Under the optimal condition of copper ions adsorption on yeast,we found some different effects among static adsorption, shaking adsorption and negative pressure cavitation adsorption, and the methods of yeast with dif...Under the optimal condition of copper ions adsorption on yeast,we found some different effects among static adsorption, shaking adsorption and negative pressure cavitation adsorption, and the methods of yeast with different pretreatments also affect adsorption of copper ions. At the same time, the change of intercellular pH before and after adsorption of copper with BCECF was studied. The copper distribution was located by using PhenGreen （dipotassium salt and diacetate）, and the surface of yeast was observed by an atomic force microscope. The results showed that negative pressure cavitation can improve bioadsorption capacity of copper ions on yeast. However, the yeasts＇ pretreatment has a higher effect on bioadsorption. It indicates that heavy metal bioadsorption on yeast has much relation with its cellular molecule basis. With the adsorping, the intercellular pH of yeast increased gradually and changed from acidity to alkalescence. These results may suggest that negative pressure cavitation can compel heavy metals to transfer from the cell surface into inside cell and make the surface of yeast coarse.展开更多
The growth ofCandida utilis NRRL Y-1084 in acid and enzymatic hydrolysates of cassava peel and on glucose in a mineral salts medium was investigated in aerobic submerged cultivation. Kinetic and stoichiometric paramet...The growth ofCandida utilis NRRL Y-1084 in acid and enzymatic hydrolysates of cassava peel and on glucose in a mineral salts medium was investigated in aerobic submerged cultivation. Kinetic and stoichiometric parameters for growth were determined. The cardinal temperatures of this yeast strain were 14 ℃, 33 ℃ and 41 ℃. C. utilis exhibited no absolute requirement for growth factors, although its maximum specific growth rate （μmax） was higher in the mineral salts medium with yeast extract than without, but its biomass yield coefficient （Yx/s） did not differ much in these two media. In the enzymatic hydrolysate, its Yx/s value on sugar was 0.44 with a μmax of 0.35 h^-1, whereas the corresponding values were 0.52 and 0.48 h^-1 in the acid hydrolysate and 0.50 and 0.37 h^-1 in the mineral salts medium without yeast extract. The crude protein content of biomass grown in the glucose medium and the acid and enzymatic hydrolysates were 47.5%, 49.1% and 56.7%, respectively. The amino acid profile of the yeast biomass compared favourably with the FAO standard. Cassava peel hydrolysate has potential as a cheap carbohydrate feedstock for the production of yeast single cell protein by using C. utilis.展开更多
Yeast single cell protein(SCP)is a nutritious protein supplement of artificial feed and food.It is expected that yeast cells grow on nonfood feedstocks instead of agricultural sugars for synthesizing high-quality prot...Yeast single cell protein(SCP)is a nutritious protein supplement of artificial feed and food.It is expected that yeast cells grow on nonfood feedstocks instead of agricultural sugars for synthesizing high-quality proteins.Herein,the protein content and quality of the edible yeast Candida utilis were investigated on utilizing ability of carbon and nitrogen sources.We found that dihydroxyacetone(DHA),a feedstock that can be chemically or enzymatically generated from one-carbon(C1)compounds such as methane,methanol and even CO_(2),was comparable with glucose but superior to acetate for C.utilis protein production.The essential amino acid score(EAAS)of DHA-cultured C.utilis protein not only met FAO/WHO(2013)standard,but also surpassed that of benchmark soybean and fish feed.Fed-batch fermentation of C.utilis utilizing DHA feedstock in a 5 L fermenter performed a growth rate of 1.3 g DCW L^(−1) h^(−1) and a total of 34.8 g L^(−1) biomass with the protein content of 60.1%DW,validating scale-up production.This work highlights that C.utilis SCP derived from low-carbon source is a high-quality protein for advancing sustainable feed and food supply.展开更多
基金The National Basic Research Program (973) of China (No. 2004CB418505)
文摘Under the optimal condition of copper ions adsorption on yeast,we found some different effects among static adsorption, shaking adsorption and negative pressure cavitation adsorption, and the methods of yeast with different pretreatments also affect adsorption of copper ions. At the same time, the change of intercellular pH before and after adsorption of copper with BCECF was studied. The copper distribution was located by using PhenGreen （dipotassium salt and diacetate）, and the surface of yeast was observed by an atomic force microscope. The results showed that negative pressure cavitation can improve bioadsorption capacity of copper ions on yeast. However, the yeasts＇ pretreatment has a higher effect on bioadsorption. It indicates that heavy metal bioadsorption on yeast has much relation with its cellular molecule basis. With the adsorping, the intercellular pH of yeast increased gradually and changed from acidity to alkalescence. These results may suggest that negative pressure cavitation can compel heavy metals to transfer from the cell surface into inside cell and make the surface of yeast coarse.
文摘The growth ofCandida utilis NRRL Y-1084 in acid and enzymatic hydrolysates of cassava peel and on glucose in a mineral salts medium was investigated in aerobic submerged cultivation. Kinetic and stoichiometric parameters for growth were determined. The cardinal temperatures of this yeast strain were 14 ℃, 33 ℃ and 41 ℃. C. utilis exhibited no absolute requirement for growth factors, although its maximum specific growth rate （μmax） was higher in the mineral salts medium with yeast extract than without, but its biomass yield coefficient （Yx/s） did not differ much in these two media. In the enzymatic hydrolysate, its Yx/s value on sugar was 0.44 with a μmax of 0.35 h^-1, whereas the corresponding values were 0.52 and 0.48 h^-1 in the acid hydrolysate and 0.50 and 0.37 h^-1 in the mineral salts medium without yeast extract. The crude protein content of biomass grown in the glucose medium and the acid and enzymatic hydrolysates were 47.5%, 49.1% and 56.7%, respectively. The amino acid profile of the yeast biomass compared favourably with the FAO standard. Cassava peel hydrolysate has potential as a cheap carbohydrate feedstock for the production of yeast single cell protein by using C. utilis.
基金the Fundamental Research Center of Artificial Photosynthesis(FReCAP)financially supported by the National Key R&D Program of China(No.2022YFC2105900)+1 种基金the National Natural Science Foundation of China(22088102)Joint Fund of the Yulin University and the Dalian National Laboratory for Clean Energy(Grant:YLU-DNL Fund 2023003).
文摘Yeast single cell protein(SCP)is a nutritious protein supplement of artificial feed and food.It is expected that yeast cells grow on nonfood feedstocks instead of agricultural sugars for synthesizing high-quality proteins.Herein,the protein content and quality of the edible yeast Candida utilis were investigated on utilizing ability of carbon and nitrogen sources.We found that dihydroxyacetone(DHA),a feedstock that can be chemically or enzymatically generated from one-carbon(C1)compounds such as methane,methanol and even CO_(2),was comparable with glucose but superior to acetate for C.utilis protein production.The essential amino acid score(EAAS)of DHA-cultured C.utilis protein not only met FAO/WHO(2013)standard,but also surpassed that of benchmark soybean and fish feed.Fed-batch fermentation of C.utilis utilizing DHA feedstock in a 5 L fermenter performed a growth rate of 1.3 g DCW L^(−1) h^(−1) and a total of 34.8 g L^(−1) biomass with the protein content of 60.1%DW,validating scale-up production.This work highlights that C.utilis SCP derived from low-carbon source is a high-quality protein for advancing sustainable feed and food supply.
