A novel optimization procedure has been developed to determine the best combination of variables in large scale fermentation systems. The self- directing optimization or the rotating simplex method of optimization was employed to determine the best suitable combination of parameters, pH (controlled), aeration rate and agitation rate for maximal production of chitinase by Trichoderma harzianum in batch culture. Extracellular enzyme activity increased from an initial value of 0.109 U under unoptimized conditions to a final value of 0.384 U after optimization. A controlled pH of 4.9, an aeration rate of 1.51 l-1 per min, and an agitation rate of 224 rpm was found to be the best combination.

T Panda

Department Of Chemical Engineering

aeration

article

Bioprocess

Bioreactor

enzyme synthesis

Fermentation

nonhuman

Process control

TRICHODERMA HARZIANUM

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

Self-directing optimization of parameters for extracellular chitinase production by Trichoderma harzianum in batch mode

Process Biochemistry

Models of single cells, cell populations, and cultures can be most useful in organizing information in a comprehensive system description, as well as in optimizing and controlling actual production operations. Models discussed in this article are of various degrees of biological structure and mathematical complexity. The models are developed based on the biomass formation, substrate consumption, and product formation. The potentials and the limitations of all the models have been reported. The parameter estimation by different methods has been discussed in this communication. These parameters will be helpful to explore the areas where future-modeling studies may be especially valuable. © 2006 Springer-Verlag.

Applied Microbiology and Biotechnology

Modeling of enzyme production kinetics

Production of microbial chitinases have received increased attention in recent years due to its potential application in various fields. There has been an all around effort to increase the production of chitinases by using genetically engineered organisms and by incorporating modern fermentation techniques. This review presents a brief outline on the production of microbial chitinases which includes information on random screening and selection of chitinolytic organisms and the rationale behind the use of genetically engineered organisms. The problems and perspectives involved in large scale production of chitinases is discussed with special reference to bioreactor studies and new fermentation methods. The present limitations in the understanding of the chitinase fermentation process is also discussed and the scope for future investigation is outlined in this communication.

Bioprocess Engineering

Production of microbial chitinases - A revisit

A kinetic analysis and optimization of reaction conditions for the enzymatic hydrolysis of chitin using chitinase produced by Trichoderma harzianum NCIM 1185 was carried out. Swollen chitin was used as the substrate for chitinase. The central composite design was followed for this optimization. The required volume ratio of the major reactants for maximum hydrolysis was determined. The pH and temperature optima were found to be 4.75 and 47 °C respectively. K(m) and V(max) for this enzyme were 4.643 kg/m3 and 0.1542 U respectively.

Parameters optimization of chitin hydrolysis by Trichoderma harzianum chitinase under assay conditions

Statistical design was used to determine the optimal levels of medium components, the optimal initial pH of the enzyme production medium, the temperature of fermentation, age of the organism in the slant growth and the age of the inoculum for the production of chitinase in shake flask fermentations. The use of high concentrations of chitin and ammonium sulphate and exclusion of peptone and urea from the medium resulted in the production of higher level of the enzyme. The optimal concentrations of the medium components were 12.5 kg/m3 and 4.2 kg/m3 for the chitin and ammonium sulphate respectively. The effect of the addition of peptone and urea to the optimized medium was studied. The optimal values of initial pH and temperature were 5.6 and 28 °C respectively. The optimal age of the slant and the inoculum were found to be 105 h and 43 h respectively. The highest level of chitinase before optimization of the above variables was 0.054 U which was maximized to the level of 0.197 U.

Optimization of carbon and nitrogen sources in the medium and environmental factors for enhanced production of chitinase by trichoderma harzianum

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.

Journal	Process Biochemistry
ISSN	13595113
Open Access	No