Study On Identification,Bioactivity And The Complete Genome Sequence Of Endophytic Actinomycete FORO54 From Dongxiang Wild Rice

Dongxiang wild rice(Oryza rufipogon Griff.)was the northernmost wild rice that distributed in the world.As an important germplasm resources,it has excellent properties with cold-resistant,insect-resistance as well as disease-resistant.Strain FORO54,isolated from phyllosphere of Dongxiang wild rice,was taken as the research object.Morphological method and molecular biology were applied for the classification and identification.In addition to whole genome sequencing,analysis of secondary metabolites synthesis gene cluster and metabolic products prediction,the antimicrobial activity and stability of the fermented liquid were studied,either.Analysis of 16 S rRNA gene sequence and phylogenetic tree show that strain FORO54 is highly similar to Micromonospora rosaria DSM 803(= NRRL No.3718 = ATCC 29337 = SCC 957).The spores and hyphae of FORO54 observed by scanning electron microscope corresponded to the features of Micromonspora sp..Compared with Micromonospora rosaria DSM 803,FORO54 is different from Micromonospora rosaria DSM 803 on polyphasic taxonomy identification including morphologic,cultural characteristics and biochemical characteristics.These features indicate that strain FORO54 may be a novel species.The whole genome of strain FORO54 was sequenced,and the differences between other 15 strains on 25 COG were analyzed by comparative genomics,and the phylogenetic trees of 16 strains were constructed.The results showed that the FORO54 was the most similar to strain AM105.GO annotation and comparative analysis showed that the number of genes in the immune system of FORO54 was significantly more than that of the L5 strain,while the L5 strain was more dominant than the FORO54 in the nutrient pool.The antibacterial,antifungi activity and physical and chemical stability of the fermentation broth of strain FORO54 were tested.The results indicated that the fermentation broth showed strong bioactive to Staphyloccocus aureus CCTCC AB 91093,Escherichia coli CCTCC AB93154,Bacillus subtilis CCTCC AB90008,Xanthomonas oryzae pv.oryzicola and Sesame Fusarium oxysporum(Sesame Fusarium Wilt pathogens)that the inhibition rate reached 80%,while no activity to Plantain Sclerotinia scleroliorum,Sclerotinia scleotiorum,Gibberella saubinetti,Chili root fusarium oxysporumf.and Rhizoctonia solani,weak activity to Pyricularia grisea sacc.This provides the possibility for the development of antimicrobial agents.Though heat treatment,UV,pH,trypsin,pepsin and proteinase K of enzyme treatment were conducted on the fermentation broth of strain FORO54,its resistance to Xanthomonas oryzae pv.oryzicola was still very strong.So,all that showed biologically active substances were stable to physical and chemical conditions.This provides the basis for the separation of products and monomer activity in the future.