Lactovum miscens gen. nov., sp. nov., an aerotolerant, psychrotolerant, mixed-fermentative anaerobe from acidic forest soil.
An aerotolerant, psychrotolerant anaerobe, anNAG3, was isolated from an acidic forest floor solution (in situ pH of 4.5). Cells of anNAG3 stained Gram-positive did not form spores, and were not motile. Cells were ovoid, approximately 1 microm long and 0.7 microm wide, mostly in pairs, and contained a multi-layered cell wall and intracytoplasmic membranes. Growth was observed at pH 3.5-7.5 and 0-35 degrees C. Glucose, galactose, fructose, mannitol, glucosamine, N-acetylglucosamine, cellobiose, and maltose supported growth. Lactate, ethanol, formate, and acetate were end products. H(2) and CH(4) were not detected, and only very minor amounts of CO(2) were produced. The relative amount of a particular product was dependent on the substrate utilized, and product profiles indicated that (i) sugars were initially metabolized to pyruvate via glycolysis, and (ii) lactate dehydrogenase and pyruvate-formate lyase were responsible for the subsequent metabolism of pyruvate. O(2) was not significantly utilized and was not toxic to growth. anNAG3 did not contain detectable membranous or cytoplasmic cytochromes. Nitrate, sulfate, and Fe(III) were not dissimilated. Thus, anNAG3 was characterized as an aerotolerant, non-acetogenic chemoorganotroph with a mixed-fermentative metabolism. The G + C content of the DNA was 37.6 mol%. The similarity of the 16S rRNA gene sequence of anNAG3 to that of its closest phylogenetic relatives (which were in the genera Lactococcus and Streptococcus) approximated 88-89%, indicating that anNAG3 constitutes the type species of a new genus. Based on the collective properties of anNAG3, it is proposed that anNAG3 be termed Lactovum miscens.
Matthies
Carola
C
Department of Ecological Microbiology, University of Bayreuth, 95440 Bayreuth, Germany.
Gössner
Anita
A
Acker
Georg
G
Schramm
Andreas
A
Drake
Harold L
HL
D039903:Actinobacteria / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism / Q000502:physiology*; D001483:Base Sequence; D006863:Hydrogen-Ion Concentration; D017045:Lactococcus; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000737:chemistry / Q000235:genetics; D016415:Sequence Alignment; D012988:Soil Microbiology; D013696:Temperature
D012336:RNA, Ribosomal, 16S