Identification Of The Marine Bacteria Notoacmeibacter Sp.BGMRC2072 And Study On Its Secondary Metabolites

In this paper,a new marine bacterium was isolated from the L.scabra attached to mangr-ove Kandelia candel in Beihai Beach(E:108°50'42",N:21°55'25"),and the bacterium num-bered as BGMRC2072.Observed the morphological characteristics of the strain,physiologic-al and biochemical tests,and sequence analysis of 16S rDNA gene,then preliminary determi-ne its phylogenetic status.The crude product of red pigment produced by this strain was sepa-rated by silica gel column chromatography,the high performance liquid chromatography was used for further purification,and the chemical structure was analyzed by IR,UV,1H NMR,13C NMR,DEPT,HMBC,HSQC and HR-ESI-MS.Finally,the effects of metal ions,temper-ature,pH,oxidants,reducing agents and food additives on the red pigment were studied,in order to provide the basic theoretical basis for its application in the food industry.The test results showed that the strain is a marine bacteria Notoacmeibacter sp.BGMRC 2072.The growth temperature of this bacterium was in the range of 15?37?,and the optimal growth temperature was in the range of 25?32 ?.The change of temperature affected the col-or of the colony.The colonies showed Black red at 15?20?,traffic red at 28?,and purple red above 35 ?.The optimal pH range was 6-10.The growth of strain required the presence of NaCl,the tolerance to salinity ranged from 1 to 11%,and the optimal growth salinity was 3%.Physiological and biochemical test results showed the catalase,urease,and Tween 40 hy-drolysis reactions were positive.Cellulase,starch hydrolysis,Tween 20 hydrolysis,Tween 80 hydrolysis,and oxidase reactions were negative.After the strain was fermented,it was extracted with chloroform and water(1:3,v/v)to obtain a crude pigment extract of 60.98 mg/mL,and the purity of a red monomer compound was 99.3%from the crude extract.The molecular weight of the pigment was[M+H]+352.2390 by HR-MS analysis.Combining NMR data,the structure was confirmed to be hept-ylprodigiosin,molecular formula is C22H29N3O.The coloring properties and the stability of the pigment were studied.After adding differ-ent metal ions,Ca2+,Na+,Mg2+,K+ had a color-enhancing effect on the pigment solution at th-e acidic condition.The stability of pigment solution was better at the temperature below 40 ?.The color of the pigment solution varied with pH,the pigment solution was generally purple at the condition of strong acid(pH=2,4),orange at pH=8-12,and UV absorption spectrum showed the maximum absorption wavelength was shifted.The oxidation agent(H2O2)has a little effect on the stability of the pigment solution.The pigment was highly sensitive to the reduci-ng agent(Na2SO3),the absorbance measured at the maximum absorption wavelength(?max = 536 nm)decreases significantly with increasing of the concentration,and the dyeing effect was almost lost.