短梗霉筛选鉴定及溶氧对其发酵影响

刘滨; 于海峰

doi:10.13386/j.issn1002-0306.2018.06.019

短梗霉筛选鉴定及溶氧对其发酵影响

刘滨,
于海峰

Screening and identification of Aureodacidium spp. and the effect of dissolved oxygen on fermentation

摘要

摘要: 从自然界中分离筛选短梗霉菌株,经平板初筛,摇瓶复筛及分子生物学鉴定确定为短梗霉菌属中的出芽短梗霉和短梗霉,分别命名为ipe-3(GenBank 登录号为 KY618121)、ipe-5(GenBank 登录号为 KY621468),将ipe-3、ipe-5经2.7 L发酵罐发酵,结果发现,在70%溶氧条件下ipe-3聚苹果酸产量为10.027 g/L,苹果酸产量为5.70 g/L,ipe-5聚苹果酸产量为0.3 g/L,苹果酸产量最高为57.24 g/L。研究了溶氧对短梗霉发酵的影响,与70%溶氧条件下发酵产量相比,在10%溶氧条件下,ipe-3聚苹果酸产量降低了41.67%,苹果酸产量降低了62.63%;ipe-5不产聚苹果酸,苹果酸产量降低了83.05%。得出溶氧降低导致菌体浓度及葡萄糖利用速率降低,从而造成短梗霉发酵产酸的产量降低。

Abstract: The Aureodacidium spp. were isolated and screened out from outdoors. After plate screening,shake flask re-screening,molecular biology identification,the ipe-3(GenBank accession number is KY618121)was identified as Aureobasidium pullulans,ipe-5(GenBank accession number is KY621468)identified as Aureobasidium spp. Ipe-3 and ipe-5 were fermented by 2.7 L fermenter respectively. The results showed that the yield of poly malic acid and malic of strain ipe-3 were 10.027 g/L and 5.7 g/L. The yield of poly malic acid of strain ipe-5 was 0.3 g/L and the maximum yield of malic acid was 57.24 g/L. The effects of dissolved oxygen on the fermentation yield of Aureodacidium spp. were studied. Compared with the yield under 70% dissolved oxygen,in 10% dissolved oxygen condition,the yield of poly malic acid and malic acid of strain ipe-3 were decreased by 41.67% and 62.63% respectively. The yield of malic acid of ipe-5 decreased by 83.05%,and without poly malic acid produce in 10% dissolved oxygen condition. The results showed that the decrease of dissolved oxygen led to the drop of biomass and the rate of glucose utilization,which cause Aureodacidium spp. produced less acid.