong Kim ◽  
Eun-Ji Kim ◽  
Ji Ho Kim ◽  
Min-Young Lee ◽  
...  
Keyword(s):  
Amino Acids ◽  
Water Soluble ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Antibacterial Effects ◽  
Drug Resistant Bacteria

scholarly journals Application of Bio-Friendly Formulations of Chitinase-Producing Streptomyces cellulosae Actino 48 for Controlling Peanut Soil-Borne Diseases Caused by Sclerotium rolfsii

2021 ◽  
Vol 7 (3) ◽  
pp. 167
Author(s):  
Gaber Abo-Zaid ◽  
Ahmed Abdelkhalek ◽  
Saleh Matar ◽  
Mai Darwish ◽  
Muhammad Abdel-Gayed
Keyword(s):  
Open Field ◽  
Biocontrol Agent ◽  
Sclerotium Rolfsii ◽  
Dry Weight ◽  
Culture Broth ◽  
Field Conditions ◽  
Damping Off ◽  
Mycelium Growth ◽  
Particle Size Analyzer ◽  
Cell Pellet

Of ten actinobacterial isolates, Streptomyces cellulosae Actino 48 exhibited the strongest suppression of Sclerotium rolfsii mycelium growth and the highest chitinase enzyme production (49.2 U L−1 min−1). The interaction between Actino 48 and S. rolfsii was studied by scanning electron microscope (SEM), which revealed many abnormalities, malformations, and injuries of the hypha, with large loss of S. rolfsii mycelia density and mass. Three talc-based formulations with culture broth, cell-free supernatant, and cell pellet suspension of chitinase-producing Actino 48 were characterized using SEM, Fourier transform infrared spectroscopy (FTIR), and a particle size analyzer. All formulations were evaluated as biocontrol agents for reducing damping-off, root rot, and pods rot diseases of peanut caused by S. rolfsii under greenhouse and open-field conditions. The talc-based culture broth formulation was the most effective soil treatment, which decreased the percentage of peanut diseases under greenhouse and open-field conditions during two successive seasons. The culture broth formulation showed the highest increase in the dry weight of peanut shoots, root systems, and yielded pods. The transcriptional levels of three defense-related genes (PR-1, PR-3, and POD) were elevated in the culture broth formulation treatment compared with other formulations. Subsequently, the bio-friendly talc-based culture broth formulation of chitinase-producing Actino 48 could potentially be used as a biocontrol agent for controlling peanut soil-borne diseases caused by S. rolfsii.

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