Oligosaccharides sophorose

The stimulation of the synthesis of the cellulase system of T. reesei QM 9414 by sophorose was established as shown by the results of experiments summarized in Table IV. Other than sophorose, of the glycosides and oligosaccharides tested, only lactose caused even a limited production of the enzymes of the cellulase system. Lactose is not as closely related structurally to sophorose as is, for example, the disaccharide laminaribiose it is more closely related structurally to cellobiose, which, despite being the major product of cellulose breakdown, does not promote enzyme production under the conditions of this experiment. It was noted that both intra- and extracellular constitutive enzyme levels produced by cells growing on glucose (or by resting cells without inducer, Table IV) are less than 0.5% of the fully induced levels and thus are negligible. 

Oligosaccharides in combination with phenols may also be removed intact by careful hydrolysis with acid. Thus, when rutin is heated with 10% aqueous acetic acid, it yields rutinose. Dilute mineral acids can, for example, be used for the removal of sophorose from kaempferol 3-sophoroside, " and of gentiobiose from p-hydroxyphenyl 9-gentiobio-side. A comparison of the use of formic acid-cyclohexanol and hydrochloric acid-acetic acid for the partial hydrolysis of glycosides has been made by Chandler and Harper. There appears to be no general rule governing the use of these acids. 

Ps. fluorescens var. cellulosa synthesized a large amount of cellulase in 0.5% cellulose or sophorose medium, and more than 90% of the enzyme formed was released in surrounding medium (exo-type synthesis). In contrast, smaller amounts of cellulase were formed upon cultures on 0.5% cello-oligosaccharides, and more than 90% of the enzyme remained within the cells (endo-type synthesis). Since the major soluble end-products of cellulolysis by Pseudomonas cellulases in vitro were cellobiose and cellotriose (28), the direct C-source utilized by the bacterium should be these sugars even if either cellulose or cello-oligosaccharides were used as C-source. The only difference between these cultures, therefore, may be in the concentration of the end-products in each medium. 

The use of vibrational spectra in oligosaccharide studies has been furthered this year. For a set of six disaccharides with different types of glycosidic linkages (a,a-trehalose, sophorose, laminaribiose, maltose, cellobiose and gentiobiose) IR and Raman spectra show good agreement with calculated frequencies below 1500 cm . No additional terms are needed in the potential energy calculations to... 

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