Emended descriptions of Bacillus sporothermodurans and Bacillus oleronius with the inclusion of dairy farm isolates of both species.

Bacillus sporothermodurans is an industrially important micro-organism because of its ability to produce endospores which resist ultra-high temperature (UHT) and industrial sterilization processes. It was described by Pettersson et al. (1996) [Pettersson, B., Lembke, F., Hammer, P., Stackebrandt, E. & Priest, F. G. (1996). Int J Syst Bacteriol 46, 759-764] based on seven genetically homogeneous isolates all from UHT milk. Bacillus oleronius, the closest phylogenetic neighbour of B. sporothermodurans, was described by Kuhnigk et al. (1995) [Kuhnigk, T., Borst, E.-M., Breunig, A., König, H., Collins, M. D., Hutson, R. A. & Kämpfer, P. (1995). Can J Microbiol 41, 699-706] based on a single strain, isolated from the hindgut of the termite Reticulitermes santonensis. A polyphasic study of a heterogeneous collection of B. sporothermodurans and B. oleronius strains isolated from various sources and geographical origins led to an emended description of both species. Additional data presented are the results of fatty acid, quinone and/or cell wall (polar lipid) analyses. DNA-DNA hybridization confirmed 3 subgroups of strains obtained after SDS-PAGE analysis of cellular proteins as B. sporothermodurans. One named B. sporothermodurans strain (R-7489) was reclassified as a Bacillus fordii strain. The phenotypic profiles of both species were rather heterogeneous, sometimes different from the original descriptions and did not differ in a large number of characteristics, although B. oleronius generally gave stronger reactions in its positive tests than did B. sporothermodurans; the variable and weak reactions for both organisms with some substrates blurred the distinction between the two. However, differences in polar lipid, SDS-PAGE and menaquinone profiles clearly allow distinction between the two species.

Lysinibacillus macroides sp. nov., nom. rev.

'Bacillus macroides' ATCC 12905(T) ( = DSM 54(T) = LMG 18474(T)), isolated in 1947 from cow dung, was not included in the Approved Lists of Bacterial Names and so it lost standing in bacteriological nomenclature. Reinvestigation of the strain, including DNA-DNA relatedness experiments, revealed that 'Bacillus macroides' is genomically distinct from its closest relatives Lysinibacillus xylanilyticus, Lysinibacillus boronitolerans and Lysinibacillus fusiformis (as determined by 16S rRNA gene sequence analysis, with pairwise similarity values of 99.2, 98.8 and 98.5 %, respectively, with the type strains of these species). Further analysis showed that 'Bacillus macroides' shares the A4α L-Lys-D-Asp peptidoglycan type with other members of the genus Lysinibacillus and can thus be attributed to this genus. These results, combined with additional phenotypic data, justify the description of strain LMG 18474(T) ( = DSM 54(T) = ATCC 12905(T)) as Lysinibacillus macroides sp. nov., nom. rev.

Pseudomonas cichorii as the causal agent of midrib rot, an emerging disease of greenhouse-grown butterhead lettuce in Flanders.

Bacterial midrib rot of greenhouse-grown butterhead lettuce (Lactuca sativa L. var. capitata) is an emerging disease in Flanders (Belgium) and fluorescent pseudomonads are suspected to play an important role in the disease. Isolations from infected lettuces, collected from 14 commercial greenhouses in Flanders, yielded 149 isolates that were characterized polyphasically, which included morphological characteristics, pigmentation, pathogenicity tests by both injection and spraying of lettuce, LOPAT characteristics, FAME analysis, BOX-PCR fingerprinting, 16S rRNA and rpoB gene sequencing, as well as DNA-DNA hybridization. Ninety-eight isolates (66%) exhibited a fluorescent pigmentation and were associated with the genus Pseudomonas. Fifty-five of them induced an HR+ (hypersensitive reaction in tobacco leaves) response. The other 43 fluorescent isolates were most probably saprophytic bacteria and about half of them were able to cause rot on potato tuber slices. BOX-PCR genomic fingerprinting was used to assess the genetic diversity of the Pseudomonas midrib rot isolates. The delineated BOX-PCR patterns matched quite well with Pseudomonas morphotypes defined on the basis of colony appearance and variation in fluorescent pigmentation. 16S rRNA and rpoB gene sequence analyses allowed most of the fluorescent isolates to be allocated to Pseudomonas, and they belonged to either the Pseudomonas fluorescens group, Pseudomonas putida group, or the Pseudomonas cichorii/syringae group. In particular, the isolates allocated to this latter group constituted the vast majority of HR+ isolates and were identified as P. cichorii by DNA-DNA hybridization. They were demonstrated by spray-inoculation tests on greenhouse-grown lettuce to induce the midrib rot disease and could be re-isolated from lesions of inoculated plants. Four HR+ non-fluorescent isolates associated with one sample that showed an atypical midrib rot were identified as Dickeya sp.

