Modern aquaculture must be sustainable in terms of energy consumption, raw materials used, and environmental impact, so alternatives are needed to replace fish feed with other raw materials. Enzyme use in the agri-foo...Modern aquaculture must be sustainable in terms of energy consumption, raw materials used, and environmental impact, so alternatives are needed to replace fish feed with other raw materials. Enzyme use in the agri-food industry is based on their efficiency, safety, and protection of the environment, which aligns with the requirements of a resource-saving production system. Enzyme supplementation in fish feed can improve digestibility and absorption of both plant- and animal-derived ingredients, increasing the growth parameters of aquacultural animals. Herein we summarized the recent literature that reported the use of digestive enzymes (amylases, lipases, proteases, cellulases, and hemicellulases) and non-digestive enzymes (phytases, glucose oxidase, and lysozyme) in fish feed. In addition, we analyzed how critical steps of the pelleting process, including microencapsulation and immobilization, can interfere with enzyme activity in the final fish feed product.展开更多
Alginate oligosaccharides(AOS),extracted from marine brown algae,are a common functional feed additive;however,it remains unclear whether they modulate the gut microbiota and microbial metabolites.The response of Salm...Alginate oligosaccharides(AOS),extracted from marine brown algae,are a common functional feed additive;however,it remains unclear whether they modulate the gut microbiota and microbial metabolites.The response of Salmonella enterica serovar Typhimurium,a common poultry pathogen,to AOS fermented with chicken fecal inocula was investigated using metabolomic and transcriptomic analyses.Single-strain cultivation tests showed that AOS did not directly inhibit the growth of S.Typhimurium.However,when AOS were fermented by chicken fecal microbiota,the supernatant of fermented AOS(F-AOS)exhibited remarkable antibacterial activity against S.Typhimurium,decreasing the abundance ratio of S.Typhimurium in the fecal microbiota from 18.94 to 2.94%.Transcriptomic analyses showed that the 855 diferentially expressed genes induced by F-AOS were mainly enriched in porphyrin and chlorophyll metabolism,oxidative phosphorylation,and Salmonella infection-related pathways.RT-qPCR confrmed that F-AOS downregulated key genes involved in fagellar assembly and the type III secretory system of S.Typhimurium,indicating metabolites in F-AOS can infuence the growth and metabolism of S.Typhimurium.Metabolomic analyses showed that 205 microbial metabolites were signifcantly altered in F-AOS.Among them,the increase in indolelactic acid and 3-indolepropionic acid levels were further confrmed using HPLC.This study provides a new perspective for the application of AOS as a feed additive against pathogenic intestinal bacteria.展开更多
Carrageenan oligosaccharides are important products that have demonstrated numerous bioactivities useful in the food,medicine,and cosmetics industries.However,the specifc structure–function relationships of carrageen...Carrageenan oligosaccharides are important products that have demonstrated numerous bioactivities useful in the food,medicine,and cosmetics industries.However,the specifc structure–function relationships of carrageenan oligosaccharides are not clearly described due to the defciency of high specifc carrageenases.Here,a truncated mutant OUC-FaKC16Q based on the reportedκ-neocarratetrose(Nκ4)-producingκ-carrageenase OUC-FaKC16A from Flavobacterium algicola was constructed and further studied.After truncating the C-terminal Por_Secre_tail(PorS)domain(responsible for substrate binding),the catalytic efciency and temperature stability decreased to a certain extent.Surprisingly,this truncation also enabled OUC-FaKC16Q to hydrolyze Nκ4 intoκ-neocarrabiose(Nκ2).The ofset of Arg265 residue in OUC-FaKC16Q may explain this change.Moreover,the high catalytic abilities,the main products,and the degradation modes of OUC-FaKC16A and OUC-FaKC16Q toward furcellaran were also demonstrated.Data suggested OUC-FaKC16A and OUC-FaKC16Q could hydrolyze furcellaran to produce mainly the desulfated oligosaccharides DA-G-(DA-G4S)2 and DA-G-DA-G4S,respectively.As a result,the spectrum of products ofκ-carrageenase OUC-FaKC16A has been fully expanded in this study,indicating its promising potential for application in the biomanufacturing of carrageenan oligosaccharides with specifc structures.展开更多
基金supported by the National Key Research and Development Program of China(2019YFD0900201)by the National Research Council of Italy(CNR)in the contest of the bilateral project(CNR Prot.n.0082796/2020)between CNRthe Ministry of Science and Technology of the People’s Republic of China(MOST).
