Mycelial growth and exo‐Biopolymer Production by submerged culture of various edible mushrooms under different media

Aims: The effect of synthetic media on the submerged mycelial growth and exo-Biopolymer Production in various edible mushrooms was investigated in shake flask culture.

Methods and Results: Among 19 mushrooms examined, the relatively high yield in mycelial biomass and exo-Biopolymer Production was achieved in potato malt peptone (PMP) medium. In particular, Ganoderma lucidum NO. 1 and Phellinus linteus KCTC 6190 showed favourable growth in PMP medium with exo-Biopolymer concentration of 1170 and 1520 mg l−1, respectively.

Conclusions: Enhanced exo-Biopolymer Production was achieved from Ganoderma lucidum NO. 1 and Phellinus linteus KCTC 6190 in a 5L batch fermentor, indicating approximately 5000 and 2410 mg l−1, respectively.

Significance and Impact of the Study: The exo-Biopolymer Production and mycelial growth from various mushrooms were found to be strongly controlled by different complex media.

stimulatory effect of plant oils and fatty acids on the exo Biopolymer Production in cordyceps militaris

Abstract The exo-Biopolymer Production and mycelial growth were substantially increased (almost tripled) by supplementation of certain vegetable oils into the medium. In particular, sunflower oil at the level of 2% led to a significant increase in exo-Biopolymer concentration from 2.3 to 7.5 g/l, while the addition of 4% olive oil dramatically increased mycelial biomass from 5.8 to 19.0 g/l. To elucidate which components in those oils increased Biopolymer Production, effects of major fatty acids that constitute plant oils were further studied. Among fatty acids tested, addition of 2% oleic acid and palmitic acid markedly stimulated the Biopolymer Production (enhancement factors were 6 and 5.5, respectively), whereas linoleic acid drastically suppressed both mycelial growth and exo-Biopolymer Production.

effect of agitation intensity on the exo Biopolymer Production and mycelial morphology in cordyceps militaris

Aims: The influence of agitation intensity on Cordyceps militaris morphology and exo-Biopolymer Production was investigated in a 5 litre stirred vessel using a six-blade Rushton turbine impeller.

Methods and Results: The mycelial morphology of C. militaris was characterized by means of image analysis, which included mean diameter, circularity, roughness and compactness of the pellets. The morphological parameters of the pellets grown under different stirring conditions were significantly different, which correspondingly altered exo-Biopolymer Production yields.

Conclusions: The compactness of the pellets was found to be the most critical parameter affecting exo-Biopolymer biosynthesis; more compact pellets were formed at 150 rev min–1 with maximum exo-Biopolymer Production (15 g l–1).

Significance and Impact of the Study: The results of this study suggest that morphological change of pellets is a good indicator for identifying the cell activity for exo-Biopolymer Production.

Mycelial growth and exo‐Biopolymer Production by submerged culture of various edible mushrooms under different media

Aims: The effect of synthetic media on the submerged mycelial growth and exo-Biopolymer Production in various edible mushrooms was investigated in shake flask culture.

Methods and Results: Among 19 mushrooms examined, the relatively high yield in mycelial biomass and exo-Biopolymer Production was achieved in potato malt peptone (PMP) medium. In particular, Ganoderma lucidum NO. 1 and Phellinus linteus KCTC 6190 showed favourable growth in PMP medium with exo-Biopolymer concentration of 1170 and 1520 mg l−1, respectively.

Conclusions: Enhanced exo-Biopolymer Production was achieved from Ganoderma lucidum NO. 1 and Phellinus linteus KCTC 6190 in a 5L batch fermentor, indicating approximately 5000 and 2410 mg l−1, respectively.

Significance and Impact of the Study: The exo-Biopolymer Production and mycelial growth from various mushrooms were found to be strongly controlled by different complex media.

effect of agitation intensity on the exo Biopolymer Production and mycelial morphology in cordyceps militaris

Aims: The influence of agitation intensity on Cordyceps militaris morphology and exo-Biopolymer Production was investigated in a 5 litre stirred vessel using a six-blade Rushton turbine impeller.

Methods and Results: The mycelial morphology of C. militaris was characterized by means of image analysis, which included mean diameter, circularity, roughness and compactness of the pellets. The morphological parameters of the pellets grown under different stirring conditions were significantly different, which correspondingly altered exo-Biopolymer Production yields.

Conclusions: The compactness of the pellets was found to be the most critical parameter affecting exo-Biopolymer biosynthesis; more compact pellets were formed at 150 rev min–1 with maximum exo-Biopolymer Production (15 g l–1).

Significance and Impact of the Study: The results of this study suggest that morphological change of pellets is a good indicator for identifying the cell activity for exo-Biopolymer Production.

effect of aeration rate on the mycelial morphology and exo Biopolymer Production in cordyceps militaris

The influence of aeration rate on Cordyceps militaris morphology and exo-Biopolymer Production was investigated in a 5-l jar fermentor. The mycelial morphology of C. militaris was characterized by image analysis, which included mean diameter, circularity, roughness, and compactness of the pellets. Cells were observed to form mainly pellets during the entire culture period irrespective of aeration conditions. There existed a notable variation in morphological parameters between the pellets grown on different aeration conditions, by which exo-Biopolymer Production yields were correspondingly altered. The mean diameter and compactness of the pellets indicated higher values at 2 vvm (volume of air per volume of culture per minute), which was closely related to exo-Biopolymer biosynthesis. The more compact pelleted form was favourable for exo-Biopolymer Production. Under extremely low and high aeration conditions (e.g. 0.5 and 4 vvm), severe deformations of pellets (autolysis of core and shaving off the outer hairy region) were observed at the later stages of fermentation associated with a decrease in morphological parameters. © 2002 Elsevier Science Ltd. All rights reserved.

