The degree of adhesion of Lactobacillus casei strain GG to human Caco‐2 cell line was investigated. Assessment of adhesion was compared to the adhesion of enterotoxigenic human Escherichia coli strain H 10407 and enterotoxigenic bovine E. coli strain B44 (non‐adhesive). Freeze‐dried Lactobacillus GG or samples from dairy products had medium to strong binding to the Caco‐2 cell line. Lactobacillus acidophilus (NCFB 1748) and L. bulgaricus showed no adhesion to the cell line while four tested Bifidobacterium strains had no or very weak adhesion to the Caco‐2 cell line.

Seven spore-forming, nitrogen-fixing bacterial isolates from spruce forest humus in Finland were studied using the polyphasic approach. PCR amplification of 16S rRNA gene fragment with specific primers showed that the isolates were members of Paenibacillus. Levels of 16S rDNA similarity between the isolates were 97 3-100 0 % and those between the isolates and other Paenibacillus species were 90 3-96 5 %. The highest similarities were observed with Paenibacillus azotofixans and Paenibacillus durus. Ribotyping with EcoRI and PvuII restriction showed a high diversity in the Paenibacillus species and distinguished the isolates from these closely related species. The main whole-cell fatty acids were anteiso-C 15 :0 (33-48 %), straight-chain C 14 :0 (7-21 %) and C 16 :0 (9-20 %), and iso-C 15 :0 (6-15 %). Electron microscopy revealed a unique striped morphology of the spore surfaces. Based on phylogenetic inference and phenotypic and chemotaxonomic characteristics, these isolates are proposed as a new species, Paenibacillus borealis sp. nov., the type strain of which is KK19 T (l DSM 13188 T l CCUG 43137 T ).

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We studied the potential of the humus layer of the Norway spruce stands to supply beneficial rhizobacteria to birch (Betula pendula), alder (Alnus incana) and fescue grass (Festuca rubra), representatives of pioneer vegetation after clear-cutting of the coniferous forest. Axenically grown seedlings of these species were inoculated with the acid spruce humus, pH 3.7^5.3. Actinorhizal propagules, capable of nodulating alder, were present in high density (10 3 g 31 ) in humus of long-term limed plots, whereas plots with nitrogen fertilization contained almost none (910 g 31 ). The genera most frequently found in the humus were Bacillus, Paenibacillus, Arthrobacter, Nocardia, Rhodococcus and Pseudomonas, independently of prior liming or fertilization of the plots. The taxa found in the seedling roots differed from that in humus by the prevalence of the Gram-negative genera Pseudomonas, Alcaligenes and Comamonas. Enrichment cultures of the roots on nitrogen-free media yielded Paenibacillus and Rhodococcus species. Nitrogen-fixing R. erythropolis and a novel Paenibacillus, closest by full sequence of 16S rDNA to P. durus, represented new classes of nitrogen-fixing rhizosphere bacteria. In addition, nitrogen-fixing R. fascians was found in the humus. The rhizoflora and humus contained high proportions of bacteria antagonistic towards plant pathogenic Rhizoctonia sp., Botrytis cinerea and Fusarium culmorum. The antagonistic isolates also commonly produced siderophores and/or cell wall degrading enzymes. ß

We studied the potential of the humus layer of the Norway spruce stands to supply beneficial rhizobacteria to birch (Betula pendula), alder (Alnus incana) and fescue grass (Festuca rubra), representatives of pioneer vegetation after clear-cutting of the coniferous forest. Axenically grown seedlings of these species were inoculated with the acid spruce humus, pH 3.7-5.3. Actinorhizal propagules, capable of nodulating alder, were present in high density (10(3) g(-1)) in humus of long-term limed plots, whereas plots with nitrogen fertilization contained almost none (