Lusine Ghazaryan

• Ben-Gurion University of the Negev

Recycling of wastewater for agricultural irrigation is an important means for sustainable reuse practices, but a major concern of such practice is the introduction of pathogens and antibiotic determinants. Previous attempts to mitigate contaminants focused on water treatment, yet the growing appreciation of the soil microbial food web brings into f...

To feed the rapidly increasing world population, food production will have to double while the amount of water and arable land remain unchanged. Therefore, we must transition to environmentally sustainable, but just as nutritious diets by 2050. This will require drastic reduction in animal-based foods and increasing plant-based foods. Plant-based d...

Duckweeds (Lemnaceae) are tiny plants that float on aquatic surfaces and are typically isolated from temperate and equatorial regions. Yet, duckweed diversity in Mediterranean and arid regions has been seldom explored. To address this gap in knowledge, we surveyed duckweed diversity in Israel, an ecological junction between Mediterranean and arid c...

Colicins, bacteriocins produced by the gram-negative bacterium Escherichia coli, are tightly regulated by the DNA damage response regulatory system (SOS), and are thus triggered at times of stress. Colicins' regulation and expression profiles were primarily studied in suspended (planktonic) cultures yet, in their natural environments E. coli cells...

Subaerial biofilms play a central role in the ecology and biodeterioration of many outdoor monuments and pieces of art. It is well established that microorganisms can face a broad range of stress by living in these subaerial environments, but their origin, taxa determinants and physiological traits are debated. Here, we hypothesized that the bacter...

Overuse of agrochemicals is linked to nutrient loss, greenhouse gases (GHG) emissions, and resource depletion thus requiring the development of sustainable agricultural solutions. Cultivated microalgal biomass could provide such a solution. The environmental consequences of algal biomass application in agriculture and more specifically its effect o...

Ecosystem engineers (EEs) are present in every environment and are known to strongly influence ecological processes and thus shape the distribution of species and resources. In this study, we assessed the direct and indirect effect of two EEs (perennial shrubs and ant nests), individually and combined, on the composition and function of arid soil b...

Ecosystem engineers (EEs) are present in every environment and are known to strongly influence ecological processes and thus shape the distribution of species and resources. In this study, we assessed the direct and indirect effect of two EEs (perennial shrubs and ant nests), individually and combined, on the composition and function of arid soil b...

Ecosystem engineers (EEs) are present in every environment and are known to strongly influence ecological processes and thus shape the distribution of species and resources. In this study, we assessed the direct and indirect effect of two EEs (perennial shrubs and ant nests), individually and combined, on the composition and function of arid soil b...

Around the world, water scarcity is advocating for treated wastewater (TWW) reuse, especially for agricultural irrigation. However, TWW contains inorganic substances, dissolved organic matter and microorganisms that may alter soil health and fertility. In this study, it was hypothesized that irrigation would differently alter the soil microbial com...

Global water scarcity necessitates the use of treated wastewater (TWW) for various purposes, including agricultural irrigation, yet this water may introduce various contaminants to the soil and crops. Therefore, application of TWW irrigation was sanctioned by barriers (drip irrigation and plastic mulch) to reduce risks to consumers; however, barrie...

Studies describing the diversity of microorganisms in drylands are based mainly on the total (DNA), and seldom on the metabolically active (RNA) portion of the bacterial communities. We predicted that in desert environments, the majority of bacteria would display low activity during the hot and dry season, resulting in comparable diversity of the t...

World-wide water scarcity is urging the use of treated wastewater (TWW) for irrigation but this practice may have adverse effects on soil and crop contamination due to the introduction of potential microbial pathogens. The objective of this study was to evaluate the potential health risks caused by TWW irrigation of soils differing in their texture...

Bacteriocins produced by Enterobacteriaceae are high molecular weight toxic proteins that kill target cells through a variety of mechanisms, including pore formation and nucleic acid degradation. What is remarkable about these toxins is that their expression results in death to the producing cells and therefore bacteriocin induction have to be tigh...

Journal of Antibiotics, official journal of the Japan Antibiotics Research Association, is a print and online publication that focuses on research on antibiotics and related types of medicinal substances

Colicins, proteinaceous antibiotics produced by Escherichia coli, specifically target competing strains killing them through one of a variety of mechanisms, including pore formation and nucleic acid degradation. The genes encoding colicins display a unique form of expression, which is tightly regulated, involving the DNA damage response regulatory...

