• Biotechnology and Bioprocess Engineering:BBE
• /
• v.11 no.3
• /
• pp.223-229
• /
• 2006

In this study, we have conducted kinetics and modelling studies of Centella asiatica cell growth and substrate uptake, in an attempt to evaluate cell growth for a better understanding and control of the process. In our bioreactor cultivation experiment, we observed a growth rate of 0.18/day, a value only 20% higher than was seen in the shake flask cultivation trial. However, the observed maximum cell dry weight in the shake flask, 10.5g/L, was 14% higher than was achieved in the bioreactor. Ninety seven percentage confidence was achieved via the fitting of three unstructured growth models; the Monod, Logistic, and Gompertz equations, to the cell growth data. The Monod equation adequately described cell growth in both cultures. The specific growth rate, however, was not effectively predicted with the Logistic and Gompertz equations, which resulted in deviations of up to 73 and 393%, respectively. These deviations in the Logistic and Gompertz models may be attributable to the fact that these models were developed for substrate-independent growth and fungi growth, respectively.

• KSBB Journal
• /
• v.6 no.1
• /
• pp.63-68
• /
• 1991

An auxotrophic regulatory mutant of Corynebacterium glutamicum ATCC 21674 produced 2.1-3.4g/1 of phenylalanine with 2.9-4.4g/l of tyrosine in the batch shake flask fermentations. At higher sugar concentration, the production of both amino acids was lower than that at low sugar concentration. There was a pronounced effect of temperature on the amino acid production. At $30^{\circ}C$, much higher levels of phenylalanine and tyrosine were produced than those at $37^{\circ}C$. The pH decrease in the shake flask fermentation was so fast that it was impossible to maintain a constant pH with calcium carbonate as a buffering agent. Even though the strains we have used are reported as tyrosine auxotrophs, they produced tyrosine and were able to grow on the minimal medium where no tyrosine was present.

• Journal of Microbiology and Biotechnology
• /
• v.5 no.6
• /
• pp.364-369
• /
• 1995

Effect of two-phase culture on Mentha piperita cell growth and essential oil formation was investigated using shake flask and air-lift bioreactors. LiChroprep RP-B(RP-B) addition did not impair M. piperita cell growth, but resulted in stimulated formation of essential oils and increased ratios of extracellular oil to intracellular oil formation. However, the combined use of RP-B and chitosan elicitor was not synergistic. Volumetric productivity of essential oils in RP-B treated culture using cell-recycled air-lift bioreactor was $6.9\;\mu\textrm{g}/l{\cdot}day$ which was substantially higher than that obtainable from the control. Our results demonstrate the potential of a second phase to enhance overall productivity for M. piperita cell culture.

• KSBB Journal
• /
• v.9 no.2
• /
• pp.180-185
• /
• 1994

The productivity of alkaloid in the airlift fermentor operation was less than that of suspension coltures of Eschscholtzia californica cells in the shake flask. To overcome the productivity reduction, a gas recycle airlift fermentor was developed because the gas-stripping in normal airlift fermentor was believed to play a significant role for productivity reduction. The alkaloid content in the gas recycle system with Eschscholtzia californica suspension cells was 2.7 times higher than that of normal airlift fermentor. The productivity of alkaloids and $CO_2$ concentration were affected by the volume of gas reservoir in the gas recycle airlift fermentor.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.3 no.1
• /
• pp.44-47
• /
• 1998

Maximum cellulase production was sought by comparing the activities of the cellulases produced by different Trichoderma reesei strains and Aspergillus niger. Trichoderma reesei Rut-C30 showed higher cellulase activity than other Trichoderma reesei stains and Aspergillus niger that was isolated from soil. By optimizing the cultivation conditions during shake flask culture, higher cellulase production could be achieved. The FP(filter paper) activity of 3.7U/ml and CMCase (Carboxymethylcellulase) activity of 60U/ml were obtained from shake flask culture. When it was grown in 2.5L fermentor, where pH and DO levels are controlled, the enzyme activities were 133.35U/ml (CMCase) and 11.67U/ml(FP), respectively. Ammonium sulfate precipitation method was used to recover enzymes from fermentation broth. The dried cellulase powder showed 3074.9U/g of CMCase activity and 166.7U/g of FP activity with 83.5% CMCase recovery.

