The four effective antagonistic Bacillus strains, isolated from the rhizosphere soil of cucumber in a greenhouse, produced antifungal volatiles. These volatiles strongly inhibited the growth of the most tested pathoge...The four effective antagonistic Bacillus strains, isolated from the rhizosphere soil of cucumber in a greenhouse, produced antifungal volatiles. These volatiles strongly inhibited the growth of the most tested pathogenic fungi with wide host plants, induced the mycelial morphological abnormalities, and decreased the sclerotoid production of Sclerotinia sclerotiorum in sealed plates. Spores of Botrytis cinerea exposed to these volatiles for 24-48 h in cavity slides cracked and the sporaceous inclusion became brown and effused to the suspension. An interesting phenomenon observed was that all the bacterial volatiles exhibited intense inhibitory activities against the pigment formation of tested pathogenic fungi, including Ascochyta citrullina, Alternaria solani, Alternaria brassicae, and so on. Interactions mediated by microbial volatiles could be widespread in soils, and volatiles may play an important role in reducing disease levels. A phylogenetic analysis based on 16S rDNA sequence placed the four bacteria in three species Paenibacillus polymyxa （BMP-11）, Bacillus subtilis （BL02）, and Bacillus pumilus （BSH-4 and ZB 13）. Through headspace sampling and GC-MS analysis, a rich profile was found from B. subtilis and overlapping volatile patterns could be found among the different species. Studies are under the way to find the possible action mechanisms and to seek the effective application of bacterial volatiles in greenhouse.展开更多
In this study, four samples of Tunisian propolis were analyzed for their volatile compounds. Static Headspace technique coupled with gas chromatography-mass spectrometry (GC/MS) was used for the volatile profile chara...In this study, four samples of Tunisian propolis were analyzed for their volatile compounds. Static Headspace technique coupled with gas chromatography-mass spectrometry (GC/MS) was used for the volatile profile characterization. Statistical investigation of the samples was made applying hierarchical clustering method, K-Means cluster and principal component analysis. Results showed that 47, 36, 30 and 24 different compounds were identified, respectively, in the samples from Zouarine, Zelligua, Bizerte and Beni Khalled. Propolis volatiles were dominated by monoterpene hydrocarbons. α-pinene was the major compound representing 81.14%, 82.67% and 90.74%, respectively, of the total propolis volatiles collected from Zelligua, Beni Khalled and Zouarine and only 45.22% of the sample from Bizerte which had a very different composition. The in vitro antifungal activity of the volatiles from all samples against Candida albicans was also assayed and reported.展开更多
基金the National Key Technology R&D Program of China (2006BAD08A03)the Shandong Agricultural University Postdoctoral Foundation (200603065)
文摘The four effective antagonistic Bacillus strains, isolated from the rhizosphere soil of cucumber in a greenhouse, produced antifungal volatiles. These volatiles strongly inhibited the growth of the most tested pathogenic fungi with wide host plants, induced the mycelial morphological abnormalities, and decreased the sclerotoid production of Sclerotinia sclerotiorum in sealed plates. Spores of Botrytis cinerea exposed to these volatiles for 24-48 h in cavity slides cracked and the sporaceous inclusion became brown and effused to the suspension. An interesting phenomenon observed was that all the bacterial volatiles exhibited intense inhibitory activities against the pigment formation of tested pathogenic fungi, including Ascochyta citrullina, Alternaria solani, Alternaria brassicae, and so on. Interactions mediated by microbial volatiles could be widespread in soils, and volatiles may play an important role in reducing disease levels. A phylogenetic analysis based on 16S rDNA sequence placed the four bacteria in three species Paenibacillus polymyxa （BMP-11）, Bacillus subtilis （BL02）, and Bacillus pumilus （BSH-4 and ZB 13）. Through headspace sampling and GC-MS analysis, a rich profile was found from B. subtilis and overlapping volatile patterns could be found among the different species. Studies are under the way to find the possible action mechanisms and to seek the effective application of bacterial volatiles in greenhouse.
文摘In this study, four samples of Tunisian propolis were analyzed for their volatile compounds. Static Headspace technique coupled with gas chromatography-mass spectrometry (GC/MS) was used for the volatile profile characterization. Statistical investigation of the samples was made applying hierarchical clustering method, K-Means cluster and principal component analysis. Results showed that 47, 36, 30 and 24 different compounds were identified, respectively, in the samples from Zouarine, Zelligua, Bizerte and Beni Khalled. Propolis volatiles were dominated by monoterpene hydrocarbons. α-pinene was the major compound representing 81.14%, 82.67% and 90.74%, respectively, of the total propolis volatiles collected from Zelligua, Beni Khalled and Zouarine and only 45.22% of the sample from Bizerte which had a very different composition. The in vitro antifungal activity of the volatiles from all samples against Candida albicans was also assayed and reported.
