Large numbers of bacteria live on the surface of various brown algae and can produce alginate lyases to consume alginate,an important component of the cell wall of brown algae.Sargassum is a genus of the largest canop...Large numbers of bacteria live on the surface of various brown algae and can produce alginate lyases to consume alginate,an important component of the cell wall of brown algae.Sargassum is a genus of the largest canopyforming brown algae of more than 150 species,which are widely distributed in tropical and subtropical environments.However,our knowledge about the epiphytic bacteria and the alginate lyase-excreting bacteria from Sargassum is still primitive.Here,we investigated the diversity of the culturable epiphytic bacteria and alginate-degrading bacteria from Sargassum samples collected from the coastal seawaters of Shandong Province,China.In total,37 strains belonging to 21 genera in 3 phyla were isolated,including 15 previously unreported genera,of which Vibrio(6/37)and Pseudoalteromonas(5/37)are the dominant genera.Eight strains,mainly Vibrio and Pseudoalteromonas species,were further identified as alginate lyase-excreting strains that can utilize alginate for growth.The extracellular alginolytic activity of the 8 strains was determined,and strains Vibrio sp.C42and Pseudoalteromonas sp.M9 showed the highest activity.These results provide a better understanding of brown algae epiphytes and alginate-degrading bacteria,and are fundamental for further studies on the interactions between brown algae and their epiphytes.展开更多
为了充分利用海藻资源,改善磷酸盐对鱼糜制品的保水性,丰富鱼糜保水剂市场的多样性,本研究以褐藻中的铜藻为主要原料,经过提取海藻酸钠,并混合磷酸盐及谷氨酰胺转氨酶等开发制取新型鲅鱼糜保水剂。铜藻海藻酸钠经酸法提取、膜过滤纯化后...为了充分利用海藻资源,改善磷酸盐对鱼糜制品的保水性,丰富鱼糜保水剂市场的多样性,本研究以褐藻中的铜藻为主要原料,经过提取海藻酸钠,并混合磷酸盐及谷氨酰胺转氨酶等开发制取新型鲅鱼糜保水剂。铜藻海藻酸钠经酸法提取、膜过滤纯化后,通过高效液相色谱、紫外光谱和红外光谱分析其组成和化学结构,并测定其主要质构参数。通过单因素实验和正交实验,优化确定复合保水剂的配方组成。结果表明:1)分离纯化后的铜藻海藻酸钠纯度较高,具有较好的弹性、强度和黏度,质构特性明显优于海带海藻酸钠。其中,铜藻海藻酸钠黏度168.50 m Pa·s,明显高于海带海藻酸钠的130.30 m Pa·s;硬度56.33 N,明显低于海带海藻酸钠的72.17 N。2)正交实验表明:将0.10%焦磷酸钠与0.20%六偏磷酸钠、0.15%三聚磷酸钠、2.00%大豆分离蛋白、0.30%谷氨酰胺转氨酶和0.40%的铜藻海藻酸钠混合配制而成的保水剂,其解冻损失率和蒸煮损失率较低,且低于其他3种保水剂。本研究表明,由铜藻提取的海藻酸钠与磷酸盐等混配制成的复合保水剂具有很好的保水效果,可用作鲅鱼糜及其他鱼糜的保水剂。展开更多
基金The National Natural Science Foundation of China under contract Nos 32170127 and 42176156the Fundamental Research Funds for the Central Universities under contract No.202141006。
文摘Large numbers of bacteria live on the surface of various brown algae and can produce alginate lyases to consume alginate,an important component of the cell wall of brown algae.Sargassum is a genus of the largest canopyforming brown algae of more than 150 species,which are widely distributed in tropical and subtropical environments.However,our knowledge about the epiphytic bacteria and the alginate lyase-excreting bacteria from Sargassum is still primitive.Here,we investigated the diversity of the culturable epiphytic bacteria and alginate-degrading bacteria from Sargassum samples collected from the coastal seawaters of Shandong Province,China.In total,37 strains belonging to 21 genera in 3 phyla were isolated,including 15 previously unreported genera,of which Vibrio(6/37)and Pseudoalteromonas(5/37)are the dominant genera.Eight strains,mainly Vibrio and Pseudoalteromonas species,were further identified as alginate lyase-excreting strains that can utilize alginate for growth.The extracellular alginolytic activity of the 8 strains was determined,and strains Vibrio sp.C42and Pseudoalteromonas sp.M9 showed the highest activity.These results provide a better understanding of brown algae epiphytes and alginate-degrading bacteria,and are fundamental for further studies on the interactions between brown algae and their epiphytes.
文摘为了充分利用海藻资源,改善磷酸盐对鱼糜制品的保水性,丰富鱼糜保水剂市场的多样性,本研究以褐藻中的铜藻为主要原料,经过提取海藻酸钠,并混合磷酸盐及谷氨酰胺转氨酶等开发制取新型鲅鱼糜保水剂。铜藻海藻酸钠经酸法提取、膜过滤纯化后,通过高效液相色谱、紫外光谱和红外光谱分析其组成和化学结构,并测定其主要质构参数。通过单因素实验和正交实验,优化确定复合保水剂的配方组成。结果表明:1)分离纯化后的铜藻海藻酸钠纯度较高,具有较好的弹性、强度和黏度,质构特性明显优于海带海藻酸钠。其中,铜藻海藻酸钠黏度168.50 m Pa·s,明显高于海带海藻酸钠的130.30 m Pa·s;硬度56.33 N,明显低于海带海藻酸钠的72.17 N。2)正交实验表明:将0.10%焦磷酸钠与0.20%六偏磷酸钠、0.15%三聚磷酸钠、2.00%大豆分离蛋白、0.30%谷氨酰胺转氨酶和0.40%的铜藻海藻酸钠混合配制而成的保水剂,其解冻损失率和蒸煮损失率较低,且低于其他3种保水剂。本研究表明,由铜藻提取的海藻酸钠与磷酸盐等混配制成的复合保水剂具有很好的保水效果,可用作鲅鱼糜及其他鱼糜的保水剂。
