The Isolation And Polyphasic Taxonomy Research Of The Butachlor Resistant Strain,BUT-6~T

Around the world,the kind of chloroacetamides herbicides are used widely.Among those,the butachlor is the most widely used within the scope of Asia as phenylacetamide herbicides,which has been one of the most applied herbicides.Nowadays,more and more butachlor are using existing unreasonably application due to the eluviation and permeation,which has an increasing side effect on the soil and water.This research isolated a strain from the sludge affected by butachlor for long term,which has a great tolerance to butachlor and was name after BUT-6~T.In this paper,a comprehensive and systematic research of physiological,biochemical and genetic features of this strain were performed.Research finds that BUT-6~T still showed a certain growth in the minimum medium with 1250mg L-6T butachlor.Cell of the strain BUT-6~T is rod shape(0.5-0.6×3.5-4.0 ?m),gram-negative,non-spore-forming,no-flagellum.On R2A medium plate,the colony of the strain present yellow color,raised surface,and semitransparent edge.BUT-6~T reached an optimum growth with the condition of 30?,1.0%NaCl(w/v),pH 7.0.The major fatty acids are iso-C15:0,iso-C17:1 ?9c,and iso-C17:0(>10%of total fatty acids);the important polar lipids are phosphatidyl methyl diethanolamine,phosphatidyl glycerol,diphosphatidyl glycerol,an unidentified aminophospholipid and another three unknown phosphonolipids;the dominated respiratory quinone is ubiquinone(Q-8);the DNA G+C mol%is 71.7 mol%;the 16SrRNA sequence of BUT-6~T has the highest relativity with Tahibacter aquaticus PYM5-11T(98.6%);the DNA-DNA hybrid homology is 47.1 ±0.71%between and the type strain Taibacter aquaticus PYM5-11T,which is much less than the threshold of 70%identified as a novel bacterial species.The strain BUT-6~T was negative for the test of catalase,oxidase,casein hydrolysis;positive for the reaction of alkaline phosphatase,esterase(C4,C8),esterase lipase(C14),leucine aryladimase,valine arylamidase,cystine arylamidase and trypsin;negative for the test of galactosidase;positive for the hydrolysis of aesculin,gelatin,urea,tween-80;without the producing of H2S and indole;no reduction of nitrate.The strain BUT-6~T can use N-acetyl glucosamine,decanoic acid,citric acid salt,benzyl acetate,5-ketone gluconic acid,malic acid salt as carbon source;not utilize sorbitol,inositol,laetrile,rhamnose,melibiose,glucose,mannose and arabinose for fermentation;The strain BUT-6~T resist the antibiotics of spectinomycin,penicillin,levofloxacin,ampicillin,chloramphenicol,ceflazidime etc.Analysis of the characteristic above together,was identified as a novel spices of genus Tahibacter,and named Tahibacter caeni sp.nov.