当前位置： SCI文献检索 > JOURNAL OF APPLIED MICROBIOLOGY期刊下所有文献 > Modified semi-continuous fermentation for resuscitating nongrowing cells during high-temperature gluconic acid production by Acetobacter senegalensis.

Modified semi-continuous fermentation for resuscitating nongrowing cells during high-temperature gluconic acid production by Acetobacter senegalensis.

Abstract：

AIMS:The formation of metabolically inactive and nongrowing cells is an inevitable by-product of intensive fermentation. This study investigated whether co-feeding can be used to resuscitate nongrowing Acetobacter senegalensis cells to enable them to produce gluconic acid in successive fermentation runs at 38°C. METHODS AND RESULTS:In the first fermentation cycle, 75 g l-1 of glucose were converted to gluconic acid. Subsequently, however, stationary-phase cells were unable to initiate a new fermentation cycle. The majority of stationary-phase cells (97%) were nonculturable on glucose at 38°C. In addition, 54 and 41% of cells contained non-active cellular dehydrogenases and a compromised cell envelope respectively. Co-feeding stationary-phase cells with a mixture of ethanol, glucose and acetic acid for 7 h enabled these cells to grow on 75 g l-1 of glucose and produce gluconic acid. Additionally, 74% of cells contained active forms of cellular dehydrogenases after 7 h of co-feeding. However, co-feeding did not improve cell envelope integrity. Quantification of cellular NAD content showed that stationary-phase cells contained moderately reduced levels of total NAD (NADt) as compared with exponential-phase cells. Interestingly, the analysis of stationary-phase cells showed that co-feeding resulted in higher levels of NADt and NADH, suggesting that the regeneration of NADH is one of the limiting factors of glucose consumption. Expression of catalase and superoxide dismutase was increased in stationary-phase cells, but analysis of protein carbonylation and lipid peroxidation did not confirm an extensive oxidative stress. CONCLUSIONS:Co-feeding with favourable nutrients may enable resuscitation of cells and utilization of less-favourable carbon sources in successive cycles. SIGNIFICANCE AND IMPACT OF THE STUDY:This study proposed a unique method for resuscitation of nongrowing cells during high-temperature fermentation. By applying this method, cells can be used for consecutive fermentation cycles.

journal_name

J Appl Microbiol

journal_title

Journal of applied microbiology

authors

Zarmehrkhorshid R,Shafiei R,Delvigne F

doi

10.1111/jam.14371

subject

Has Abstract

pub_date

2019-10-01 00:00:00

pages

1101-1112

issue

eissn

1364-5072

issn

1365-2672

journal_volume

127

pub_type

杂志文章

在线工具

Modified semi-continuous fermentation for resuscitating nongrowing cells during high-temperature gluconic acid production by Acetobacter senegalensis.