Comparative analysis of the diversity of aerobic spore-forming bacteria in raw milk from organic and conventional dairy farms.

Bacterial contamination of raw milk can originate from different sources: air, milking equipment, feed, soil, faeces and grass. It is hypothesized that differences in feeding and housing strategies of cows may influence the microbial quality of milk. This assumption was investigated through comparison of the aerobic spore-forming flora in milk from organic and conventional dairy farms. Laboratory pasteurized milk samples from five conventional and five organic dairy farms, sampled in late summer/autumn and in winter, were plated on a standard medium and two differential media, one screening for phospholipolytic and the other for proteolytic activity of bacteria. Almost 930 isolates were obtained of which 898 could be screened via fatty acid methyl ester analysis. Representative isolates were further analysed using 16S rRNA gene sequencing and (GTG)(5)-PCR. The majority of aerobic spore-formers in milk belonged to the genus Bacillus and showed at least 97% 16S rRNA gene sequence similarity with type strains of Bacillus licheniformis, Bacillus pumilus, Bacillus circulans, Bacillus subtilis and with type strains of species belonging to the Bacillus cereus group. About 7% of all isolates may belong to possibly new spore-forming taxa. Although the overall diversity of aerobic spore-forming bacteria in milk from organic vs. conventional dairy farms was highly similar, some differences between both were observed: (i) a relatively higher number of thermotolerant organisms in milk from conventional dairy farms compared to organic farms (41.2% vs. 25.9%), and (ii) a relatively higher number of B. cereus group organisms in milk from organic (81.3%) and Ureibacillus thermosphaericus in milk from conventional (85.7%) dairy farms. One of these differences, the higher occurrence of B. cereus group organisms in milk from organic dairy farms, may be linked to differences in housing strategy between the two types of dairy farming. However, no plausible clarification was found for the relatively higher number of thermotolerant organisms and the higher occurrence of U. thermosphaericus in milk from conventional dairy farms. Possibly this is due to differences in feeding strategy but no decisive indications were found to support this assumption.

Raman microspectroscopy as an identification tool within the phylogenetically homogeneous 'Bacillus subtilis' group.

Vibrational methods have multiple advantages compared to more classic, chemotaxonomic and even molecular microbial tools for the identification of bacteria. Nevertheless, their definite breakthrough in diagnostic microbiology laboratories is determined by their identification potential. This paper reports on the profound evaluation of Raman spectroscopy to identify closely related species by means of 68 Bacillus strains that are assigned or closely related to the phylogenetically homogeneous 'Bacillus subtilis'-group (sensu stricto). These strains were chosen to represent biological variation within the selected species and to create a realistic view on the possibilities of this technique The evaluation resulted in 49/54 correct identifications at the species level for intern and 15/19 for extern testing. The correct identification of strains, which were not represented in the training set, supports the potential as an identification tool within the 'B. subtilis group'. Considering the vague borderline between the species studied, Raman spectroscopy can be regarded here as a promising application for identifications at the species level.

Paenibacillus wynnii sp. nov., a novel species harbouring the nifH gene, isolated from Alexander Island, Antarctica.

