Paenibacillu jamilae sp nov., an exopolysaccharide-producing bacterium able to grow in olive-mill wastewater

Endospore-forming strains were isolated from corn-compost treated with oliv e-mill wastewater ('alpechin'). The strains were taxonomically studied and proposed as a novel Paenibacillus species. These organisms (strains B.3(T), B.7 and B.9) were particularly distinguishable from other aerobic spore-fo rming species by their ability to grow optimally in 100% (v/v) olive-mill w astewater at 30 degreesC and pH 7.0 and concomitant production of an intere sting exopolysaccharide. Chemotaxonomic analysis revealed that MK-7 was the predominant menaquinone, the major fatty acid was anteiso C-15:0 and the c ell wall contained meso-diaminopimelic acid. The DNA G+C content was 40.7 m ol%. Comparative sequence analysis of 16S rDNA with different reference spe cies from the genera Bacillus, Paenibacillus, Brevibacillus, Aneurinibacill us, Alicyclobacillus, Halobacillus, Virgibacillus, Amphibacillus, Coprobaci llus and Gracilibacillus indicated that the isolated strains were highly re lated to the genus Paenibacillus. Strain B.3(T) formed an evolutionary line age distinct from other species within the evolutionary radiation encompass ing the genus Paenibacillus. Strain B.3(T) was a close relative of Paenibac illus polymyxa, but DNA-DNA relatedness data with this species was very low (relative binding ratio < 16%). Based on the morphological and physiologic al characteristics, as well as on the phylogenetic position determined by 1 6S rDNA analysis and DNA-DNA relatedness data, it is concluded that these s trains should be designated a novel species, for which the name Paenibacill us jamilae sp. nov. is proposed. The type strain is B.3(T) (= CECT 5266(T) = DSM 13815(T)).