富铁酿酒酵母菌株的选育及其培养条件优化  

Breeding of iron-enriched Saccharomyces cerevisiae strains and optimization of culture conditions

作　　者：曾艳 ZENG Yan(Hunan Institute of Microbiology,Changsha,Hunan 410009,China)

机构地区：[1]湖南省微生物研究院,湖南长沙410009

出　　处：《西北农林科技大学学报（自然科学版）》2024年第3期19-29,共11页Journal of Northwest A&F University(Natural Science Edition)

基　　金：湖南省自然科学基金面上项目(2022JJ30353)。

摘　　要：【目的】分离鉴定高效富铁酿酒酵母菌株,优化其培养基组分和发酵条件。【方法】从果园根际土壤中分离选育耐铁酿酒酵母菌,对其进行形态学、生理生化分析和26 S rDNA基因序列分析鉴定;采用单因素试验,分别设置不同碳源种类(葡萄糖、蔗糖、乳糖、果糖、麦芽糖)、氮源种类(硫酸铵、酵母膏、蛋白胨、尿素)及不同质量浓度Fe^(2+)(100,200,300,…,1000,1200,1600,2000μg/mL)、碳源(10,20,30,40,50,60,70,80,90 g/L)、氮源(无机氮源2,4,6,8,10,20 g/L;有机氮源4,8,12,16,20,24,28 g/L)、无机盐(MgSO4·7H2O 0.3,0.5,1.0,1.5,2.0 g/L;KH2PO40.5,1.5,2.5,3.5,4.5 g/L)的培养基进行试验,探究不同培养基组分对酿酒酵母富铁能力的影响。采用单因素试验研究温度(26,28,30,32,34,36,38℃)、初始pH值(3.5,4.0,4.5,5.0,5.5,6.0,6.5,7.0,7.5)、接种量(2%,4%,6%,8%,10%,12%)、转速(140,160,180,200,220 r/min)、装液量(250 mL三角瓶中分别装20,30,40,50,60,70 mL)对酿酒酵母富铁能力的影响。选择温度、初始pH值、接种量、转速进行L9(34)正交试验设计,获得最佳发酵培养条件,并进行验证试验。【结果】从三叶木通果园土壤中分离鉴定获得1株耐铁酿酒酵母菌株ZY-JM16,通过单因素试验,获得该菌株最优培养基组成为:蔗糖50 g/L、尿素4 g/L、酵母膏24 g/L、KH_(2)PO_(4)2.5 g/L、MgSO_(4)·7H_(2)O 0.5 g/L、Fe^(2+)900μg/mL(FeSO_(4)·7H_(2)O 4.5 g/L);通过单因素试验和正交试验优化,发现该菌株高富铁率最佳发酵条件为:起始pH值4.8、温度28℃、转速180 r/min、接种量6%、装液量50 mL(250 mL锥形瓶),发酵时间为40 h。在此条件下,该菌株铁富集率达到91.80%,较优化前提高了229.27%;菌体生物量达13.06 g/L,较优化前提高了59.07%。【结论】获得1株高效富铁酿酒酵母菌ZY-JM16,对其培养条件进行了优化,明晰了其生长规律。【Objective】Isolate and identify Saccharomyces cerevisiae strains with high enrichment rate of iron,and optimize the composition of their medium and fermentation conditions.【Method】Iron-tolerant Saccharomyces cerevisiae were isolated and bred from the rhizosphere soil of orchards,and identified by morphological,physiological and biochemical analysis and 26 S rDNA gene sequence analysis;Single factor test was used to set different types of carbon sources(glucose,sucrose,lactose,fructose,maltose)and nitrogen sources(ammonium sulfate,yeast extract,peptone,urea),and different mass concentrations of Fe^(2+)(100,200,300,…,1000,1200,1600,2000μg/mL),carbon sources(10,20,30,40,50,60,70,80,90 g/L),nitrogen sources(inorganic nitrogen 2,4,6,8,10,20 g/L;organic nitrogen 4,8,12,16,20,24,28 g/L),inorganic salts(MgSO 4·7H 2O 0.3,0.5,1.0,1.5,2.0 g/L;KH 2PO 40.5,1.5,2.5,3.5,4.5 g/L),and to explore the effects of different medium components on the iron-rich ability of Saccharomyces cerevisiae.Single factor test was used to study temperature(26,28,30,32,34,36,38℃),and initial pH value(3.5,4.0,4.5,5.0,5.5,6.0,6.5,7.0,7.5),inoculation amount(2%,4%,6%,8%,10%,12%),speed(140,160,180,200,220 r/min),liquid loading(20,30,40,50,60,70 mL in 250 mL triangle bottle)on the iron-rich capacity of Saccharomyces cerevisiae.The L 9(34)orthogonal experiment design was carried out by selecting temperature,initial pH value,inoculation amount and rotational speed to obtain the best fermentation culture conditions,and the verification experiment was carried out.【Result】An iron-tolerant saccharomyces Cerevisiae strain ZY-JM16 was isolated and identified from the soil of Sanyemutong Orchard.Through single factor test,the optimal medium composition was obtained as follows:sucrose 50 g/L,urea 4 g/L,yeast extract 24 g/L,KH_(2)PO_(4)2.5 g/L,MgSO_(4)·7H_(2)O 0.5 g/L,Fe^(2+)900μg/mL(FeSO_(4)·7H_(2)O 4.5 g/L).Single factor test and orthogonal test were used to optimize,and the optimum fermentation parameters for high iron content of the strain

关 键 词：酿酒酵母 菌株选育 饲料添加剂 培养基优化 培养条件优化 

分 类 号：S816.72[农业科学—饲料科学]