Abstract:

Six strains were screened and isolated for their ability to degrade carotenoids and produce flavor compounds
from the soil on which perennial flowering plants are grown. Morphological observation and 16S rDNA sequence
analysis showed that three of the six strains were clustered with Bacillus subtills and Bacillus tequilensis, two of
them had a higher similarity with Bacillus methylotrophicus and Bacillus pumilus, and one had the closest genetic
relationship with Bacillus lichniformis. Degradation of carotenoid was determined by observing the transparent circles
in carotenoid agar plates and detecting the optical density (OD) at 495 nm. The degradation products were determined
preliminarily by gas chromatography-mass spectrometry (GC-MS). The identified major products were 2-heptanone,
palmitic acid, phthalic anhydride and other substances.

Key words: carotenoids, Bacillus sp., screening, transparent circle