Background: Evolutionary arms race plays a major role in shaping biological diversity. In microbial systems, competition often involves chemical warfare and the production of bacteriocins, narrow-spectrum toxins aimed at killing closely related strains by forming pores in their target's membrane or by degrading the target's RNA or DNA. Although ma...

Community dynamics of bacteriocin producers in an unstractured environment. Time evolution is illustrated by the bacteriocin producers strains A (blue line) and B (red line); both strains are strong inducers but bacteriocin B is slightly more potent. The strains were simulated to compete at equal initial frequencies and the more potent strain preva...

Growth rate of E. coli strains. Data presented as mean ± standard deviation (rounded to two decimal points). (DOCX)

Community dynamics of colicin producers in an unstractured environment. Competitions between bacteriocin producers in an unstructured environment were tested to illustrate the density-dependent competition between various strains’ inducers. (A) We followed the fluorescently labeled ColA over time to illustrate the competition between a pore former...

Community dynamics of bacteriocin producers in a structured environment. Static-plate environment was initiated by randomly depositing 24 droplets from pure culture of strains ColA and ColE6 (A). A separate set of experiments explored the interactions between ColA and ColE7 (B). The changing spatial pattern of the community was documented and the m...

Time evolution of two competing species in a structured environment. Fronts separate regions dominated by different species. These fronts are moving away from the dominant species (A), until its competitor is almost eliminated (B). (DOCX)

Primers used in this study. (DOCX)

Colicin reporter vector induction by 0.5 ng mL−1 mitomycin C. Data presented as mean ± standard deviation. (DOCX)

We studied survival and development of preimagoes and the ability to withstand starvation of adults in two flea species, host-specific Parapulex chephrenis and host-opportunistic Xenopsylla ramesis, when parent fleas fed on a typical (Acomys cahirinus and Dipodillus dasyurus, respectively) or an atypical (D. dasyurus and A. cahirinus, respectively)...

We studied whether (a) previous infestation of a rodent host with fleas and (b) the reproductive effort of fleas affect the rate of CO(2) emission in two flea species, host-specific Parapulex chephrenis and host-opportunistic Xenopsylla ramesis when feeding on their typical and atypical rodent hosts. We measured the rate of CO(2) emission in preovi...

1. We examined whether identity of the rodent host and previous infestation of the host affect feeding and reproduction of fleas. We predicted that feeding and reproductive success of fleas would be higher when feeding on (i) a typical host than on an atypical host; and (ii) a pristine host than on a host previously exposed to parasitism. We also p...

The dramatic rise in antibiotic-resistant pathogens has renewed efforts to identify, develop, and redesign antibiotics active against the resistant bacteria. This review will focus on the increasing number of patents aimed at employing the potential of antimicrobial polypeptides i.e., the bacteriocins, in vetrinary medicine and human health. Bacter...

We studied dietary intakes and time budgets in two desert gerbillids, Psammomys obesus, a diurnal herbivore, and Meriones crassus, a nocturnal granivore. P. obesus was offered fresh leaves of Atriplex halimus while M. crassus was offered millet seeds and Atriplex halimus, mainly as a source of water. We predicted that the (1) nocturnal rodent will...

Immunocompetence is the general capacity of an organism to mount an immune response against pathogens and parasites. We studied the relationship between the immunocompetence of a rodent host, Meriones crassus (Sundevall's Jird) and parasitism by the flea Xenopsylla ramesis . We hypothesized that flea parasitism affects physiological and immunologic...

Fleas consume and digest blood from their hosts. We hypothesized that the energy costs of digestion of blood by fleas is dependent on the host species. To test this hypothesis, we studied CO2 emission, a measure of energy expenditure, during digestion of a blood meal taken by Parapulex chephrenis from a preferred (Acomys cahirinus) and a non-prefer...

We studied time budgets and dietary intake in two desert gerbillids, Psammomys obesus, a diurnal herbivore, and Meriones crassus, a nocturnal granivore feeding three different types of diet (millet seeds together with leaves of Atriplex halimus for M. crassus, fresh leaves of A. halimus or fresh stems of Anabasis syriaca for P. obesus). M. crassus...

We studied dietary intakes and time budgets in two desert gerbillids, �Psammomys obesus, �a diurnal herbivore, and �Meriones crassus, �a nocturnal granivore. �P. obesus �was offered fresh leaves of �Atriplex halimus �while �M. crassus �was offered millet seeds and �Atriplex halimus, �mainly as a source of water. We predicted that the (1) nocturnal...