Yoram Gerchman

Yoram Gerchman
Oranim college and University of Haifa, Israel · Biology and Environment

Professor

About

187
Publications
111,746
Reads
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Introduction
A biochemist with a deep interest in evolution and environmental questions and how we can use what we learn to enhance biotechnological and applicable process. Some of my current research projects: * Constructed wetlands for small scale wastewater treatment. * Biofuels - Agriculture waste pretreatment - Fermenting yeast from naturally high sugar environments * Natural products and ecology - Glucosinolates and myrosenase from O. Baccatus, a desert plant * Harsh environment bacteria as a source for enzymes
Research Experience
July 2019 - August 2019
Oranim college and University of Haifa, Israel
Position
  • Professor (Associate)
January 2011 - December 2012
University of Haifa
Position
January 2004 - December 2007
Princeton University
Position

Publications

Publications (187)
Article
Lignocellulosic-based ethanol is a viable alternative to corn-based ethanol. However, the use of such feedstock is more complex than the use of sugar or starch due to the necessity for a pretreatment stage. Here we tested three pretreatment processes of oat straw: (1) submerged ozonation in water, (2) low temperature (40 °C) diluted sulphuric acid...
Article
Here we describe the structure elucidation and quantification of six glucosinolates (GSLs) from the roots of the desert plant Ochradenus baccatus, Delile 1813 (family Resedaceae; order Brassicales). The structure elucidation was established on the corresponding enzymatically desulfated derivatives of the native GSLs of the plant. Among these GSLs w...
Article
Worldwide shortages of personal protective equipment during COVID-19 pandemic has forced the implementation of methods for decontaminating face piece respirators such as N95 respirators. The use of UV irradiation to reduce bioburden of used respirators attracts attention, making proper testing protocols of uttermost importance. Currently artificial...
Article
Full-text available
Rising socioeconomic level and increasing popularity of e-commerce have dramatically increased the use of cardboard packaging materials, and consequent related recycling and wastes. Large amounts of sludge (up to 40% of input mass) is formed through the recycling process, with sludge solids that are very rich in cellulose fibers (~ 75% w/w). To dat...
Poster
Full-text available
1. The COVID-19 situation has raised the interest in the use of UV for prevention of respiratory system pathogens 2. The use of UV for disinfection is highly dependent on the optical properties of the matrix around the pathogens in question 3. Respiratory pathogens (SARS-CoV-2 included) are transmitted mostly through mucosa droplets that are produc...
Poster
Full-text available
The COVID-19 situation has raised the interest in the use of UV for prevention of viruses, specifically such from the Corona family. Light-emitting diodes (UV-LEDs) are an emerging UV source for disinfection. When compared to classical UV sources (i.e. mercury lamps) UV-LEDs allow design flexibility due to their small size and control of radiation...
Article
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We present here a data set generated from a multinational survey on opinions of university community members on the prospect of consuming food grown with human urine as fertiliser and about their urine recycling perceptions in general. The data set comprises answers from 3,763 university community members (students, faculty/researchers, and staff)...
Article
Ultraviolet (UV) disinfection efficiency by low-pressure (LP) mercury lamp depends on the UV fluence (dose): the product of incident irradiance (fluence rate) and exposure time, with correction factors. Time–dose reciprocity may not always apply, as higher UV–LP inactivation of E. coli was obtained at a higher irradiance over shorter exposure time,...
Article
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Bacterial surface adhesion, the first step in many important processes including biofilm formation and tissue invasion, is a fast process that occurs on a time scale of seconds. Adhesion patterns tend to be stochastic and spatially heterogeneous, especially when bacteria are present in low population densities and at early stages of adhesion to the...
Article
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Plants have been explored and used as sources for antimicrobial extract and compounds for many years, but galls—specialized structures forms on such by diversity of organisms—have been explored much less. Aphid galls host many insects in closed, humid and sugar rich environments for long periods. We have tested the antimicrobial properties of Slavu...
Poster
Full-text available
The poster describe our exploration of the interaction between plants and frugivorous birds, demonstrating the conflict between the two - where the plant 'wish' to disperse its seeds (hence fleshy fruits) and the birds 'wish' to digest the seeds, as a protein/nitrogen source. The poster also present the role of gut bacteria in mitigating this confl...
Article
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Source-separating sanitation systems offer the possibility of recycling nutrients present in wastewater as crop fertilisers. Thereby, they can reduce agriculture’s impacts on global sources, sinks, and cycles for nitrogen and phosphorous, as well as their associated environmental costs. However, it has been broadly assumed that people would be relu...
