台灣東北角地區能利用葡萄糖或半乳糖為單一碳源的細菌之分離與特性研究

Abstract

葡萄糖與半乳糖為生物體內重要的六碳單糖，是生物合成雙糖乃至於多糖時最重要的單體。本研究於2006年七月到十月間，前後共計兩次，在台灣北部鼻頭角、南雅、八斗子與深澳等地方之沿岸，進行海水樣本採集，以PY broth、葡萄糖或半乳糖為單一碳源的CM培養基來分別培養水樣中的菌種。 各海水樣本所含菌數採MPN法計數，結果顯示，在這四個樣區中不管是以PY broth、葡萄糖或半乳糖為單一碳源的CM培養基所獲得的生菌數皆介於102-104個/ml；而在時間序列上，2006年七月採樣時所獲得的生菌數較2006年十月採樣所獲得的生菌數要低，但彼此間並沒有顯著的差異。 本實驗經採樣、培養、分離、純化後共得到96株細菌，依其革蘭氏反應、可生長鹽度等生理生化表型特徵與16S rDNA序列分析共可分為9群。各菌株所得之16S rDNA序列片段與已知菌種相比對之結果可區分為Vibrio、Photobacterium、Enterobacter、Pseudomonas、Alteromonas、Idiomarina、Pseudoalteromonas、Listonella以及Pseudovibrio等屬，結果顯示台灣東北角地區具有豐富的弧菌菌相，而所分離而得的96菌株中只有一株屬於Alphaproteobacteria綱，其他皆屬於Gammaproteobacteria綱。 雖然有六株菌株的16S rDNA序列與已發表菌種之序列相似度低於97%，但其是否為Photobacterium屬的新穎細菌則需要進一步的生理生化與分生測試才能斷定。 台灣東北角地區沿岸海水中所分離出能利用葡萄糖或半乳糖為單一碳源的細菌以Gammaproteobacteria綱為優勢群可區分為8個屬，但也從中分離出一株屬於Alphaproteobacteria綱Pseudovirbio屬的菌株，由此顯見，此海域中能利用葡萄糖或半乳糖為單一碳源的細菌具有豐富之多樣性。

Glucose and galactose are two of the important monosaccharides in cells. For cell metabolism and biochemistry activity, both of glucose and galactose play important roles. In this study, during July 2006 to October 2006, seawater samples were collected two times from the coast regions of north Taiwan, and use PY broth and CM broth ( glucose or galactose for single carbon source) for enumeration of bacteria in seawater samples. MPN method was used to calculate cell counting values for all of the seawater samples, and the cell counting values were estimated to be in the range of 102-104 unit/ml; and the cell counting values of seawater samples collected during July 2006 were generally lower than the values of seawater samples collected during October 2006, but there is not have significant between the values of July 2006 and the values of October 2006. In this study, there are 96 strains were collected from all seawater samples. According to the differences of phenotypic characterizations (ex: gram reaction) and 16S rDNA gene sequences, all of the strains can be divided into 9 groups. All of the sequences were analyzed, and they can be divided into 9 genera: Vibrio、Photobacterium、Enterobacter 、Pseudomonas 、Alteromonas 、Idiomarina 、Pseudoalteromonas 、Listonella and Pseudovibri. On the basis of physiological and molecular properties, it is proposed that there is present high vibrio bacteria diversity in Taiwan northeast coast, and there is only one strain belonged to the class: Alphaproteobacteria, all the other 95 strains are belonged to the class: Gammaproteobacteria. 16S rDNA sequence similarity of six strains are lower than 97% with type strain, but we need more tests to determine if these strains are a novel bacteria.