The effect of fermentation parameters on the production of Mucor miehei acid protease in a chemically defined medium

Abstract

Batch shake flask experiments were carried out with a fungal strain of Mucor miehei ATCC 3420 to study the effects of five fermentation parameters; initial D‐glucose concentration, temperature, initial pH, agitation rate and inoculum ratio, on the production of rennin in a chemically defined medium. A statistical design was used to assign the experimental levels of five fermentation parameters for the determination of optimum conditions. The highest concentration of milk‐clotting activity (MCA) obtained was 2286 SU cm−3 (without concentration of the broth) at 29.6 g dm−3 initial D‐glucose concentration, 6.8 initial pH, 37.6 °C temperature, 81 stroke per min agitation rate and 5.2% (v/v) inoculum ratio. Although enzyme secretion was a function of all the operational parameters investigated, the pH range (4.6–5.2) reached at the time of enzyme production had a profound effect on milk‐clotting activity levels. In the fermentation sample at maximum milk‐clotting activity the R factor, the ratio of milk‐clotting activity to proteolytic activity, was determined as 1 SU PU−1, denoting similar characteristics to a commercial animal rennet.© 2001 Society of Chemical Industry

Production of Milk-Clotting Protease from Bacillus subtilis

“…Finally, this is one of the few studies carried out for studying the influence of production parameters on increasing milk-clotting production through statistical methods and in SSF or biphasic systems. To the best of the authors' knowledge, the only reference to the use of statistical design for mcp production has been reported by Ayhan et al [13] for Mucor sp.…”

“…4). On the contrary, Ayhan et al [13] have reported using 5.2% (v/v) of inoculum for Fig. 4 Effect of different moistening agents on mcp production in SSF Fig.…”

Optimization of the production and characterization of milk clotting enzymes by Bacillus subtilis natto

“…Various animals, plants and microbial proteases have been suggested as milk coagulants (Chazarra et al 2007 ; D’Ambrosio et al 2003 ; Silva & Malcata 2005 ; Zhang et al 2011 ). However, attention has been focused on the production of milk-clotting enzymes (MCEs) from microbial sources for use as rennin substitutes (Ayhan et al 2001 ; Cavalcanti et al 2004 ; Hashem 1999 ; Silveira et al 2005 ). Although there are many microorganisms that produce MCEs (Ding et al 2011 ; He et al 2011 ; Li et al 2012 ; Vishwanatha et al 2010 ), only the MCEs produced by strains of Rhizomucor miehei , Rhizomucor pusillus var.…”

“…Previous works on the optimization of parameters for MCE production were conducted using " one-factor-at -a-time" technique (Ayhan et al 2001 ; Cavalcanti et al 2004 ; Hashem 1999 ; Silveira et al 2005 ). Unfortunately, it frequently fails to locate the region of optimum response because the joint effects of factors on the response are not taken into account in such procedure.…”

Isolation of clt Genes Encoding milk clotting enzyme and characterization of milk clotting enzyme from new isolate Streptomyces pseudogriseolusNRC-15

“…being marketed since the 1970s have proved satisfactory for the production of different kinds of cheese. The molecular and enzymatic properties of chymosins have been studied extensively (Jonk and Birkkjacer, 1985;Crawford, 1985;Ayhan et al, 2001).In this study the production conditions of milk clotting enzyme from new strain Streptomyces pseudogrisiolus NRC 15 were optimized. In addation the milk clotting enzyme was also purified and characterized.…”