Jeana Starosvetsky

Publications of Jeana Starosvetsky

• Bacteriophage ecology in a small community sewer system related to their indicative role in sewage pollution of drinking water.

  Authors: Efrat Gino, Jeana Starosvetsky, Robert Armon

  Environmental microbiology. 10/2007; 9(10):2407-16.

  In view of various studies looking for the merit of coliphages as indicators of water pollution with viruses originating from faecal material, a small agricultural community (population ofIn view of various studies looking for the merit of coliphages as indicators of water pollution with viruses originating from faecal material, a small agricultural community (population of approximately 1500 inhabitants of all ages, 2-3 km from Haifa) was selected in order to understand these bacteriophage ecology (F-RNA and somatic coliphages) in its sewer and oxidation pond system. Along the sewer lines, it was possible to isolate constantly both bacteriophage types (F-RNA and somatic coliphages) at 10(2)-10(4) plaque-forming units (pfu) ml(-1). The average numbers of somatic and F-RNA phages isolated from oxidation pond were 10(3)-10(4) pfu ml(-1); however, somatic coliphages were undetectable for several months (April-August). Significant high correlation (0.944 < R(2) < 0.99) was found between increased anionic detergent concentrations and F-RNA coliphage numbers. Infants less than 1 year old excreted both phage types and few only F-RNA coliphages (at high numbers > 10(5) pfu g(-1)) for up to 1 year. The excretion of F-RNA coliphages was highly linked to Escherichia coli F(+) harborage in the intestinal track as found in their faecal content. Finally, three bacterial hosts E. coli F(+), F(-) and CN(13) tested for survivability in sewage filtrate revealed that E. coli F(+) had the highest survivability under these conditions. Presence of somatic and F male-specific phages in sewer lines of a small community are influenced by several factors such as: anionic detergents, nutrients, temperature, source (mainly infants), shedding and survival capability of the host strain. Better understanding of coliphages ecology in sewer systems can enhance our evaluation of these proposed indicator/index microorganisms used in tracking environmental pollution of water, soil and crop contamination with faecal material containing enteric viruses.

• Pitting corrosion of carbon steel caused by iron bacteria

  Authors: David Starosvetsky, Robert Armon, Josef Yahalom, Jeana Starosvetsky

  International Biodeterioration & Biodegradation.

  Corrosion mechanism of 1020 AISI carbon steel was studied in iron bacteria contaminated water. A mixed culture of iron oxidizing bacteria, originally isolated from rust deposits of a clogged carbonCorrosion mechanism of 1020 AISI carbon steel was studied in iron bacteria contaminated water. A mixed culture of iron oxidizing bacteria, originally isolated from rust deposits of a clogged carbon steel heat exchanger was used. Weight loss and electrochemical measurements were carried out in 1 g l−1 NaCl solution with or without the addition of iron bacteria culture. The experimental results show that addition of the iron bacteria culture to 1 g l−1 NaCl solution induces a drastic ennoblement of corrosion potential (Ecorr) from −0.75 to −0.25 V (SCE) and surface passivation. Through further exposure, Ecorr slowly shifted back and the steel underwent a severe pitting attack, an effect which was not observed with 1 g l−1 NaCl solution alone or when augmented with a nutrient medium. Electrochemical measurements show that the experimentally observed strong acceleration in pitting corrosion process occurred due to an increase in both cathodic and anodic reaction rates, induced by the iron bacteria.