Isolation and Physical Characterization of Hydrophobin-Like Proteins (HLP) from Aerial Conidia of <i>Metarhizium Anisopliae</i> Var. <i>Anisopliae</i>

Abstract

The aim of this study was to isolate and physically characterized Hyrophobin-Like Proteins (HLP) from the aerial conidia of two local isolates of Metarhizium anisopliae var. anisopliae, namely, TA and LR2. The protein samples were isolated based on their insolubility in hot Sodium Dodecyl Sulfate (SDS). The SDS-insoluble proteins were then purified in cold 98% formic acid and performic acid. The molecular weight of the Formic Acid Extracted (FAE) proteins fell in the range of 13-17 kDa with the contents of 3.80 and 3.56 mg mL −1 for TA and LR2, respectively. Due to the stringent protocol of isolation and purification, the FAE proteins can be verified as Hydrophobin-Like Proteins (HLP). Both the HLP samples isolated from M. anisopliae isolates TA and LR2 have low contact angles of 57.06±0.38 and 58.43±0.25°, respectively. The HLP also revealed good emulsification effect in the oil-water phase. Conidia showed good dispersion in aqueous solution with the application of HLP. Paper precoated with HLP resisted wetting by water for up to 439 sec. These unique properties of HLP from local isolates of M. anisopliae var. anisopliae are of great potential to be used in wide range of industrial applications.

Exploring malted barley waste for fungi producing surface active proteins like hydrophobins

“…Images of drops were captured in Digital Camera (Sony SLT alpha 58). Contact angles were measured by low-bond axisymmetric drop shape analysis (LB-ASDSA) using Image J plugin software [34][35][36]. Contact angle for each sample was calculated in duplicates by placing drops on three different points of the Teflon surface.…”

“…Surface was sterilized by washing three times with ethanol followed by rinsing three times with water and air dried for 12 h. 100 µl of the extracted proteins (50 µg protein ml −1 ) was applied on Teflon surface and dried for 16 h. Each slide was washed by 2% SDS at 90 °C and rinsed three times with water followed by drying for 16 h. Control slides were prepared identically without applying protein sample. Surface hydrophobicity of modified surface was measured in duplicates by measuring contact angle of water drop (10 µl) placed on three different points using digital camera (Sony SLT alpha 58) and analyzed using Image J software with LB-ASDSA plugin [34][35][36].…”

“…To mention a few, hydrophobins isolated from Paecilomyces farinosus PfaH1 and PfaH2 has made the contact angle of 118° with Teflon which was lowered by 3.9° than water(121.9°) [55]. Hydrophobins of Metarhizium anisopliae have made contact angles of 57.06° and 58.43° with Teflon, these CA were too small compared to CA made by water with Teflon surface of about 121° [34]. b) Wetting ability Determination of isolated Surface active proteins:…”

Spores of Beauveria bassiana and Trichoderma lignorum as a bioinsecticide for the control of Atta cephalotes

“…For all of the above reasons, the use of biological controls in agriculture has grown continuously, especially biocontrols composed of the spores of filamentous fungi such as Beauveria bassiana , an entomopathogenic fungus, which infects the insect by adhesion to the cuticle insect host by adhesion proteins (Mad 1, Mad 2— Adhesin - like proteins ; Hyd 1, Hyd 2, Hyd 3— Hydrophobins [14, 15], followed of the formation of the appressorium, which generates the breakdown of chitin by means of a combination of mechanical strength and enzymatic degradation (proteases, chitinases and lipases) [16], which also focuses enzymatic activity through the production of a mucilage on the site of contact, isolating the point from the outside [17]. The evasion of the immune system is mediated by the expression of Mcl1 proteins [18], the secretion of destruxins A and E, production of trehalase and expression of faith genes involved in the cycle cell, allowing rapid multiplication and differentiation of hyphae in the host’s hemolymph, leading to host mummification [14, 19–21].…”