ABSTRACT Fungal polysaccharides possess an important bioactive potential, including antioxidant and anticarcinogenic activity. The aim of this work was to determine the antioxidant activity and cytotoxicity against tumour and non-tumour cell lines acidic polysaccharides (NAAPs) of the fungus Nothophellinus andinopatagonicus . The effect of NAAPs on tumour cells lines was evaluated by MTT assay and flow cytometry. The analyses determined that glucose was the most abundant monomer and IR spectrum showed the typical peaks of β-glucans in the NAAPs. The cell viability assays revealed significant activity of NAAPs against HL-60, HCT-116 and MCF-7 tumour cell lines (IC50 = 767,16 μg mL-1, 1256 μg mL-1 and 4241,7 μg mL-1, respectively); but a much lower cytotoxicity against the non-tumour cell line HGF-1 (outside the range of the highest concentration tested (>10 mg mL-1)). NAAPs affected the cell cycle of HL-60 tumour cells, increasing the percentage of cells in the sub G1 phase and reducing it in the S/G2/M phases. Moreover, low concentrations of NAAPs also showed an effective cytotoxic activity against tumour cell lines while the non-tumour cell line was unaffected, maintaining a viability close to 100%. The antioxidant activity of the highest NAAPs concentration tested was 6.24% and 4.63%, for DPPH and ABTS method, respectively.

ABSTRACT The removal of organic contaminants, especially trimethylamine (TMA), have been successfully achieved using carbon activate. In this article, we report the formation of carbon activate (CA-SM) isolated from sub-bituminous coal in small mantles (SM) at the Mine “Mantos Negros” (Lebu, Chile). This coal was subjected to thermal oxidation with CO2 at 950 °C and their TMA adsorption capacity evaluated. SM and CA-SM were physically and chemically characterized showing that the activated carbon increased the surface porosity as well as the Iodine Index from 2.5 mg I2/g to 434 mg I2/g coal. The proximal and elementary analyses of CASM showed a significant reduction of sulfur, nitrogen and hydrogen, and increased composition of carbon and oxygen. These results together with FTIR and Boehm titration suggest that the surface composition of the activated carbon is acidic in nature. The adsorption of TMA by CA-SM was evaluated in dissolution at different pH and exposure time conditions. We found that TMA can be fully absorbed (50 ml TMA at 4 mg/L and 0.2000g of CA-SM) under neutral and basic pH after 60 minutes of exposure. The feasibility of producing activated carbon from sub-bituminous coal from Province of Arauco, Chile, is a promising alternative to develop coal-based products displaying adsorbent properties useful to control amine-derived contaminants produced in the fishing industry.

ABSTRACT Global dissemination of mcr-like genes represents a serious threat to public health since it jeopardizes the effectiveness of colistin, an antibiotic used as a last-resort treatment against highly antibiotic-resistant bacteria. In 2017, a mcr-1-positive isolate of Escherichia coli was found in Chile for the first time. Herein we report the genetic features of this strain (UCO-457) by whole-genome sequencing (WGS) and conjugation experiments. The UCO-457 strain belonged to ST4204 and carried a 285 kb IncI2-type plasmid containing the mcr-1 gene. Moreover, this plasmid was transferred by conjugation to an E. coli J53 strain at high frequency. The isolate harbored the cma, iroN, and iss virulence genes and did carry resistance genes to trimethoprim/sulfamethoxazole and fluoroquinolones. Other antibiotic resistance determinants such as β-lactamases-encoding genes were not detected, making the isolate highly susceptible to these antibiotics. Our results revealed that such susceptible isolates could be acting as platforms to disseminate plasmid-mediated colistin resistance. Based on this evidence, we consider that mcr-like prevalence deserves urgent attention and should be examined not only in highly resistant bacteria but also in susceptible isolates.