Pinibacter aurantiacus gen. nov., sp. nov., isolated from rhizospheric soil of a pine tree

A Gram-stain-negative, aerobic and rod-shaped novel bacterial strain, designated MAH-26^T, was isolated from rhizospheric soil of a pine tree. The colonies were orange coloured, smooth, spherical and 0.7-1.8 mm in diameter when grown on Reasoner's 2A (R2A) agar for 2 days. Strain MAH-26^T was able to grow at 10-40 °C, at pH 6.0-9.0 and with 0-1.0 % NaCl. Cell growth occurred on nutrient agar, R2A agar, tryptone soya agar and Luria-Bertani agar. The strain gave positive results in oxidase and catalase tests. Strain MAH-26^T was closely related to Flavihumibacter sediminis CJ663^T and Parasegetibacter terrae SGM2-10^T with a low 16S rRNA gene sequence similarity (92.8 and 92.9 %, respectively) and phylogenetic analysis indicated that the strain formed a distinct phylogenetic lineage from the members of the closely related genera of the family Chitinophagaceae. Strain MAH-26^T has a draft genome size of 6 857 405 bp, annotated with 5173 protein-coding genes, 50 tRNA and two rRNA genes. The genomic DNA G+C content was 41.5 mol%. The predominant isoprenoid quinone was menaquinone 7. The major fatty acids were identified as iso-C_15:0, iso-C_15:1 G and iso-C_17:0 3OH. On the basis of phylogenetic inference and phenotypic, chemotaxonomic and molecular properties, strain MAH-26^T represents a novel species of a novel genus of the family Chitinophagaceae, for which the name Pinibacter aurantiacus gen. nov., sp. nov. is proposed. The type strain of Pinibacter aurantiacus is MAH-26^T (=KACC 19749^T=CGMCC 1.13701^T).

The bifidogenic effects and dental plaque deformation of non-digestible isomaltooligosaccharides synthesized by dextransucrase and alternansucrase

Non-digestible isomaltooligosaccharides (NDIMOS) are functional food and beverage ingredients that contributed to human health benefits through metabolism of gastrointestinal microorganism. In this study, NDIMOS were synthesized by combine dextransucrase from Leuconostoc mesenteroides B512F/KM and alternansucrase from L. mesenteroides NRRL 1355CF10/KM using sucrose as substrate and maltose as acceptor. Their digestibility was confirmed by using digestive enzymes including α-amylase and amyloglucosidase. NDIMOS inhibited insoluble glucan formation through mutansucrase from Streptococcus mutans. The bifidogenic effect of NDIMOS was investigated by growth of four strains of Bifidobacterium in MRS broth containing NDIMOS, compared with MRS broth contain glucose and negative control. Additionally, Bifidobacterium bifidum or Bifidobacterium adolescentis inhibited the growth of Salmonella enterica serovar typhimurium when they were co-cultivation in MRS broth containing NDIMOS. These results suggested that NDIMOS is potential functional ingredient for food, beverage, and pharmaceutical application.

CRISPR is a useful biological tool for detecting nucleic acid of SARS-CoV-2 in human clinical samples

The recent pandemic of novel coronavirus disease (COVID-19) has spread globally and infected millions of people. The quick and specific detection of the nucleic acid of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) remains a challenge within healthcare providers. Currently, quantitative reverse transcription-polymerase chain reaction (RT-qPCR) is the widely used method to detect the SARS-CoV-2 from the human clinical samples. RT-qPCR is expensive equipment and needs skilled personnel as well as lengthy detection time. RT-qPCR limitation needed an alternative healthcare technique to overcome with a fast and cheaper detection method. By applying the principles of CRISPR technology, several promising detection methods giving hope to the healthcare community. CRISPR-based detection methods include SHERLOCK-Covid, STOP-Covid, AIOD-CRISPR, and DETECTR platform. These methods have comparative advantages and drawbacks. Among these methods, AIOD-CRISPR and DETECTR are reasonably better diagnostic methods than the others if we compare the time taken for the test, the cost associated with each test, and their capability of detecting SARS-CoV-2 in the clinical samples. It may expect that the promising CRISPR-based methods would facilitate point-of-care (POC) applications in the CRISPR-built next-generation novel coronavirus diagnostics.