Mycelium immobilization

PeniciIlium chrysogenum was immobilized in collagen membrane, calcium alginate gel, and polyacrylamide gel. Penicillin production by different immobilized mycelia are compared in Table 1. The mycelium immobilized in calcium alginate gel... 

This might be due to the inactivation of the mycelium with the tanning reagents, viz., glutaraldehyde. The mycelium immobilized in polyacrylamide gel showed fairly good activity. 

The decolorization of diazo dye RB5 by T. pubescens immobilized on stainless steel sponges in a fixed-bed reactor was studied [66]. Laccase production in the presence of RB5 reached its maximum value of 1,025 U/L. They found that decolorization was due to dye adsorption onto the fungus mycelium and dye decolorization by laccase enzymes produced by the fungus. 

Abraham TE, Jamuna R, Bansilal CV, Ramakrishna SV (1991) Continuous synthesis of glucoamylase by immobilized fungal mycelium of Aspergillus niger. Starch-Starke 43 113-116... 

Fiedurek J, Ilczuk Z (1991) Glucose oxidase biosynthesis using immobilized mycelium of Aspergillus niger. World J Microbiol Biotechnol 7 379-384... 

Livemoche, D. Jurasek L. Desrochers, M. Dorica J. Veliky, LA. Removal of color from Kraft mill wastewaters with the cultures of white-rot fungi and with immobilized mycelium of Coriolus versicolor. Biotechnol. Bioengg. 1983, 25, 2055-2065. 

Targonski and Pielecki investigated the production of cellulase using immobilized mycelium of Trichoderma reesei mutants on polyurethane foam impregnated... 

The dedd cells of the mycelium of Rhizopus arrhizus constitute d naturally immobilized lipdse very active in organic solvents. This immobilized enzyme was used for hydrolysis and synthesis of ester bonds triglycerides hydrolysis, and interesterification, esters and glycerides synthesis. More recently, the catalytic system has been applied in drug synthesis to the resolution of racemic esters with a good enantioselectivity. 

After drying and delipidation this biomass can be considered as a naturally immobilized enzyme (Fig, 3.). The hydrolytic activity measured on olive oil in di-isopropyl-ether is around 75 to 200 micromoles per g of dry mycelium and per mn. The chain length specificity spectrum is broad, as shown before (from C14 to C22). 

Rhizopus arrhizus dead mycelium was found to be very active in organic solvents as a naturally immobilized lipase. Triglycerides hydrolysis and interesterification, esters and glycerides synthesis, natural flavour esters preparation and racemic mixtures resolution in pharmaceutical drugs synthesis are among the successfully designed processes, each of one with a specific reactional medium. 

The mycelium biomass recovered from 200 mL of the seed culture was mixed with 200 mL of sterile 2% (w/v) K-carrageenan (E407 Ceca, Paris, France) at 42°C. The mycelium-carrageenan suspension was then pumped through a couple of needles and dropped into sterile KC1 solution (0.3 M) to form gel beads with an average diameter of 3 mm. Gel beads were soaked for 30 min in the same KC1 solution. All immobilization experiments were carried out under aseptic conditions. 

Interesterification of blends of milk fat and palm kernel olein by a mycelium-bound lipase from Rhizomucor miehei or a commercially immobilized enzyme preparation resulted in a lower slip melting point and solid fat content. An interesterified product made from a 70 30 mixture of palm kernel olein and anhydrous milk fat was considered to be suitable for use in ice cream (Liew et al., 2001). 

A few reports have appeared in the literature on the use of living immobilized whole cells for producing traditional fermentation products (3,12). In this paper, our work on the immobilization of Penicillium chrysogenum ATCC 12690 in polyacrylamide gel, collagen membrane, and calcium alginate and the production of penicillin G from glucose by the immobilized mycelium are described. 

Screening of Carriers for Immobilization. Washed mycelium produced penicillin G similar to the results described by Halliday and Arnstein (13) when it was resuspended in an incubation medium. Under similar conditions, the average rate... 

However, the rate of penicillin production of the immobilized mycelium was lower than that of washed mycelium. This might arise from the inactivation of the mycelium by polymerization reagents, such as monomers, APS, and TEMED. The reagents, such as acrylamide and TEMED, severely and adversely affected the penicillin-producing activity by the washed mycelium. These results suggested that the multi-enzyme system required for penicillin synthesis was inactivated by the reagents individually. Therefore, the amounts of acrylamide and TEMED were decreased to as low as possible. Five percent of acrylamide and 0.05 % TEMED were used for polymerization of the gel. 

