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Biodegradation of diuron by endophytic Bacillus licheniformis strain SDS12 and its application in reducing diuron toxicity for green algae
2019
Singh, Anil Kumar | Singla, Poonam
The endophytic bacteria live in close nuptial relationship with the host plant. The stress experienced by the plant is expected to be transferred to the endophytes. Thus, plants thriving at polluted sites are likely to harbor pollutant-degrading endophytes. The present study reports the isolation of phenylurea herbicides assimilating Bacillus sps. from Parthenium weed growing at diuron-contaminated site. The isolated endophytes exhibited plant growth–promoting (PGP) activities. Among five isolated diuron-degrading endophytes, the most efficient isolate Bacillus licheniformis strain SDS12 degraded 85.60 ± 1.36% of 50 ppm diuron to benign form via formation of degradation intermediate 3, 4-dichloroaniline (3,4-DCA). Cell-free supernatant (CFS) obtained after diuron degradation by strain SDS12 supported algal growth comparable with the pond water. The chlorophyll content and photosynthetic efficiency of green algae decreased significantly in the presence of diuron-contaminated water; however, no such change was observed in CFS of strain SDS12, thus, suggesting that strain SDS12 can be applied in aquatic bodies for degrading diuron and reducing diuron toxicity for primary producers. Further, the use of PGP and diuron-degrading bacteria in agriculture fields will not only help in remediating the soil but also support plant growth.
Afficher plus [+] Moins [-]Parthenium hysterophorus L.: Harmful and Beneficial Aspects - A Review
2015
Bhateria Rachna | . Renu | . Snehlata
Invasive plant species have the potential to damage crops, industries, environment and public health, hence scientists, academicians, leaders of industry and land managers are realizing that invasive species are serious environmental threats for the 21st century. Parthenium weed is an annual herb in the family Asteraceae which is native to northern Mexico and southern USA. It is spreading across the length and breadth of our country. It gets easily established in almost all the places such as wasteland, roadsides, forests, railway tracks, crop fields, etc. Its high germination ability throughout the year, an enormous seed bank, rapid spread, colonization and extreme adaptability in a wide range of habitats is responsible for its wide spread occurrence. Parthenium hysterophorus L. was reported to be one of the seven most dangerous weeds of the world. It has achieved a major weed status in India and Australia within a relatively short period due to its fast multiplication, rapid growth and its ability to compete with other native flora. There are many ways like mechanical, chemical, cultural and biological to control it, but it cannot be controlled by using a single approach. Integrated approach should be the better way to manage this noxious weed. The aim of this review is to provide general information about the physiology, distribution, ill effects and management of Parthenium.
Afficher plus [+] Moins [-]Phytoextraction of heavy metals by potential native plants and their microscopic observation of root growing on stabilised distillery sludge as a prospective tool for in situ phytoremediation of industrial waste
2017
Ram Chandra, | Winīta Kumāra,
The safe disposal of post-methanated distillery sludge (PMDS) in the environment is challenging due to high concentrations of heavy metals along with other complex organic pollutants. The study has revealed that PMDS contained high amounts of Fe (2403), Zn (210), Mn (126), Cu (73.62), Cr (21.825), Pb (16.33) and Ni (13.425 mg kg⁻¹) along with melanoidins and other co-pollutants. The phytoextraction pattern in 15 potential native plants growing on sludge showed that the Blumea lacera, Parthenium hysterophorous, Setaria viridis, Chenopodium album, Cannabis sativa, Basella alba, Tricosanthes dioica, Amaranthus spinosus L., Achyranthes sp., Dhatura stramonium, Sacchrum munja and Croton bonplandianum were noted as root accumulator for Fe, Zn and Mn, while S. munja, P. hysterophorous, C. sativa, C. album, T. dioica, D. stramonium, B. lacera, B. alba, Kalanchoe pinnata and Achyranthes sp. were found as shoot accumulator for Fe. In addition, A. spinosus L. was found as shoot accumulator for Zn and Mn. Similarly, all plants found as leaf accumulator for Fe, Zn and Mn except A. spinosus L. and Ricinus communis. Further, the BCF of all tested plants were noted <1, while the TF showed >1. This revealed that metal bioavailability to plant is poor due to strong complexation of heavy metals with organic pollutants. This gives a strong evidence of hyperaccumulation for the tested metals from complex distillery waste. Furthermore, the TEM observations of root of P. hysterophorous, C. sativa, Solanum nigrum and R. communis showed formation of multi-nucleolus, multi-vacuoles and deposition of metal granules in cellular component of roots as a plant adaptation mechanism for phytoextraction of heavy metal-rich polluted site. Hence, these native plants may be used as a tool for in situ phytoremediation and eco-restoration of industrial waste-contaminated site.
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