The ability to grow in heavy metal contaminated areas and absorb heavy metals from the environment make fungi a potentially viable biological‐based technology for remediating hazardous heavy metals in soil. In this study, 10 fungi from a copper (Cu)‐polluted area in Malaysia were isolated, with the four highest growth fungi identified as Simplicillium subtropicum, Fusarium solani, Aspergillus tamari, and Aspergillus niger. Results from toxicity and biosorption testing showed that A. niger and F. solani grew the fastest in the presence of Cu, but exhibited lower Cu uptake per unit of biomoass. In contrast, A. tamarii and S. subtropicum had lower growth rates, but showed better uptake of Cu per unit of biomass. S. subtropicum was identified as the best species for bioremediation because it had the highest Cu uptake and positive growth measured in the presence of Cu at concentrations below 100 mg/L. A niger proved to be most suitable for bioremediation if the concentration of Cu exceeds 100 mg/L.

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Extremophilic actinomycetes species are capable of surviving in extreme environment and producing antibiotics. In this study, we hypothesize that extremophiles produce antimicrobial compounds that are potentially novel agent(s) effective against drug resistant pathogens. The goal of this study is to test inhibitory activity of the extracts derived from extremophilic actinomycetes species against the most prevalent drug-resistant bacteria in Kazakhstani hospitals, and preliminarily analyze chemical composition of the active extracts. Actinomycetes species isolated from the soil of Kazakhstan were cultured in modified media mimicking extreme environment the species were isolated from. Antimicrobial compound(s) extracted with organic solvent were tested against conditionally pathogenic and multi-drug resistant pathogens Acinetobacter baumanni and Pseudomonas aeruginosa. Our study generated promising results regarding the potential discovery of novel components effective against drug resistant pathogens. Future studies will focus on further chemical analysis to identify the active component within these extremophilic extracts.

Background: The so-called “liquid biopsy” has become a powerful tool for cancer research in the recent years, with circulating cell-free DNA (cfDNA) that originates from tumors as one of the most promising analytes. In contrast to plasma derived cfDNA, only a few studies were performed investigating urinary cfDNA. One reason might be quick degradation and hence relatively low concentrations of urinary cfDNA. This study focused on examining the stability of cfDNA in urine using different ways of preservation under various storage conditions. Methodology: To mimic patient samples, a pool of healthy male and female urine donors was spiked with a synthetic cfDNA reference standard (fragment size 170 bp) containing the T790M mutation in the EGFR gene and preserved with three different buffers and no buffer over four different storage periods (0; 4; 12; 24 h) at room temperature vs. fridge. Preservatives used were the Urinary Analyte Stabilizer (UAS, Novosanis), the Urine Conditioning Buffer (UCB, Zymo) and a self-prepared buffer called “AlloU”. The cfDNA was extracted with the QIAamp MinElute ccfDNA Mini Kit (Qiagen) and the concentration measured with the Qubit™ 4 fluorometer (Thermo Fisher Scientific). Droplet digital PCR (ddPCR) was used for detection and quantification of the T790M mutation (Bio-Rad) Results: From the model samples with no preservation buffer, almost no spiked cfDNA could be recovered and the T790M variant could not be detected using ddPCR, indicating that without preservation cfDNA was degraded below the detection limit by the nucleases present in urine. The most effective stabilizing buffer over all storage periods and at room as well as fridge temperature was the UAS, resulting in accurate detection of the T790M variant using ddPCR. Conclusion: From a technical point of view, urinary cfDNA might be useful for non-invasive disease monitoring when the samples are stabilized and stored adequately during clinical routine. Citation Format: Carolin Münch, Saikal Shamkeeva, Mitja Heinemann, Berend Isermann, Sabine Kasimir-Bauer, Bahriye Aktas, Ivonne Nel. Stability of urinary cell-free DNA and detection of T790M variant. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6693.