| 摘要: |
| 从中国南海海域分离到了一株具有较高琼胶降解活性的弧菌 Vibrio sp.QJH-12,该菌株为革兰氏阴性菌,呈弯曲杆状,极生单根鞭毛,氧化酶阳性,过氧化氢酶阳性,O/129试验阳性。在琼胶平板上生长可软化琼胶, 并在菌落周围产生凹陷。通过单因子实验和正交实验确定了培养基的最佳组成:琼胶2.0‰,柠檬酸三铵1.0‰,K2HPO41.0‰,NaCl1.0%。 确定该菌株的最适发酵产酶条件:装液量为250mL的三角瓶中装入125mL的液体发酵培养基,培养基起始pH6.5,摇瓶转速150r/min,30℃ 发酵培养26h,发酵液的酶活力达到332U/mL。结果表明,该菌株从产酶活力和发酵特点等各方面具备工业化开发的潜力。 |
| 关键词: 海洋弧菌 琼胶酶 培养基 发酵条件 |
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| Optimization of cultivation conditions of marine agarase-producing strain Vibrio sp. QJH-12 |
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| Abstract: |
| A marine bacterium Vibrio sp. QJH-12 with high activity of decomposing agar was isolated from the South China Sea coast. The strain was gram negative, polar flagellated and arced. When cultured on agar plate, this isolate produced a diffusable agarase, which softened agar and produced pits around the colonies on the agar plate. By the test of single factor and orthogonal test, the optimum culture medium was determined as follows: agar 2.0‰,ammomium citrate tribasic 1.0‰, K2HPO4 1.0‰ and NaCl 1.0%. By measuring the agarase activity, the optimum ferment conditions were determined as follows: 125 mL fresh medium in 250 mL flask, the beginning pH 6.5 of the ferment medium, stirrer speed 150 r/min and 30°C. After cultivation under above conditions for 26 h, the production of agarase reached the peak, with an activity of 332U/mL. The results indicated that QJH-12 might act as a potential candidate for the industrial application. |
| Key words: Marine Vibrio agarase culture medium fermentation conditions |
