title: Nucleic acids of species of Lactobacillus.
abstract: Nucleic acid composition of 17 cultures representing the type or neotype strains of 15 named Lactobacillus species was studied. Nucleic acid characterization of these isolates was accompanied by a comparative study of conventional phenotypic reactions. The overall guanine plus cytosine mean deoxyribonucleic acid base composition ranged from 33 to 50% and genome sizes varied between 700 and 1500 X 10(6) daltons. Sporolactobacillus inulinus contained 2500 X 10(6) daltons of chromosomal deoxyribonucleic acid and was therefore similar in size to members of the genus Bacillus. Deoxyribonucleic acid hybridization at a temperature 15 degrees C below the thermal melting temperature confirmed the extreme molecular heterogeneity of many species. The genus can be divided into three major groups, each containing four or more species based on a combination of nucleic acid characteristics and conventional phenotypic reactions. Group I (33 to 39% guanine plus cytosine) contains Lactobacillus jensenii, Lactobacillus helveticus, Lactobacillus helveticus nov. ssp. jugurt, Lactobacillus acidophilus, Lactobacillus salivarius, and Lactobacillus sanfrancisco. Group II (42 to 48% guanine plus cytosine contains Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacillus casei, and Lactobacillus brevis, and Group III (48 to 50% guanine plus cytosine) contains Lactobacillus delbrueckii, Lactobacillus delbrueckii nov. ssp. bulgaricus, Lactobacillus delbrueckii nov. ssp. lactis, Lactobacillus delbrueckii nov. ssp. leichmanii, Lactobacillus fermentum, and Lactobacillus fermentum nov. ssp. cellobiosis.
mesh_terms: D001482:Base Composition; D003596:Cytosine / Q000032:analysis; D004269:DNA, Bacterial / Q000032:analysis*; D005798:Genes, Bacterial; D006147:Guanine / Q000032:analysis; D007778:Lactobacillus / Q000032:analysis* / Q000235:genetics; D007779:Lactobacillus acidophilus / Q000032:analysis / Q000235:genetics; D007780:Lacticaseibacillus casei / Q000032:analysis / Q000235:genetics; D009693:Nucleic Acid Hybridization
chemical_list: D004269:DNA, Bacterial; D006147:Guanine; D003596:Cytosine