Identification of Beauveria bassiana extracellular protease as a virulence factor in pathogenicity toward the migratory grasshopper, Melanoplus sanguinipes

Production of extracellular protease by a Brazilian strain of Beauveria bassiana reactivated on coffee berry borer, Hypothenemus hampei

“…1C) of the culture medium increased after 2 nd day and coincided with 80% of the total of the extracellular protease production, after a small lag period of 24 h shorter than obtained by two isolates of B. Bassiana (Arcas et al, 1999). These results could be related with the production of complex proteolityc enzymes during the reactivation of the inoculum on coffee berry borer alive, using liquid medium without inducer substrates such as the cuticle (Havukkala et al 1993;Urtz and Rice, 2000) or extract from insects (Bidochka and Khachatourians, 1990, 1991GiraldoCardozo et al, 2001). The active growth continued until the 5 th day when the enzyme was released in the culture medium reaching the maximum extracellular protease activity.…”

“…The stimulatory effects of a series of 24 nitrogen sources including inorganic, organic nonprotein, proteins and complex natural media on the production of proteases in submerged cultures demonstrated that the maximum amount of protease into the maize meal, yeast extract, ground maize and wheat bran broth was released 3 days after inoculation (Kucera, 1971). Others studies that used inducer substrates to produce proteases from B. bassiana, stopped the cultures in between 3 rd to 6 th day of the cultivation as 0.2% lyophilized porcine blood plasma and 0.5% ground larval of Apis mellifera with higher release at 3 rd day by B. Bassiana 278 (Chrzanowska et al, 2001), 1% gelatin at 3 rd and 4 th day by B bassiana GK2016 Khachatourians, 1987 and1988), 1% gelatin and casein, at 4 th day by B. bassiana 11892A (Urtz and Rice, 2000), ground migratory grasshopper cuticle, at 5 th day by B bassiana GK2016 and GK2018 (Bidochka and Khachatourians, 1990, 1991, colloidal chitin, at 6 th day (Havukkala et al 1993), and liquid medium with cuticle ground from the own coffee berry borer, Hypothenemus hampei at 5 th to 7 th days after the inoculation (GiraldoCardozo et al, 2001). The biomass production (Fig.…”

Pathogens of bark beetles (Curculionidae: Scolytinae) and other beetles in Bulgaria

“…They produce extracellular enzymes, lysing the host cuticula, and penetrate through the arthropod integument with support of mechanical pressure of the growing tubes of the germinating fungal conidia (St. Leger et al 1986;Draganova 1988;Bidochka & Khachatourians 1990;Gupta et al 1992;St. Leger 1995).…”

Lepidopteran species have a variety of defence strategies against bacterial infections

“…Proteases are a known virulence factor in S. marcescens as well as in other pathogen species (e.g. Bidochka & Khachatourians 1990, Kurz et al 2003, Liehl et al 2006. They are especially important for parasites in penetrating the insect gut membrane or even the outer cuticle of the body (Bidochka & Khachatourians 1990, Abuhatab et al 1995, Ffrench-Constant et al 2003.…”

“…Bidochka & Khachatourians 1990, Kurz et al 2003, Liehl et al 2006. They are especially important for parasites in penetrating the insect gut membrane or even the outer cuticle of the body (Bidochka & Khachatourians 1990, Abuhatab et al 1995, Ffrench-Constant et al 2003. This offers a likely explanation why ENV is avirulent to A. plantaginis in oral infection whereas ENT is able to penetrate the epithelium causing a septic infection through the midgut, and also why ENT is generally more virulent in septic injury in both hosts.…”