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 22167(T) (= DSM 16318(T)), LMG 22166(T) (=DSM 16319(T)) and LMG 22165(T) (=DSM 16317(T)) as the respective type strains.
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.
ABSTRACT Bacterial contamination of gelatin is of great concern. Indeed, this animal colloid has many industrial applications, mainly in food and pharmaceutical products. In a previous study (E. De Clerck and P. De Vos, Syst. Appl. Microbiol. 25: 611-618), contamination of a gelatin production process with a variety of gram-positive and gram-negative bacteria was demonstrated. In this study, bacterial contamination of semifinal gelatin extracts from several production plants was examined. Since these extracts are subjected to harsh conditions during production and a final ultrahigh-temperature treatment, the bacterial load at this stage is expected to be greatly reduced. In total, 1,129 isolates were obtained from a total of 73 gelatin batches originating from six different production plants. Each of these batches was suspected of having bacterial contamination based on quality control testing at the production plant from which it originated. For characterization and identification of the 1,129 bacterial isolates, repetitive-element PCR was used to obtain manageable groups. Representative strains were identified by means of 16S rRNA genesequencing, species-specific gyrB PCR, and gyrA and rpoB sequencing and were tested for gelatinase activity. The majority of isolates belonged to members of Bacillus or related endospore-forming genera. Representative strains were identified as Bacillus cereus , Bacillus coagulans , Bacillus fumarioli , Bacillus amyloliquefaciens , Bacillus licheniformis , Bacillus pumilus , Bacillus sonorensis , Bacillus subtilis , Bacillus gelatini , Bacillus thermoamylovorans , Anoxybacillus contaminans , Anoxybacillus flavithermus , Brevibacillus agri , Brevibacillus borstelensis , and Geobacillus stearothermophilus . The majority of these species include strains exhibiting gelatinase activity. Moreover, some of these species have known pathogenic properties. These findings are of great concern with regard to the safety and quality of gelatin and its applications.
Contamination of gelatine may affect the safety and/or quality of its applications. Characterisation of bacterial isolates from semi-final gelatine batches revealed thermotolerant, aerobic, endosporeforming contaminants. In this paper, bacterial contamination in gelatine batches is analysed without previous isolation, by means of denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rDNA sequences. V9 and V6-V8 regions of the 16S rDNA gene were found more suitable for this purpose than V1 or V3 regions. Bacillus fumarioli, Bacillus licheniformis, members of the 'Bacillus cereus group', Bacillus subtilis, Bacillus shackletonii, Brevibacillus borstelensis and Brevibacillus agri were detected.