scholarly journals Role of Bacillus cereus in Improving the Growth and Phytoextractability of Brassica nigra (L.) K. Koch in Chromium Contaminated Soil

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1569
Author(s):  
Nosheen Akhtar ◽  
Noshin Ilyas ◽  
Humaira Yasmin ◽  
R. Z. Sayyed ◽  
Zuhair Hasnain ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Seed Germination ◽  
Plant Growth ◽  
Bacillus Cereus ◽  
Contaminated Soil ◽  
Metal Tolerance ◽  
Heavy Metal Tolerance ◽  
Bacterial Strains ◽  
Bacterial Inoculation ◽  
Phytoextraction Potential

Plant growth-promoting rhizobacteria (PGPR) mediate heavy metal tolerance and improve phytoextraction potential in plants. The present research was conducted to find the potential of bacterial strains in improving the growth and phytoextraction abilities of Brassica nigra (L.) K. Koch. in chromium contaminated soil. In this study, a total of 15 bacterial strains were isolated from heavy metal polluted soil and were screened for their heavy metal tolerance and plant growth promotion potential. The most efficient strain was identified by 16S rRNA gene sequencing and was identified as Bacillus cereus. The isolate also showed the potential to solubilize phosphate and synthesize siderophore, phytohormones (indole acetic acid, cytokinin, and abscisic acid), and osmolyte (proline and sugar) in chromium (Cr+3) supplemented medium. The results of the present study showed that chromium stress has negative effects on seed germination and plant growth in B. nigra while inoculation of B. cereus improved plant growth and reduced chromium toxicity. The increase in seed germination percentage, shoot length, and root length was 28.07%, 35.86%, 19.11% while the fresh and dry biomass of the plant increased by 48.00% and 62.16%, respectively, as compared to the uninoculated/control plants. The photosynthetic pigments were also improved by bacterial inoculation as compared to untreated stress-exposed plants, i.e., increase in chlorophyll a, chlorophyll b, chlorophyll a + b, and carotenoid was d 25.94%, 10.65%, 20.35%, and 44.30%, respectively. Bacterial inoculation also resulted in osmotic adjustment (proline 8.76% and sugar 28.71%) and maintained the membrane stability (51.39%) which was also indicated by reduced malondialdehyde content (59.53% decrease). The antioxidant enzyme activities were also improved to 35.90% (superoxide dismutase), 59.61% (peroxide), and 33.33% (catalase) in inoculated stress-exposed plants as compared to the control plants. B. cereus inoculation also improved the uptake, bioaccumulation, and translocation of Cr in the plant. Data showed that B. cereus also increased Cr content in the root (2.71-fold) and shoot (4.01-fold), its bioaccumulation (2.71-fold in root and 4.03-fold in the shoot) and translocation (40%) was also high in B. nigra. The data revealed that B. cereus is a multifarious PGPR that efficiently tolerates heavy metal ions (Cr+3) and it can be used to enhance the growth and phytoextraction potential of B. nigra in heavy metal contaminated soil.

scholarly journals Bacterial Tolerance to Heavy Metal Contents Present in Contaminated and Uncontaminated Soils

2016 ◽  
Vol 29 (2) ◽  
pp. 56-61
Author(s):  
FZ Tanu ◽  
S Hoque
Keyword(s):  
Heavy Metal ◽  
Bacillus Subtilis ◽  
Bacillus Cereus ◽  
Metal Tolerance ◽  
Micrococcus Luteus ◽  
Heavy Metal Tolerance ◽  
Subtilis Strain ◽  
Rrna Gene ◽  
Bacterial Strains ◽  
Metal Tolerant Bacteria

