当前位置： SCI文献检索 > APPLIED AND ENVIRONMENTAL MICROBIOLOGY期刊下所有文献 > Transcriptomic insights into the physiology of Aspergillus niger approaching a specific growth rate of zero.

Transcriptomic insights into the physiology of Aspergillus niger approaching a specific growth rate of zero.

Abstract：

:The physiology of filamentous fungi at growth rates approaching zero has been subject to limited study and exploitation. With the aim of uncoupling product formation from growth, we have revisited and improved the retentostat cultivation method for Aspergillus niger. A new retention device was designed allowing reliable and nearly complete cell retention even at high flow rates. Transcriptomic analysis was used to explore the potential for product formation at very low specific growth rates. The carbon- and energy-limited retentostat cultures were highly reproducible. While the specific growth rate approached zero (<0.005 h(-1)), the growth yield stabilized at a minimum (0.20 g of dry weight per g of maltose). The severe limitation led to asexual differentiation, and the supplied substrate was used for spore formation and secondary metabolism. Three physiologically distinct phases of the retentostat cultures were subjected to genome-wide transcriptomic analysis. The severe substrate limitation and sporulation were clearly reflected in the transcriptome. The transition from vegetative to reproductive growth was characterized by downregulation of genes encoding secreted substrate hydrolases and cell cycle genes and upregulation of many genes encoding secreted small cysteine-rich proteins and secondary metabolism genes. Transcription of known secretory pathway genes suggests that A. niger becomes adapted to secretion of small cysteine-rich proteins. The perspective is that A. niger cultures as they approach a zero growth rate can be used as a cell factory for production of secondary metabolites and cysteine-rich proteins. We propose that the improved retentostat method can be used in fundamental studies of differentiation and is applicable to filamentous fungi in general.

journal_name

Appl Environ Microbiol

journal_title

Applied and environmental microbiology

authors

Jørgensen TR,Nitsche BM,Lamers GE,Arentshorst M,van den Hondel CA,Ram AF

doi

10.1128/AEM.00450-10

subject

Has Abstract

pub_date

2010-08-01 00:00:00

pages

5344-55

issue

eissn

0099-2240

issn

1098-5336

pii

AEM.00450-10

journal_volume

pub_type

杂志文章

在线工具

Transcriptomic insights into the physiology of Aspergillus niger approaching a specific growth rate of zero.