Study On Co-selection Of Boron And Antibiotics Of Algoriphagus And Polyphasic Taxonomy On Three Bacterial Strains

The long-term abuse of antibiotics has increased the resistance of bacteria and accelerated the spread of antibiotic resistance genes.Studies have shown that there is co-selection of metals and antibiotics.In the areas with severe metal pollution,antibiotic resistance genes were discovered even in the absence of antibiotics.However,boron as a semi-metallic element widely distributed in the environment,and its co-selection with antibiotics is a blank field of scientific research.In this experiment,Algoriphagus were selected as the research object,the growth curve of 8 Algoriphagus,the minimum inhibitory concentration of 7 Algoriphagusantibiotics and boron were determined.Algoriphagus resistens NH1T,Algoriphagus marinus am2T,and Algoriphagus boritolerans JCM 1 8970T were selected to research co-selection of boron and antibiotics.Under the condition of 10 mmol/1 boron,the resistance to antibiotics was studied through the intergenerational culture of 30 generations.The results showed that Algoriphagus resistens NHlT have co-selection of boron and antibiotics.The transcriptome of Algoriphagus resistens was determined,and 35 1 differential genes(351 up-regulated genes and 237 down-regulated genes)were screened,which were the response genes of resistance to Algoriphagus to ofloxacin stress.135 differential genes(48 up-regulated genes and 87 down-regulated genes)were screened,which were differential genes in the intergenerational culture;11 5 differential genes were screened(98 up-regulated genes,down-regulated genes)1 7),which were the response genes of Algoriphagus against boron stress;10 genes were selected in combination with boron and antibiotics,and the gene numbers were AS141 RS04315,AS141_RS04360,AS141 RS04375,AS141 RS04380,AS141_RS11640,AS141_RS11660,AS141 RS12925,AS141 RS15695,AS141 RS21740,AS141 RS22360.This paper completed the polyphasic taxonomy of three bacteria.A Gram-stain-negative,non-motile,rod-shaped,oxidase-positive,red-pigmented bacterium,strain N3T,was isolated from Fuxian lake,a freshwater lake in Yunnan Province.China.Strain N3T was facultatively anaerobic,heterotrophic and negative for catalase.Optimal growth occurred at 30 0C(range 4-15?),pH 7.0-8.0(range 6.5-9.5).Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain N3-T was 97.4%similar to the type strain of Algoriphagus aquaeductus,97.3%to the type strain of Algoriphagus shivajiensis and 97.2%to the type strain of Algoriphagus alkaliphilus.The G+C content of the genomic DNA was 43.9 mol%.The quinone system contained menaquinone MK-7 as the sole component.The major fatty acids were iso-C15:0,summed feature 9(10-methyl C16:0 and/or iso-C17:1?9c),summed feature 3(C16:1?6c and/or C16:1?7c)and iso-Ci6:0.Major polar lipids were phosphatidylcholine(PC),phosphatidylethanolamine(PE),an unidentified glycolipid(GL),two unidentified phospholipids(PL1,PL2),two unidentified aminolipids(AL1,AL2)and four unidentified lipids(L1,L2,L3,L4).On the basis of morphological,physiological and molecular properties as well as phylogenetic distinctiveness,strain N3T should be placed into the genus Algoriphagus as a novel species,for which the name Algoriphagus lacus sp.nov.is proposed.The type strain is N3T(=KCTC 62622T=MCCC 1H00308T).Strains F3105T and B3213T were isolated from Rongcheng.Gram-stain-negative,rod-shaped,facultative anaerobic.The 16S rRNA gene and phylogenetic analysis indicated that they belong to the genus Aliidiomarina.They were named Aliidiomarina celeris sp.nov.9 the type strain is F3105T(= MCCC 1H00223T = KCTC 52891T);Aliidiomarina marinisedimentorum sp.nov.,the type strain is B3213T(=MCCC 1H00321T = KCTC 62446T).