Article
UV light-emitting diodes (UV LEDs) are an emerging technology and a UV source for pathogen inactivation, however low UV-LED wavelengths are costly and have low fluence rate. Our results suggest that the sensitivity of human Coronavirus (HCoV-OC43 used as SARS-CoV-2 surrogate) was wavelength dependent with 267 nm ~ 279 nm > 286 nm > 297 nm. Other vi...
Preprint
Full-text available
UV light-emitting diodes (UV LEDs) are an emerging technology and a UV source for pathogen inactivation, however low UV-LED wavelengths are still expensive and of low fluence. Our results 27 suggest that the sensitivity of human Coronavirus was wavelength dependent with 267nm~279nm>286nm>297nm. UV LED with peak emission at ~286 nm could serve as an...
Article
Full-text available
Olive mill solid waste (OMSW) is an abundant agricultural waste without viable solution. The effects of OMSW different pretreatments (microwave or autoclave), different additives (water, formic, or sulfuric acid), and utilization of different saccharification enzymes (Cellic® CTec2 or Accellerase® 1500) were tested on saccharification process and s...
Preprint
Full-text available
Mobbing, a group attack of prey on predator, is a strategy enacted by many animal species. Here we report bacterial mobbing carried out by the bacterium Pseudomonas aeruginosa towards Acanthamoeba castellanii, a common bacterivore. This behavior consists of bacterial taxis towards the amoebae, adhesion en masse to amoebae cells, and eventual killin...
Article
Cholesterol is one of the hallmarks of animals. In vertebrates, the cholesterol synthesis pathway (CSP) is the primary source of cholesterol that has numerous structural and regulative roles [1]. Nevertheless, the few invertebrates tested for cholesterol synthesis show complete sterol auxotrophy [2, 3, 4, 5, 6], raising questions about how animals...
Article
UV light-emitting diodes (UV-LEDs) have emerged as a new technology for water disinfection. Multiwell plates are a common tool in biological research, but they have never been used for UVC/UVB-inactivation experiments of microorganisms. In this study, a novel, rapid and simple UVC/UVB-inactivation assay was developed for a UV-LED system using a mul...
Article
The COP9 signalosome (CSN) is a conserved eukaryotic complex, essential for vitality in all multicellular organisms and critical for the turnover of key cellular proteins through catalytic and non-catalytic activities. Saccharomyces cerevisiae is a powerful model organism for studying fundamental aspects of the CSN complex, since it includes a cons...
Chapter
Full-text available
Olives (Olea europaea L.) are the leading commercial tree crop, with olive oil production being one of the most economically important agro-food sectors, in the Mediterranean basin. In addition to oil, the three-phase oil industry generates olive mill solid waste (OMSW) and olive mill wastewater byproducts. Disposal of these waste products in the f...
Preprint
24 Today, two types of lamp systems dominate the UV disinfection industry: low-pressure 25 (LP) UV lamps and medium-pressure (MP) polychromatic lamps. Both lamp types have 26 their advantages and disadvantages in microorganism inactivation, with LP lamps being 27 cheaper, having longer life, and working at lower temperature, hence reducing fouling,...
Article
Full-text available
Lignocellulosic waste (here municipal trimmings) is a promising sustainable feedstock for ethanol production, but requires costly and polluting pretreatment, often resulting in toxic by-products. Ozonation, nonpolluting, effective pretreatment method, is not used commercially due to high energy requirements of ozone production at high ozone doses n...
Article
Today, two types of lamp systems dominate the UV disinfection industry: low-pressure (LP) UV lamps and medium-pressure (MP) polychromatic lamps. Both lamp types have their advantages and disadvantages in microorganism inactivation, with LP lamps being cheaper, having longer life, and working at lower temperature, hence reducing fouling, and MP lamp...
Article
Full-text available
Surface attachment is an important factor in the life of many microbial species. Late stages of attachment (i.e., mature biofilms) are rigorously studied, but data on the very early stages is scarce. The lack of robust research methods may go a long way in explaining this situation. We have developed a method that allows the rapid kinetic measureme...
Article
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Styrene analogs are known to be naturally synthesized in the leaves of pears and in other plant species, including several trees in the Styracaceae family. Styrene analogs are potential contributors to the aroma of wine, perfumes , pharmaceuticals, and other fermented foods and beverages. In addition, styrene analogs perform important ecological fu...
