活性污泥PHA 生成菌多樣性之研究

The Diversity of PHA-producing Bacteria in Activated Sludge Systems

陳碧苓(Bi-Ling Chen)

指導教授 ： 游勝傑

中原大學/工學院/土木工程學系/碩士(2007年)

https://doi.org/10.6840/cycu200700452

摘要

活性污泥法為國內最常使用的生物處理程序，其中廢水處理過程中所產生的副產物便是廢棄污泥，此類的廢棄污泥已成為危害環境生態的負擔。其中廢棄污泥特定菌種體內所含的有機物，稱為聚羥基烷酯類(Polyhydroxyalkanoates , 簡稱PHAs )，可經加工成為生物可分解塑膠。而在活性污泥中的PHA生成菌，稱為磷蓄積菌(Phosphate Accumulating Organisms, PAOs ) ，在生物除磷系統中則可以達到污水中磷的去除。由於廢棄污泥是危害環境生態的負擔，所以廢棄物減量和資源與能源化便相當的重要，因此本研究利用分子生物技術進行內湖污水處理廠活性污泥中PHA生成菌的多樣性分析，並探討菌體中PHA的含量，且找出菌體累積PHA的最佳化條件，最後將研究廢棄污泥厭氧消化上澄液利用PHA生成菌株進行PHA合成之可行性。

由實驗結果顯示，在內湖污水處理廠PHA生成菌多樣性方面，利用 PCR偵測，可篩選出61株菌，經分類比對結果推估該廠活性污泥中PHA生成菌之優勢菌種為Ralstonia sp.以及 Zoogloea ramigera，各佔總分類菌株的25.9％以及11.9％；在內湖污水處理廠污泥phaC基因多樣性方面，觀察其親緣圖發現，各菌株間的PHA synthase 基因的歧異度大。

在PHA生成菌累積PHA方面，以葡萄糖供給碳源時，各菌株之PHA含量約佔細胞乾重之6~35％不等，其中以菌株301 (定序比對為Zoogloea ramigera)這株菌，所能累積的PHA較高，約佔細胞乾重的35.08％，其次為菌株318(定序比對為alpha proteobacterium 5Z2111)，其PHA含量約佔細胞乾重的19.38％。
在PHA生成菌之PHA含量最佳化方面，以葡萄糖供給碳源時，培養之pH值控制為6或7以及培養溫度設定在30℃時，大部份之菌株可以累積較多含量之PHA，其中以菌株301 (定序比對為Zoogloea ramigera)、菌株320 (定序比對為Mycobacterium mageritense)以及菌株417(定序比對為Micrococcus luteus)這些菌株可以獲得較高之PHA含量，皆約佔細胞乾重的30％左右；另外以醋酸為碳源時，各菌株之PHA含量則會降低許多，約佔細胞乾重之1~3％不等。

在廢棄污泥厭氧消化上澄液合成PHA方面，PHA生成菌株利用上澄液中的短鏈脂肪酸為碳源，其合成PHA之含量僅佔細胞乾重的1％，此部分結果與以醋酸為碳源其PHA含量偏低相符合。

關鍵字

活性污泥 ； 為聚羥基烷酯類

並列摘要

In Taiwan the use constantly of biological treatment processes is activated
sludge, and a residual product from wastewater treatment process is
wasteslugde haven become a burden that is harm to environment. The organic
compound of specific bacteria’s cell among wasteslugde are called
Polyhydroxyalkanoates (PHAs) that can be manufactured to become
biodegradable plastic. PHA-producing bacteria in activated sludge are called
Phosphate Accumulating Organisms (PAOs) that can be reached to removal of
phosphorus from wastewater in Biological Phosphorus Removal system. Due
to wasteslugde is a burden that is harm to environment, so the reduce of waste
slugde and the source of energy are very important. Therefore, this study would
analysis the diversity of PHA-producing bacteria in activated sludge of Nei Hu
sewage treatment plant by using biotechnology of molecule, and confer the
PHA content in bacterial , and find the optimization condition of accumulative
PHA . Last, the feasibility study is about PHA-producing bacteria accumulate
PHA by using the above liquid of wasteslugde anaerobic digestion.
Experimental results have shown the number of PHA-producing bacteria
in Nei Hu sewage treatment plant are about sixty-one by using PCR detective.
Calculating the advantage baterial of PHA-producing bacteria in Nei Hu
sewage treatment plant are Ralstonia sp. and Zoogloea ramigera which are
around 25.9 and 11.9％ in all PHA-producing bacteria. In the diversity of
phaC gene in Nei Hu sewage treatment plant’s sludge,the phylogenic tree is
shown that the relation of in these bacteria is extremely wide.
In the PHA content of PHA-producing bacteria, the results have shown the
PHA content of several PHA-producing bacteria is 6 to 35％ of cell dry weight
by using glucose as carbon source , among them Zoogloea ramigera is get
highest PHA content , is around 35.08％ of cell dry weight.The next is alpha
proteobacterium 5Z2111, the PHA content of alpha proteobacterium is around
19.38％ of cell dry weight.
In optimization condition of PHA-producing bacteria’s PHA content, the
results have shown that when pH of medium is controlled at 6 or 7 and
cultivated temperature is controiied at 30℃, the greater part of PHA-producing
bacteria are get higher PHA content by using glucose as carbon source. Besides
the PHA content of PHA-producing bacteria is iower by using acetate as carbon
source, is around 1 to 3％ of cell dry weight.
In the PHA content of PHA-producing bacteria by using the above liquid
of wasteslugde anaerobic digestion, the results have shown that
PHA-producing bacteria use the excess carbon from the above liquid of
anaerobic digestion, the PHA content of cell dry weight is about 1％.The
result of PHA content which is lower in this part is the same with PHA content
by using acetate as carbon source.

並列關鍵字

activated sludge ； PHA(polyhydroxyalkanoates)

參考文獻

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