Chinese Academy of Fishery Sciences

About: Chinese Academy of Fishery Sciences is a nonprofit organization based out in Beijing, China. It is known for research contribution in the topics: Population & Gene. The organization has 8107 authors who have published 7929 publications receiving 92095 citations. The organization is also known as: Zhōngguó shuǐchǎn Kēxuéyánjiūyuàn & Chinese Academy of Fishery Sciences.

Evidence of Coexistence of C3 and C4 Photosynthetic Pathways in a Green-Tide-Forming Alga, Ulva prolifera

Abstract: Ulva prolifera, a typical green-tide-forming alga, can accumulate a large biomass in a relatively short time period, suggesting that photosynthesis in this organism, particularly its carbon fixation pathway, must be very efficient. Green algae are known to generally perform C3 photosynthesis, but recent metabolic labeling and genome sequencing data suggest that they may also perform C4 photosynthesis, so C4 photosynthesis might be more wide-spread than previously anticipated. Both C3 and C4 photosynthesis genes were found in U. prolifera by transcriptome sequencing. We also discovered the key enzymes of C4 metabolism based on functional analysis, such as pyruvate orthophosphate dikinase (PPDK), phosphoenolpyruvate carboxylase (PEPC), and phosphoenolpyruvate carboxykinase (PCK). To investigate whether the alga operates a C4-like pathway, the expression of rbcL and PPDK and their enzyme activities were measured under various forms and intensities of stress (differing levels of salinity, light intensity, and temperature). The expression of rbcL and PPDK and their enzyme activities were higher under adverse circumstances. However, under conditions of desiccation, the expression of rbcL and ribulose-1, 5-biphosphate carboxylase (RuBPCase) activity was lower, whereas that of PPDK was higher. These results suggest that elevated PPDK activity may alter carbon metabolism and lead to a partial operation of C4-type carbon metabolism in U. prolifera, probably contributing to its wide distribution and massive, repeated blooms in the Yellow Sea.

Effects of non‐starch polysaccharides enzyme, phytase and citric acid on activities of endogenous digestive enzymes of tilapia (Oreochromis niloticus × Oreochromis aureus)

Abstract: Non-starch polysaccharides (NSPs) enzyme, phytase and citric acid have been shown to increase digestibility in pigs, poultry and some fish. To examine their roles in digestion in tilapia (Oreochromis niloticus × Oreochromis aureus), the present study was designed to evaluate their effects on activities of a number of endogenous digestive enzymes in tilapia. Neither NSPs enzyme (1 g kg−1) nor phytase (1 g kg−1) affected the activities of protease in digestive organs. In contrast, NSPs enzyme increased the activities of amylase in the hepatopancreas and intestine by 11.4% and 49.5%, respectively, while phytase (1 g kg−1) increased the activities of amylase in the hepatopancreas and intestine by 14.0% and 24.1%, respectively. Citric acid (10 g kg−1) increased the activities of protease in stomach by 29.6%, but reduced the activities of protease in the intestine by 35.1%. Citric acid increased the activities of amylase in the hepatopancreas and intestine by 30.7% and 29.4%. Lipase activities were not affected by NSPs enzyme, phytase or citric acid. Above results suggest that NSPs enzyme, phytase and citric acid primarily influence the activities of amylase in digestive tract of tilapia.