Reclassification ofBacillus brevis was first described by Migula (1900). Subsequently, many strains, including some that were not in accordance with the criteria of Bacillus brevis sensu stricto, were classified as Bacillus brevis, according mainly to phenotype; as a result, Bacillus brevis has become a heterogeneous species, similar to Bacillus circulans (Nakamura & Swezey, 1983a, b). In the 1990s, based on polyphasic taxonomic studies of Bacillus brevis and its relatives, many species or strains were reclassified as novel species of the genera Brevibacillus and Aneurinibacillus (Nakamura, 1991(Nakamura, , 1993Takagi et al., 1993; Shida et al., 1994a Shida et al., , b, 1995Shida et al., , 1996 MeierStauffer et al., 1996;Heyndrickx et al., 1997). Recently, Brevibacillus invocatus was proposed as a novel species, according to the polyphasic identification of Bacillus and Brevibacillus strains from clinical, dairy and industrial specimens (Logan et al., 2002). Thus, at the time of writing, 11 species are recognized to belong to the genus Brevibacillus and three species are recognized to belong to the genus Aneurinibacillus. However, with the exception of the thermophilic species Brevibacillus thermoruber and Aneurinibacillus thermoaerophilus, distinguishing between these species is extremely difficult, as most strains are unreactive or weak in many biochemical tests and few have useful differential phenotypic characteristics (Heyndrickx Abbreviation: HV, hypervariable.

Moderately thermophilic, acidophilic, spore-forming bacteria (146 strains) were isolated from various beverages and environments. Based on the results of sequence analysis of the hypervariable region of the 16S rRNA gene, eight of the strains represent novel species of the genus Alicyclobacillus. These strains were designated 3-A191T, 4-A336T, 5-A83JT, 5-A167N, 5-A239-2O-AT, E-8, RB718T and S-TABT. Phylogenetic analyses of 16S rRNA and DNA gyrase B subunit (gyrB) nucleotide sequences confirmed that the eight strains belonged to the Alicyclobacillus clade. Cells of the eight strains were Gram-positive or Gram-variable, strictly aerobic and rod-shaped. The strains grew well under acidic and moderately thermal conditions, produced acid from various sugars, contained menaquinone 7 as the major isoprenoid quinone and did not produce guaiacol. ω-Alicyclic fatty acids were the predominant lipid component of strains 4-A336T, 5-A83JT, 5-A167N, RB718T and S-TABT. No ω-alicyclic fatty acids were detected in strains 3-A191T, 5-A239-2O-AT or E-8, but iso- and anteiso-branched fatty acids and small amounts of straight-chain saturated fatty acids were detected instead. According to the DNA–DNA hybridization data and distinct morphological, physiological, chemotaxonomical and genetic traits, the eight strains represent six novel species within the genus Alicyclobacillus, for which the following names are proposed: Alicyclobacillus contaminans sp. nov. (type strain 3-A191T=DSM 17975T=IAM 15224T), Alicyclobacillus fastidiosus sp. nov. (type strain S-TABT=DSM 17978T=IAM 15229T), Alicyclobacillus kakegawensis sp. nov. (type strain 5-A83JT=DSM 17979T=IAM 15227T), Alicyclobacillus macrosporangiidus sp. nov. (type strain 5-A239-2O-AT=DSM 17980T=IAM 15370T), Alicyclobacillus sacchari sp. nov. (type strain RB718T=DSM 17974T=IAM 15230T) and Alicyclobacillus shizuokensis sp. nov. (type strain 4-A336T=DSM 17981T=IAM 15226T).

A Gram-positive, endospore-forming, lactic acid bacterium was isolated from spoiled orange juice. The organism, strain QC81-06 T , grew microaerobically or anaerobically at 30-45 6C (optimum 35 6C) and pH 3.5-5.5 (optimum pH 4.5), and produced acid from various sugars. D-Lactic acid was produced. It contained menaquinone-7 as the major isoprenoid quinone. The G+C content of the genomic DNA was 47.5 mol%. The predominant cellular fatty acids of the strain were iso-C 16 : 0 , anteiso-C 15 : 0 and anteiso-C 17 : 0 . Phylogenetic analyses based on the 16S rRNA gene and gyrB gene (DNA gyrase B subunit gene) revealed that strain QC81-06 T clustered with Sporolactobacillus species but the strain was clearly distinct from other Sporolactobacillus species with significant bootstrap values. The levels of 16S rRNA gene and gyrB gene sequence similarities between strain QC81-06 T and the other strains of the cluster were 96.0-97.0 % and 75.1-77.2 %, respectively. On the basis of these results, strain QC81-06 T should be classified as a novel Sporolactobacillus species for which the name Sporolactobacillus putidus is proposed. The type strain is strain QC81-06 T (5DSM 21265 T 5JCM 15325 T ).The genus Sporolactobacillus (Kitahara & Suzuki, 1963) consists of Gram-positive, catalase-negative, endosporeforming, homofermentative lactic acid bacteria. The type species is Sporolactobacillus inulinus, which was first isolated from chicken feed (Kitahara & Suzuki, 1963;Kitahara & Lai, 1967). Later Yanagida et al. (1987aYanagida et al. ( , b, 1997 proposed four species and one subspecies, Chang et al. (2008) proposed one species, and Bacillus laevolacticus (Andersch et al., 1994) was transferred to the genus Sporolactobacillus (Hatayama et al., 2006), so the genus Sporolactobacillus now comprises seven species and one subspecies (S. inulinus, S. lactosus, S. laevolacticus, S. nakayamae, S. nakayamae subsp. racemicus, S. kofuensis, S. terrae and S. vineae). A living culture of S. lactosus has unfortunately been lost, so the strain can not be used as an experimental reference in a taxonomic study at present. Although Sporolactobacillus species are typically isolated from soil, they are occasionally isolated from fermented or spoiled foods (Yanagida et al., 1997). During the course of a microbiological survey of spoiled orange juice, we ascertained that the spoilage was caused by an unusual heat-tolerant lactic acid bacterium. In this paper, we describe a novel Gram-positive, endospore-forming species of the genus Sporolactobacillus.Strain QC81-06 T was isolated from a spoiled orange juice sample with an organic acid odour by using the dilution plating technique on MRS agar (Merck). Based on partial 16S rRNA gene sequence analyses (Goto et al., 2000(Goto et al., , 2002, the strain was grouped into the Sporolactobacillus cluster. The strain, however, was found to be distinct from previously described species of the genus Sporolactobacillus. (Okada et al., 1986). The catalase activity of the cells grown on GYP agar was determined by addi...