Yue-Ji Zhang

Modestobacter roseus sp. nov., an endophytic actinomycete isolated from the coastal halophyte Salicornia europaea Linn., and emended description of the genus Modestobacter.

A novel actinomycete, designated strain KLBMP 1279(T), was isolated from surface-sterilized roots of a coastal halophyte, Salicornia europaea Linn., collected from Jiangsu Province, in the east of China. The taxonomic status of this organism was established using a polyphasic approach. 16S rRNA gene sequence analysis indicated that strain KLBMP 1279(T) was closely related to Modestobacter marinus 42H12-1(T) (99.5% 16S rRNA gene sequence similarity), Modestobacter versicolor CP153-2(T) (98.4%) and Modestobacter multiseptatus AA-826(T) (97.5%). Chemotaxonomic characteristics were consistent with its assignment to the genus Modestobacter in that the isolate had meso-diaminopimelic acid as the diagnostic diamino acid in the cell wall, MK-9(H4) as major menaquinone and a polar lipid profile containing diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannosides, two unknown aminophospholipids and an unknown phospholipid. The predominant fatty acids were iso-C16:0, iso-C15:0 and C17:1ω8c. The DNA G+C content was 71.7 mol%. However, DNA-DNA hybridization assays as well as physiological and biochemical analyses differentiated strain KLBMP 1279(T) from its closest phylogenetic relatives. On the basis of phenotypic, chemotaxonomic and phylogenetic evidence, the isolate KLBMP 1279(T) represents a novel species of the genus Modestobacter, for which the name Modestobacter roseus sp. nov. is proposed; the type strain is KLBMP 1279(T) (=KCTC 19887(T)=NBRC 108673(T)=DSM 45764(T)). An emended description of the genus Modestobacter is also proposed.

Streptomyces halophytocola sp. nov., an endophytic actinomycete isolated from the surface-sterilized stems of a coastal halophyte Tamarix chinensis Lour.

A novel actinomycete, designated KLBMP 1284(T), was isolated from the surface-sterilized stems of a coastal halophyte Tamarix chinensis Lour. collected from the city of Nantong, Jiangsu Province, east China. The strain was found to have morphological and chemotaxonomic characteristics typical of members of the genus Streptomyces. Analysis of the 16S rRNA gene sequence of strain KLBMP 1284(T) revealed that the strain formed a distinct clade within the phylogenetic tree based on 16S rRNA gene sequences and the highest sequence similarity (99.43 %) was to Streptomyces sulphureus NRRL B-1627(T). 16S rRNA gene sequence similarity to other species of the genus Streptomyces was lower than 97 %. Based on DNA-DNA hybridization values and comparison of morphological and phenotypic data, KLBMP 1284(T) could be distinguished from the closest phylogenetically related species, Streptomyces sulphureus NRRL B-1627(T). Thus, based on these data, it is evident that strain KLBMP 1284(T) represents a novel species of the genus Streptomyces, for which the name Streptomyces halophytocola sp. nov. is proposed. The type strain is KLBMP 1284(T) (= KCTC 19890(T) = NBRC 108770(T)).

Synthesis of biocontrol macromolecules by derivative of chitosan with surfactin and antifungal evaluation.

A derivative of chitosan was prepared with chitosan and β-cyclodextrins, which was synthesized by the immobilization reaction, as a carrier to adsorb surfactin produced from Bacillus amyloliquefaciens and got biological macromolecules. The antifungal activity against three sapstain fungi by a combination of macromolecules was tested. The results showed that the macromolecules inhibited the mycelium growth of sapstain fungi Lasiodiplodia rubropurpurea, L. crassispora, and L. theobromae by about 73.22%, 76.72%, and 70.22%, respectively. The macromolecules were relatively thermally stable with more than 50% of the antifungal activity even after being held at 121°C for 30 min. Meanwhile, the activity of the macromolecules remained more than 55% at a pH value ranging from 4 to 12. The macromolecules were resistant to hydrolysis by most protein-denaturing detergents and other enzymes. The results indicated the macromolecules might provide an alternative bioresource for the bio-control of sapstain.

Erratum to: Isolation of ACC deaminase-producing habitat-adapted symbiotic bacteria associated with halophyte Limonium sinense

Owing to an error during the submission process, the original article was inadvertently published with an incorrect version of Fig. 2. The correct image and caption is shown below.