Potato tubers (Solanum tuberosum L. cv. Binje) were stored at 18 and 4oC in order to verify changes in mitochondrial metabolism, especially in the activities of the alternative oxidase (AOX) and plant uncoupling mitochondria protein (PUMP). Tubers were also sliced and submitted to artificial aging. The oxygen consumption rate (OCR), respiratory control (RC) and ADP/O ratio for mitochondria obta...

The present study was undertaken to examine the viability, motility and morphology of spermatozoa that were frozen-thawed at different temperature followed by the storage at 4oC until 10 hours under the condition of tropical area. The frozen semen derived from a Holstein-Friesian bull with the egg-yolkbase extender was thawed at 23oC or 37oC for 30 seconds or 15 seconds, respectively, and kept ...

Animal origin egg yolk extender has been associated with microbial contamination and interference with microscopic examination. Therefore, replacement of such extender with plant origin compound is inevitable without compromising the desired qualities of an ideal extender. In the current experiment, we compared the effect of soy-based extender (25% and 50%) of five adult Holstein-Friesian bulls...

Migrants of the eastern North American population of the monarch butterfly, Danaus plexippus, are often subjected to subzero temperatures, heavy dews and frost in late September and October during the autumn migration to overwintering sites in Mexico. Adults of this generation had the capacity to rapidly increase their cold-hardiness. A chilling period of 1 h at +4OC before exposure to -4OC for...

Ninety one streptomycetes strains were isolated from permafrost soil in Spitsbergen, Arctic Ocean. Five of them showed antimicrobial activity against Gram-positive, Gram-negative bacteria, yeasts and fungi. The strains were psychrotolerant with growth at temperatures between 4oC and 28oC. Morphological, physiological and biochemical characterizations were investigated and the starins could be a...

To study the role of calcium in cold acclimation, we examined the relationship between calcium influx and accumulation of transcripts of two cas (cold acclimation-specific) genes of alfalfa, cas75 and cas78. Whereas a decline in temperature from 25 to 15OC had little effect on the influx of extracellúlar 45Ca2+, an increasing influx was observed when the temperature was lowered further. The inf...

Survival and growth of Listeria monocytogenes L56 (IMR isolate) was studied in trypticase soy broth (TSB) grown at 37oC before being subjected to three selected sublethal stress temperatures (55oC, 28oC and 4oC). The morphological changes and motility as affected by temperature stresses were determined using Scanning Electron Microscopy (SEM) and motility media, respectively. For this purpose, ...

The respiration rate (RR) (CO2 production), activation energy (Ea) and Q10 of maleic hydrazide-treated onion bulbs (Allium cepa, cv. Rouge Amposta) at 20.10-6 mol.L-1 (MH1) and 45.10 -6 mol.L-1 (MH2) were measured at 4, 10 and 20oC. Immediately after treatment, the Q10 of MH-treated and control bulbs were not significantly different. After 8 weeks of storage, Q10 of control and both MH-treated ...