Growth behaviour and glucoamylase production by Aspergillus niger N402 and a glucoamylase overproducing transformant in recycling culture without a nitrogen source

Autor:	A. H. Stouthamer, H. W. van Verseveld, J.M. Schrickx
Rok vydání:	1995
Předmět:	Strain (chemistry) biology Hypha Nitrogen fungi Aspergillus niger Hyphal tip General Medicine biology.organism_classification Applied Microbiology and Biotechnology Transformation Genetic Botany Bioreactor Fermentation Food science Glucan 1 4-alpha-Glucosidase Overproduction Mycelium Biotechnology
Zdroj:	Applied Microbiology and Biotechnology. 43:109-116
ISSN:	1432-0614 0175-7598
Popis:	When wild-type Aspergillus niger N402 and a glucoamylase-overproducing transformant were grown in recycling culture without a nitrogen source, hyphal tip extension and glucoamylase production still occurred, but overproduction of glucoamylase by the transformant strain stopped. The mycelium retained a low metabolic activity. Light micrographs of mycelial samples showed that some hyphae were broken at their tip and partially empty, while after continuing recycling fermentation for more than 500 h many small and empty pieces of broken mycelium could be found. A model has been developed to calculate the mycelial growth and death rates. The mycelial death rate just exceeded the mycelial growth rate and as a consequence the amount of biomass in the fermentor vessel slightly decreased. It is concluded that the cytoplasmic contents of broken mycelial threads were released into the medium and acted as a nitrogen source for the growing parts of the mycelium.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::7b866323c8f51f9e15232a42e9b76df4 https://doi.org/10.1007/bf00170631 Zobrazit plný text záznamu Full text from SpringerLink