Effect of Substrates on Penicillin Production. It is known that penicillin G is synthesized from three amino acids (L- -aminoadipic acid, L-cysteine, and L-valine) and the sidechain precursor, phenyl acetate. Furthermore, penicillin acyltrans-ferase, an enzyme presumably involved in the final step of penicillin G synthesis, catalyzes penicillin G synthesis from 6-aminopenicillanic acid (6-APA) and phenyl acetate. Therefore, the effect of these substrates on penicillin production by the immobilized mycelium was examined (Table II). Penicillin productivity by inmobilized mycelium in each substrate was expressed relative to that observed in glucose-(NH.)2S0, medium. As shown in Table II, the rate of penicillin produStTon in a... 

Penicillin Production by Immobilized Mycelium. Repeated penicillin production by immobilized mycelium was examined in a batch system. Experiments were performed as follows about 1... 

The respiration activity of the immobilized mycelium was examined by using an oxygen electrode. The rate of oxygen uptake by the immobilized mycelium was about 30 % of that of the washed mycelium. Furthermore, penicillin production by the immobilized mycelium was performed under air and nitrogen atmospheres and the penicillin produced was determined. Only a small amount of penicillin was produced by the immobilized mycelium under anaerobic conditions. Therefore, oxygen was required for the system synthesizing penicillin in mycelium. 

In addition, viable mycelium could be recovered from the ground, immobilized mycelium in a germ-free box. These results suggest that at least a fraction of the mycelium was living after entrapment in the polyacrylamide gel and that the living mycelium was responsible for production of penicillin from glucose and (NH )2S0. ... 

From these studies it was also obvious that the nutrients were rapidly taken up and immobilized internally when added to the colony since diffusion through the medium stopped almost instantaneously (Fig 2.7). From the immobilized stores the nutrients were redistributed to the rest of the mycelium. 

By glutaraldehyde cross-linking of the enzyme in the presence of ovalbumin, D-glucose oxidase has been immobilized on mycelium pellets of Aspergillus species.The preparation was successfully used in batch and column reactors for conversion of D-glucose to D-gluconic acid. 

D-Glucose isomerase has continued to be immobilized with retention of activity the large-scale commercial form is available as immobilized Sweet-zyme . In another instance, the enzyme has been fixed to an organism mycelium and as such immobilized by spraying a mixture with gelatin into... 

This quasi immobilized mycelium can be compared with a pellet-formed mycelium which, in its very compact form, synthesizes much higher yields of pectinolytic enzymes than a mycelium growing in a diffuse form. 

Fig, 6. Laboratory tube reactor with quasi-immobilized mycelium for polygalacturonase production, 1 reactor 2 support 3 separating plate 4 pump 5 heat exchanger 6 distributor for medium 7 mycelium layer (Kbrner et al, 1984),... 

Production of hydrolytic enzymes is one of the key steps in any process involving biodegradation of natural biopolymers. The use of immobilized microorganisms as an enzyme source generally eliminates the high costs of enzyme production. In this context, studies on the production of 3-glucanase system by immobilized A. tenuissima mycelium are reported. 

The mycelium was washed with Isotonic saline, resuspended In mineral salts medium with glucose (1% w/v) and mixed with a suspension of activated support. The mixture was stirred at 20 0 for 20 h and free mycelial forms were separated. The amount of bound dry weight per gram of carrier (the efficiency of Immobilization) was determined on the basis of nitrogen quantity by Kjeldahl s method. 

Immobilized Alternarla tenulsslma cells were prepared by a procedure ensuring the maximum proportion of the bound cell fraction. Preliminary experiments revealed that the efficiency of immobilization is markedly affected by the manner of carrier activation (reaction time and glutaraldehyde concentration). The age of mycelium has no significant effect. 

Fig. 2. Elution of A. tenulsslma 3-l 3-glucanase system from immobilized mycelium column. The column was run at a flow rate of 2.2 (A),...

Rozman, D., Pertot, E., Komel., R. and Prosek, M. (1989) Production of lysergic acid derivatives with immobilized Claviceps paspali mycelium. Appl. Microbiol. Biotecbnol., 32, 5-10. 

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