文摘Modern aquaculture must be sustainable in terms of energy consumption, raw materials used, and environmental impact, so alternatives are needed to replace fish feed with other raw materials. Enzyme use in the agri-food industry is based on their efficiency, safety, and protection of the environment, which aligns with the requirements of a resource-saving production system. Enzyme supplementation in fish feed can improve digestibility and absorption of both plant- and animal-derived ingredients, increasing the growth parameters of aquacultural animals. Herein we summarized the recent literature that reported the use of digestive enzymes (amylases, lipases, proteases, cellulases, and hemicellulases) and non-digestive enzymes (phytases, glucose oxidase, and lysozyme) in fish feed. In addition, we analyzed how critical steps of the pelleting process, including microencapsulation and immobilization, can interfere with enzyme activity in the final fish feed product.
基金This work was supported by the National Key Research and Development Program of China(2019YFD0901800 and 2019YFD0900201)National Natural Science Foundation of China(32202064)China Postdoctoral Science Foundation(2021M701547).
文摘Alginate oligosaccharides(AOS),extracted from marine brown algae,are a common functional feed additive;however,it remains unclear whether they modulate the gut microbiota and microbial metabolites.The response of Salmonella enterica serovar Typhimurium,a common poultry pathogen,to AOS fermented with chicken fecal inocula was investigated using metabolomic and transcriptomic analyses.Single-strain cultivation tests showed that AOS did not directly inhibit the growth of S.Typhimurium.However,when AOS were fermented by chicken fecal microbiota,the supernatant of fermented AOS(F-AOS)exhibited remarkable antibacterial activity against S.Typhimurium,decreasing the abundance ratio of S.Typhimurium in the fecal microbiota from 18.94 to 2.94%.Transcriptomic analyses showed that the 855 diferentially expressed genes induced by F-AOS were mainly enriched in porphyrin and chlorophyll metabolism,oxidative phosphorylation,and Salmonella infection-related pathways.RT-qPCR confrmed that F-AOS downregulated key genes involved in fagellar assembly and the type III secretory system of S.Typhimurium,indicating metabolites in F-AOS can infuence the growth and metabolism of S.Typhimurium.Metabolomic analyses showed that 205 microbial metabolites were signifcantly altered in F-AOS.Among them,the increase in indolelactic acid and 3-indolepropionic acid levels were further confrmed using HPLC.This study provides a new perspective for the application of AOS as a feed additive against pathogenic intestinal bacteria.
基金This work was supported by the National Key Research and Development Program of China(2022YFF1100202)Natural Science Foundation of Shandong Province(ZR2020JQ15)+1 种基金Taishan Scholar Project of Shandong Province(tsqn201812020)Fundamental Research Funds for the Central Universities(201941002).
文摘Carrageenan oligosaccharides are important products that have demonstrated numerous bioactivities useful in the food,medicine,and cosmetics industries.However,the specifc structure–function relationships of carrageenan oligosaccharides are not clearly described due to the defciency of high specifc carrageenases.Here,a truncated mutant OUC-FaKC16Q based on the reportedκ-neocarratetrose(Nκ4)-producingκ-carrageenase OUC-FaKC16A from Flavobacterium algicola was constructed and further studied.After truncating the C-terminal Por_Secre_tail(PorS)domain(responsible for substrate binding),the catalytic efciency and temperature stability decreased to a certain extent.Surprisingly,this truncation also enabled OUC-FaKC16Q to hydrolyze Nκ4 intoκ-neocarrabiose(Nκ2).The ofset of Arg265 residue in OUC-FaKC16Q may explain this change.Moreover,the high catalytic abilities,the main products,and the degradation modes of OUC-FaKC16A and OUC-FaKC16Q toward furcellaran were also demonstrated.Data suggested OUC-FaKC16A and OUC-FaKC16Q could hydrolyze furcellaran to produce mainly the desulfated oligosaccharides DA-G-(DA-G4S)2 and DA-G-DA-G4S,respectively.As a result,the spectrum of products ofκ-carrageenase OUC-FaKC16A has been fully expanded in this study,indicating its promising potential for application in the biomanufacturing of carrageenan oligosaccharides with specifc structures.
