FATTY-ACID ANALYSIS OF MICROSPORIDIA

Fatty acid methyl ester (FAME) compositions of three species of micros poridia, Thelohania sp., Vairimorpha necatrix, and Nosema algerae from two insect hosts, were studied. This is the first report on the utili ty of fatty acid analysis as a parameter for the identification of mic rosporidia, a group of ubiquituous, intracellular parasites. Three aci ds, palmitic (16:0), oleic (18:1 omega 9 cis), and two closely eluting acids combined as Summed Feature 6 (18:2 <(omega)over bar> 6,9 cis an d 18:0 anteiso), compose 60% or more of the total differentiated by a combination of qualitative and quantitative FAME profile features. The lohania sp. and N. algerae had myristic (14:0) and gondoic acid (20:1 omega 9 cis). Thus they were qualitatively differentiated from V. neca trix, in which 14:0 and 20:1 <(omega)over bar> 9 cis were not detected . Thelohania sp. had significantly lower amounts of oleic acid than th e other two species and significantly higher amounts of 20:1 <(omega)o ver bar> 9 cis than N. algerae. FAME composition of N. algerae appeare d to be influenced by the insect host. Two acids present in N. algerae isolated from the mosquito, Anopheles quadrimaculatus, were not detec ted in N. algerae recovered from the corn earworm, Helicoverpa zea. Qu antitatively, host-related differences included higher levels of Summe d Feature 6 in N. algerae from H. zea, compared to N. algerae from A. quadrimaculatus. The utility of FAME profiles for microsporidian taxon omy will depend on: (1) obtaining profiles from a wider range of micro sporidian species, and (2) considering environmental and physiological influences of the host. (C) 1996 Academic Press, Inc.