[Differentiation and Identification of Alicyclobacillus Strains by Fourier Transform Near-Infrared Spectroscopy].

Fourier transform near-infrared spectroscopy (FT-NIR) can reflect the overall molecular composition of microbial cells to identify different types of microorganisms. To establish an accurate, effective method about the differentiation and identification of Alicyclobacillus strains between different species, the present research performed the following studies by FT-NIR: (1) The FT-NIR spectra about seven type stains was clustered for data analysis. After preprocessing, reduction of data was performed by Principal Component Analysis (PCA) and Linear Discriminant Analysis(LDA), exploring the feasibility of differentiation and identification between different species, the result suggested that the PCA model can cluster the seven species of Alicyclobacillus strains correctly and the LDA model I can predict the unknown species with 100% accuracy. It evidenced that the method could identify different species of Alicyclobacillus strains preliminary. (2)In order to improve the robustness and practicability of the model, a total of 41 Alicyclobacillus strains including type and isolated strains were prepared for LDA model II, using the same methods as mentioned before. The result indicated that the LDA model validated by fifteen sample with 86.67% accuracy. It was more perfect and more comprehensive. As a result, the FT-NIR technology combined with chemometrics method can accurately and effectively identify Alicyclobacillus strains between different microbial species.

Streptomyces zinciresistens sp. nov., a zinc-resistant actinomycete isolated from soil from a copper and zinc mine.

A filamentous actinomycete, designated strain CCNWNQ 0016(T), was isolated from soil from a zinc and copper mine in Shaanxi province, north-western China. A polyphasic taxonomic study was carried out to establish the status of strain CCNWNQ 0016(T). Chemical and morphological properties of the isolate were similar to those of species of the genus Streptomyces. Analysis of the almost complete 16S rRNA gene sequence placed strain CCNWNQ 0016(T) in the genus Streptomyces where it formed a distinct phyletic line with recognized species of this genus. The strain exhibited highest sequence similarities to Streptomyces niveoruber NBRC 15428(T) (98.8  %), Streptomyces griseoviridis NBRC 12874(T) (98.7  %) and Streptomyces aurantiogriseus NBRC 12842(T) (98.7  %). Furthermore, DNA-DNA hybridization studies between the novel isolate and these three strains showed relatedness values of 49.6 ± 0.6, 47.2 ± 0.9 and 46.9 ± 1.1  %, respectively. A number of phenotypic properties also enabled the isolate to be differentiated from related species of the genus Streptomyces. Therefore, it is proposed that strain CCNWNQ 0016(T) (=K42(T) =ACCC 41871(T) =HAMBI 3107(T)) should be classified as the type strain of a novel species in the genus Streptomyces, Streptomyces zinciresistens sp. nov. The maximum level of resistance to Zn²+ for strain CCNWNQ 0016(T) is 35 mM.