Biodegradation of toxic organic compounds using a newly isolated Bacillus sp. CYR2

Reddy, M. Venkateswar; Yajima, Yoshiaki; Choi, DuBok; Chang, Young-Cheol

doi:10.1007/s12257-017-0117-0

Cited by 7 publications

(1 citation statement)

References 40 publications

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“…The highest degradation efficiency was achieved with an inoculum size of 1%. Similar results indicate the degradation of toxic and hazardous organic phenols by Bacillus CYR2 is strongly influenced by the inoculum level, with alkylphenols removed from the medium as the inoculum level increases from 2 to 4% (Reddy et al 2017 ), which is similar to the results of this study. In addition, the inoculum concentration in the system was increased by the combined colonies for better degradation, and the mixture can be used for the synergistic biodegradation of aromatic-aliphatic co-polyester plastics.…”

Section: Resultssupporting

confidence: 91%

Mechanisms of oxidative response during biodegradation of malathion by S. oneidensis MR-1

Pan,

Li,

Zhang

et al. 2024

Environ Sci Pollut Res

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Malathion, an extensively used organophosphorus pesticide, poses a high potential risk of toxicity to humans and the environment. Shewanella (S.) oneidensis MR-1 has been proposed as a strain with excellent bioremediation capabilities, capable of efficiently removing a wide range of hard-to-degrade pollutants. However, the physiological and biochemical response of S. oneidensis MR-1 to malathion is unknown. Therefore, this study aimed to examine how S. oneidensis MR-1 responds physiologically and biochemically to malathion while also investigating the biodegradation properties of the pesticide. The results showed that the 7-day degradation rates of S. oneidensis MR-1 were 84.1, 91.6, and 94.0% at malathion concentrations of 10, 20, and 30 mg/L, respectively. As the concentration of malathion increased, superoxide dismutase and catalase activities were inhibited, leading to a significant rise in malondialdehyde content. This outcome can be attributed to the excessive production of reactive oxygen species (ROS) triggered by malathion stress. In addition, ROS production stimulates the secretion of soluble polysaccharides, which alleviates oxidative stress caused by malathion. Malathion-induced oxidative damage further exacerbated the changes in the cellular properties of S. oneidensis MR-1. During the initial stages of degradation, the cell density and total intracellular protein increased significantly with increasing malathion exposure. This can be attributed to the remarkable resistance of S. oneidensis MR-1 to malathion. Based on scanning electron microscopy observations, continuous exposure to contaminants led to a reduction in biomass and protein content, resulting in reduced cell activity and ultimately leading to cell rupture. In addition, this was accompanied by a decrease in Na+/K+- ATPase and Ca2+/Mg2+-ATPase levels, suggesting that malathion-mediated oxidative stress interfered with energy metabolism in S. oneidensis MR-1. The findings of this study provide new insights into the environmental risks associated with organophosphorus pesticides, specifically malathion, and their potential for bioremediation. Graphical Abstract

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Section: Resultssupporting

confidence: 91%

Mechanisms of oxidative response during biodegradation of malathion by S. oneidensis MR-1

Pan,

Li,

Zhang

et al. 2024

Environ Sci Pollut Res

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Biodegradation of endocrine disrupting compounds from the wastewater by the immobilized indigenous bacteria

Rajaselvam,

Kadaikunnan,

Alharbi

et al. 2024

Environmental Quality Mgmt

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Abstract4‐tert‐octyl phenol is one of the important endrocrine‐disrupting compounds and is considered a major health hazard. A total of six isolates degraded 4‐tert‐octylphenol, and the strains Bacillus velezensis LG16 and Pseudomonas aeruginosa AC20 exhibited maximum 4‐tert‐octylphenol degradation. Co‐culture of these two strains improved 4‐tert‐octylphenol degradation from the wastewater. One variable at a time approach showed that 40°C incubation temperature, pH 8.0, and an initial 4‐tert‐octylphenol (60 mg/L) influenced biodegradation. The bacterial strains were immobilized in sodium alginate beads, and improved biodegradation was achieved. The biocatalytic process mediated by the immobilized cells was optimized by a statistical approach (two‐level full factorial design and response surface methodology). In a two‐level factorial model, 4‐tert‐octylphenol degradation varied from 1.1% to 55.2%. The 4‐tert‐octylphenol degradation was maximum at pH 6, 0.01 mg/L 4‐tert‐octylphenol, and 10 mg/L glucose with 20 g beads/L. ANOVA revealed that the designed model was statistically significant (p = 0.0310). A central composite design was used to analyze the interactive effect of significant variables and to explore the optimum conditions for 4‐tert‐octylphenol degradation by immobilized bacteria. The maximum phenol degradation was observed (97.4%) at pH 7.0, 0.06 4‐tert‐octylphenol, and 13.75 g sodium alginate beads/L. ANOVA showed that the designed model was statistically significant (p = 0.0091). The designed CCD model, the correlation coefficient value, and the lack of fit value showed that the designed CCD model was significant. The immobilized bacterial cells could more effectively degrade 4‐tert‐octylphenol than free bacterial cells. The high degradation potential indicated its application in degrading 4‐tert‐octylphenol from wastewater under optimized conditions.

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Biodegradation of phenolic pollutants and bioaugmentation strategies: A review of current knowledge and future perspectives

Wang,

Zhang,

et al. 2024

Journal of Hazardous Materials

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Biodegradation of toxic organic compounds using a newly isolated Bacillus sp. CYR2

Cited by 7 publications

References 40 publications

Mechanisms of oxidative response during biodegradation of malathion by S. oneidensis MR-1

Mechanisms of oxidative response during biodegradation of malathion by S. oneidensis MR-1

Biodegradation of endocrine disrupting compounds from the wastewater by the immobilized indigenous bacteria

Biodegradation of phenolic pollutants and bioaugmentation strategies: A review of current knowledge and future perspectives

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