Contribution of microbial activity to virus reduction in saturated soil.

Application of wastewater to soil may result in the contamination of groundwater and soil with pathogenic microorganisms and other biological and chemical agents. This study was performed to determine the antiviral microbial activity of soil saturated with secondary effluent. Low concentrations (0.05mg/ml) of protease pronase resulted in the inactivation of more than 90% of seeded Cox-A9 virus, whereas Poliovirus type 1, Hepatitis A virus (HAV) and MS2 bacteriophages were found to be insensitive to the enzyme activity. Exposure of Cox A9 virus to P. aeruginosa extracellular enzymes resulted in 99% inactivation of the seeded virus. Hepatitis A virus was found to be as sensitive as the Cox A9 virus, whereas Poliovirus 1 and MS2 were found to be insensitive to P. aeruginosa extracellular enzymatic activity. Furthermore, the time required for 99% reduction (T99) of Cox A9 and MS-2 Bacteriophage, at 15 degrees C, in soil saturated with secondary effluent was found to be 7 and 21 days, respectively. Faster inactivation was observed for MS2 and Cox A9 in soil saturated with secondary effluent incubated at 30 degrees C, T99 of 2 and 0.3 days, respectively. Although the concentration of the total bacterial count in the soil samples increased from 10(3) cfu/g to 10(5) cfu/g after 20 days of incubation at 30 degrees C, the proteolytic activity was below the detection level. The results of this study indicate that the virucidal effect of microbial activity is virus type dependent. Furthermore microbial activity in the soil material can be enhanced by the application of secondary effluent at higher temperature. The results also showed that MS2 bacteriophage can be used to predict viral contamination of soil and groundwater.

Aut7p, a soluble autophagic factor, participates in multiple membrane trafficking processes.

Aut7p, a protein recently implicated in autophagic events in the yeast Saccharomyces cerevisiae, exhibits significant homology to a mammalian protein, p16, herein termed GATE-16 (Golgi-associated ATPase Enhancer of 16 kDa), a novel intra-Golgi transport factor. Here we provide evidence for the involvement of Aut7p in different membrane trafficking processes. Aut7p largely substitutes for the activity of GATE-16 in mammalian intra-Golgi transport in vitro. In vivo, AUT7 interacts genetically with endoplasmic reticulum to Golgi SNAREs, specifically with BET1 and SEC22. Aut7p interacts physically with the following two v-SNAREs: Bet1p, which is involved in endoplasmic reticulum to Golgi vesicular transport, and Nyv1p, implicated in vacuolar inheritance. We suggest that, in addition to its role in autophagocytosis, Aut7p has pleiotropic effects and participates in at least two membrane traffic events.