Search PubMed⌕ Search

Biomedical subjects

M Moo-Young

Publications and source records attributed to M Moo-Young.

45 records · Page 3Linked to original sources

SCP production by Chaetomium cellulolyticum, a new thermotolerant cellulolytic fungus.

Chaetomium cellulolyticum, a newly isolated cellulolytic fungus, showed 50-100% faster growth rates and over 80% more final biomass-protein formation than Trichoderma viride, a well-known high cellulase-producing cellulolytic organism, when cultivated on Solka-floc (a purified, predominantly amorphorous form of cellulose) or partially delignified sawdust (consisting of a mixture of hardwoods) as the sole-carbon source in the fermentation media. However, in both cases, T, viride produced much higher quantities of free cellulases at faster rates and also degraded more substrate than C. cellulolyticum. It is concluded that the synthesis mechanisms and/or the nature of the cellulase complexes of the two types of organisms are quite different such taht C. cellulolyticum is more optimal for single-cell protein (SCP) production, while T. viride is more optimal for the production of extracellular cellulase. It was also found that the amino acid composition of C. cellulolyticum is generally better than that of T. viride and compares favorably with those of the FAO reference protein, alfalfa, and soya meal. In addition, preliminary feeding trials on rats have shown no adverse effects of the SCP produced by C. cellulolyticum fermentations.

Amino Acids↗

A model for diauxic growth.

A model is developed to predict batch and continuous culture behavior of fermentations on two different carbon and energy sources. The basic assumption of the model is that the permease for the favored substrate is constitutive, whereas the premease for the second substrate is subject to induction and catabolite repression. Simulations of the model show features of diauxic growth described in the literature.

Adenosine Triphosphate↗

Increased heterologous protein production in Aspergillus niger fermentation through extracellular proteases inhibition by pelleted growth.

The dependence of filamentous fungal protease secretion on morphology was investigated by employing the recombinant Aspergillus niger strain AB4.1[pgpdAGLAGFP] which contains a gene for the glucoamylase-GFP (green fluorescence protein) fusion protein. Different inoculum levels were used to obtain different sizes of pellet or free mycelia. The extracellular protease activity of the cultures varied with the pellet size and decreased dramatically when the morphology was changed from free mycelia to pellets. The culture with an optimal pellet size of 1.6 mm was obtained from an inoculum of 4 x 10(6) spores/mL. It resulted in a specific protease activity of 158 units/L, only one-third of that in free mycelial growth, and a maximum specific GFP yield of 0.98 mg/g (cell mass) compared to 0. 29 mg/g for free mycelial growth with an inoculum of 10(7) spores/mL. The results indicate that this bioprocessing strategy can be effectively used to inhibit protease activity in filamentous fungal fermentation and thereby to enhance heterologous protein production.

Aspergillus niger↗