高通量筛选鉴定耐受和吸附重金属Pb^2+的酵母菌

High-throughput Screening and Identification for Yeasts of the Absorption and Tolerance to Heavy Metal as Pb^2+

随着环境污染中重金属对人和动物健康威胁的加剧,关于可食用酵母菌对Pb^2+的耐受和吸附研究备受关注,然而高繁重、高成本的分离筛选工作一直以来制约着研究的进展。本文基于深孔板建立了一种高通量快速活化、筛选高耐受和高吸附Pb^2+菌株的方法,研究驯化前、后菌株对Pb^2+耐受性和吸附性之间的关系。结果表明,从采自内蒙古重金属污染区的19份样品中分离得到104株酵母菌,经高通量筛选,26株对Pb^2+的耐受质量浓度在5 000 mg/L以上,其中4株异常威克汉姆酵母(Wickerhamomyces anomalus)、3株胶红酵母(Rhodotorula mucilaginosa)、2株金佩梅奇酵母(Metschnikowia chrysoperlae)常应用于人和动物。这9株菌中同属种菌株对Pb^2+表现出相似的耐受性和吸附性,经耐受Pb^2+的驯化,耐受性均有较大的提高,而对Pb^2+的去除率而言,1株未发生变化,5株发生下降,3株有所提高;同时,菌株的耐受性与吸附性间不存在对应关系,低耐受Pb^2+的2株金佩梅奇酵母去除率高达92.56%以上,而高耐受的3株胶红酵母对Pb^2+的去除率最高仅23.14%,只有4株异常威克汉姆酵母对Pb^2+的耐受质量浓度在6 000~7 000 mg/L之间,去除率同样可达78.94%~91.67%,具备一定的研究、应用潜力。建立的高通量筛选方法也可应用于其它微生物耐受和吸附重金属离子的筛选试验中。

With the growing threat to human and animal health aggravated by heavy metals in environmental pollution,research in Pb^2+tolerance and adsorbent of edible yeast has received more concerns.However,the research is facing the limitation from heavy and costly separation and screening work.In this paper,a high throughput rapid activation,high Pb^2+tolerance and adsorbent yeast screening method based on Deep-well Plate(DWP)was established,and the relationship between strains’Pb^2+tolerance and adsorbent before and after domestication was revealed.The results are as followed:All strains were isolated from 19 samples which were collected from heavy metal pollution area in Inner Mongolia,the high throughput screening indicated that 26 strains yeast in 104 isolated possess high tolerance of Pb^2+over than 5000 mg/L,4 Wickerhamomyces anomalus,3 Rhodotorula mucilaginosa and 2 Metschnikowia chrysoperlae among them are usually used in human and animals.In these 9 strains,similar tolerance and adsorbent can be found between strains of the same genus,and their tolerance was upgraded after domestication;for Pb^2+removal rate,however,5 of them were declined,3 of them were increased and the remaining strain was not changed;meanwhile,correspondence between tolerance and adsorbent was not found in strains,removal rate of 2 low-tolerance Metschnikowia chrysoperlae can reach up to 92.56%,removal rate of 3 high-tolerance Rhodotorula mucilaginosa only 23.14%,and Pb^2+tolerance concentration of 4 Wickerhamomyces anomalus was in the scope of 6000-7000 mg/mL,and their removal was 78.94%-91.67%.The high throughput screening method established in this paper can also applied in other microorganisms’heavy metal tolerance and adsorbent test,showed outstanding research and application potential.