Psychrotolerant Strains of <em>Phoma herbarum</em> with Herbicidal Activity

The search for stress-tolerant producer strains is a key factor in the development of biological mycoherbicides. The aim of the study was to assess the herbicidal potential of phoma-like fungi. Morphological and physiological features of two Antarctic psychrotolerant strains 20-A7-1.M19 and 20-A7-1.M29 were studied. Multilocus sequence analysis was used to identify these strains. They happened to belong to Phoma herbarum Westend. The psychrotolerant properties of these strains were suggested not only by ecology, but also by their capability to grow in a wide temperature range from 5 °C to 35 °C, being resistant to high insolation, UV radiation, aridity, and other extreme conditions. It was shown that treatment with their cell-free cultural fugate, crude mycelium extract, and culture liquid significantly reduced the seed germination of troublesome weeds such as dandelion and goldenrod. Cell-free cultural fugate and culture liquid also led to the formation of chlorosis and necrotic spots on leaves. Thus, psychrotolerant strains P. herbarum 20-A7-1.M19 and 20-A7-1.M29 demonstrate high biotechnological potential. Our next step is to determine the structures of biologically active substances and to increase their biosynthesis, as well as the development of biological and biorational mycoherbicides. New mycoherbicides can reduce the chemical load on agroecosystems and increase the effectiveness of applied chemicals

Commercial synthetic hydrotalcite as an adsorbent nanomaterial for removal of bacteria from contaminated water

Layered double hydroxides (LDHs) are regarded as potential adsorbents for water treatment from a wide range of pollutants. However, there are only a few studies concerning application of LDHs for elimination of microorganisms from aquatic systems. In this work, experiments were conducted to investigate the efficiency of commercial synthetic hydrotalcite Mg6Al2(CO3)(OH)16∙4H2O as an adsorbent for water purification from fecal indicator bacteria Escherichia coli BIM B-378 and Enterococcus faecalis BIM B-1530. Our findings indicate that exposure for 4 h to hydrotalcite (5 g/L) in suspension resulted in the removal of about 40% of coliforms and 25% of enterococci from water, at a high bacterial load (2×1010 CFU/L), and the removal efficiency of E. coli and E. faecalis did not significantly change when both bacteria were present in water. In addition, the percentage of removed bacteria increased with increasing of hydrotalcite concentration in the suspension (0.5 to 10 g/L), contact time (1-7 h) and decrease of pH (5.5), and decreased at low incubation temperature (16°C). Finally, hydrotalcite did not exhibit bactericidal activity and retention of bacteria was found to be reversible. Therefore, our findings suggest that commercial synthetic hydrotalcite could be potentially used in technologies of water treatment from bacterial contamination.publishe