RÉSUMÉ
Itajahya rosea was found growing in association with Leucaena leucocephala plants at Savitribai Phule Pune University campus in India. The species identity was confirmed by phylogenetic analysis based on ITS and LSU regions of rDNA, wherein, our fugus was placed along with I. rosea in phylogenetic tree. It represents first record of I. rosea from India.Frequent visitation by Drosophila species on I. rosea fruiting body particularly on gleba was observed. The Drosophila got attracted to the detached gleba under the laboratory conditions and even sometimes, they prefer to sit over the gleba as compare to their food banana. It suggested that I. rosea gleba or pseudostipe produces some compounds for attraction and feeding behavior of Drosophila species. Therefore, we characterized the volatile attractants produced by gleba and pseudostipe of I. rosea by GC-MS analysis. Nineteen compounds were identified from gleba while nine compounds were recovered from the pseudostipe. Out of them, blends of three abundant odor producing volatile compounds were reported namely, Hexadecane, Pentadecane and Nonadecane, which are responsible for attraction of Drosophila toward the gleba. Three fatty acids namely 9,12-octadecadienoic acid (Z,Z), hexadecanoic acid and benzoic acid ethyl ester produced are served as an appetitive signal through olfactory response of Drosophila, so the flies were feed on the gleba. Two pheromones’ compounds, heneicosane and (þ)-(5S,9S)-5,9-dimethylpentadecane, were also reported in pseudostipe and gleba, respectively, which play a role in Drosophila for breeding. Our study highlights an intriguing chemical ecology of fungus–Drosophila interaction.
RÉSUMÉ
Itajahya rosea was found growing in association with Leucaena leucocephala plants at Savitribai Phule Pune University campus in India. The species identity was confirmed by phylogenetic analysis based on ITS and LSU regions of rDNA, wherein, our fugus was placed along with I. rosea in phylogenetic tree. It represents first record of I. rosea from India.Frequent visitation by Drosophila species on I. rosea fruiting body particularly on gleba was observed. The Drosophila got attracted to the detached gleba under the laboratory conditions and even sometimes, they prefer to sit over the gleba as compare to their food banana. It suggested that I. rosea gleba or pseudostipe produces some compounds for attraction and feeding behavior of Drosophila species. Therefore, we characterized the volatile attractants produced by gleba and pseudostipe of I. rosea by GC-MS analysis. Nineteen compounds were identified from gleba while nine compounds were recovered from the pseudostipe. Out of them, blends of three abundant odor producing volatile compounds were reported namely, Hexadecane, Pentadecane and Nonadecane, which are responsible for attraction of Drosophila toward the gleba. Three fatty acids namely 9,12-octadecadienoic acid (Z,Z), hexadecanoic acid and benzoic acid ethyl ester produced are served as an appetitive signal through olfactory response of Drosophila, so the flies were feed on the gleba. Two pheromones’ compounds, heneicosane and (þ)-(5S,9S)-5,9-dimethylpentadecane, were also reported in pseudostipe and gleba, respectively, which play a role in Drosophila for breeding. Our study highlights an intriguing chemical ecology of fungus–Drosophila interaction.
RÉSUMÉ
Xylophagous termites are capable of degrading lignocellulose by symbiotic gut microorganisms along with the host’s indigenous enzymes. Therefore, the termite gut might be a potential niche to obtain natural yeasts with celluloytic, xylanolytic and ethanologenic traits required for bioethanol production from lignocellulosic biomass. In this study, we cultured 79 yeasts from three different termites viz. Coptotermes heimi, Odontotermes javanicus and Odontotermes obesus. After suitable screening methods, we identified 53 yeasts, which belonged to 10 genera and 16 different species of both ascomycetous and basidiomycetous yeasts. Most yeasts in the present study represent their first-ever isolation from the termite gut. Representative strains of identified yeasts were evaluated for their cellulolytic, xylanolytic, and ethanologenic abilities. None of the isolates showed cellulase activity; 22 showed xylanolytic activity, while six produced substantial quantities of ethanol. Among xylanolytic cultures, Pseudozyma hubeiensis STAG 1.7 and Hannaella pagnoccae STAG 1.14 produced 1.31 and 1.17 IU of xylanase. Among ethanologenic yeasts, the strains belonging to genera Candida and Kodamaea produced high amount of ethanol. Overall, highest ethanol level of 4.42 g/L was produced by Candida tropicalis TS32 using 1% glucose, which increased up to 22.92 g/L at 35 °C, pH 4.5 with 5% glucose. Fermentation of rice straw hydrolysate gave 8.95 g/l of ethanol with a yield of 0.42 g/g using the strain TS32. Our study highlights the gut of wood-feeding termites as a potential source of diverse yeasts that would be useful in the production of xylanase and bioethanol.
