Enzyme production by filamentous fungi: analysis of the secretome of Trichoderma reesei grown on unconventional carbon source

<p>Abstract</p> <p>Background</p> <p>Spent hydrolysates from bioethanolic fermentation processes based on agricultural residues have potential as an abundant and inexpensive source of pentose sugars and acids that could serve as nutrients for industrial enzyme-producing microorganisms, especially filamentous fungi. However, the enzyme mixtures produced in such media are poorly defined. In this study, the secretome of <it>Trichoderma reesei </it>Rut C-30 grown either on a spent hydrolysate model medium (SHMM) or on a lactose-based standard medium (LBSM) was explored using proteomics.</p> <p>Results</p> <p>Our results show that both the SHMM and LBSM serve as excellent growth media for <it>T. reesei </it>Rut C-30. In total, 52 protein spots on 2-D gels were identified by using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) and electrospray ionization liquid chromatography tandem mass spectrometry (ESI-LC MS/MS). As expected, a considerable number of the identified proteins were related to the degradation of lignocellulosic biomass. The enzyme production profiles in the two media were similar, but β-glucosidase and β-galactosidase were only produced in LBSM. The main cellobiohydrolases (Cel7A/Cel6A) and endoglucanases (Cel7B/Cel5A) were identified in both media and the cellobiohydrolases, i.e. Cel7A and Cel6A, were the most abundant cellulolytic enzymes. Moreover, both media can also serve as a potent inducer of xylanolytic enzymes. Several key enzymes involved in sugar assimilation and regulation of cellulase formation were identified, and were found to be differentially expressed in the two growth media.</p> <p>Conclusions</p> <p>This study not only provides a catalogue of the prevalent proteins secreted by <it>T. reesei </it>in the two media, but the results also suggest that production of hydrolytic enzymes using unconventional carbon sources, such as components in spent hydrolysates, deserves further attention in the future.</p

Zsírok propilgalláttartalma mint jelzőanyag és az alkilgallátok néhány egyszerű kimutatási eljárása zsírokban és olajokban

Der Nachweis von zu Fetten und ölen zugefügten Alkylgallaten erfolgt am einfachsten und dabei mit genügender Empfindlichkeit vermittels konzentriertem Ammoniaks. Die auftretende rosenrote Färbung tritt noch empfindlicher zutage, wenn das Ammoniak womöglich von dem Fett oder Öl getrennt wird undzwar dadurch, dass wir dasselbe in einem Lösungsmittel höheren spezifischen Gewichtes, z. B. in Chloroform oder Kohlenstofftetrachlorid auflösen. Nachweisverfahren: In einem Reagensglas wird 1 g Fett — höchtens durch gelindes Erwärmen — oder 1 g ö l in 2 ml Chloroform (Kohlenstofftetrachlorid) gelöst, darauf mit 1 ml konz. Ammoniak einigemal kurz durchgeschüttelt. In Gegenwart von Gallaten färbt sich der Inhalt rosenrot und auf seiner Oberfläche erscheint alsbald ein rot gefärber Flüssigkeitsring. Among the methods for the detection of alkyl gallates added to fats and oils, those using concentrated ammonia are the simplest, having simultaneously an adequate sensitivity. The appearing pink colour reaction becomes even more sensitive when ammonia is separated from fats and oils by dissolving the latter in a solvent of higher specific gravity, as chloroform or carbon tetrachloride. The method of detection is as follows: Dissolve in a test tube about 1 g of fat (at most by gentle heating) or 1 g of oil in 2 ml of chloroform (or carbon tetrachloride), add 1 ml of concentrated ammonia and shake several times for a short period. In the presence of gallates the liquid turns pink and a reddish ring appears shortly on the surface. Les méthodes ä prouver les alcylgallates, ajoutés aux graisses et aux huiles, fournies par l’ammoniaque saturé, semblent d’étre les plus simples, et, de plus, d’une sensibilité süffisante. La réaction de couleur de rose qui s’y présente est susceptible ä étre rendue encore plus sensible, si l’ammoniaque est séparé de la graisse ou de l’huile en la dissolvant en un agent dissolvant de poids spécifique élévé, par exemple en chloroforme ou en tétrachloride de carbone. La méthode ä indiquer est comme да: dissolver 1 g sóit de graisse (tout ou plus en la chauffant faiblement), sóit d’huile en 2 ml de chloroforme (ou tétrachloride de carbone) dans une éprouvette, puis, en les réunissant avec 1 ml d’ammoniaque saturé, secouer l’éprouvette quelques instants. Son contenu. dü á la présence des gallates, prend un couleur de rose, puis un anneau liquide rouge transparente se présente bientöt sur la surface