降解高含盐溴氨酸菌种的选育与鉴定

Breeding and identification of bacteria for high-salt bromamine acid

从生物接触氧化池的生物膜中筛选分离出10株在高盐条件下对蒽醌染料中间体溴氨酸有降解脱色作用的菌株.通过对10株菌株的逐级驯化复筛,得到一株脱色效果好且脱色能力稳定的菌株C-7,经鉴定为弗氏柠檬酸杆菌(Citrobacter freundil).菌株C-7的耐盐性试验结果表明,盐的质量分数为1%～3%时,对菌株的生长和脱色没有影响,脱色率为80%以上;盐的质量分数为7%时,菌株C-7也具有较高的耐受力,脱色率可达到50%以上;盐的质量分数为10%时,对菌株的生长产生抑制作用,不能降解溴氨酸.菌株最适生长条件为:蛋白胨7g.L-1,pH7.0,摇床转速160r.min-1,250mL摇瓶中装液量120mL,接种量10%,在此条件下,在盐的质量分数为1%、蛋白胨为唯一氮源的培养基中,溴氨酸(100mg·mL-1)的脱色率可达85%以上.

10 strains,capable of degrading and decolorizing bromamine acid under high salt conditions,which is an intermediate of anthraquinone dye,were isolated from the biomembrane of a bio-contact oxidation tank.A strain named C-7 which has good decolorizing effect and stable decolorization ability was obtained by acclimating the 10 strains.It was identified as Citrobacter freundil.Salt tolerance test results show that the strain C-7 can grow with a decolorization rate of more than 80% when the mass fraction of NaCl is 1% to 3%,and NaCl has no effect on the growth and decolorization of the strain.When the mass fraction of NaCl is 7%,C-7 show high tolerance and the decolorization rate is more than 50%.NaCl can inhibit the growth of the strain C-7 and bromamine acid cannot be degraded when the mass fraction increases to 10%.Under the optional growth conditions of pH 7.0,the rotating rate of 160r·min^-1,the liquid volume of 120mL in a 250mL flask,inocula of 10% and peptone of 7g·L^-1 as the only nitrogen source,when the mass fraction of NaCl is 1%,the decolorization rate of bromamine acid（100mg·L^-1）can reach to 85% or higher.