Soil taken from 12 different locations at Mars Oasis on Alexander Island, Antarctica, yielded unidentified isolates of endospore-forming bacteria. Soil from four of the locations contained Gram-negative, facultatively anaerobic, motile rods that were able to grow at 4 degrees C and which formed ellipsoidal spores that lay paracentrally or subterminally in swollen or slightly swollen sporangia. All of the strains harboured the nitrogenase gene nifH. Phenotypic tests, amplified rDNA restriction analysis (ARDRA), fatty acid analysis and SDS-PAGE analysis suggested that the isolates represented a novel taxon of Paenibacillus. 16S rRNA gene sequence comparison supported the proposal of a novel species, Paenibacillus wynnii sp. nov. (type strain, LMG 22176(T)=CIP 108306(T)).

Six novel Arthrobacter species isolated from deteriorated mural paintings.

A group of 21 bacterial strains was isolated from samples of biofilm formation in the Servilia tomb (necropolis of Carmona, Spain) and the Saint-Catherine chapel (castle at Herberstein, Austria). A polyphasic taxonomic study of these isolates, including morphological, biochemical and chemotaxonomic characterization, rep-PCR fingerprinting, 16S rRNA gene sequence analysis, DNA base ratio and DNA-DNA relatedness studies, allocated them to the genus Arthrobacter. The isolates represent six novel species, for which the names Arthrobacter castelli sp. nov., Arthrobacter monumenti sp. nov., Arthrobacter parietis sp. nov., Arthrobacter pigmenti sp. nov., Arthrobacter tecti sp. nov. and Arthrobacter tumbae sp. nov. are proposed. The respective type strains are LMG 22283(T) (=DSM 16402(T)), LMG 19502(T) (=DSM 16405(T)), LMG 22281(T) (=DSM 16404(T)), LMG 22284(T) (=DSM 16403(T)), LMG 22282(T) (=DSM 16407(T)) and LMG 19501(T) (=DSM 16406(T)).

Bacillus arenosi sp. nov., Bacillus arvi sp. nov. and Bacillus humi sp. nov., isolated from soil.

A group of nine Gram-positive endospore-forming bacteria was isolated from soil of the Drentse A agricultural research area in The Netherlands. Using (GTG)5-PCR genomic fingerprinting and fatty acid analysis, the nine isolates were divided into three consistent groups. On the basis of 16S rRNA gene sequence similarity of representative strains, the nine isolates were shown to belong to the genus Bacillus. The first group of four isolates was most closely related to Bacillus carboniphilus (95.5 %) and Bacillus sporothermodurans (95.5 %). The second and third groups of three and two isolates, respectively, showed highest sequence similarity to Bacillus neidei (97.0 and 97.1 %, respectively) and Bacillus pycnus (both 96.7 %). A DNA-DNA relatedness study confirmed the consistency of the three groups delineated by (GTG)5-PCR and fatty acid analysis. A small number of phenotypic characters allowed differentiation of the three groups of isolates. The three groups therefore represent novel species, for which the names Bacillus humi, Bacillus arenosi and Bacillus arvi are proposed, with LMG 22167T (=DSM 16318T), LMG 22166T (=DSM 16319T) and LMG 22165T (=DSM 16317T) as the respective type strains.

Study of mural painting isolates, leading to the transfer of 'Bacillus maroccanus' and 'Bacillus carotarum' to Bacillus simplex, emended description of Bacillus simplex, re-examination of the strains previously attributed to 'Bacillus macroides' and description of Bacillus muralis sp. nov.

