Kinetic characterization, antioxidant and in vitro toxicity potential evaluation of the extract M116 from Bacillus amyloliquefaciens, a Cuban southern coastmarine microorganism

Abstract Context: Marine ecosystems are sources of bioactive compounds. Thirty-eight microorganism strains from the Cuban platform were screened, which allowed us to identify an extract from Bacillus amyloliquefaciens, strain CBM-116, as a source for obtaining bioproducts with biomedical applications. Aims: To physiologically characterize the culture of Bacillus amyloliquefaciens (CBM-116 strain) and to evaluate the antioxidant and toxic potentialities in vitro of the M116 extract obtained from CBM-116. Methods: The growth and metabolite production of the culture were evaluated at a sieve scale. The chemical composition of the M116 extract obtained from the fermented CBM-116 culture was qualitatively characterized. The extract antioxidant activity was measured by DPPH• and FRAP assays, while cytotoxicity was evaluated in MDCK, J774, CT26, 4T1, MCF-7, A549 cell lines and in Caulobacter crescentus, as well as the effects on genetic material by SOS colorimetric and Rifampicin Resistance, in the last model. Results: Grow kinetic parameters of CBM-116 showed the formation of protein metabolites, while the extract revealed antioxidant capacity, which was evidenced by its iron-reducing capacity. M116 was not cytotoxic up to 2000 μg/mL in C. crescentus; however, it induced mutagenicity and primary damage to the DNA of the bacteria. The extract significantly inhibited cell viability of CT26, 4T1, MCF-7, A549 cells after 48 hours’ exposure. Mean inhibitory concentration (IC50) was calculated for CT26 and 4T1 cells with values of 384 and 488 µg/mL, respectively, in the MTT assay. In the neutral red assay, the values were 478.6 and 398 µg/mL, respectively. Meanwhile, the selectivity index showed values above 2 for both assays. MDCK and J774 cells were not affected. Conclusions: The M116 extract obtained from B. amyloliquefaciens showed bioactive properties with potential application for developing new anti-tumor agents

Perceptions of wood in rivers and challenges for stream restoration in the United States

This article reports a study of the public perception of large wood in rivers and streams in the United States. Large wood is an element of freshwater aquatic ecosystems that has attracted much scientific interest in recent years because of its value in biological and geomorphological processes. At the heart of the issue is the nature of the relationship between scientific recognition of the ecological and geomorphological benefits of wood in rivers, management practices utilizing wood for river remediation progress, and public perceptions of in-channel wood. Surveys of students' perceptions of riverscapes with and without large wood in the states of Colorado, Connecticut, Georgia, Illinois, Iowa, Missouri, Oregon, and Texas suggest that many individuals in the United States adhere to traditionally negative views of wood. Except for students in Oregon, most respondents considered photographs of riverscapes with wood to be less aesthetically pleasing and needing more improvement than rivers without wood. Analysis of reasons given for improvement needs suggest that Oregon students are concerned with improving channels without wood for fauna habitat, whereas respondents elsewhere focused on the need for cleaning wood-rich channels for flood risk management. These results underscore the importance of public education to increase awareness of the geomorphological and ecological significance of wood in stream systems. This awareness should foster more positive attitudes toward wood. An integrated program of research, education, and policy is advocated to bridge the gap between scientific knowledge and public perception for effective management and restoration of river systems with wood