SPORE GERMINATION OF CITRUS JUICE-RELATED FUNGI AT LOW-TEMPERATURES

Germination of Cladosporium cladosporioides conidia, arthrospores of a Geotrichum sp. and conidia of Penicillium citrinum, P. digitatum and P. italicum was observed on orange juice serum agar (OJSA; pH 4) and n on-nutrient water agar (WA: pH 4 and 7) incubated at 0, 3, 7 and 10 de grees C. At 0 degrees C, C. cladosporioides conidia germinated signifi cantly faster (P < 0.05) than those of P. italicum or Geotrichum arthr ospores. Spores of the other fungi did not germinate at 0 degrees C. A ll fungal conidia/arthrospores germinated at 10 degrees C. Penicillia conidia germinated readily on OJSA but did not germinate on WA4 or WA7 at any temperature tested thereby suggesting a requirement for extern al nutrients for germination to occur. C. cladosporioides and Geotrich um spores germinated on both WA4 and WA 7 C. cladosporioides conidia g erminated more readily than Geotrichum arthrospores at 0 and 3 degrees C on both media. Sensitivity to lower pH was noted for both fungi.