A group of 24 strains was isolated from deteriorated mural paintings situated in Spain (necropolis of Carmona) and Germany (church of Greene-Kreiensen). (GTG)5-PCR genomic fingerprinting was performed on these strains to assess their genomic variability and the strains were delineated into four groups. Representatives were studied by 16S rRNA gene sequencing and were found to be closely related to Bacillus simplex and the species 'Bacillus macroides' (strain NCIMB 8796) and 'Bacillus maroccanus' (names not validly published) according to a fasta search. The close similarity between B. simplex, 'B. macroides' NCIMB 8796, 'B. maroccanus' and the mural painting isolates was confirmed by additional (GTG)5-PCR, ARDRA, FAME and SDS-PAGE analyses. Furthermore, these techniques revealed that strains of 'Bacillus carotarum', another name that has not been validly published, also showed high similarity to this group of organisms. On the other hand, it was shown that the strains labelled 'B. macroides' in different collections do not all belong to the same species. Strain NCIMB 8796 can be allocated to B. simplex, while strain DSM 54 (=ATCC 12905) shares the highest 16S rRNA gene sequence similarity with Bacillus sphaericus and Bacillus fusiformis (both around 98.6 %). On the basis of further DNA-DNA hybridization data and the study of phenotypic characteristics, one group of five mural painting strains was attributed to a novel species in the genus Bacillus, for which the name Bacillus muralis sp. nov. is proposed. Finally, the remaining mural painting strains, one (LMG 18508=NCIMB 8796) of two strains belonging to 'B. macroides' and strains belonging to 'B. maroccanus' and 'B. carotarum' are allocated to the species B. simplex and an emended description of B. simplex is given.

Brevibacterium picturae sp. nov., isolated from a damaged mural painting at the Saint-Catherine chapel (Castle Herberstein, Austria).

Three strains showing highly similar (GTG)5-PCR patterns were isolated from a heavily damaged mural painting at the Saint-Catherine chapel (Castle Herberstein, Austria). On the basis of 16S rRNA gene sequence similarity, the strains were attributed to Brevibacterium, with Brevibacterium casei (96.7 %), Brevibacterium iodinum (96.7 %) and Brevibacterium linens (96.6 %) as the closest related species. Chemotaxonomic data [peptidoglycan contains meso-diaminopimelic acid; mycolic acids absent; MK-8(H2) as the major menaquinone; polar lipids phosphatidylglycerol and diphosphatidylglycerol present; anteiso-C(15 : 0) and anteiso-C(17 : 0) as major fatty acids] supported the affiliation of the strains to the genus Brevibacterium. Additional physiological and biochemical tests confirmed the taxonomic position of the strains and allowed phenotypic differentiation from Brevibacterium species with validly published names. The isolates from the mural painting, therefore, represent a novel species, for which the name Brevibacterium picturae sp. nov. is proposed, with LMG 22061T (= DSM 16132T) as the type strain.

Anoxybacillus contaminans sp. nov. and Bacillus gelatini sp. nov., isolated from contaminated gelatin batches.

Aerobic, endospore-forming bacteria that are attributed to the genus Bacillus or related genera constitute a hazard to the quality of gelatin. During repetitive extragenic palindromic DNA (rep)-PCR screening of gelatin isolates, a group of five isolates (group 1) and a group of 66 isolates (group 2) that did not match any pattern in our database were found. On the basis of 16S rDNA sequence analysis, representative strains of the different rep-PCR fingerprint types of group 1 were shown to be related most closely to Anoxybacillus species, but with sequence similarity of <97 %. Likewise, representative strains of group 2 were shown to be related most closely to Bacillus species, with 16S rDNA sequence similarity of <97 %. DNA-DNA reassociation values of isolates that displayed the most divergent rep-PCR profiles revealed that strains within each group belonged to a single species, according to recommendations for species delineation. A mean fatty acid profile could be calculated for each group. Isolates within a single group had similar patterns of results in API and other phenotypic tests; no correlation of patterns of results with rep-PCR groups was seen. Physiological characterization of group 1 isolates allows their distinction from other Anoxybacillus species. Despite the weak reaction of group 2 isolates in API tests, physiological characterization allows distinction between Bacillus species that react weakly in API tests. Two novel species are therefore proposed, with the names Anoxybacillus contaminans sp. nov. (type strain, LMG 21881(T)=DSM 15866(T)) and Bacillus gelatini sp. nov. (type strain, LMG 21880(T)=DSM 15865(T)).