Article
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Cellulose nanocrystals (CNCs) have gained increased interest worldwide for their unique properties. CNC production by acid hydrolysis of cellulose-rich biomass is well established, but its' quantification is still complicated. In this study, a rapid method for the determination of CNC concentration using Calcofluor White (CW) fluorescence dye is de...
Poster
Full-text available
Initial findings regarding Pseudomonas aeruginosa mobbing behavior towards amoeba and paramecia
Method
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Protocol and results of attachment kinetics of Pseudomonas aeruginosa PAO1 in several salt concentrations with a complementary measurement of crystal violet staining at the last time point
Poster
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Antibiotics resistance is a global threat of increasing significance (1)  Established methods focus on killing bacteria, leading to emergence of resistance (Antibacterials)  Targeting diseases factors instead may reduce resistance development (Antivirulants)  One of the most significant factors is biofilm formation developing trough bacterial at...
Article
In this study, the influence of vegetation type and environmental temperature on performance of constructed wetlands (CWs) was investigated. Results of vegetation types indicated that the removal of most nutrients in polyculture was greater than those in monoculture and unplanted control. The greatest removal percentages of NH4+-N, total nitrogen (...
Article
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Background: Pear psylla is a major obstacle to efficient integrated pest management in pear orchards in Israel and around the world. We used two accessions with natural resistance to pear psylla Cacopsylla bidens (Šulc) - Py.760-261 and Py.701-202 - as interstock grafts to confer psylla resistance to the commercially important 'Spadona Estiva' sci...
Article
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Commercial Activated Carbon (CAC) and biochar are useful adsorbents for removing heavy metals (HM) from water, but their production is costly. Biochar production from olive solid waste from two olive cultivars (Picual and Souri) and two oil production process (two- or three-phase) and two temperatures (350 and 450°C) was tested. The biochar yield w...
Article
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Brevibacterium halotolerans is currently classified as a member of the Brevibacterium genus, a genus that groups together many bacterial species of similar morphology but diverse biochemical and physiological features. Here we suggest, based on multiple gene sequencing and microbial and biochemical characterization of two environmental isolates and...
Article
Helicobacter pylori is the most frequent and persistent bacterial infection worldwide, and a risk factor for active gastritis, peptic ulcers, mucosa-associated lymphoid tissue lymphoma, and gastric cancer. Although combined antibiotics treatment is effective cases of antibiotic resistance are reported at an alarming rate. The H. pylori urease enzym...
Article
Microalgae harvesting is a major hurdle in the use of microalgae for oil production. Here we describe the use of a standard cationic polymer used for water treatment, Polydiallyldimethylammonium chloride (PDADMAC), for sedimentation of Chlorella vulgaris and comparison of its flocculation properties with two other polymers, chitosan and Superfloc®....
Article
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Flower-color polymorphisms are well-documented, but how color morph frequencies change over time is usually unknown. We studied this question using the milk thistle, Silybum marianum (Asteraceae). Purple flowers commonly occur in Israel, but an infrequent white morph has been recorded since the 1920s, at first from the south of the country. Over se...
Article
This study demonstrates the potential of a new BiOCl0.875 Br0.125 photocatalyst to disinfect Escherichia coli in water under simulated solar irradiation. Photocatalytic efficiency was examined for different photocatalyst loadings, solar wavelengths, exposure times, photocatalyst concentration × contact time (Ct) concept, and with the use of scaveng...
Data
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Article
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In contrast to most other plant tissues, fleshy fruits are meant to be eaten in order to facilitate seed dispersal. Although fleshy fruits attract consumers, they may also contain toxic secondary metabolites. However, studies that link the effect of fruit toxins with seed dispersal and predation are scarce. Glucosinolates (GLSs) are a family of bit...
Article
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The Phycobilisome (PBS) is an extremely large light harvesting complex, common in cyanobacteria and red-algae, composed of rods and core substructures. These substructures are assembled from chromophore-bearing Phycocyanin and Allophycocyanin subunits, non-pigmented linker proteins and in some cases additional subunits. To-date, despite the determi...
Article
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Identifying the processes that drive community assembly has long been a central theme in ecology. For microorganisms, a traditional prevailing hypothesis states that "everything is everywhere, but the environment selects". Although the bacterial community in floral nectar may be affected by both atmosphere (air-borne bacteria) and animals as disper...
