Surfactant pollution,an emerging threat to ecosystem: Approaches for effective bacterial degradation

The use of surfactants in households and industries is inevitable and so is their discharge into the environment, especially into the water bodies as effluents. Being surface-active agents, their utilization is mostly seen in soaps, detergents, personal care products, emulsifiers, wetting agents, etc. Anionic surfactants are the most used class. These surfactants are responsible for the foam and froth in the water bodies and cause potential adverse effects to both biotic and abiotic components of the ecosystem. Surfactants are capable of penetrating the cell membrane and thus cause toxicity to living organisms. Accumulation of these compounds has been known to cause significant gill damage and loss of sight in fish. Alteration of physiological and biochemical parameters of water decreases the amount of dissolved oxygen and thus affecting the entire ecosystem. Microbes utilizing surfactants as substrates for energy form the basis of the biodegradation of these compounds. The main organisms for surfactant biodegradation, both in sewage and natural waters, are bacteria. Several Pseudomonas and Bacillus spp. have shown efficient degradation of anionic surfactants namely: sodium dodecyl sulphate (SDS), linear alkylbenzene sulphonate (LAS), sodium dodecylbenzenesulphonate (SDBS). Also, several microbial consortia constituting Alcaligenes spp., Citrobacter spp., etc. have shown efficacy in the degradation of surfactants. The biodegradation efficiency studies of these microbes/microbial consortia would be of immense help in formulating better solutions for the bioremediation of surfactants and help to reduce their potential environmental hazards.     

Trichoderma viride—Mediated Modulation of Oxidative Stress Network in Potato Challenged with Alternaria solani

Potato is a staple food crop cultivated globally. Heavy losses to potato production are reported annually due to soil borne phytopathogens. Trichoderma viride is a potential biocontrol agent that improves host defense. In the present study, potato tubers bio-primed with T. viride were studied for its effect on growth promotion and modulation of antioxidant system as well as defense-related enzymes in potato plants when challenged with Alternaria solani. Potato tubers treated with T. viride and after 45 days of sowing, plants were challenged with pathogen. Significant improvement in various growth parameters was recorded in bio-primed plants. While, in pathogen-challenged plants, an enhanced intracellular concentration of H₂O₂ and O₂^? was observed. Interestingly, T. viride when applied with pathogen, significantly improved the redox homeostasis by modulating the antioxidant enzyme activities. The significant induction of defense enzymes and free phenolic content suggested that T. viride-treated plants provide enhanced protection from oxidative stress induced during A. solani challenge via. elevated accumulation of antioxidant enzymes, polyphenolic compounds, and defense-related enzymes.

     

Accumulation,translocation, and toxicity of arsenic in barley grown in contaminated soil

Plant and Soil - Saprophytic fungi are important agents of soil mineralization and carbon cycling. Their community structure is known to be affected by soil conditions such as organic matter and...