RÉSUMÉ
Xylophagous termites are capable of degrading lignocellulose by symbiotic gut microorganisms along with the host’s indigenous enzymes. Therefore, the termite gut might be a potential niche to obtain natural yeasts with celluloytic, xylanolytic and ethanologenic traits required for bioethanol production from lignocellulosic biomass. In this study, we cultured 79 yeasts from three different termites viz. Coptotermes heimi, Odontotermes javanicus and Odontotermes obesus. After suitable screening methods, we identified 53 yeasts, which belonged to 10 genera and 16 different species of both ascomycetous and basidiomycetous yeasts. Most yeasts in the present study represent their first-ever isolation from the termite gut. Representative strains of identified yeasts were evaluated for their cellulolytic, xylanolytic, and ethanologenic abilities. None of the isolates showed cellulase activity; 22 showed xylanolytic activity, while six produced substantial quantities of ethanol. Among xylanolytic cultures, Pseudozyma hubeiensis STAG 1.7 and Hannaella pagnoccae STAG 1.14 produced 1.31 and 1.17 IU of xylanase. Among ethanologenic yeasts, the strains belonging to genera Candida and Kodamaea produced high amount of ethanol. Overall, highest ethanol level of 4.42 g/L was produced by Candida tropicalis TS32 using 1% glucose, which increased up to 22.92 g/L at 35 °C, pH 4.5 with 5% glucose. Fermentation of rice straw hydrolysate gave 8.95 g/l of ethanol with a yield of 0.42 g/g using the strain TS32. Our study highlights the gut of wood-feeding termites as a potential source of diverse yeasts that would be useful in the production of xylanase and bioethanol.
RÉSUMÉ
Colletotrichum gloeosporioides is an economically important fungal pathogen causing substantial yield losses indifferent host plants. To understand the genetic diversity and molecular epidemiology of this fungus, we have developed a novel, high-resolution multi-locus microsatellite typing (MLMT) method. Bioinformatic analysis of C. gloeosporioides unannotated genome sequence yielded eight potential microsatellite loci, of which five, CG1 (GT)(n), CG2 (GT1)(n), CG3 (TC)(n), CG4 (CT)(n), and CG5 (CT1)(n) were selected for further study based on their universal amplification potential, reproducibility, and repeat number polymorphism. The selected microsatellites were used to analyze 31 strains of C. gloeosporioides isolated from 20 different host plants from India. All microsatellite loci were found to be polymorphic, and the approximate fragment sizes of microsatellite loci CG1, CG2, CG3, CG4, and CG5 were in ranges of 213–241, 197–227, 231–265, 209–275, and 132–188, respectively. Among the 31 isolates, 55 different genotypes were identified. The Simpson's index of diversity (D) values for the individual locus ranged from 0.79 to 0.92, with the D value of all combined five microsatellite loci being 0.99. Microsatellite data analysis revealed that isolates from Ocimum sanctum, Capsicum annuum (chili pepper), and Mangifera indica (mango) formed distinct clusters, therefore exhibited some level of correlation between certain genotypes and host. The developed MLMT method would be a powerful tool for studying the genetic diversity and any possible genotype-host correlation in C. gloeosporioides.