Article
Ochradenus baccatus is a widely distributed shrub in desert regions of the Middle East and North Africa. This plant's nematicidal activity against the root‐knot nematode Meloidogyne javanica was evaluated because it has been found to contain exceptionally high levels of glucosinolates. In in vitro assays with aqueous extracts of the plant, 100% of...
Article
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Insect herbivores often use chemical signals obtained from their food plants to deter enemies and/or attract sexual partners. Do plant-based visual signals act similarly, i.e., repel consumers' enemies and appeal to potential mates? We explored this question using the pollen-feeding beetle Pygopleurus israelitus (Glaphyridae), a specialized pollina...
Article
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Fleshy, ripe fruits attract seed dispersers but also seed predators. Although many fruit consumers (legitimate seed dispersers as well as seed predators) are clearly exposed to plant secondary compounds (PSCs), their impact on the consumers' physiology and foraging behaviour has been largely overlooked. Here, we document the divergent behavioural a...
Article
Recently, the nature of gall pigmentation phenomenon has gained interest, with different, and often contradicting, explanations and hypotheses. A recent, welcome contribution by Connor et al. (Arthropod–Plant Interact 6:489–495, 2012) suggested that gall pigmentation is a mere “fabricational noise” of the gall development, caused by the production...
Article
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Food and water resources are limiting factors for animals in desert ecosystems. Fleshy fruits are a rare water source in deserts and when available they tend to attract a wide variety of organisms. Here we show that two congeneric rodent species, Acomys cahirinus and A. russatus, employ different fruit eating strategies that result in either disper...
Article
The response of a representative virus and indicator bacteria to heating, solar irradiation, or their combination, was investigated in a controlled solar simulator and under real sun conditions. Heating showed higher inactivation of Escherichia coli compared to the bacteriophage MS2. Heating combined with natural or simulated solar irradiation demo...
Article
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The phyllosphere is one of the largest habitats for terrestrial microorganisms. To gain a better insight into the factors underlying the composition of bacterial communities inhabiting leaf surfaces we performed culture-dependent and independent (Denaturing Gradient Gel Electrophoresis) analyses on the bacteria associated with the leaves of three p...
Article
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Water shortage is an ongoing cardinal issue in the Middle East region. Wastewater reuse offers some remediation, but to-date many rural communities in the Palestinian Authority (PA) and in Jordan are not connected to centralized wastewater treatment plants (WWTPs), many of them are disposing of their wastewater using infiltration septic tanks. This...
Article
Plant secondary metabolites (SMs) acting as defensive chemicals in reproductive organs such as fruit tissues play roles in both mutualistic and antagonistic interactions between plants and seed dispersers/predators. The directed-deterrence hypothesis states that SMs in ripe fruits deter seed predators but have little or no effect on seed dispersers...
Article
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The evolution of several floral traits is thought to be driven by multiple selective agents, including pollinators and herbivores. Similar combinations of selection pressures may have shaped extra-floral traits. The conspicuous purple tufts of leaves (“flags”), which often terminate vertical inflorescences in the Mediterranean annual Salvia viridis...
Article
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Cerumen, also known as ear wax, is a yellowish waxy substance secreted from specialized glands in the ear canal of mammals. Human cerumen is rich in protein (mainly keratin), lipids (long-chain fatty acids), alcohols, squalene, and cholesterol. To-date the role of cerumen is not totally clear but it is believed to have antimicrobial properties. Her...
Article
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In the recent years, we have been facing an exponential increase in energy demand. To date, fossil fuels are the fuel of choice, but rise in costs, depletion of reservoirs and growing awareness to the environmental effects, have elevated the appeal of renewable energy sources. Among the most attractive substitutes, especially in the context of fuel...
Article
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Floral nectar is regarded as the most important reward available to animal-pollinated plants to attract pollinators. Despite the vast amount of publications on nectar properties, the role of nectar as a natural bacterial habitat is yet unexplored. To gain a better understanding of bacterial communities inhabiting floral nectar, culture-dependent an...
Article
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Gall-formers are parasitic organisms that manipulate plant traits for their own benefit. Galls have been shown to protect their inhabitants from natural enemies such as predators and parasitoids by various chemical and mechanical means. Much less attention, however, has been given to the possibility of defense against microbial pathogens in the hum...
Article
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The presence and role of melatonin in plants are still under debate owing to difficulties of identification and quantification. Accordingly, although it has been frequently proposed that melatonin acts as an antioxidant in phototrophic organisms, experimental data on its physiological role are scarce. This study describes the use of a rapid and sim...