The principal objective of the present research involved the achievement of high biodegradation degrees of perfluorooctanoic acid (PFOA) and perfluorosulfonic acid (PFOS) using pure individual bacterial strains. The use of such microorganisms can contribute to the improvement of the wastewater treatment process in sewage treatment plants through bioaugmentation or other bioremediation processes. Thus, in this study, we investigated the biodegradation potential of PFOA and PFOS. Bacterial strains tested in this study were from the Pseudomonas genus, namely: Pseudomonas aeruginosa and Pseudomonas putida, due to their known capacity to degrade xenobiotic compounds. The results indicated that Pseudomonas aeruginosa was able to transform 27.9% of PFOA and 47.3% of PFOS in 96 h, while Pseudomonas putida managed to transform 19.0% of PFOA and 46.9% of PFOS in the same time frame. During the biodegradation tests, PFHxA was recognized as the principal biotransformation product of PFOA in the presence of Pseudomonas aeruginosa, and PFPeA, PFPxA and PFHpA were recognized as the biotransformation products in the presence of Pseudomonas putida. For PFOS, only two biotransformation products (PHHxA and PFHpA) were observed as a consequence of biodegradation by both bacterial strains.

This study aimed to evaluate the behavior of Mentha piperita under Cd, Pb, Ni, and As soil contamination and their transfer from soil in plants as well as translocation in the roots/stems/leaves system compared with a control without metal addition. The mint seedlings were exposed for a three-month period using two metal mixtures in the same concentrations such as AsCd and AsCdNiPb (23.7 mg/kg As, 5 mg/kg Cd, 136 mg/kg Ni, and 95 mg/kg Pb). The results of metal concentration in plants showed that Cd, Ni, and Pb were accumulated in different parts of the plant, except for As. In plants organs, the order of metal accumulation was roots > stems > leaves. No significant impact on the growth, development, and chlorophyll content compared to the control was observed in the first month of exposure. After three months of exposure, phytotoxic effects occurred. Generally, the transfer coefficients and translocation factors values were less than 1, indicating that Mentha piperita immobilized the metals in root. The laboratory experiments highlighted that for a short period of time, Mentha piperita has the capacity to stabilize the metals at the root level and was a metal-tolerant plant when using a garden rich-substrate.

Background: Romania is one of the European countries reporting very high antimicrobial resistance (AMR) rates and consumption of antimicrobials. We aimed to characterize the AMR profiles and clonality of 304 multi-drug resistant (MDR) Acinetobacter baumannii (Ab) and Pseudomonas aeruginosa (Pa) strains isolated during two consecutive years (2018 and 2019) from hospital settings, hospital collecting sewage tanks and the receiving wastewater treatment plants (WWTPs) located in the main geographical regions of Romania. Methods: The strains were isolated on chromogenic media and identified by MALDI-TOF-MS. Antibiotic susceptibility testing and confirmation of ESBL- and CP- producing phenotypes and genotypes were performed. The genetic characterization also included horizontal gene transfer experiments, whole-genome sequencing (WGS), assembling, annotation and characterization. Results: Both clinical and aquatic isolates exhibited high MDR rates, especially the Ab strains isolated from nosocomial infections and hospital effluents. The phenotypic resistance profiles and MDR rates have largely varied by sampling point and geographic location. The highest MDR rates in the aquatic isolates were recorded in Galați WWTP, followed by Bucharest. The Ab strains harbored mostly bla_OXA-23, bla_OXA-24, bla_SHV, bla_TEM and bla_GES, while Pa strains bla_IMP, bla_VIM, bla_NDM, bla_VEB, bla_GES and bla_TEM, with high variations depending on the geographical zone and the sampling point. The WGS analysis revealed the presence of antibiotic resistance genes (ARGs) to other antibiotic classes, such as aminoglycosides, tetracyclines, sulphonamides, fosfomycin, phenicols, trimethoprim-sulfamethoxazole as well as class 1 integrons. The molecular analyses highlighted: (i) The presence of epidemic clones such as ST2 for Ab and ST233 and ST357 for Pa; (ii) The relatedness between clinical and hospital wastewater strains and (iii) The possible dissemination of clinical Ab belonging to ST2 (also proved in the conjugation assays for bla_OXA-23 or bla_OXA-72 genes), ST79 and ST492 and of Pa strains belonging to ST357, ST640 and ST621 in the wastewaters. Conclusion: Our study reveals the presence of CP-producing Ab and Pa in all sampling points and the clonal dissemination of clinical Ab ST2 strains in the wastewaters. The prevalent clones were correlated with the presence of class 1 integrons, suggesting that these isolates could be a significant reservoir of ARGs, being able to persist in the environment.

Ecotoxicological Behavior of some Cationic and Amphoteric Surfactants (Biodegradation, Toxicity and Risk Assessment) | InTechOpen, Published on: 2013-06-14. Authors: Stefania Gheorghe, Irina Lucaciu, Iuliana Paun, et

Microplastics (MPs) pollution has become a persisting problem over the last decades and is a critical issue for environmental protection and human health. In this context, scientific data able to reveal MPs presence and improve the characterization and identification of this pollution via different systems are valuable. The aim of this paper is to assess available techniques for determining MPs in real freshwater samples and subsequently to highlight the occurrence and type of MPs in the study case area (Somesul Mic River). The MPs sampling was performed from fresh water and sediment using planktonic nets and sieves with different mesh sizes (from 20 to 500 µm). Using both classical microscopic techniques as well as scanning electron microscopy (SEM), large (1–5 mm) and small (1 µm to 1 mm) MPs were observed in the shape of fibers, fragments, foam, foils and spheres in various colors (red, green, blue, purple, pink, white, black, transparent, and opaque). Raman and FT-IR spectroscopic methods were used for MPs identification. The presence of polyethylene (PE), polypropylene (PP), and polystyrene (PS) was registered for all sampling points. The MPs laboratory investigations have raised some issues regarding the identification of MPs particles smaller than 500 µm, these being characterized especially under microscope. Some small MPs particles were identified using micro-Raman spectroscopy that highlighted the same type of polymers. No differences were registered between the sampling points due to the widespread presence of MPs. The sediment samples presented a greater abundance as compared to the water samples. Overall, it is necessary to continue the optimization of MPs separation protocol and identification according to the complexity of samples, mainly due to the limitation and lack of spectral databases.