Colin R. Monk

Clostridium fervidus sp. nov., a new chemoorganotrophic acetogenic thermophile

Clostridium fervidus sp. nov. was isolated from a hot spring in New Zealand. The cells were strictly anaerobic, gram negative, sporeforming, and sluggishly motile rods (0.65 to 0.75 μ wide and 2 to 3 μm long). The spherical spores were subterminal to terminal and did not distend the sporangium. Lysis of the culture occurred at the onset of stationary phase. The deoxyribonucleic acid guanine-plus-cytosine content was 39 mol%. The temperature optimum was 68°C (range, > 37 and 5.5 and < 9.0). Growth occurred on Trypticase peptone (BBL Microbiology Systems) or yeast extract. However, with the exception of serine, which could be catabolized as the sole carbon source, either peptone or yeast extract was essential for the fermentation of carbohydrates including glucose, maltose, mannose, xylan, starch, and pyruvate. Acetate was always the major fermentation end product. CO2, H2, and minor quantitites of valerate, butyrate, ethanol, and lactate were also produced. C. fervidus (type strain Rt4-B1T) has been deposited with the American Type Culture Collection (ATCC 43204).

Determination of agmatine, argenine, citrulline and ornithine by reversed-phase liquid chromatography using automated pre-column derivatization with o-phthalaldehyde

A method is presented for the pre-column derivatization of agmatine, arginine, citrulline or ornithine with o-phthalaldehyde-2-mercaptoethanol, and subsequent separation of the derivatives by reversed-phase liquid chromatography. Fluorescent response is linear from 10 to 150 pmol of injected analyte and detection limits range from 28 to 100 fmol. Response factors relative to the internal standard, homocysteic acid, were 1.16 (agmatine and arginine), 1.03 (citrulline) and 0.34 (ornithine). The applicability of the method to the measurement of arginase, arginine deaminase, arginine decarboxylase and other enzyme activities in bacterial extracts was examined.

Laboratory-scale investigations into the use of extremely thermophilic proteinases for cleaning ultrafiltration membranes fouled during whey processing

Abstract The potential of proteolytic enzymes from extremely thermophilic eubacteria to clear ultrafiltration membranes fouled during the processing of whey was investigated. The enzymes were initially tested for their ability to hydrolyse freeze-dried preparations of material removed from fouled ultrafiltration membranes. Under the conditions used, the serine proteinases from Thermus strains were more efficient than the metalloproteinase from Bacillus strain EA.1, and were subsequently investigated for their ability to clear fouled membrane discs using purpose-built laboratory scale equipment. The proteinase from Thermus strain Rt4.1A proved most effective and gave a linear increase of water flux with time when used to treat fouled membranes at 70°C. The rate of clearing and final flux levels obtained using enzyme alone were lower than those obtained using alkaline-EDTA. The performance of the enzyme was, however, synergistically enhanced using the anionic detergent sodium dodecyl sulphate in combination with the enzyme.