Influence of the combination of nutrient feed with dissolved oxygen control on taxol production in suspension cultures of Taxus chinensis (Pilg.) Rehd. was investigated in bioreactors. Addition of feeding medium with ...Influence of the combination of nutrient feed with dissolved oxygen control on taxol production in suspension cultures of Taxus chinensis (Pilg.) Rehd. was investigated in bioreactors. Addition of feeding medium with 20 g/L sucrose on day 16 enhanced both the biomass and taxol production in 5-L bioreactors. Further investigation of the fed-batch cultures in a 20-L bioreactor showed that cultivation under a low dissolved oxygen tension (DOT) of 20% for the entire culture resulted in the highest taxol content of 0.98 mg/g DW, while the taxol production was lower than that with 40% and 60% DOT. Moreover, taxol accumulation was remarkably improved by the cultivation of cells initially under DOT of 60% for 20 d followed by changing the DOT to 20% for another 12 d. By combining the use of these two strategies, a maximum taxol content of 18.7 mg/L was obtained in a 20-L bioreactor.展开更多
In complex feed structures, there exist main chemical functional groups which are associated with nutrient utilization and availability and functionality. Each functional group has unique molecular structure therefore...In complex feed structures, there exist main chemical functional groups which are associated with nutrient utilization and availability and functionality. Each functional group has unique molecular structure therefore produce unique molecular vibration spectral profile. Feed processing has been used to improve nutrient utilization for many years. However, to date, there was little study on processing-induced changes of feed intrinsic structure and functional groups on a molecular basis within intact tissue. This is because limited research technique is available to study inherent structure on a molecular basis. Recently bioanalytical techniques： such as Synchrotron Infrared Microspectroscopy as well as Diffuse Reflectance Infrared Fourier Transform molecular spectroscopy have been developed. These techniques enable to detect molecular structure change within intact tissues. These techniques can prevent destruction or alteration of the intrinsic protein structures during processing for analysis. However, these techniques have not been used in animal feed and nutrition research. The objective of this review was show that with the advanced technique, sensitivity and responses of functional groups to feed processing on a molecular basis could be detected in my research team. These functional groups are highly associated with nutrient utilization in animals.展开更多
Mortality is normal and natural in aquaculture experiments. However, it becomes a problem when measuring feed intake as a component of nutrient utilization parameters such as： feed conversion ratio, feed conversion e...Mortality is normal and natural in aquaculture experiments. However, it becomes a problem when measuring feed intake as a component of nutrient utilization parameters such as： feed conversion ratio, feed conversion efficiency, apparent net protein utilization, protein efficiency ratio and protein productive value. In order to accurately evaluate feed intake with due consideration of mortality encountered, a formulae was developed using empirical data obtained from an experiement that had mortality. The formulae Fwas： total feed consumed by numbers of survived fishes=DL∑i=1n（Fi/Ni）N. Where, D=Numbers of days fishes were fed within each period ibefore it was adjusted（e.g fortnight）, it was constant throught period of experiment; F=Uantity of feed fed per day for a fortnight before the quantity was adjusted, it changed every fortnight; L=Numbers of living fishes at the end of experimental period; N=Numbers of fishes at each weighing period, it might change every fortnight or might be constant if no mortality occurred; while n=Numbers of times fishes were weighed and quantity of feed was adjusted but this did not include the final weighing at the termination of experiment. However, if the fishes were weighed weekly, then D=6.展开更多
Background： To our knowledge, there is little study on the interaction between nutrient availability and molecular structure changes induced by different processing methods in dairy cattle. The objective of this stud...Background： To our knowledge, there is little study on the interaction between nutrient availability and molecular structure changes induced by different processing methods in dairy cattle. The objective of this study was to investigate the effect of heat processing methods on interaction between nutrient availability and molecular structure in terms of functional groups that are related to protein and starch inherent structure of oat grains with two continued years and three replication of each year.Method： The oat grains were kept as raw（control） or heated in an air-draft oven（dry roasting： DO） at 120 °C for 60 min and under microwave irradiation（MIO） for 6 min. The molecular structure features were revealed by vibrational infrared molecular spectroscopy.Results： The results showed that rumen degradability of dry matter, protein and starch was significantly lower（P 〈0.05） for MIO compared to control and DO treatments. A higher protein α-helix to β-sheet and a lower amide I to starch area ratio were observed for MIO compared to DO and/or raw treatment. A negative correlation（-0.99, P 〈 0.01）was observed between α-helix or amide I to starch area ratio and dry matter. A positive correlation（0.99, P 〈 0.01） was found between protein β-sheet and crude protein.Conclusion： The results reveal that oat grains are more sensitive to microwave irradiation than dry heating in terms of protein and starch molecular profile and nutrient availability in ruminants.展开更多