Bacillus novalis sp. nov., Bacillus vireti sp. nov., Bacillus soli sp. nov., Bacillus bataviensis sp. nov. and Bacillus drentensis sp. nov., from the Drentse A grasslands.

A group of 42 isolates were isolated from the soil of several disused hay fields, in the Drentse A agricultural research area (The Netherlands), that were taken out of production at different times. The group represents hitherto-uncultured Bacillus lineages that have previously been found, by a non-cultural method, to be predominant in soil. The strains were subjected to a polyphasic taxonomic study, including (GTG)5-PCR, 16S rDNA sequence analysis, DNA-DNA hybridizations, DNA base-ratio determination, fatty acid analysis and morphological and biochemical characterization. By comparing the groupings obtained by (GTG)5-PCR and 16S rDNA sequence analysis, six clusters of similar strains could be recognized. A DNA-DNA relatedness study showed that these clusters represented five novel genospecies. Further analysis supported the proposal of five novel species in the genus Bacillus, namely Bacillus novalis sp. nov. (type strain IDA3307T=R-15439T=LMG 21837T=DSM 15603T), Bacillus vireti sp. nov. (type strain IDA3632T=R-15447T=LMG 21834T=DSM 15602T), Bacillus soli sp. nov. (type strain IDA0086T=R-16300T=LMG 21838T=DSM 15604T), Bacillus bataviensis sp. nov. (type strain IDA1115T=R-16315T=LMG 21833T=DSM 15601T) and Bacillus drentensis sp. nov. (type strain IDA1967T=R-16337T=LMG 21831T=DSM 15600T).

Multiplex PCR screening of soil isolates for novel Bacillus-related lineages.

A16S rDNA multiplex PCR-based high-throughput protocol is presented to screen bacterial isolates in large amounts for the appearance of novel lineages of bacteria, especially hitherto unknown Bacillus relatives. The 16S rDNAs of 4224 isolates from a comprehensive cultivation campaign were screened for similarity to predominant uncultured soil bacteria. Soil suspensions were plated in serial dilutions on various media. After 2, 4 and 6 weeks, colonies were collected with toothpicks and transferred to microtiterplates for cell lysis and storage plates for subculture. Cell lysis was a simple freeze-heating cycle in distilled water. The multiplex PCR was adapted to operate sufficiently for Gram positives under these conditions. Approximately 10.6% of all picked colonies reacted with a primer targeting a Bacillus fraction containing novel Bacillus benzoevorans-relatives previously detected as predominant soil bacteria by culture-independent studies. From these 446 colonies detected by multiplex PCR, 363 (81.4%) could be successfully used for continued subculture and 16S rDNA sequencing. All identification was done by 16S rDNA sequencing. This revealed that more than 60% of them represented a variety of candidates for potentially new species. Twelve colonies were identified as almost identical matches to 16S rDNA sequences of hitherto uncultured but apparently predominant soil bacteria cloned from directly extracted soil DNA. Also, novel lineages of unpredicted phylogenetic diversity like novel Paenibacillus, Sporosarcina and even Xanthomonads were represented.

Bacillus decolorationis sp. nov., isolated from biodeteriorated parts of the mural paintings at the Servilia tomb (Roman necropolis of Carmona, Spain) and the Saint-Catherine chapel (Castle Herberstein, Austria).

Microbial growths causing discoloration on the Roman wall paintings of the Servilia tomb at the necropolis of Carmona (Spain) and the medieval wall paintings of the Saint-Catherine chapel at Castle Herberstein (Austria) were investigated and from four different samples, a group of ten strains with similar characteristics was isolated. The isolates were characterized in a polyphasic taxonomic study, including 16S rDNA sequence analysis, (GTG)5-PCR genomic fingerprinting, DNA-DNA hybridization, DNA base ratio, fatty acid analysis, morphological and biochemical characterization. The data obtained attribute the isolates to a novel species of the genus Bacillus, for which the name Bacillus decolorationis sp. nov. is proposed. The type strain is strain LMG 19507T (=DSM 14890T).

