Related Experiment Video
Updated: Jun 21, 2026
07:45
Soil Sampling and Isolation of Entomopathogenic Nematodes (Steinernematidae, Heterorhabditidae)
Published on: July 11, 2014
Nocardioides terrae sp. nov., isolated from forest soil
Jia-Yue Zhang1, Xing-Yu Liu, Shuang-Jiang Liu
1State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, PR China.
Summary
A novel bacterial species, Nocardioides terrae VA15(T), was discovered in Chinese forest soil. This Gram-positive, aerobic bacterium expands the known diversity within the Nocardioides genus.
Area of Science:
- Microbiology
- Bacteriology
- Taxonomy
Background:
- The genus Nocardioides comprises Gram-positive, aerobic actinobacteria found in diverse environments.
- Accurate taxonomic classification is crucial for understanding microbial diversity and ecological roles.
Purpose of the Study:
- To characterize a newly isolated bacterial strain, VA15(T), from forest soil.
- To determine the phylogenetic and taxonomic position of strain VA15(T) within the genus Nocardioides.
Main Methods:
- Isolation and cultivation of bacterial strain VA15(T) from forest soil.
- Morphological, physiological, and biochemical characterization.
- Analysis of chemotaxonomic markers, including respiratory quinones and cell-wall composition.
- 16S rRNA gene sequencing for phylogenetic analysis.
- DNA-DNA hybridization to assess relatedness to known species.
Main Results:
- Strain VA15(T) exhibited Gram-positive staining, aerobic respiration, and rod-to-coccoid morphology.
- Optimal growth occurred at 29°C, pH 6.2–6.5, and low salinity (0–0.25%).
- Chemotaxonomic analysis revealed MK-8(H(4)) as the major quinone and ll-2,6-diaminopimelic acid in the cell wall.
- Phylogenetic analysis based on 16S rRNA gene sequences showed highest similarity (up to 97.7%) to Nocardioides species.
- DNA-DNA relatedness values with closely related species (N. panacihumi and N. marinus) were low (16–21%).
- DNA G+C content was determined to be 71.6 mol%.
Conclusions:
- Strain VA15(T) represents a distinct lineage within the Nocardioides genus.
- Based on polyphasic taxonomic data, strain VA15(T) is proposed as a novel species, Nocardioides terrae sp. nov.
- The type strain is VA15(T) (=CGMCC 1.7056(T) =NBRC 104259(T)).
Related Concept Videos
01:29Soil Microbial Ecology
Soil microbial ecology is defined by highly diverse, spatially structured communities that drive nutrient cycling, organic matter turnover, and overall ecosystem stability. Although a gram of soil can contain thousands of bacterial and archaeal taxa, the ecological processes they mediate are even more crucial for sustaining terrestrial life.Microhabitats and NichesSoil is a heterogeneous mixture of minerals, organic matter, water, and air. Microbes inhabit distinct microhabitats formed by...
02:11The Roles of Bacteria and Fungi in Plant Nutrition
Plants have the impressive ability to create their own food through photosynthesis. However, plants often require assistance from organisms in the soil to acquire the nutrients they need to function correctly. Both bacteria and fungi have evolved symbiotic relationships with plants that help the species to thrive in a wide variety of environments.
01:25Microbial Mats
Microbial communities forming biofilms and mats represent complex, spatially structured ecosystems where metabolic processes are stratified according to light, oxygen, and nutrient gradients. Biofilms are initial colonization stages, only a few millimeters thick, while mature microbial mats can reach centimeter-scale thickness and display intricate vertical organization. Their structural and functional heterogeneity allows microorganisms to occupy distinct ecological niches within a few...
02:23The Soil Ecosystem
Plants obtain inorganic minerals and water from the soil, which acts as a natural medium for land plants. The composition and quality of soil depend not only on the chemical constituents but also on the presence of living organisms. In general, soils contain three major components:
02:40Epiphytes, Parasites, and Carnivores
Plants often form mutualistic relationships with soil-dwelling fungi or bacteria to enhance their roots’ nutrient uptake ability. Root-colonizing fungi (e.g., mycorrhizae) increase a plant’s root surface area, which promotes nutrient absorption. While root-colonizing, nitrogen-fixing bacteria (e.g., rhizobia) convert atmospheric nitrogen (N2) into ammonia (NH3), making nitrogen available to plants for various biological functions. For example, nitrogen is essential for the biosynthesis of the...
01:28Fungal Phylum Microsporidia
Microsporidia are a group of obligate intracellular fungi that were initially classified as protists but were later reclassified based on phylogenetic, molecular, and structural evidence linking them to the Chytridiomycota. These unicellular, non-motile organisms are highly specialized parasites that infect a wide range of animal hosts, including humans. They have evolved extensive genomic and metabolic reductions, making them highly dependent on their hosts for survival.Morphology and Genomic...