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The Rhizospheric Soil of Sparganium erectum L. Plant: A new Source of Efficient Bacteria for Azo Dye Decolorization
2023
Nikkhah, Masoumeh | Pourbabaei, Ahmad Ali | Shariati, Shayan | Shakiba, Mina
The purpose of our study was to identify the native bacteria with the ability to degrade azo dyes from the rhizosphere of Sparganium erectum L., and Typha latifolia L. plants that were grown on a drain of a textile mill. Eight and one strain with decolorization ability of Cibacron Brilliant Red EB and Terasil Red 3BL-01 were isolated from the saline rhizosphere of Sparganium erectum L. and latifolia L. plant respectively. Results showed that the bacteria isolated from the rhizosphere of Sparganium erectum L. are more capable of decolorizing azo dyes. Based on the 16S rRNA sequencing, selected strains were identified as follows: Enterobacter ludwigii strain SNP3 (OL719291), Rhodococcus fascians strain SNP5 (OL759129), Pseudomonas aeruginosa strain SNP10 (OL759126), and Bacillus safensis strain SNP13 (OL759127). The results of azo dyes biodegradation tests revealed that strains SNP10, SNP3, and SNP5 were more capable of decolorizing 94-97%, 72.53-73.8, 72.53%, and 71.13-73.5% of Cibacron Brilliant Red EB at concentration 10-20 mg/L within 72 h, respectively. Besides, strain SNP13 was the fastest strain in decolorization of Cibacron Brilliant Red EB with 68% and 59% decolorization activity at 10 and 20 mg/L respectively (24 h). Only strains SNP3 and SNP13 could decolorize 83% and 77% of Terasil Red 3BL-01 (30 mg/L), respectively. For the first time, our research findings illustrated that indigenous rhizospheric bacterial strains isolated from Sparganium erectum L. plants have the potential to apply as an azo dye breakdown tool in textile effluent treatment or other ecosystems.
Afficher plus [+] Moins [-]Diversity and Degradative Potency of Extant Autochthonous Crude Oil-Metabolizing Species in a Chronically Polluted River
2023
Osadebe, Anwuli | Ogugbue, Chimezie | Okpokwasili, Gideon
Persistent pollution of surface waters by hydrocarbon compounds is one of the foremost threats to limited global freshwater resources. This study analyzed the abundance, diversity and degradative capacities of hydrocarbon-utilizing bacteria in chronically polluted Kono River in the Nigerian Niger Delta in order to establish the bacterial drivers of ecological regeneration of the river after an oil spill. The study further aimed to develop a specialized bacterial consortium for application in bioremediation interventions. Bacillus, Pseudomonas and Enterobacter spp. were predominant out of the 82 isolates obtained. Klebsiella pneumoniae and two species of Enterobacter cloacae were identified as the most efficient hydrocarbon utilizers. The isolates were also confirmed as biosurfactant producers and possessed the alkB1 and nahAc genes for degradation of aliphatics and aromatics. E. cloacae-K11, K. pneumoniae-K05, E. cloacae-K12 and their consortium were able to degrade the total petroleum hydrocarbons and polycyclic aromatic hydrocarbons in batch systems by 59.37% – 96.06% and 68.40% – 92.46% respectively. K. pneumoniae-K05 showed the greatest petroleum degradation capacity of the three isolates but hydrocarbon degradation was most efficient with the bacterial consortium. The results obtained showed no significant differences at p≤0.05 between the degradation capacities of K. pneumoniae-K05 and the consortium for PAHs but a significant difference (p≤0.05) was seen with TPH degradation. A viable hydrocarbon degrading bacterial consortium was developed at the end of the study and it was concluded that the polluted river water displayed inherent potential for effective natural attenuation.
Afficher plus [+] Moins [-]Environmental Toxicity, Human Hazards and Bacterial Degradation of Polyethylene
2023
N. Yoezer, D. B. Gurung and K. Wangchuk
Plastics are the most rapidly growing materials in terms of production and consumption. The durability, inertness, light weight, flexibility, and low cost are the key characteristics that make plastic suitable for application in various fields, including the construction, automotive, electronics, and packaging industries. Due to widespread usage in daily life and many industrial processes and operations, more than 300 million tons of plastic waste are produced globally annually. Indiscriminate use of plastics such as polyethylene causes environmental pollution and impacts human health due to irreversible changes in the ecological cycle. Due to its low biodegradability, polyethylene accumulation has recently emerged as a momentous environmental concern. The conventional methods, such as recycling or disposing of polyethylene, are exorbitant, and incineration results in the emission of toxic chemical compounds. Therefore, the most recent research progressively focused on the biodegradation of polyethylene with the application of bacteria as novel approaches to counteract plastic waste. This review summarizes the type of polyethylene and the environmental issues. It also briefly discussed the genes and enzymes of bacteria involved in the degradation of polyethylene. In addition, it attempts to address factors influencing degradation and techniques used for monitoring degradation.
Afficher plus [+] Moins [-]Petroleum-Based Plastics Versus Bio-Based Plastics: A Review
2023
Shikha Kumari, Alka Rao, Manjeet Kaur and Geeta Dhania
Plastic needs have expanded along with population growth, industrialization, and urbanization. Plastic is unrivaled due to its useful properties and is used to prepare numerous important goods daily. This paper encloses the different kinds and applications of petroleum-based plastic and the drawbacks related to their use, i.e., its nonbiodegradability which leads to their stay in the environment for a very long time. Additionally, there are not enough effective disposal techniques for the large volume of plastic waste produced; thus, plastic garbage builds up in the environment and endangers it. Limiting the usage of plastic is necessary to protect the environment. This can be done with the help of bioplastic, which is an excellent substitute for plastic. The different kinds of bioplastic and their biodegradability in different mediums, viz., soil compost and aquatic systems, are addressed in this paper. Along this, the different areas of application of bioplastic have been explored. The present study also addresses the underlying mechanism of plastic polymerization and biodegradation and the current status of bioplastics in the global market.
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