An attempt to produce ethanol from a cellulosic substrate by a single-stage process using intergeneric hybrids obtained from Trichoderma reesei QM 9414 and Saccharomyces cerevisiae NCIM 3288 fusants is described. Two hundred one fused strains were isolated using two different combinations of hybridization, followed by polyethylene glycol treatment of protoplasts derived from parent and mutant strains. Some fusants were either diploids or heterokaryons, as verified by a protoplast fused system obtained by auxotrophic mutants derived from T. reesei QM 9414 and S. cerevisiae NCIM 3288. Of the 201 fusants, 170 were found to be relatively stable. Two fusants (M14 and M62) showed the highest synthesis of ethanol from filter paper cellulose, producing 0.0149 and 0.0191 g l-1, respectively. © 1994.

T Panda

Department Of Chemical Engineering

J. Anjani Kumari

alcohol

cellulose

article

Fermentation

Hybridization

membrane fusion

nonhuman

PROTOPLAST

Saccharomyces cerevisiae

TRICHODERMA REESEI

HYPOCREA JECORINA

TRICHODERMA

Bioconversion

Ethanol

Glycols

stability

Substrates

Synthesis (chemical)

yeast

AUXOTROPHIC MUTANTS

INTERGENERIC HYBRIDIZATION

PROTOPLAST FUSION

Biotechnology

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Intergeneric hybridization of Trichoderma reesei QM9414 and Saccharomyces cerevisiae NCIM 3288 by protoplast fusion

Enzyme and Microbial Technology

The combined effect of pH and temperature on carboxymethyl cellulase from two intergeneric fusants (M 14 and M 62) of Trichoderma reesei QM 9414/Saccharomyces cerevisiae NCIM 3288 was studied using response surface methodology. A central composite design for two variables was employed for the optimization studies. This study was compared with similar studies carried out with Trichoderma reesei QM 9414. The optimal pH and temperature for the enzymes derived from these organisms were: for the fusant M 14 - pH 5.7 and 41.7°C, for the fusant M 62 - pH 5.3 and 43°C, and for Trichoderma reesei QM 9414 - pH 4.31 and 38.3°C.

Journal of Industrial Microbiology and Biotechnology

pH and thermal stability studies of carboxymethyl cellulase from intergeneric fusants of Trichoderma reesei/Saccharomyces cerevisiae

Single-stage direct bioconversion of cellulosic materials to ethanol, under almost the same fermentation conditions applied to the Saccharomyces cerevisiae-ethanol process, was attempted using intergeneric fusants of Trichoderma reesei QM 9414/S. cerevisiae NCIM 3288. Optimization of medium constituents was made using the Box-Behnken design method. The combined effect of pH and temperature on the fermentation was analyzed by the central composite design method. Under optimal conditions the fusant produced 0.17 g l-1 ethanol in 30 h. © 1995.

Direct conversion of cellulosic material to ethanol by the intergeneric fusant Trichoderma reesei QM 9414/Saccharomyces cerevisiae NCIM 3288

The regeneration of Saccharomyces cerevisiae, NCIM 3288, cells from its sphaeroplasts were found to be influenced by a number of factors. The most suitable conditions of regeneration were also dependent on growth medium, that is, using malt-extractglucose-yeast extract-peptone (MGYP) medium: mannitol 0.7 M, pH 6.5, 30 °C and using yeast extract-peptone-glucose (YPG) medium: sucrose 0.7 M, pH 5.0 and 30 °C. The maximum regeneration frequency was observed in YPG medium. © 1994 Springer-Verlag.

Bioprocess Engineering

Analysis of factors responsible for the regeneration to intact cells from sphaeroplasts of Saccharomyces cerevisiae

To compare the efficiency of various whole cell immobilization techniques for the production of gluconic acid by Aspergillus niger were investigated using potassium ferrocyanide-treated cane molasses as the substrate. The techniques followed were: (1) Calcium alginate entrapment, (2) cross-linking with glutaraldehyde after cell permeabilization with (a) acetone, (b) toluene and (c) isopropanol and (3) development of granular catalyst. A comparative analysis of yield has revealed that calcium alginate entrapment was the most suitable technique as it had given the maximum product yield (0.40 g gluconic acid/g total reducing sugar supplied). The properties of immobilized A.niger in sodium alginate gel have been thoroughly investigated and compared with those of free cells under most suitable conditions of fermentation. © 1994 Springer-Verlag.

Comparative analysis of different whole cell immobilized aspergillus niger catalysts for gluconic acid fermentation using pretreated cane molasses

Important parameters in the regeneration of protoplasts are viability, the capacity to synthesize cell walls and the retention of properties of the parent cell. Mycelial protoplasts of Trichoderma longibrachiatum (Trichoderma reesei) have been regenerated. Factors influencing the regeneration of protoplasts of T. longibrachiatum QM 9414 were found to be, the nature of osmotic stabilizer, the concentration of osmotic stabilizer, pH, temperature, and the composition of regeneration medium. With glucose-mineral regeneration medium, the optimum conditions for protoplasts regeneration were 0.5 M KCl, pH 6.0 and temperature 30°C. With Czapek-Dox medium, the optimum conditions were 0.7 M mannitol, pH 6.0 and temperature 30°C. Maximum regeneration frequency of T. longibrachiatum protoplasts were obtained using glucose-mineral medium. © 1993 Springer-Verlag.

Improved technique on reversion of mycelial protoplast of Trichoderma reesei into mycelia

Efficient synthesis of a large number of viable protoplasts from Trichoderma longibrachiatum (Trichoderma reesei) mycelium has been found to be influenced by a number of factors. In this case, Trichoderma harzianum NCIM 1185 culture filtrate has been used to prepare protoplasts from Trichoderma longibrachiatum QM 9414. A method has been devised to isolate a large number of viable protoplasts from the mycelium. Detailed analysis of different factors affecting the synthesis of protoplasts from T. longibrachiatum has not yet been reported. The most suitable conditions for protoplasting were as follows: age of the organism in slant, 3 days; mycelium age, 20 h; volume of lytic enzymes, 190 ml; mycelial weight (dry equivalent), 1.66 g; time of contact with lytic enzymes, 2 h; temperature of protoplasting, 30°C; phosphate buffer, 25 mm, pH 6.5; KCl as osmotic stabilizer, 0.7 m. Proper spreading of the mycelium in contact with the lytic enzymes was also found to be necessary. © 1992.

Studies on critical analysis of factors influencing improved production of protoplasts from Trichoderma reesei mycelium

Journal	Enzyme and Microbial Technology
ISSN	01410229
Open Access	No