Thermotalea metallivorans gen. nov., sp. nov., a thermophilic, anaerobic bacterium from the Great Artesian Basin of Australia aquifer

Abstract

A strictly anaerobic, thermophilic bacterium, designated strain B2-1 T , was isolated from microbial mats colonizing a runoff channel formed by free-flowing thermal water from a Great Artesian Basin, Australia, bore well (registered number 17263). The cells of strain B2-1 T were slightly curved rods (3.0-3.5¾0.6-0.7 mm) which stained Gram-negative. The strain grew optimally in tryptone-yeast extract-glucose medium at 50 6C (temperature growth range 30-55 6C) and a pH of 8 (pH growth range 6.5-9). Strain B2-1 T grew poorly on yeast extract (0.2 %) and/or tryptone (0.2 %), which were obligately required for growth on other energy sources, including a range of other carbohydrates and organic acids, but not amino acids. The end-products of glucose fermentation were ethanol and acetate. In the presence of 0.2 % yeast extract, iron(III), manganese(IV) and elemental sulfur were reduced but sulfate, thiosulfate, sulfite, nitrate and nitrite were not reduced. Growth was inhibited by chloramphenicol, streptomycin, tetracycline, penicillin, ampicillin, sodium azide and by NaCl concentrations greater than 4 % (w/v). The DNA G+C content was 48±1 mol% as determined by the thermal denaturation method. 16S rRNA gene sequence analysis indicated that strain B2-1 T was a member of the family Clostridiaceae, class Clostridia, phylum Firmicutes and was most closely related to Geosporobacter subterraneus DSM 17957 T (89.9 % similarity). On the basis of 16S rRNA gene sequence comparisons and physiological characteristics, strain B2-1 T is considered to represent a novel species of a new genus, for which the name Thermotalea metallivorans gen. nov., sp. nov. is proposed. The type strain is B2-1 T (5KCTC 5625 T 5JCM 15105 T 5DSM 21119 T ).The Great Artesian Basin (GAB) underlies approximately 22 % of the arid and subarid regions of the Australian continent, an area of over 1.7610 6 km 2 , with a water storage capacity of 8.7610 12 m 3 , and is considered to be the world's largest geothermal subsurface aquifer (Habermahl, 1980). The GAB was formed between 100 and 250 million years ago and contains groundwaters which are estimated to be 2 million years old. It is composed of alternating layers of water-bearing permeable sandstone aquifers and non-water-bearing impermeable shale and includes two regions that contain the largest onshore oil and gas reserves in Australia. These geological formations have an immense influence on the chemical composition of GAB groundwaters, which can be bicarbonate-, chloride-, sulfate-or iron-rich. The GAB subsurface waters flow from the recharge areas at the edge of the basin to the discharge areas in central Australia as mound springs at an estimated rate of 1-5 m year 21 and are heated by the Earth's magma due to the aquifer's great depth. The GAB is tapped by more than 5000 free-flowing bores which provide vital water to outback communities where it is used for agricultural, industrial and domestic purposes. These bores can be found up to 3000 m deep, with source temperatures ranging from 30 to 100 u C d...

Geosporobacter ferrireducens sp. nov., an anaerobic iron-reducing bacterium isolated from an oil-contaminated site

“…To sporulate the cells, cultures of strain IRF9 T grown in the basal medium were treated in 65 and 80°C water baths for several hours or kept at room temperature for 4 weeks (Ogg and Patel 2009;Zhang et al 2013). For the heat resistance test, heat treatment times at 80°C varied from several hours to 2 days.…”

Brassicibacter mesophilus gen. nov., sp. nov., a strictly anaerobic bacterium isolated from food industry wastewater

“…Utilization of substrates was confirmed by analysing fermentation products using HPLC with an ion exclusion column (Aminex hpx-87h; Bio-Rad). To determine potential electron acceptors, elemental sulfur (0.1 %, w/v), sulfate (20 mM), thiosulfate (20 mM), nitrate (10 mM) and nitrite (5 mM) were added to the basal medium lacking the reductant Na 2 S, and the results were analysed as described by Ogg & Patel (2009). The methyl red and Voges-Proskauer reactions, H 2 S and indole production and catalase and oxidase activities were determined as described by Wu et al (2010a).…”

Tepidibacter mesophilus sp. nov., a mesophilic fermentative anaerobe isolated from soil polluted by crude oil, and emended description of the genus Tepidibacter

“…Oxygen was removed as described by Grishchenkov et al (2000). Reduction of the electron acceptors was tested by using the method described by Ogg & Patel (2009). Production of H 2 S was tested in sulfate-free medium by using lead acetate paper, as indicated by Alain et al (2002).…”