Present study dealt with identification of some heavy metal tolerant bacteria from contaminated industrial soils of Dhaka Export Processing Zone (DEPZ) at Savar, tannery area at Hazaribagh and uncontaminated agricultural soils of Dhamrai and Kushtia in Bangladesh and determination of their tolerance to chromium (Cr6+) and cadmium (Cd2+). A total of 15 isolates from four soil samples were provisionally identified as different species of Bacillus, Micrococcus and Pseudomonas based on their morphological, physiological, and biochemical characteristics. Among them eight colonies were separated based on high level of heavy metal tolerance and identified at molecular level by PCR technique and 16S rRNA gene sequencing as Micrococcus luteus strain P43 (E4), Bacillus pocheonensis strain TR2-6 (T6), Bacillus megaterium strain H2 (T8), Bacillus amyloliquefaciens strain SCSAAB0007 (D10), Bacillus cereus isolate PGBw4 (D11), Bacillus cereus strain ES-4a1 (K12), Bacillus subtilis strain 1320, (K13), and Bacillus subtilis strain DP14 (K14). The Maximum Tolerable Concentration (MTC) of bacterial strains to Cr6+ and Cd2+ ranged between 250-1250 ?g/ml and 30-150 ?g/ml, respectively in nutrient broth medium. From the metal tolerance investigation Bacillus was found as the most heavy metal tolerant to both Cr6+ and Cd2+ among the three genera. The identified heavy metal tolerant bacteria could be useful for the bioremediation of heavy metal contaminated environment.Bangladesh J Microbiol, Volume 29, Number 2, Dec 2012, pp 56-61

Isolation and characterization of heavy metal tolerant Gram-positive bacteria with bioremedial properties from municipal waste rich soil of Kestopur canal (Kolkata), West Bengal, India

Biologia ◽  
2012 ◽  
Vol 67 (5) ◽  
Author(s):  
Kamala Gupta ◽  
Chitrita Chatterjee ◽  
Bhaskar Gupta
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Tolerance ◽  
Environmental Pollutants ◽  
Heavy Metal Tolerance ◽  
Antibiotic Sensitivity ◽  
Bacterial Strains ◽  
High Concentration ◽  
Isolation And Characterization ◽  
Bacillus Weihenstephanensis

AbstractThe present study was conducted to determine the culturable bacterial profile from Kestopur canal (Kolkata, India) and analyze their heavy metal tolerance. In addition to daily sewage including solid and soluble wastes, a considerable load of toxic metals are released into this water body from industries, tanneries and agriculture, household as well as health sectors. Screening out microbes from such an environment was done keeping in mind their multifunctional application especially for bioremediation. Heavy metals are major environmental pollutants when present in high concentration in soil and show potential toxic effects on growth and development in plants and animals. Some edible herbs growing in the canal vicinity, and consumed by people, were found to harbour these heavy metals at sub-toxic levels. The bioconcentration factor of these plants being <1 indicates that they probably only absorb but not accumulate heavy metals. All the thirteen Grampositive bacteria isolated from these plants rhizosphere were found to tolerate high concentration of heavy metals like Co, Ni, Pb, Cr, Fe. Phylogenetic analysis of their 16S rDNA genes revealed that they belonged to one main taxonomic group — the Firmicutes. Seven of them were found to be novel with 92–95% sequence homology with known bacterial strains. Further microbiological analyses show that the alkaliphilic Bacillus weihenstephanensis strain IA1 and Exiguobacterium aestuarii strain CE1, with selective antibiotic sensitivity along with high Ni2+ and Cr6+ removal capabilities, respectively, can be prospective candidates for bioremediation.

scholarly journals Heavy metal tolerance and multiple drug resistance of heterotrophic bacterial isolates from metal contaminated soil

2012 ◽  
Vol 30 (1) ◽  
pp. 58 ◽  
Author(s):  
M. P. Krishna ◽  
Rinoy Varghese ◽  
A. A. Mohamed Hatha
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Nalidixic Acid ◽  
Contaminated Soil ◽  
Metal Tolerance ◽  
Multiple Drug Resistance ◽  
Heavy Metal Tolerance ◽  
Multiple Drug ◽  
Bacterial Isolates ◽  
Cadmium Resistance

