Beneficial Microbes: Food, Pharma, Aqua & Beverages Industry

Endophytes are potentially benefi cial microbes that live inside plants and can be utilized as biofertilizers and biocontrol

agents by promoting plant growth and/or suppressing phytopathogens. Few endophytes have previously been isolated

from the cucurbit plant family which includes economically important crops including watermelon, cucumber, cantaloupe,

pumpkin and squash. In the present study, 169 bacterial endophytes and 10 fungal endophytes were isolated from seeds of

diff erent varieties of diverse cucurbits; the most comprehensive characterization of endophytes from this plant family. 16S

rDNA and internal transcribed spacers (ITS4 and ITS1F) fi ngerprinting were used to taxonomically classify the isolated

bacteria and fungi, respectively. Phylogenetic analysis of bacterial isolates showed Bacilli was the most abundant class including

six diff erent bacterial families. Th e γ-proteobacteria and Actinobacteria were also represented in four diff erent families. Bacillus

was the core microbiota that was conserved across tested cucurbits genera. Strains of the genus Paenibacillus were exclusively

isolated from Cucumis sativus L, Cucumis melo L and Cucurbita pepo L. var pepo L. Th ree diff erent genera of lactic acid bacteria

(LAB) were recovered from C. sativus L, C. melo L., Citrullus lanatus var. lanatus and Cucurbita pepo L var. turbinata. Our

results suggest co-evolution of seed microbial consortia with their host plants. We now propose to test these novel endophytic

microbial strains for their ability to suppress important fungal and bacterial pathogens of the cucurbit family.