Two consecutive growth studies were conducted to investigate the age-dependent nutrient and energy deposition in male and female meat-type chickens (Ross 308) based on feather and feather-free body fraction data deter...Two consecutive growth studies were conducted to investigate the age-dependent nutrient and energy deposition in male and female meat-type chickens (Ross 308) based on feather and feather-free body fraction data determined according to the comparative slaughter technique. Birds were reared under standardized housing conditions (15 floor pens per gender, 5 birds per pen). Both the starter (day 1 to 22) and grower diets (day 22 to 36) were based on corn, wheat, soybean meal, soybean protein concentrate and crystalline feed amino acids. Diets were formulated to ensure an equal feed protein quality close to the ideal amino acid ratio by adjusting a constant mixture of the feed proteins. Individual body weight (BW) and feed intake per pen were recorded weekly. At the start (day 1) as well as on a weekly basis until the end of the 5th week, 15 birds per gender (each 3 pens of 5 birds) were selected and euthanized following 24 h feed deprivation. Subsequently, the feathers were manually removed and quantified. Crude nutrient analysed in representative samples of both feather and feather-free body fractions. The nutrient and energy deposition in the bodies of both genders were significantly increased with increasing age (p . Male birds deposited significantly higher body protein (p and female birds significantly more fat and energy in the whole body (p during the entire growth period. In contrast, no differences were found in protein contents of the BW gain between genders dependent on age (p > 0.05). However, the protein partitioning in the gain of both analyzed body fractions provided oppositional results. Accordingly, male birds yielded relatively more protein in the feather-free body fraction (p and females relatively more feather protein (p as related to the whole body protein gain.展开更多
文摘Influence of the combination of nutrient feed with dissolved oxygen control on taxol production in suspension cultures of Taxus chinensis (Pilg.) Rehd. was investigated in bioreactors. Addition of feeding medium with 20 g/L sucrose on day 16 enhanced both the biomass and taxol production in 5-L bioreactors. Further investigation of the fed-batch cultures in a 20-L bioreactor showed that cultivation under a low dissolved oxygen tension (DOT) of 20% for the entire culture resulted in the highest taxol content of 0.98 mg/g DW, while the taxol production was lower than that with 40% and 60% DOT. Moreover, taxol accumulation was remarkably improved by the cultivation of cells initially under DOT of 60% for 20 d followed by changing the DOT to 20% for another 12 d. By combining the use of these two strategies, a maximum taxol content of 18.7 mg/L was obtained in a 20-L bioreactor.
基金supported by grants from the Natural Sciences and Engineering Research Council of Canada (NSERC)SaskCanola Funding+1 种基金Saskatchewan Agricultural Development Fund (ADF)Ministry of Agriculture Strategic Research Chair Fund (Saskatchewan,Canada)
文摘In complex feed structures, there exist main chemical functional groups which are associated with nutrient utilization and availability and functionality. Each functional group has unique molecular structure therefore produce unique molecular vibration spectral profile. Feed processing has been used to improve nutrient utilization for many years. However, to date, there was little study on processing-induced changes of feed intrinsic structure and functional groups on a molecular basis within intact tissue. This is because limited research technique is available to study inherent structure on a molecular basis. Recently bioanalytical techniques： such as Synchrotron Infrared Microspectroscopy as well as Diffuse Reflectance Infrared Fourier Transform molecular spectroscopy have been developed. These techniques enable to detect molecular structure change within intact tissues. These techniques can prevent destruction or alteration of the intrinsic protein structures during processing for analysis. However, these techniques have not been used in animal feed and nutrition research. The objective of this review was show that with the advanced technique, sensitivity and responses of functional groups to feed processing on a molecular basis could be detected in my research team. These functional groups are highly associated with nutrient utilization in animals.
