一株丁二酮高产菌株的鉴定及发酵条件优化

Identification and fermentation optimization of a high butanedione yielding strain

天然丁二酮是一种香精载体,为提高其产量,有必要筛选出丁二酮高产菌株及其最佳发酵条件.从保存的一株丁二酮高产菌株6-1(2)出发,通过分子生物学方法对其进行鉴定,采用单因素试验和最佳单因素组合实验的方法筛选出该菌株的最佳发酵条件.结果表明,实验菌株6-1(2)与植物乳杆菌Lactobacillus plantarum的AB326301.1序列同源性最高,初步鉴定为植物乳杆菌;发酵条件经过优化后,丁二酮的产量从初始的38 mg/L提高到167.56 mg/L,提高了340.95%,产量提高显著.优化发酵条件为:牛肉膏10 g/L,柠檬酸氢二胺2 g/L,酵母浸粉15 g/L,磷酸氢二钾2 g/L,乙酸钠2 g/L,葡萄糖20 g/L,蛋白胨30 g/L,吐温-80 1 mL/L,初始pH 6.2-6.4,接种量1.5%,37℃静置培养10 h;该发酵条件下的丁二酮产量提高显著.本研究对丁二酮的工业化生产具有一定的参考价值.

Industrial production of butanedione is of great significance because the natural flavor carrier cannot meet the needs of people＇s life.This research aimed to select a high butanedione yielding strain and to optimize its fermentation conditions for greater output of butanedione.Methods of molecular biology were used to identify the high butanedione yielding strain named 6-1（2）;single factor tests and response surface methods were also used to determine its optimum fermentation conditions.The results showed that the experimental strain named 6-1（2） shared the highest homology with Lactobacillus plantarum AB326301.1 sequence,therefore determined as L.plantarum.Its optimum fermentation conditions were：beef paste 10 g/L,citric acid hydrogen diamine 2 g/L,yeast extract 15 g/L,potassium hydrogen phosphate 2 g/L,sodium acetate 2 g/L,glucose 20 g/L,peptone 30 g/L,twain-80 1 ml/L,the initial pH 6.2- 6.4,the quantity of 1.5%,37℃ stewing for 10 h.Under such fermentation conditions,the output of butanedione increased significantly for more than 3 times,from the original 38 mg/L to 167.56 mg/L.The results proved that the strain 6-1（2） can be high butanedione yielding in optimized fermentation conditions,which can be of great value for industrial butanedione production.