Virgibacillus carmonensis sp. nov., Virgibacillus necropolis sp. nov. and Virgibacillus picturae sp. nov., three novel species isolated from deteriorated mural paintings, transfer of the species of the genus salibacillus to Virgibacillus, as Virgibacillus marismortui comb. nov. and Virgibacillus salexigens comb. nov., and emended description of the genus Virgibacillus.

A group of 13 strains was isolated from samples of biofilm formation on the mural paintings of the Servilia tomb (necropolis of Carmona, Spain) and the Saint-Catherine chapel (castle at Herberstein, Austria). The strains were subjected to a polyphasic taxonomic study, including (GTG)5-PCR, 16S rDNA sequence analysis, DNA-DNA hybridizations, DNA base ratio determination, analysis of fatty acids, polar lipids and menaquinones and morphological and biochemical characterization. In a phylogenetic tree based on neighbour-joining of 16S rDNA sequences, the strains are divided in two major groups, representing three novel species according to DNA-DNA relatedness, that are positioned at approximately equal distances from Virgibacillus and Salibacillus. After comparison of the novel results with existing data, the transfer of the species of Salibacillus to Virgibacillus is proposed, with the resulting new combinations Virgibacillus marismortui comb. nov. and Virgibacillus salexigens comb. nov. Additionally, three novel species are described, for which the names Virgibacillus carmonensis sp. nov., Virgibacillus necropolis sp. nov. and Virgibacillus picturae sp. nov. are proposed. The respective type strains are LMG 20964T (=DSM 14868T), LMG 19488T (=DSM 14866T) and LMG 19492T (= DSM 14867T). Finally, an emended description of the genus Virgibacillus is given.

Brachybacterium fresconis sp. nov. and Brachybacterium sacelli sp. nov., isolated from deteriorated parts of a medieval wall painting of the chapel of Castle Herberstein (Austria).

From two samples of microbial biofilms, damaging the mural paintings at the Saint-Catherine chapel of Castle Herberstein (Austria), four and nine coryneform bacteria were isolated, respectively. A polyphasic taxonomic study of these isolates, including morphological, biochemical and chemotaxonomic characterization, REP-PCR fingerprinting, 16S rDNA sequence analysis, DNA base ratio and DNA-DNA hybridizations, allocated them to the genus Brachybacterium. The isolates of the two samples both represent new species, for which the names Brachybacterium fresconis sp. nov. and Brachybacterium sacelli sp. nov. are proposed. The respective type strains are LMG 20336T (= DSM 14564T) and LMG 20345T (= DSM 14566T).

Fluorescent amplified fragment length polymorphism and repetitive extragenic palindrome-PCR fingerprinting reveal host-specific genetic diversity of Vibrio halioticoli-like strains isolated from the gut of Japanese abalone.

When analyzed by fluorescent amplified fragment length polymorphism and repetitive extragenic palindrome-PCR fingerprinting, a total of 47 Vibrio halioticoli strains isolated from four Japanese abalone species and one turban shell species formed three clusters that roughly reflect the different species of host abalone from which they were isolated. The V. halioticoli isolates from turban shells were distributed evenly among the clusters. Representative isolates from two clusters were deemed separate species or subspecies by DNA-DNA hybridization.

Halomonas muralis sp. nov., isolated from microbial biofilms colonizing the walls and murals of the Saint-Catherine chapel (Castle Herberstein, Austria).

A group of seven halophilic strains (optimal growth at 2.5-10.0% NaCl) was isolated from samples of a wall and a mural painting, both heavily contaminated by microbial growth, inside the Saint-Catherine chapel of Castle Herberstein (Austria). The strains were subjected to a polyphasic taxonomic study that included DNA-DNA relatedness studies, DNA base-ratio determinations, 16S rDNA sequence analysis, rep-PCR genomic fingerprinting, fatty acid analysis and phenotypic and biochemical characterization. The data obtained indicate that the strains belong to the genus Halomonas and represent a novel species, for which the name Halomonas muralis sp. nov. is proposed. The type strain is strain LMG 20969(T) ( = DSM 14789(T)).