Simplified technique for identification of the aerobic spore-forming bacteria by phenotype.

Abstract

The use of modern research approaches of genetics, biochemistry and molecular biology has led to progress in bacterial taxonomy. Systematic study of the aerobic spore-forming bacteria has resulted in the realignment of the genus Bacillus into several new genera. In the meantime, the identification process has become more difficult for the non-specialist in Bacillus taxonomy. This paper presents a key for the simplified phenotypic identification of the mesophilic, aerobic, spore-forming bacteria belonging to the genera Bacillus, Paenibacillus, Brevibacillus, Aneurinibacillus, Geobacillus and Virgibacillus. A total of 81 species were included and 115 morphological and physiological tests were analysed for their discriminative efficiency. This key is practical for rough but quick identification of aerobic spore-forming bacteria isolated from nature. Such preliminary identification will be helpful for the selection of reference strains and methods for more precise identification using the newest techniques. The reliability of the proposed identification key was tested on 100 cultures from the Ukrainian Collection of Microorganisms. The developed identification key is represented in interactive mode on a website (http://www/imv.kiev.ua/key/). Keywords : identification, phenotype, spore-forming bacteria INTRODUCTIONAerobic spore-forming bacteria represent a major microflora in many natural biotopes, where they play an important role in ecosystem development ; they are able to transform many chemical compounds, including industrial pollutants. Therefore, the investigation of these micro-organisms is highly important for microbiologists dealing with ecological studies and environment protection. The identification of aerobic spore-forming bacteria was always a difficult task, but has recently become almost impossible to the nonspecialist in the field of bacillus systematics and identification. Many of the up-to-date, sophisticated genetic and biochemical methods that have permitted improvements in bacilli taxonomy are too difficult for routine use. A prominent trend of current microbiological practice is the identification of microorganisms based only on 16S rRNA sequences, which provides rather limited resolution (Schloter et al., 2000 ;Stackebrandt & Goebel, 1994) incorrect identification and, more dangerously, to incorrect association of DNA sequences in a genetic database with particular species, which will multiply the error many times. It would be useful to supply scientists with a method to check quickly whether their strains identified by 16S rRNA agree with the corresponding species characteristics.In recent years, twelve new genera of aerobic sporeforming bacteria have been proposed : Alicyclobacillus (Wisotzkey et al., 1992), Amphibacillus (Niimura et al., 1990), Aneurinibacillus and Brevibacillus (Shida et al., 1996), Filobacillus (Schlesner et al., 2001), Geobacillus (Nazina et al., 2001), Halobacillus (Spring et al., 1996), Paenibacillus (Ash et al., 1993), Virgibacillus (Heyndrickx et al., 1998), Gracili...

Metabolomics and microbiological profile of Italian mozzarella cheese produced with buffalo and cow milk

“…Gram-negative isolates from PCA and VRBGA plates were also tested for behaviour in TSI (triple sugar iron agar, Microbiol), then grouped according to the criteria of Mossel, Corry, Struijk, and Baird (1995) and identified by API 20E and API 20NE (bioMérieux, Marcy l'Etoile, France). Aerobic spore-forming bacteria were identified according to Claus and Berkeley (1986), and Reva, Sorokulova, and Smirnov (2001), and the identification confirmed by using the API 50 CHB galleries (bioMérieux). Gram-positive, catalase-negative isolates from M17 and MRS agar plates were tested for growth at 10, 15 and 45°C in 4 and 6.5% NaCl, gas production from glucose (MRS broth with inverted Durham tubes) and production of NH 3 from arginine, as described by Schillinger and Lücke (1987).…”

The Safety of Two Bacillus Probiotic Strains for Human Use

“…An identification key proposed previously [27] was used for identification. This key is represented on-line at the following website http://www.imv.kiev.ua/key/.…”

Utilization of a polyphasic approach in the taxonomic reassessment of antibiotic- and enzyme-producing Bacillus spp. isolated from the Philippines

“…The use of phenotypic characteristics, although classical, has been successfully used in the identification of the aerobic spore-forming bacteria (Reva et al 2001). Analyses showed that some isolates possessed a number of characteristics quite different from those of their type strains, suggesting that those isolates were misclassified.…”