The influence of medium ingredients on extracellular dextransucrase production by a new bacterial strain Weissella confusa Cab3 (Genbank Accession Number JX649223) was evaluated using fractional factorial design of Ta...The influence of medium ingredients on extracellular dextransucrase production by a new bacterial strain Weissella confusa Cab3 (Genbank Accession Number JX649223) was evaluated using fractional factorial design of Taguchi's orthogonal array. Four metabolism influencing factors viz. sucrose, yeast extract, K2HPO4 and Tween80 were selected to optimize dextransucrase production by W. confusa Cab3 using fractional factorial design of Taguchi methodology. Based on the influence of interaction components of fermentation, least significant factors of individual level have higher interaction severity index and vice versa for enzyme production from Weissella confusa Cab3. Sucrose and yeast extract were found to be the most significant factors which positively influenced the dextransucrase production. The optimized medium composition consisted of sucrose—5%;yeast extract—2%;K2HPO4—1.0%;Tween80—0.5%, based on Taguchi orthogonal array method. The optimized composition gave an experimental value of dextransucrase activity of 17.9 U/ml at shake flask level which corresponded well with the predicted value of 17.54 U/ml by the model. The optimized medium by Taguchi method gave significant (3 fold) enhancement of dextransucrase activity as compared to unoptimised enzyme activity of 6.0 U/ml. The dextransucrase production was scaled up in lab scale bioreactor resulting in further enhancement of enzyme activity (22.0 U/ml).展开更多
Taxonomic studies of the Odorrana versabilis group have been consistently disorganized,and they have often been incorrectly associated with an abandoned subgenus or genus Bamburana in existing literature.In this study...Taxonomic studies of the Odorrana versabilis group have been consistently disorganized,and they have often been incorrectly associated with an abandoned subgenus or genus Bamburana in existing literature.In this study,we conducted an integrative taxonomic analysis using molecular phylogenetic analysis of two mitochondrial gene fragments(16S rRNA and CO1)and morphological examination of 41 specimens collected during herpetological surveys in southern China.Our results confirmed the monophyly of O.versabilis group which exhibited distinct morphological traits.We also identified a cryptic lineage sister with O.exiliversabilis.Additionally,our study revealed that O.trankieni was nested within O.nasuta.Consequently,we redefined the morphological characteristics of the O.versabilis group,described a new species in this group,O.confusa sp.nov.,and proposed that O.trankieni be considered a junior synonym of O.nasuta.One of the most significant findings of this study was the observation of distinct morphological changes in adult males across all species within the O.versabilis group between the non-breeding and breeding seasons.This study contributes to research on various aspects of Asian amphibian fauna,including taxonomy,ecology,evolution,and physiology.展开更多
文摘The influence of medium ingredients on extracellular dextransucrase production by a new bacterial strain Weissella confusa Cab3 (Genbank Accession Number JX649223) was evaluated using fractional factorial design of Taguchi's orthogonal array. Four metabolism influencing factors viz. sucrose, yeast extract, K2HPO4 and Tween80 were selected to optimize dextransucrase production by W. confusa Cab3 using fractional factorial design of Taguchi methodology. Based on the influence of interaction components of fermentation, least significant factors of individual level have higher interaction severity index and vice versa for enzyme production from Weissella confusa Cab3. Sucrose and yeast extract were found to be the most significant factors which positively influenced the dextransucrase production. The optimized medium composition consisted of sucrose—5%;yeast extract—2%;K2HPO4—1.0%;Tween80—0.5%, based on Taguchi orthogonal array method. The optimized composition gave an experimental value of dextransucrase activity of 17.9 U/ml at shake flask level which corresponded well with the predicted value of 17.54 U/ml by the model. The optimized medium by Taguchi method gave significant (3 fold) enhancement of dextransucrase activity as compared to unoptimised enzyme activity of 6.0 U/ml. The dextransucrase production was scaled up in lab scale bioreactor resulting in further enhancement of enzyme activity (22.0 U/ml).
基金This work was supported by DFGP Project of Fauna of Guangdong-202115Nanling National Park Construction Project(No.ZD22-ZC016AG)2022 Wildlife Monitoring Projects of the Guangdong Forestry Bureau,and the National Animal Collection Resource Center,China.
文摘Taxonomic studies of the Odorrana versabilis group have been consistently disorganized,and they have often been incorrectly associated with an abandoned subgenus or genus Bamburana in existing literature.In this study,we conducted an integrative taxonomic analysis using molecular phylogenetic analysis of two mitochondrial gene fragments(16S rRNA and CO1)and morphological examination of 41 specimens collected during herpetological surveys in southern China.Our results confirmed the monophyly of O.versabilis group which exhibited distinct morphological traits.We also identified a cryptic lineage sister with O.exiliversabilis.Additionally,our study revealed that O.trankieni was nested within O.nasuta.Consequently,we redefined the morphological characteristics of the O.versabilis group,described a new species in this group,O.confusa sp.nov.,and proposed that O.trankieni be considered a junior synonym of O.nasuta.One of the most significant findings of this study was the observation of distinct morphological changes in adult males across all species within the O.versabilis group between the non-breeding and breeding seasons.This study contributes to research on various aspects of Asian amphibian fauna,including taxonomy,ecology,evolution,and physiology.