The development of multiple metal/antibiotic resistances among the bacterial population causes a potential risk to human health. Metal contamination in natural environments could have an important role in the maintenance and proliferation of antibiotic resistance. In the present study, a total of 46 heterotrophic bacterial isolates from metal contaminated soil were tested for their sensitivity to 10 widely used antibiotics such as ampicillin, erythromycin, gentamicin, nalidixic acid, penicillin, amikacin, lincomycin, novobiocin, vancomycin and tetracycline. Metal tolerant ability of these isolates against five heavy metals such as lead, zinc, copper, cadmium and nickel were also determined. The results revealed that most of the bacterial isolates were resistant to one or more heavy metals/ antibiotics against which they are tested. Tolerance to heavy metal showed the following pattern; lead > zinc > nickel > copper > cadmium. Resistance to ampicillin (73.91%), penicillin (60.8%), lincomycin (43.47%) and nalidixic acid (21.73%) were encountered frequently. None of the isolates were resistant to amikacin, while resistance to gentamicin and tetracycline were low (2.17%). Out of the 46 bacterial isolates, 36 isolates showed multiple metal and antibiotic resistances. Isolate LOC 10 showed significantly high tolerance (100-300�g/mL) to all the metals and was resistant to 6 antibiotics.

scholarly journals Heavy Metals and Seed Germination in Medicinal and Aromatic Plants

HortScience ◽  
1998 ◽  
Vol 33 (2) ◽  
pp. 206d-206 ◽  
Author(s):  
Ekaterina A. Jeliazkova ◽  
Valtcho D. Jeliazkov ◽  
Lyle E. Craker ◽  
Baoshan Xing
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Seed Germination ◽  
Essential Oils ◽  
Plant Species ◽  
Metal Tolerance ◽  
Heavy Metal Tolerance ◽  
Aromatic Plants ◽  
Medicinal And Aromatic Plants ◽  
Foeniculum Vulgare

Phytoremediation has been suggested as a solution to heavy metal—polluted soils, but the choices of suitable plant species for phytoremediation have been limited. Medicinal and aromatic plants appear to be excellent selections for these plantings, since these plants are grown for economically valuable secondary products (essential oils), not for food or feed. Preliminary research indicates that heavy metals are not accumulated in essential oils, permitting the oil to be used commercially. Productivity of some, but not all aromatic plants was reduced, however, by the heavy metals. The objective of our experiment was to distinguish the mechanism of heavy metal tolerance of plants using germinating seeds of medicinal and aromatic plant species. Seeds from medicinal and aromatic plants were germinated in solutions with selected levels of heavy metals (cadmium at 6 and 10 (μg·L-1; copper at 60 and 150 μg·L-1; lead at 100 and 500 μg·L-1; zinc at 400 and 800 μg·L-1) and in distilled water. Tests on Anethum graveolens L., Carum carvi L., Cuminum cyminum L., Foeniculum vulgare Mill., Pimpinella anisum L., Ocimum basilicum L., and the hyperaccumulator species Brassica juncea L. and Alyssum bertolonii established that different plant species reacted in different ways to the heavy metals. For example, cadmium did not decrease seed germination of Alyssum, O. basilicum, and B. juncea compared with germination in water but did decrease germination of C. cyminum. Lead did not affect germination of A. bertolonii and B. juncea as compared with water but did negatively affect germination of P. anisum, F. vulgare, and C. cyminum. Except for B. juncea, F. vulgare, and C. cyminum, copper had a negative effect on germination. Zinc decreased germination in all tested species except B. juncea.

scholarly journals Characterization of bacterial communities associated with the exotic and heavy metal tolerant wetland plant Spartina alterniflora

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ying Yang ◽  
Jian Ding ◽  
Yulang Chi ◽  
Jianjun Yuan
Keyword(s):  
Heavy Metal ◽  
Spartina Alterniflora ◽  
Metal Tolerance ◽  
Bacterial Species ◽  
Heavy Metal Tolerance ◽  
Acc Deaminase ◽  
Heavy Metal Stress ◽  
Bacterial Strains ◽  
Invasion Mechanisms ◽  
Biochemical Assays

