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Harsh Bais - University of Delaware. Newark, DE, US

Harsh Bais

Associate Professor, Plant and Soil Sciences | University of Delaware


Prof. Bais conducts research in plant signaling – how plants recognize and communicate with one another.






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Harsh Bais is a Plant Biotechnologist at the University of Delaware who focuses on understanding the biological significance of root exudation. His research pursues a multidisciplinary approach by interfacing plant biology and chemistry to unravel the underground communication process.

Industry Expertise (3)

Plant Engineering and Operations

Food Production

Food Processing

Areas of Expertise (7)

Plant-Microbe Interactions

Plant Biology

Plant Signaling

Root Exudation

Plant and Soil Sciences and Horticulture

Environmental Genomics

Critical Zone Research

Media Appearances (6)

Speeding up pathogenic bacteria testing

Food Processing  online


Researchers from the University of Delaware have set out to spot these bacteria before anyone consumes an affected product. As set out in an article published in the Journal of Food Safety, UD and Delaware-based startup Biospection aim to speed up testing. Faculty members Harsh Bais and Kali Kniel, alongside former graduate student Nick Johnson, teamed up with Andy Ragone of Biospection to detect foodborne pathogens in three to six hours.

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Test before you taste | UDaily

University of Delaware  online


University of Delaware researchers want to spot these bacteria before anyone ever falls ill. As detailed in an article published in the Journal of Food Safety, UD and Delaware-based startup Biospection are about to speed up testing — a lot. Faculty members Harsh Bais and Kali Kniel, alongside former graduate student Nick Johnson, teamed up with Andy Ragone of Biospection to detect foodborne pathogens in three to six hours.

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Double-edged sword | UDaily

University of Delaware  


A recent paper published in Plants by University of Delaware plant biologist Harsh Bais and postdoctoral researcher Amanda Rosier has shown that UD1022, a UD-patented beneficial bacteria, can protect alfalfa plants from fungal pathogens that cause plant disease.

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BBC  online


And the science of salads - how the salmonella bacteria has found a way to avoid being washed off our green leaves

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Oh No, Salmonella Has Found a Way to Avoid Being Washed Off Our Salads

Science Alert  online


"What's new is how the non-host bacteria are evolving to bypass plant immune response," says plant biologist Harsh Bais from the University of Delaware.

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UD researchers explore ways to prevent future salmonella outbreaks

Delaware Public Media  online


Harsh Bais is an associate professor at UD. He explains these pathogens can use the same holes the plant uses to breath, even after the plant closes them up for protection. “You are seeing these opportunist pathogens to gain an entry actually. This was surprising to us because this is a feature that you would see in classical plant pathogens, you would not expect to see this in bacteria that use this plant as a vector. So these are not their real hosts.”

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Articles (5)

Deep ultraviolet fluorescence sensing with multispectral imaging to detect and monitor food‐borne pathogens on the leafy green phyllosphere

Journal of Food Safety

2023 Demand for sustainable and safe raw agricultural commodities is growing rapidly worldwide. Reducing the risk of foodborne illnesses associated with fresh produce is a task which the industry and academic researchers have been struggling with for many years. There is an immediate need to devise a non‐invasive optical detection system to monitor the food‐borne pathogens on the leaf surface. The detection of foodborne pathogens on leafy produce is performed often too late because of the invasive techniques used to evaluate the pathogen colonization. Use of deep ultraviolet fluorescence (DUVF) sensing and visible–near infrared multispectral imaging (MSI) has previously been used to monitor plant interactions against both biotic and abiotic stress regimes.