• Advances in environmental research
• /
• v.3 no.4
• /
• pp.283-292
• /
• 2014

Iron precipitating organisms play a significant role in the formation of ferric hydroxide precipitate, which acts as strong adsorbent for toxic metal. In this respect four different iron precipitating cultures were isolated from Hutti gold mine surface winze water sample on citrate agar medium. The best isolate was screened out for metal removal study on the basis of fast visual iron precipitation. The selected isolate was identified as Enterobacter sp. based on routine biochemical tests and Biolog GN microplate results and as Enterobacter cloacae subsp. dissolvens by 16S rRNA gene sequence analysis (GenBank accession number EU429448). Influence of medium composition, medium initial pH, the influence of inoculum size, effect of various media and ferric ammonium citrate concentration were studied on metal removal in shake flask experiments. Under the optimized conditions studied, E. cloacae showed $94{\pm}2$, $95{\pm}2$ and $70{\pm}2%$ of cadmium, copper and mercury removal from a simulated waste in shake flask studies. In lab scale column reactor more than 85% of copper and mercury removal was achieved.

• Journal of Microbiology and Biotechnology
• /
• v.14 no.5
• /
• pp.944-951
• /
• 2004

The influences of inoculum size, pH, and medium composition on mycelial growth and exopolysaccharides (EPS) production were investigated in shake flasks and in a bioreactor. The optimum inoculum size for both mycelial growth and EPS production was identified to be 10% (v/v) in shake flask cultures. The optimal initial pH for mycelial growth and EPS production in shake flask cultures were found to be 5.0 and 7.0, respectively. However, the optimal pH was 5.0 for both mycelial growth and EPS production in bioreactor cultures where the pH was regulated. The optimal mass ratio of the two major carbon sources, glucose to dextrin, was 1:4. The optimal mass ratio of the two major nitrogen sources, yeast extract to soy tone peptone, was 2:1. When 500 mg $1^{-1}$ of $MnSO_4-5H_2O$ was added to the bioreactor culture, both mycelial growth and EPS production were enhanced by approximately 10%. Under the optimized conditions, a mycelial biomass of 9.85 g $1^{-1}$ and an EPS concentration of 4.92 g $1^{-1}$ were obtained in 4 days.

• Journal of Microbiology and Biotechnology
• /
• v.8 no.3
• /
• pp.208-213
• /
• 1998

The effect of the addition of wheat bran to the growth medium on the production of cellulolytic enzymes of Trichoderma reesei Rut C30 was studied in batch culture using shake flasks. The activity of cellulase was enhanced by the addition of wheat bran to the cellulase production medium. $KH_2PO_4$-$K_2HPO_4$ buffer was used for pH control during cellulase production. As a result, high cellulase activities were obtained in shake flask culture; a CMC (carboxymethyl cellulose) activity of 125.78 U/ml was obtained from 2% Avicel- and 3% wheat bran-containing medium and an FP (filter paper) activity of 12.85U/ml was obtained from 1% Avicel- and 5% wheat bran-containing medium after 6 days of cultivation.

• Plant Biotechnology Reports
• /
• v.2 no.2
• /
• pp.133-136
• /
• 2008

Cell cultures of Commiphora wightii (Arnott.) Bhandari were grown in shake flasks and a bioreactor and an increase in guggulsterone accumulation up to $18{\mu}g\;l^{-1}$ was recorded in cells grown in the production medium containing a combination of sucrose:glucose (4% total), precursors (phenylalanine, pyruvic acid, xylose, and sodium acetate), morphactin, and 2iP. A yield of $10g\;l^{-1}$ biomass and ${\sim}200{\mu}g\;l^{-1}$ guggulsterone was recorded in a 3-l flask and in a 2-l stirred tank bioreactor compared with 6.6 g biomass and $67{\mu}g\;l^{-1}$ guggulsterone in 250-ml flasks. Increased vessel size was correlated with increased biomass and guggulsterone accumulation. 2iP alone was not effective for biomass and guggulsterone accumulation in cell cultures of C. wightii.

• KSBB Journal
• /
• v.8 no.3
• /
• pp.295-299
• /
• 1993

The effect of fungal elicitor, Pluronic F-68 and methylcellulose on suspension culture of M piperita cells was investigated in shake flasks. About a two-fold increase in oil production was observed in response to the treatment of the fungal elicitor prepared from Rhodotorula rubra. Low concentration of Pluronic F-68 or methylcellulose enhanced Peppermint cell growth at 100 rpm of agitation.