Isolation and characterization of constituents in hemolymph from healthy and diseased japanese beetle larvae

Abstract

Studies are reviewed on the composition of hemolymph from Japanese beetle larvae, Popillia japonica. This research was conducted to determine the chemical environment required for sporulation of the milky disease organism, Bacillus popilliae. Amino acids, proteins, organic acids, lipids, carbohydrates, and oxygen content were determined in hemolymph from healthy and diseased larvae. Oxygen content of hemolymph was measured by microelectrodes implanted in the hemocoel of living larvae. Vegetative growth of the pathogen reduces the dissolved oxygen; however, as sporulation occurs, oxygen concentration approaches normal values. Trehalose, the major hemolymph sugar, is reduced by ca. 50% during the course of milky disease. Neutral lipids, phospholipids, and hydrocarbons decrease markedly with infection. Both branched‐chain and normal alkanes occur in hemolymph. Milky disease causes an increase in concentration of pyruvic, malic, glycolic, tartaric, and glyoxylic acids. The major hemolymph protein, a lipoglycoprotein, has a mol. wt. of ca. 500,000. Reduced concentration of this protein is accompanied by the appearance of a smaller protein. Amino acids that increase significantly as a result of infection are: Glutamic acid, aspartic acid, β‐alanine, phenylalanine, threonine, lysine, and serine. Hemolymph contains few peptides of low molecular weight.

Disruptions of the genes involved in lysine biosynthesis, iron acquisition, and secondary metabolisms affect virulence and fitness in Metarhizium robertsii

“…S5). Moreover, the hemocoele is not expected to be a growth-limiting environment for lysine auxotrophs as lysine concentration in hemolymph exceeds 1 mM (Bennett and Shotwell, 1973;Locke, 1980;Piyankarage et al, 2008). Loss of siderophores, on the other hand, was associated with a much larger decline in virulence than lysine auxotrophy.…”