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Spo0A-dependent antifungal activity of a plant growth promoting rhizobacteria Bacillus subtilis strain UD1022 against the dollar spot pathogen (Clarireedia jacksonii)

Biological Control

2023 Dollar spot is an economically important foliar disease of turfgrass caused by Clarireedia spp. Increased use of chemical fungicides for disease management has possible negative effects on the environment and human health. The quest for eco-friendly alternatives to fungicides is driving the development of new biological strategies for managing dollar spot. In the present study, an analysis of antifungal activity of the plant growth promoting rhizobacteria (PGPR) Bacillus subtilis strain UD1022 (hereafter UD1022) and plant health products (PHPs) (Acibenzolar-S-methyl, kelp extract, fosetyl-Al, and trinexapac-ethyl) against Clarireedia jacksonii for control of the turfgrass fungal disease dollar spot was conducted.

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The Use of Synthetic Microbial Communities (SynComs) to Improve Plant Health


2023 Despite the numerous benefits plants receive from probiotics, maintaining consistent results across applications is still a challenge. Cultivation-independent methods associated with reduced sequencing costs have considerably improved the overall understanding of microbial ecology in the plant environment. As a result, now it is possible to engineer a consortium of microbes aiming for improved plant health. Such synthetic microbial communities (SynComs) contain carefully chosen microbial species to produce the desired microbiome function. Microbial biofilm formation, production of secondary metabolites and ability to induce plant resistance are some of the microbial traits to take into consideration when designing SynComs.

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Surfactin and Spo0A-Dependent Antagonism by Bacillus subtilis Strain UD1022 against Medicago sativa Phytopathogens


2023 Plant growth-promoting rhizobacteria (PGPR) such as the root colonizers Bacillus spp. may be ideal alternatives to chemical crop treatments. This work sought to extend the application of the broadly active PGPR UD1022 to Medicago sativa (alfalfa). Alfalfa is susceptible to many phytopathogens resulting in losses of crop yield and nutrient value. UD1022 was cocultured with four alfalfa pathogen strains to test antagonism. We found UD1022 to be directly antagonistic toward Collectotrichum trifolii, Ascochyta medicaginicola (formerly Phoma medicaginis), and Phytophthora medicaginis, and not toward Fusarium oxysporum f. sp. medicaginis.

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Protocol: a simple method for biosensor visualization of bacterial quorum sensing and quorum quenching interaction on Medicago roots

Plant Methods

2022 Background Defining interactions of bacteria in the rhizosphere (encompassing the area near and on the plant root) is important to understand how they affect plant health. Some rhizosphere bacteria, including plant growth promoting rhizobacteria (PGPR) engage in the intraspecies communication known as quorum sensing (QS). Many species of Gram-negative bacteria use extracellular autoinducer signal molecules called N-acyl homoserine lactones (AHLs) for QS. Other rhizobacteria species, including PGPRs, can interfere with or disrupt QS through quorum quenching (QQ). Current AHL biosensor assays used for screening and identifying QS and QQ bacteria interactions fail to account for the role of the plant root.

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Education (2)

University of Mysore: PhD 2002

Birla Institute of Technology and Science, Pilani: MS, Biotechnology

Patents (2)




Methods for producing greater biomass in a plant, increasing the drought tolerance of a plant, producing a decreased lignin concentration in a plant, producing a greater iron concentration in a plant, or inhibiting fungal infection in a plant comprise administering Bacillus subtilis FB17 to the plant, the seed of the plant, or soil surrounding the plant or the seed in an amount effective to produce greater biomass, increase the drought tolerance, produce a decreased lignin concentration, produce a greater iron concentration, or inhibit fungal infection in the plant compared to an untreated plant, respectively. Agricultural carriers and seed coatings comprising Bacillus subtilis FB17 are provided. The biomass of a plant which has been administered Bacillus subtilis FB17 can be converted to a biofuel or can be used as a food crop or in other uses.

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Abstract: The present invention provides a soil composition having improved water retention. The composition comprises soil particles and Bacillus subtilis UD1Q22. For example, the composition may comprise soil particles having a particle size no greater than 2 mm and at least 50% of the soil particles have a particle size in the range of 0.05-2 mm. A method for improving water retention of a soil composition is also provided. The method comprises applying an effective amount of Bacilus subtilis UD1022 to the soil composition to improve water retention of the soil composition.

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