The remediation of sulfonamides from the environment by Pleurotus eryngii mycelium. Efficiency, products and mechanisms of mycodegradation

Application of fungal-based microbial fuel cells for biodegradation of pharmaceuticals: Comparative study of individual vs. mixed contaminant solutions

The present study focuses on the application of fungal-based microbial fuel cells (FMFC) for the degradation of organic pollutants including Acetaminophen (APAP), Para-aminophenol (PAP), Sulfanilamide (SFA), and finally Methylene Blue (MB). The objective is to investigate the patterns of degradation (both individually and as a mixture solution) of the four compounds in response to fungal metabolic processes, with an emphasis on evaluating the possibility of generating energy. Linear Sweep Voltammetry (LSV) has been used for electrochemical analysis of the targeted compounds on a Glassy Carbon Electrode (GCE). A dual chamber MFC has been applied wherein the cathodic compartment, the reduction reaction of oxygen was catalyzed by an elaborated biofilm of Trametes trogii, and the anodic chamber consists of a mixed solution of 200 mg L-1 APAP, PAP, MB, and SFA in 0.1 M PBS and an elaborated biofilm of Trichoderma harzianum. The obtained results showed that all the tested molecules were degraded over time by the Trichoderma harzianum. The biodegradation kinetics of all the tested molecules were found to be in the pseudo-first-order. The results of half-lives and the degradation rate reveal that APAP in its individual form degrades relatively slower (0.0213 h-1) and has a half-life of 33 h compared to its degradation in a mixed solution with a half-life of 20 h. SFA showed the longest half-life in the mixed condition (98 h) which is the opposite of its degradation as individual molecules (20 h) as the fastest molecule compared to other pollutants. The maximum power density of the developed MFC dropped from 0.65 mW m-2 to 0.32 mW m-2 after 45.5 h, showing that the decrease of the residual concentration of molecules in the anodic compartment leads to the decrease of the MFC performance.

Micropollutants (ciprofloxacin and norfloxacin) remediation from wastewater through laccase derived from spent mushroom waste: Fate, toxicity, and degradation

Fluoroquinolone antibiotics frequently found in environmental matrices (wastewater treatment plants, hospital wastewater, industrial wastewater and surface wastewater) causes potential threat to the environment. Enzymatic treatment for degradation of antibiotics from environmental matrices is a green and sustainable approach. Focusing on this, this study aimed to degrade two frequently found fluroquinolone emergent pollutants, ciprofloxacin and norfloxacin from wastewater. The trinuclear cluster of copper ions present in laccase has the ability to effectively remove organic micropollutants (OMPs). The uniqueness of this study is that it utilizes laccase enzyme extracted from spent mushroom waste (SMW) of P. florida for degradation of ciprofloxacin and norfloxacin and to achieve highest degradation efficiency various parameters were tweaked such as pH (3-6), temperature (30 °C and 50 °C), and ABTS (0.05, 0.6, and 1 mM) concentration. The results showed that the most effective degradation of ciprofloxacin (86.12-75.94%) and norfloxacin (83.27-65.94%) was achieved in 3 h at pH 4.5, temperature 30 °C, and 2,2'-azino-bis 3-ethylbenzothiazoline-6-sulfonic acid (ABTS), 0.05 mM concentration. Nevertheless, achieving degradation at 50 °C for both antibiotics, indicates thermostability nature of laccase (P. florida). Further, the fate of transformed products obtained from laccase mediated degradation was confirmed by liquid chromatography (LC-MS). Both the antibiotics undergo decarboxylation, depiperylyzation, dealkylation and defluorination as a result of laccase-mediated bond breakage. Anti-microbial activity of the biodegraded products was monitored by residual anti-bacterial toxicity test (E. coli and Staphylococcus aureus). The biodegraded products were found to be non-toxic and resulted in the growth of E. coli and Staphylococcus aureus, as determined by the agar-diffusion method. Moreover, the storage stability of laccase was determined for 28-day duration at varying pH (3-10) and temperature (4-50 °C). The maximum storage stability was obtained at pH 4.5 and temperature 30 °C. Therefore, utilizing SMW for the degradation of OMPs from wastewater not only benefits in degradation but also reuses SMW agro waste, shedding light on agro waste management. Thus, SMW is a one-pot solution for both OMPs biodegradation and circularity in the economy.

