Hyper thermophilic fermentative bacteria in Malaysian petroleum reservoirs
M.S. Madihah, A.B. Ariff*, F.H. Akmam1, A.G. Baharuddin1 and MIA Karim
Department of Biotechnology, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia; 1Land & General Berhad, No 7, Persiaran Dagang, Bandar Sri Damansara, 52200 Kuala Lumpur, Malaysia.
(Received 9 September 1997 / Accepted 18 November 1997)
Abstract.
Production waters, collected from 9 petroleum reservoirs in Malaysia, were examined chemically and microbiologically to investigate the potential for microbiological enhanced oil recovery. For all petroleum reservoirs investigated, surface water is injected into the reservoirs as part of the secondary oil recovery processes. The depth, temperature, salinity and pH of the reservoirs ranged from 697 to 2,412 metres, 35oC to 94.5oC, 29,250 mg/I to 126,500 mg/I and 6.36 to 8.41, respectively. Chemical analysis indicated a lack of soluble nitrogen and phosphorus in all production waters. However, the waters from all reservoirs are rich with metal ions. The partially characterized strains isolated from the reservoirs were assigned to three morphologically distinctive groups (i) pleomorphic rodshaped which appeared singly or in pairs, (ii) sheathed rod shaped bacteria with single terminal spheroids, and (iii) non sheathed rod shaped with terminal sporulation. These bacteria grew well around neutral pH and temperatures ranging from 60oC to 90oC. Growth of all bacteria was supported individually by yeast extract. The bacteria also grew well in fermentable carbon sources such as glucose, mannose and lactate with significant production of ethanol, acetone, organic acids (oxalic, tartaric, malic, acetic and succinic), C02 and H2' suggesting that the bacteria were fermentative.
Keywords: Extreme Thermophile, Anaerobic Bacteria, Fermentative Bacteria, Petroleum Reservoirs.
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