Colorectal cancer is one of the most common cancers worldwide. The anticancer effect of Wolfberry (Lycium barbarum) polysaccharide (LBP) on colon cancer cells is largely unknown. To investigate the growth effect of LBP on human colon cancer cell and its possible mechanisms, human colon cancer SW480 and Caco-2 cells were treated with 100-1,000 mg/l LBP for 1-8 days. Cell growth was measured by MTT assay and crystal violet assay. Distribution of the cell cycle was analyzed by flow cytometry. Western blotting was used to indicate changes in the level of cyclins and cyclin-dependent kinases (CDKs). LBP treatment inhibited both colon cancer cell lines in a dose-dependent manner. At concentrations from 400 to 1,000 mg/l, LBP significantly inhibited the growth of SW480 cells (400 mg/l, P < 0.01; 800 and 1,000 mg/l, P < 0.001); while at concentrations from 200 to 1,000 mg/l, LBP significantly inhibited the growth of Caco-2 cells (200 mg/l, P < 0.05; 400-1,000 mg/l, P < 0.001). Crystal violet assay showed that LBP had a long-term anti-proliferative effect. More importantly, cells were arrested at the G0/G1 phase. The changes in cell-cycle-associated protein, cyclins, and CDKs were consistent with the changes in cell-cycle distribution. This is one of the first studies to focus on LBP-induced interruption of the cell cycle in human colon carcinoma cells. The results suggest that LBP is a candidate anticancer agent.

A novel actinomycete, designated strain NEAU-GRX11(T), was isolated from muddy soil collected from a stream of Jinlong Mountain in Harbin, north China. The organism was found to have morphological and chemotaxonomic characteristics typical of the genus Micromonospora. The 16S rRNA gene sequence of strain NEAU-GRX11(T) showed highest similarity to Micromonospora zamorensis CR38(T) (99.2 %), Micromonospora saelicesensis Lupac 09(T) (99.0 %), Micromonospora chokoriensis 2-19/6(T) (98.7 %), Micromonospora coxensis 2-30-b/28(T) (98.5 %), Micromonospora aurantiaca ATCC 27029(T) (98.4 %) and Micromonospora lupini lupac 14N(T) (98.3 %). Phylogenetic analysis based on the 16S rRNA gene and gyrB gene demonstrated that strain NEAU-GRX11(T) was a member of the genus Micromonospora and supported the closest phylogenetic relationship to M. zamorensis CR38(T), M. saelicesensis Lupac 09(T), M. chokoriensis 2-19/6(T) and M. lupini lupac 14N(T). A combination of DNA-DNA hybridization and some phenotypic characteristics indicated that the novel strain could be readily distinguished from these closest phylogenetic relatives. Therefore, it is proposed that NEAU-GRX11(T) represents a novel species of the genus Micromonospora, for which the name Micromonospora jinlongensis sp. nov. is proposed. The type strain is NEAU-GRX11(T) (=CGMCC 4.7103(T)=DSM 45876(T)).

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Ralstonia solanacearum is a major phytopathogenic bacterium that attacks many crops and other plants around the world. In this study, a novel actinomycete, designated strain NEAU-SSA 1T, which exhibited antibacterial activity against Ralstonia solanacearum, was isolated from soil collected from Mount Song and characterized using a polyphasic approach. Morphological and chemotaxonomic characteristics of the strain coincided with those of the genus Streptomyces. The 16S rRNA gene sequence analysis showed that the isolate was most closely related to Streptomyces aureoverticillatus JCM 4347T (97.9%). Phylogenetic analysis based on 16S rRNA gene sequences indicated that the strain formed a cluster with Streptomyces vastus JCM4524T (97.4%), S. cinereus DSM43033T (97.2%), S. xiangluensis NEAU-LA29T (97.1%) and S. flaveus JCM3035T (97.1%). The cell wall contained LL-diaminopimelic acid and the whole-cell hydrolysates were ribose, mannose and galactose. The polar lipids were diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), hydroxy-phosphatidylethanolamine (OH-PE), phosphatidylinositol (PI), two phosphatidylinositol mannosides (PIMs) and an unidentified phospholipid (PL). The menaquinones were MK-9(H4), MK-9(H6), and MK-9(H8). The major fatty acids were iso-C17:0, C16:0 and C17:1 ω9c. The DNA G+C content was 69.9 mol %. However, multilocus sequence analysis (MLSA) based on five other house-keeping genes (atpD, gyrB, recA, rpoB, and trpB), DNA–DNA relatedness, and physiological and biochemical data showed that the strain could be distinguished from its closest relatives. Therefore, it is proposed that strain NEAU-SSA 1T should be classified as representatives of a novel species of the genus Streptomyces, for which the name Streptomyces sporangiiformans sp. nov. is proposed. The type strain is NEAU-SSA 1T (=CCTCC AA 2017028T = DSM 105692T).

Lycium barbarum polysaccharide (LBP) is extracted from the traditional Chinese herb Lycium barbarum, and has potential anticancer activity. However, the detailed mechanisms are largely unknown. The purpose of this study was to observe the anticancer effect of LBP on human gastric cancer, and its possible mechanisms. Human gastric cancer MGC-803 and SGC-7901 cells were treated with various concentrations of LBP for 1-5 days, and cell growth was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. Distribution of the cell cycle was analyzed by flow cytometry. Western blotting was used to indicate changes in the level of cyclins and cyclin-dependent kinases (CDKs). LBP treatment inhibited growth of MGC-803 and SGC-7901 cells, with cell-cycle arrest at the G0/G1 and S phase, respectively. We believe that this is the first study to show that LBP arrested different cell lines from the same types of cancer at different phases. The changes in cell-cycle-associated protein, cyclins, and CDKs were consistent with the changes in cell-cycle distribution. This study suggests that induction of cell-cycle arrest participates in the anticancer activity of LBP on gastric cancer cells.