Sophorose metabolism and cellulase induction in Trichoderma

Loewenberg, J. R.; Chapman, Clifford M.

doi:10.1007/bf00428581

Cited by 48 publications

(20 citation statements)

References 8 publications

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“…Coincident with several other authors (Mandels et al, 1962;Nisizawa et al, 1970;Loewenberg & Chapman, 1977;Sternberg & Mandels, 1979) it was found that best induction (i.e. highest rate of synthesis and highest final activity) was achieved with sophorose.…”

Section: Induction Of Endoglucanase Synthesis In T Reeseisupporting

confidence: 73%

Involvement of a Conidial Endoglucanase and a Plasma-membrane-bound -Glucosidase in the Induction of Endoglucanase Synthesis by Cellulose in Trichoderma reesei

Kubicek¹

1987

Microbiology

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The induction of endo-1,4-beta-glucanase synthesis by Trichoderma reesei QM 9414 was investigated in conidia, mycelia and protoplasts. Cellulose induced endoglucanase synthesis only in conidia, but not in glucose-grown mycelia or protoplasts. Cellooligosaccharides and sophorose induced endoglucanase synthesis in mycelia, conidia and protoplasts. Only conidia exhibited detectable basal endoglucanase levels, whereas beta-glucosidase activity was found in conidia, mycelia and protoplasts. The beta-glucosidase was inhibited in vitro by nojirimycin and glucono-delta-lactone. Addition of either of these inhibitors to the induction medium blocked de noro synthesis of endo-1,4-beta-glucanase with cellulose (conidia) or cellooligosaccharides (protoplasts and mycelia) as inducer, whereas induction by sophorose remained unaffected. The results are consistent with the assumption that basal constitutive levels of endoglucanase and beta-glucosidase are involved in the induction of cellulase synthesis by cellulose in T. reesei.

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Section: Induction Of Endoglucanase Synthesis In T Reeseisupporting

confidence: 73%

Involvement of a Conidial Endoglucanase and a Plasma-membrane-bound -Glucosidase in the Induction of Endoglucanase Synthesis by Cellulose in Trichoderma reesei

Kubicek¹

1987

Microbiology

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“…In Trichoderma viride, concentrations exceeding 0.2 "/b sophorose (which is a potent cellulase inducer in this fungus) cause catabolite repression of cellulase formation . This finding has recently been corroborated by Loewenberg & Chapman (1977), who investigated the metabolic fate of sophorose and found that several low, repeated feedings of this sugar induced the formation of much more cellulase than an equivalent single dose.…”

Section: Discussionmentioning

confidence: 63%

Induction and Catabolite Repression of Cellulase Synthesis in the Thermophilic Fungus Sporotrichum thermophile

Canevascini

Coudray

Southgate

et al. 1979

Journal of General Microbiology

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A strain of Sporotrichum thermophile (var. 2), grown in submerged culture at 44 "C, decayed crystalline cellulose by the secretion of cellulolytic enzymes into the culture medium.Dialysed culture filtrates, after growth on cellobiose, wese also effective in degrading crystalline cellulose (Avicel). Cellulase, measured viscometrically with carboxymethylcellulose as substrate and therefore referred to as C M-cellulase, was induced by cellulose, glucomannan, cellobiose and, to a limited extent, by laminaribiose and cellobionic acid. Low CM-cellulase activities were also detectable when the organism was grown on other carbon sources. In culture media supplemented with readily metabolized non-inducing substrates, such as glucose, CM-cellulase activity did not increase after their exhaustion indicating that no derepression of constitutive CM-cellulase occurred. CM-cellulase synthesis induced during growth on cellobiose was strongly inhibited, although not completely suppressed, by glucose and other carbon sources. In cultures grown on glucose and cellobiose, glucose was utilized first and CM-cellulase synthesis was repressed ; cellobiose utilization occurred only after glucose exhaustion and triggered CM-cellulase formation. When glucose was added to a culture growing on cellobiose, further utilization of the latter was prevented and CM-cellulase synthesis was inhibited. The use of glucose analogues gave some indications that cellobiose did not compete with glucose for the same transport carrier and that glucose catabolism was a prerequisite for the inhibition of CM-cellulase synthesis.

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“…Sophorose is rapidly catabolized to CO 2 and H 2 O by Trichoderma and only small amounts are used to induce cellulase biosynthesis. Uptake of sophorose occurs after a lag phase of 1 h and the half life in the medium is less than 5 h (Loewenberg and Chapman, 1977). Previous studies have shown that the transport of sophorose into the mycelia is inhibited by glucose (Kubicek et al, 1993).…”

Section: Sophorosementioning

confidence: 99%