Abstract Heavy metal pollution has seriously disrupted eco-balance and transformed estuaries into sewage depots. Quanzhou bay is a typical heavy metal-contaminated estuary, in which Spartina alterniflora has widely invaded. Plant-associated microbial communities are crucial for biogeochemical cycles, studies of which would be helpful to demonstrate the invasion mechanisms of plants. Meanwhile, they are indispensable to phytoremediation by enhancing the heavy metal tolerance of plants, facilitating heavy metal absorption rate and promoting growth of plants. In the present study, S. alterniflora-associated rhizo- and endobacterial communities from 3 experimental sites were investigated by 454-pyrosequencing. Heavy metal screening generated 16 culturable isolates, further biochemical assays suggested these clones possess various abilities such as phosphate solubilization, indole-3-acetic acid (IAA) production and 1-aminocyclopropane-1-carboxylate (ACC) deaminase production to accelerate heavy metal uptake and growth of the host. This study revealed the bacterial community structures and characterized the predominant resident bacterial strains of S. alterniflora-associated rhizo- and endobacteria under heavy metal stress, and isolated several bacterial species with potential ecological function.

Improving Heavy Metal Tolerance through Plant Growth Regulators and Osmoprotectants in Plants

2020 ◽  
pp. 69-98
Author(s):  
Farha Ashfaque ◽  
Samreena Farooq ◽  
Priyanka Chopra ◽  
Himanshu Chhillar ◽  
Khan M. Iqbal R.
Keyword(s):  
Heavy Metal ◽  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Metal Tolerance ◽  
Heavy Metal Tolerance

scholarly journals Isolation, Characterization and Evaluation of a High-Siderophore-Yielding Bacterium from Heavy Metal Contaminated Soil

2021 ◽  
Author(s):  
Ya-Jun Wang ◽  
Wei Huang ◽  
Ya-Qian Li ◽  
Fang-Bo Yu ◽  
Petri Penttinen
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Seed Germination ◽  
Plant Growth ◽  
Lolium Perenne ◽  
Contaminated Soil ◽  
Germination Rate ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Plant Growth Promoting Traits

Abstract Heavy metal resistant siderophore-producing bacteria (SPB) with plant growth promoting traits can assist in phytoremediation of heavy metal contaminated soil. We isolated siderophore producing bacteria from lead and zinc mine soil in Shangyu, Zhejiang, China. The isolate with highest siderophore production, strain SX9, was identified as Burkholderia sp. The strain SX9 produced catecholate type siderophore, with highest production at a pH range 6.0 to 8.0, a temperature range 20 to 30 °C and NaCl concentration below 2%. Siderophore production was highest without Fe3+ and became gradually lower with increasing Fe3+ concentration. Minimal inhibitory concentrations (MIC) of Pb2+, Zn2+, Cu2+ and Cd2+ were 4000, 22000, 5000 and 2000 μmol·L-1, respectively. The strain SX9 was sensitive to doxycycline hyclate and rifampicin. The strain had a strong metal solubilization ability: the contents of Cu2+, Zn2+ and Cd2+ in the supernatant were 47.4%, 133.0% and 35.4% higher, respectively, in the strain SX9 inoculated cultures than in the not inoculated controls. The siderophore produced by strain SX9 could combine with Fe3+, Zn2+ and Cd2+ with good effectiveness. The plant growth promoting traits of the strain included indole acetic acid (IAA) production, 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity and phosphate solubilization capability. Compared to uninoculated growth medium and SX9 culture supernatant, the germination rate of Lolium perenne seeds was higher when inoculated with the strain SX9 culture. In the experiment of seed germination, adding bacterial culture or supernatant could alleviate the toxicity of heavy metals to Lolium perenne seed germination. Under Cu2+ and Zn2+ stress, the strain SX9 promoted the germination rate. Taken together, the strain SX9 had properties beneficial in the microbial enhancement of phytoremediation of soil contaminated with heavy metals.

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