Optimization of submerged-culture conditions for mycelial growth and exo-Biopolymer Production by Auricularia polytricha (wood ears fungus) using the methods of uniform design and regression analysis.

This paper is concerned with the optimization of submerged culture conditions for mycelial growth and exo-Biopolymer Production by Auricularia polytricha by one-factor-at-a-time and uniform design (UD) methods. First, the one-factor-at-a-time method was adopted to investigate the effects of environmental factors (i.e., initial pH and temperature) and variables of medium components (i.e., carbon, nitrogen and mineral sources) on mycelial growth and exo-Biopolymer Production. Sucrose, yeast extract, and K2HPO4 were identified to be the most suitable carbon, nitrogen, and mineral sources, respectively. The optimal temperature and initial pH for mycelial growth and exo-Biopolymer Production were found to be 25 degrees C and 5.0, respectively. Subsequently, the concentrations of sucrose, yeast extract, and K2HPO4 were optimized using the UD method. The optimal concentrations for the enhanced Production were determined as 6% (w/v) sucrose, 2.5% (w/v) yeast extract, and 0.3% (w/v) K2HPO4 for mycelial yield, and 6% (w/v) sucrose, 1.28% (w/v) yeast extract, and 0.3% (w/v) K2HPO4 for exo-Biopolymer Production, respectively. Subsequent experiments confirmed the validity of the models. This optimization strategy in shake-flask culture led to a mycelial yield of 6.14 g/l, and exo-Biopolymer Production of 2.12 g/l, respectively, which were considerably higher than those obtained in the preliminary studies. By using the optimized medium, the maximum concentrations of mycelial biomass and exo-Biopolymer in a 5 litre stirred-tank bioreactor indicated 35.3 g/l and 3.1 g/l, respectively.

optimization of physical parameters for exo Biopolymer Production in submerged mycelial cultures of two entomopathogenic fungi paecilomyces japonica and paecilomyces tenuipes

Aims: In the present study, two different optimization techniques were used to determine the suitable operating parameters for exo–Biopolymer Production in submerged mycelial cultures of two entomopathogenic fungi Paecilomyces japonica and Paecilomyces tenuipes. Methods and Results: First, the rotating simplex method, a nonstatistical optimization technique, was employed to obtain the best combination of physical parameters (viz. pH, agitation intensity, aeration rate) for maximum exo–Biopolymer Production by P. japonica in a batch bioreactor. The optimal combination was determined to be a pH of 8AE06, an aeration of 3 vvm, without any impeller agitation, producing a 17-time increase in exopolymer Production (34AE 5gl )1 ) when compared with that achieved in unoptimized flask cultures. Second, the uniform design method, a statistical optimization technique, was employed to determine the best operating parameters for submerged culture of P. tenuipes. The optimal combination for mycelial growth was determined to be a pH of 4AE88, an aeration of 2 vvm and an agitation of 350 rpm, while a pH of 4, an aeration of 2 vvm and an agitation of 150 rpm was best for exo–Biopolymer Production. Conclusions: The exo–Biopolymer Production in P. japonica optimized by the rotating simplex method was strikingly improved (max. 34AE 5gl )1 ), and the exo–Biopolymer Production in P. tenuipes optimized by the uniform design method was also significantly increased (max. 3AE 4gl )1 ). Significance and Impact of the Study: The successful application of these two different optimization techniques in this study implies that these methods are worthy of applying to other fermentation systems for the Production of bioactive mycelial biomass and exo–Biopolymers in liquid culture of higher fungi.

optimization of submerged culture conditions for mycelial growth and exo Biopolymer Production by auricularia polytricha wood ears fungus using the methods of uniform design and regression analysis

This paper is concerned with the optimization of submerged culture conditions for mycelial growth and exo-Biopolymer Production by Auricularia polytricha by one-factor-at-a-time and uniform design (UD) methods. First, the one-factor-at-a-time method was adopted to investigate the effects of environmental factors (i.e., initial pH and temperature) and variables of medium components (i.e., carbon, nitrogen and mineral sources) on mycelial growth and exo-Biopolymer Production. Sucrose, yeast extract, and K2HPO4 were identified to be the most suitable carbon, nitrogen, and mineral sources, respectively. The optimal temperature and initial pH for mycelial growth and exoBiopolymer Production were found to be 25 ◦ Ca nd 5.0, respectively. Subsequently, the concentrations of sucrose, yeast extract, and K2HPO4 were optimized using the UD method. The optimal concentrations for the enhanced Production were determined as 6% (w/v) sucrose, 2.5% (w/v) yeast extract, and 0.3% (w/v) K2HPO4 fo rm ycelial yield, and 6% (w/v) sucrose, 1.28% (w/v) yeast extract, and 0.3% (w/v) K2HPO4 fo re xo-Biopolymer Production, respectively. Subsequent experiments confirmed the validity of the models. This optimization strategy in shake-flask culture led to a mycelial yield of 6.14 g/l, and exoBiopolymer Production of 2.12 g/l, respectively, which were considerably higher than those obtained in the preliminary studies. By using the optimized medium, the maximum concentrations of mycelial biomass and exo-Biopolymer in a 5 litre stirred-tank bioreactor indicated 35.3 g/l and 3.1 g/l, respectively.