| Summary: | 碩士 === 國立中興大學 === 土壤環境科學系所 === 98 === Previous studies have suggested that members of the Geobacteraceae can use electrodes as electron acceptors for anaerobic respiration. In order to isolate dissimilatory Fe(III)-reducing bacteria with capability and better efficiency to produce electricity in microbio fuel cell research, an anaerobic technique was began to set up in laboratory. On the basis of the method which used to isolate Methanogen, this research choose roll tube method which was developed by Hungate in 1969 to isolate Fe(III)-reducing bacteria. Three isolates, strain CC-ZLW3-321, CC-ZLW3-322 and CC-ZLW3-323, were derived from a sediment that gathered from monitoring well of natural gas in Guan-Zih-Ling hot spring area in Tainan, Taiwan. The cell of these strain were motile, gram-negative, curved rods, 0.4×1.5-6 μm in size and with one to three peritrichous flagella. Strain CC-ZLW3-321, CC-ZLW3-322 and CC-ZLW3-323 were capable of reducing Fe(III)-citrate in the presence of acetate. 16S rRNA gene sequence analysis demonstrated that these isolates is unique, showing less the 91.8% similarity to bacteria of the Sporomusa–Pectinatus–Selenomomas phyletic group, including Dendrosporobacter quercicolus (91.8%), Anaerosinus glycerini (91.1%), Pelosinus fermentans (90.9%) and Sporotalea propionica (90.8%). On the basis of phylogenetic analysis and physiological test, strain ZLW3-321, ZLW3-322, ZLW3-323 is proposed to represent a novel species, probably a novel genus in the Sporomusa–Pectinatus–Selenomomas phyletic group. But still need more research to complete the characteristic of this genus. Another isolate, strain CC-ZNRSeC-1111, was derived from the sediment of an estuary in Jhu-Nan, Taiwan. The cell of this strain was none-motile, gram-positve, slightly curved rods, 0.5×6-10 μm in size and no flagella or pili was found. Strain CC-ZNRSeC-1111 was capable of reducing Fe(III)-citrate in the presence of acetate. According to 16S rRNA gene sequence analysis, bacteria which has the closest similarity is Bacillus soli (97.4%) in the Sporomusa–Pectinatus–Selenomomas phyletic group.
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