文摘Mortality is normal and natural in aquaculture experiments. However, it becomes a problem when measuring feed intake as a component of nutrient utilization parameters such as： feed conversion ratio, feed conversion efficiency, apparent net protein utilization, protein efficiency ratio and protein productive value. In order to accurately evaluate feed intake with due consideration of mortality encountered, a formulae was developed using empirical data obtained from an experiement that had mortality. The formulae Fwas： total feed consumed by numbers of survived fishes=DL∑i=1n（Fi/Ni）N. Where, D=Numbers of days fishes were fed within each period ibefore it was adjusted（e.g fortnight）, it was constant throught period of experiment; F=Uantity of feed fed per day for a fortnight before the quantity was adjusted, it changed every fortnight; L=Numbers of living fishes at the end of experimental period; N=Numbers of fishes at each weighing period, it might change every fortnight or might be constant if no mortality occurred; while n=Numbers of times fishes were weighed and quantity of feed was adjusted but this did not include the final weighing at the termination of experiment. However, if the fishes were weighed weekly, then D=6.
基金supported by grants from the Prairie Oat Grower Association(POGA)Natural Sciences and Engineering Research Council of Canada(NSERC-federal government)Ministry of Agriculture Strategic Research Chair(PY)Program
文摘Background： To our knowledge, there is little study on the interaction between nutrient availability and molecular structure changes induced by different processing methods in dairy cattle. The objective of this study was to investigate the effect of heat processing methods on interaction between nutrient availability and molecular structure in terms of functional groups that are related to protein and starch inherent structure of oat grains with two continued years and three replication of each year.Method： The oat grains were kept as raw（control） or heated in an air-draft oven（dry roasting： DO） at 120 °C for 60 min and under microwave irradiation（MIO） for 6 min. The molecular structure features were revealed by vibrational infrared molecular spectroscopy.Results： The results showed that rumen degradability of dry matter, protein and starch was significantly lower（P 〈0.05） for MIO compared to control and DO treatments. A higher protein α-helix to β-sheet and a lower amide I to starch area ratio were observed for MIO compared to DO and/or raw treatment. A negative correlation（-0.99, P 〈 0.01）was observed between α-helix or amide I to starch area ratio and dry matter. A positive correlation（0.99, P 〈 0.01） was found between protein β-sheet and crude protein.Conclusion： The results reveal that oat grains are more sensitive to microwave irradiation than dry heating in terms of protein and starch molecular profile and nutrient availability in ruminants.
文摘Two consecutive growth studies were conducted to investigate the age-dependent nutrient and energy deposition in male and female meat-type chickens (Ross 308) based on feather and feather-free body fraction data determined according to the comparative slaughter technique. Birds were reared under standardized housing conditions (15 floor pens per gender, 5 birds per pen). Both the starter (day 1 to 22) and grower diets (day 22 to 36) were based on corn, wheat, soybean meal, soybean protein concentrate and crystalline feed amino acids. Diets were formulated to ensure an equal feed protein quality close to the ideal amino acid ratio by adjusting a constant mixture of the feed proteins. Individual body weight (BW) and feed intake per pen were recorded weekly. At the start (day 1) as well as on a weekly basis until the end of the 5th week, 15 birds per gender (each 3 pens of 5 birds) were selected and euthanized following 24 h feed deprivation. Subsequently, the feathers were manually removed and quantified. Crude nutrient analysed in representative samples of both feather and feather-free body fractions. The nutrient and energy deposition in the bodies of both genders were significantly increased with increasing age (p . Male birds deposited significantly higher body protein (p and female birds significantly more fat and energy in the whole body (p during the entire growth period. In contrast, no differences were found in protein contents of the BW gain between genders dependent on age (p > 0.05). However, the protein partitioning in the gain of both analyzed body fractions provided oppositional results. Accordingly, male birds yielded relatively more protein in the feather-free body fraction (p and females relatively more feather protein (p as related to the whole body protein gain.