Microalgae enhanced co-metabolism of sulfamethoxazole using aquacultural feedstuff components: Co-metabolic pathways and enzymatic mechanisms

The application of antibiotics in freshwater aquaculture leads to increased contamination of aquatic environments. However, limited information is available on the co-metabolic biodegradation of antibiotics by microalgae in aquaculture. Feedstuffs provide multiple organic substrates for microalgae-mediated co-metabolism. Herein, we investigated the co-metabolism of sulfamethoxazole (SMX) by Chlorella pyrenoidosa when adding main components of feedstuff (glucose and lysine). Results showed that lysine had an approximately 1.5-fold stronger enhancement on microalgae-mediated co-metabolism of SMX than glucose, with the highest removal rate (68.77% ± 0.50%) observed in the 9-mM-Lys co-metabolic system. Furthermore, we incorporated reactive sites predicted by density functional theory calculations, 14 co-metabolites identified by mass spectrometry, and the roles of 18 significantly activated enzymes to reveal the catalytic reaction mechanisms underlying the microalgae-mediated co-metabolism of SMX. In lysine- and glucose-treated groups, five similar co-metabolic pathways were proposed, including bond breaking on the nucleophilic sulfur atom, ring cleavage and hydroxylation at multiple free radical reaction sites, together with acylation and glutamyl conjugation on electrophilic nitrogen atoms. Cytochrome P450, serine hydrolase, and peroxidase play crucial roles in catalyzing hydroxylation, bond breaking, and ring cleavage of SMX. These findings provide theoretical support for better utilization of microalgae-driven co-metabolism to reduce sulfonamide antibiotic residues in aquaculture.

A Review about the Mycoremediation of Soil Impacted by War-like Activities: Challenges and Gaps

(1) Background: The frequency and intensity of war-like activities (war, military training, and shooting ranges) worldwide cause soil pollution by metals, metalloids, explosives, radionuclides, and herbicides. Despite this environmentally worrying scenario, soil decontamination in former war zones almost always involves incineration. Nevertheless, this practice is expensive, and its efficiency is suitable only for organic pollutants. Therefore, treating soils polluted by wars requires efficient and economically viable alternatives. In this sense, this manuscript reviews the status and knowledge gaps of mycoremediation. (2) Methods: The literature review consisted of searches on ScienceDirect and Web of Science for articles (1980 to 2023) on the mycoremediation of soils containing pollutants derived from war-like activities. (3) Results: This review highlighted that mycoremediation has many successful applications for removing all pollutants of war-like activities. However, the mycoremediation of soils in former war zones and those impacted by military training and shooting ranges is still very incipient, with most applications emphasizing explosives. (4) Conclusion: The mycoremediation of soils from conflict zones is an entirely open field of research, and the main challenge is to optimize experimental conditions on a field scale.

Antimicrobial resistance, Extended-Spectrum β-Lactamase production and virulence genes in Salmonella enterica and Escherichia coli isolates from estuarine environment

The impact of antimicrobial resistance (AMR) on global public health has been widely documented. AMR in the environment poses a serious threat to both human and animal health but is frequently overlooked. This study aimed to characterize the association between phenotype and genotype of AMR, virulence genes and Extended-Spectrum β-Lactamase (ESBL) production from estuarine environment. The Salmonella (n = 126) and E. coli (n = 409) were isolated from oysters and estuarine water in Thailand. The isolates of Salmonella (96.9%) and E. coli (91.4%) showed resistance to at least one antimicrobial agent. Multidrug resistance (MDR) was 40.1% of Salmonella and 23.0% of E. coli. Resistance to sulfamethoxazole was most common in Salmonella (95.2%) and E. coli (77.8%). The common resistance genes found in Salmonella were sul3 (14.3%), followed by blaTEM (11.9%), and cmlA (11.9%), while most E. coli were blaTEM (31.5%) and tetA (25.4%). The ESBL production was detected in Salmonella (1.6%, n = 2) of which one isolate was positive to blaTEM-1. Eight E. coli isolates (2.0%) were ESBL producers, of which three isolates carried blaCTX-M-55 and one isolate was blaTEM-1. Predominant virulence genes identified in Salmonella were invA (77.0%), stn (77.0%), and fimA (69.0%), while those in E. coli isolates were stx1 (17.8%), lt (11.7%), and stx2 (1.2%). Logistic regression models showed the statistical association between resistance phenotype, virulence genes and ESBL production (p < 0.05). The findings highlighted that estuarine environment were potential hotspots of resistance. One Health should be implemented to prevent AMR bacteria spreading.

