Open AccessInterspecies interaction based on transfer of a thioredoxin‐like compound in anaerobic chitin‐degrading mixed cultures
Author(s) -
Pel Roel,
Gottschal Jan C.
Publication year - 1989
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1989.tb03390.x
Subject(s) - chitin , fermentation , biochemistry , bacteria , chemistry , strain (injury) , cysteine , enzyme , food science , microbiology and biotechnology , biology , chitosan , genetics , anatomy
Fermentation of chitin by mixed cultures of the chitinolytic Clostridium sp. strain 9.1 and various non‐chitinolytic bacteria proceeded up to eight times faster than in pure cultures. The addition of spent media of such mixed cultures also resulted in a marked stimulation of chitinolysis in pure cultures of strain 9.1. Pure cultures fermented chitin much faster if supplemented with either spent media or cell‐free extracts of the non‐chitinolytic bacteria. The compound responsible for this stimulation was thermostable (10 min at 85° C) and could not be removed by passage over Sephadex G‐25, indicating a molecular weight of more than 1500. The heat stable enzyme thioredoxin (from Saccharomyces cerevisiae ) was shown to stimulate the chitin fermentation in a similar manner. Alkylation of this enzyme reduced its stimulatory action significantly indicating its (di)thiol: disulfide interchanging activity. It is hypothesized that essential sulfhydryl groups in the chitinolytic system of strain 9.1 are reduced by thioredoxin and/or similar thiol: disulfide transhydrogenases present in the cell‐free extracts and spent media, resulting in an acceleration of chitin hydrolysis and fermentation. This stimulation may thus be the result of a new type of interspecies interaction in anaerobic mixed cultures.