Bioremediation of Insecticides by White-Rot Fungi and Its Environmental Relevance

Environmental bioremediation of pharmaceutical residues: microbial processes and technological innovations: a review

The ubiquitous presence of pharmaceuticals and personal care products (PPCPs) in the environment has become a significant concern due to their persistence, bioaccumulation potential in biota, and diverse implications for human health and wildlife. This review provides an overview of the current state-of-the-art in environmental bioremediation techniques for reducing pharmaceutical residues, with a special emphasis on microbial physiological aspects. Numerous microorganisms, including algae, bacteria or fungi, can biodegrade various pharmaceutical compounds such as antibiotics, analgesics and beta-blockers. Some microorganisms are capable of transferring electrons within the cell, and this feature can be harnessed using Bio Electrochemical Systems (BES) to potentiate the degradation of pharmaceuticals present in wastewater. Moreover, researchers are evaluating the genetic modification of microbial strains to improve their degradation capacity and expand list of target compounds. This includes also discuss how environment changes, such as fluctuations in temperature or pH, may affect bioremediation efficiency. Furthermore, the presence of pharmaceuticals in the environment is emphasised as a major public health issue because it increases the chance for antibiotic-resistant bacteria emerging. This review combines existing information and outlines needed research areas for improving bioremediation technologies in the future.

How to deal with xenobiotic compounds through environment friendly approach?

Every year, a huge amount of lethal compounds, such as synthetic dyes, pesticides, pharmaceuticals, hydrocarbons, etc. are mass produced worldwide, which negatively affect soil, air, and water quality. At present, pesticides are used very frequently to meet the requirements of modernized agriculture. The Food and Agriculture Organization of the United Nations (FAO) estimates that food production will increase by 80% by 2050 to keep up with the growing population, consequently pesticides will continue to play a role in agriculture. However, improper handling of these highly persistent chemicals leads to pollution of the environment and accumulation in food chain. These effects necessitate the development of technologies to eliminate or degrade these pollutants. Degradation of these compounds by physical and chemical processes is expensive and usually results in secondary compounds with higher toxicity. The biological strategies proposed for the degradation of these compounds are both cost-effective and eco-friendly. Microbes play an imperative role in the degradation of xenobiotic compounds that have toxic effects on the environment. This review on the fate of xenobiotic compounds in the environment presents cutting-edge insights and novel contributions in different fields. Microbial community dynamics in water bodies, genetic modification for enhanced pesticide degradation and the use of fungi for pharmaceutical removal, white-rot fungi's versatile ligninolytic enzymes and biodegradation potential are highlighted. Here we emphasize the factors influencing bioremediation, such as microbial interactions and carbon catabolism repression, along with a nuanced view of challenges and limitations. Overall, this review provides a comprehensive perspective on the bioremediation strategies.

Biodegradation of decabromodiphenyl ethane (DBDPE) by white-rot fungus Pleurotus ostreatus: Characteristics, mechanisms, and toxicological response

Decabromodiphenyl ethane (DBDPE) can pose a potential toxic threat to human beings and the environment. P. ostreatus, as one of the typical white-rot fungi, can effectively degrade various refractory pollutants. The biodegradable characteristics of DBDPE by P. ostreatus, as well as the mechanisms, and toxicological response were investigated in this study. The removal rate reached 47.73% and 43.20%, respectively, for 5 and 20 mg/L DBDPE after 120-h degradation by P. ostreatus. As a coexisting substance, Pb could inhibit the biodegradation. It is found that both the intracellular enzyme (P450) and extracellular enzymes (manganese peroxidase (MnP), lignin peroxidase (LiP), and laccase (Lac)) played a very important role in the biodegradation of DBDPE, of which Lac dominated the degradation. The toxic response was monitored during the degradation. The activities of SOD and CAT were enhanced to eliminate excess ROS in P. ostreatus triggered by DBDPE. In addition, debromination, hydroxylation, and oxidation were inferred as the main degradation pathways preliminarily. The findings provide a theoretical basis for the application of microbial degradation of DBDPE contamination.

Engineering Analysis of Plant and Fungal Contributions to Bioretention Performance

While the use of bioretention for stormwater management is widespread, data about the impacts of plants and microorganisms on long-term treatment efficacy remain region-specific. To help address this knowledge gap for the Pacific Northwest region of the United States, we installed twelve under-drained bioretention mesocosms built to Washington State Department of Ecology stormwater management standards in an urban watershed in Seattle, WA that included a busy portion of Interstate 5. Six mesocosms were planted with Pacific ninebark (Physocarpus capitatus) and six were inoculated with the wine cap mushroom (Stropharia rugoso-annulata) resulting in four replicated factorial treatments. Because region-specific studies must be mindful of the prevailing regulatory framework, all mesocosms used the Washington State Department of Ecology design standard soil: a blend of 60% sand and 40% compost by volume, despite the known leaching problems with high compost volume fraction soils. Five water quality sampling events over 15 months of continuous stormwater loading were analyzed for dozens of water quality parameters. Multiple linear regression analyses of treatment differences over the 400-day loading period illustrate that incorporating fungi into the wood mulch slowed the release of total and ortho-phosphorus from the bioretention soil; however net export of phosphorus from this compost rich media continued through 400 days of loading for all treatments. Multivariate ordination methods illustrate that time and temperature dramatically affect performance of this media, but the impact of planting and fungal inoculation had marginal detectible effects on overall water quality during the study timeframe. These results demonstrate that future studies of this media blend must plan for at least one year of nutrient and metal leaching before the time-dependent heterogenous variance introduced by these exports will no longer pose an obstacle to analysis of other performance changing factors. The results highlight important physical and chemical considerations for this media blend, and the opportunity for continued research on the use of fungal inoculated mulch application as a new ecological engineering tool for reducing phosphorus leaching from soils.