Edible Pleurotus eryngii Papery Food Prepared by Papermaking Process

The objective of the current study was to evaluate the feasibility of papery food with Pleurotus eryngii (P. eryngii) as a raw material using the papermaking process. The physical, chemical, structural, and thermal degradation properties were studied as well as the sensory evaluation of the papery food from P. eryngii mycelia (PMP), stems (PSP), caps (PCP), and whole fruiting bodies (PEP). The results indicated that the colors from PSP, PCP, and PEP were clearly different from PMP. Thicker PSP and PMP had a smoother surface and better crispness compared to PCP. Moreover, PSP had better moisture resistance and thermal decomposition performance compared to the other groups. Nutritional composition and Fourier-transform infrared spectroscopy suggested abundant polysaccharide and protein content in all of the papery food. Finally, sensory evaluation showed that the formability, mouth feel, and overall palatability of PSP and PMP were more popular among consumers. Overall, this study provides a novel method for the preparation of papery food and provides a potential new mechanism for the further development and utilization of the fruiting bodies and mycelium of P. eryngii.

Synthetic organic antibiotics residues as emerging contaminants waste-to-resources processing for a circular economy in China: Challenges and perspective

Synthetic antibiotics have been known for years to combat bacterial antibiotics. But their overuse and resistance have become a concern recently. The antibiotics reach the environment, including soil from the manufacturing process and undigested excretion by cattle and humans. It leads to overburden and contamination of the environment. These organic antibiotics remain in the environment for a very long period. During this period, antibiotics come in contact with various flora and fauna. The ill manufacturing practices and inadequate wastewater treatment cause a severe problem to the water bodies. After pretreatment from pharmaceutical industries, the effluents are released to the water bodies such as rivers. Even after pretreatment, effluents contain a significant number of antibiotic residues, which affect the living organisms living in the water bodies. Ultimately, river contaminated water reaches the ocean, spreading the contamination to a vast environment. This review paper discusses the impact of synthetic organic contamination on the environment and its hazardous effect on health. In addition, it analyzes and suggests the biotechnological strategies to tackle organic antibiotic residue proliferation. Moreover, the degradation of organic antibiotic residues by biocatalyst and biochar is analyzed. The circular economy approach for waste-to-resource technology for organic antibiotic residue in China is analyzed for a sustainable solution. Overall, the significant challenges related to synthetic antibiotic residues and future aspects are analyzed in this review paper.

Spent waste from edible mushrooms offers innovative strategies for the remediation of persistent organic micropollutants: A review

Urgent and innovative strategies for removal of persistent organic micropollutants (OMPs) in soil, groundwater, and surface water are the need of the hour. OMPs detected in contaminated soils and effluents from wastewater treatment plants (WWTPs) are categorized as environmentally persistent pharmaceutical pollutants (EPPPs), and endocrine disrupting chemicals (EDCs), their admixture could cause serious ecological issues to the non-target species. As complete eradication of OMPs is not possible with the extant conventional WWTPs technology, the inordinate and reckless application of OMPs negatively impacts environmental regenerative and resilience capacity. Therefore, the cardinal focus of this review is the bioremediation of persistent OMPs through efficient application of an agro-waste, i.e. spent mushroom waste (SMW). This innovative, green, long-term strategy embedded in the circular economy, based on state of the art information is comprehensively assessed in this paper. SMW accrues ligninolytic enzymes such as laccase and peroxidase, with efficient mechanism to facilitate biodegradation of recalcitrant organic pollutants. It is vital in this context that future research should address immobilization of such enzymes to overcome quantitative and qualitative issues obstructing their widespread use in biodegradation. Therefore, dual benefit is gained from cultivating critical cash crops like mushrooms to meet the escalating demand for food resources and to aid in biodegradation. Hence, mushroom cultivation has positive environmental, social, and economic implications in developing countries like India.

Bimetallic modified halloysite particle electrode enhanced electrocatalytic oxidation for the degradation of sulfanilamide

The treatment of antibiotics wastewater by electrocatalytic oxidation has attracted much attention. In the paper, a novel halloysite bimetallic (HLS-Cu-Mn) particle electrode material was prepared and a bench-scale electrocatalytic reaction tank was designed. A three-dimensional electrocatalytic oxidation reactor composed of HLS-Cu-Mn and a bench-scale electrocatalytic reaction tank was used to degrade Sulfanilamide (SA) wastewater. Characterization of the synthesized material was conducted with Scanning electron microscopy (SEM), X-ray polycrystalline powder diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller (BET). The electron spin resonance spectroscopy test results confirmed that HLS-Cu-Mn produced a large number of •OH. The electrochemical workstation confirmed that HLS-Cu-Mn had strong electrocatalytic activity and repolarization ability. Under the optimum preparation conditions and degradation process parameters, the removal efficiency of SA and TOC was 99.84% and 88.95% respectively. The method also has good degradation efficiency for aniline, phenol, herbicides, antibiotics, and dyeing wastewater. It was found that 4 main intermediates appeared in the degradation process by Ultra-high performance liquid chromatography/triple tandem quadrupole mass spectrometry (LC-MS). In sum, it was believed that this work provides a new vision and idea for water treatment.

Green Biotechnology of Oyster Mushroom (Pleurotus ostreatus L.): A Sustainable Strategy for Myco-Remediation and Bio-Fermentation

The field of biotechnology presents us with a great chance to use many organisms, such as mushrooms, to find suitable solutions for issues that include the accumulation of agro-wastes in the environment. The green biotechnology of mushrooms (Pleurotus ostreatus L.) includes the myco-remediation of polluted soil and water as well as bio-fermentation. The circular economy approach could be effectively achieved by using oyster mushrooms (Pleurotus ostreatus L.), of which the substrate of their cultivation is considered as a vital source for producing biofertilizers, animal feeds, bioenergy, and bio-remediators. Spent mushroom substrate is also considered a crucial source for many applications, including the production of enzymes (e.g., manganese peroxidase, laccase, and lignin peroxidase) and bioethanol. The sustainable management of agro-industrial wastes (e.g., plant-based foods, animal-based foods, and non-food industries) could reduce, reuse and recycle using oyster mushrooms. This review aims to focus on the biotechnological applications of the oyster mushroom (P. ostreatus L.) concerning the field of the myco-remediation of pollutants and the bio-fermentation of agro-industrial wastes as a sustainable approach to environmental protection. This study can open new windows onto the green synthesis of metal-nanoparticles, such as nano-silver, nano-TiO2 and nano-ZnO. More investigations are needed concerning the new biotechnological approaches.

Antibiotic residues in environment: antimicrobial resistance development, ecological risks, and bioremediation

The overuse of antibiotics and their disposal without processing are leading the environment and its inhabitants towards a serious health emergency. There is abundance of diverse antibiotic resistance genes and bacteria in environment, which demands immediate attention for the effective removal of antibiotics. There are physical and chemical methods for removal, but the generation of toxic byproducts has directed the efforts towards bioremediation for eco-friendly and sustainable elimination of antibiotics from the environment. Various effective and reliable bioremediation approaches have been used, but still antibiotic residues pose a major global threat. Recent developments in molecular and synthetic biology might offer better solution for engineering of microbe-metabolite biodevices and development of novel strains endowed with desirable properties. This review summarizes the impact of antibiotics on environment, mechanisms of resistance development, and different bioremediation approaches.