• Biotechnology and Bioprocess Engineering:BBE
• /
• 제9권4호
• /
• pp.278-284
• /
• 2004

Leuconostoc citreum is one of the representative strains of Leuconostoc spp. that show fast growth rates in fermented vegetables. Sequential experimental designs including the Plackett-Burman design, fractional factorial design, steepest ascent analysis, central composite design and response surface methodology were introduced to optimize and improve the medium for L. citreum. Fifteen medium ingredients were examined and glucose ($20 g/\ell$), yeast extract ($12.5g/\ell$), sodium acetate trihydrate ($6.12g/\ell$), potassium phosphate ($42.55g/\ell$), and dibasic ammonium citrate ($4.12g/\ell$), were chosen as the best components to give a critical and positive effect for cell-growth. The biomass was increased to ($2.79g/\ell$), (169%), compared to the $1.65g/\ell$ in MRS medium.

• Journal of Microbiology and Biotechnology
• /
• 제20권11호
• /
• pp.1597-1602
• /
• 2010

Chitinase is one of the most important mycolytic enzymes with industrial significance. This enzyme is produced by a number of organisms including bacteria. In this study, we describe the optimization of media components with increased production of chitinase for the selected bacteria, Stenotrophomonas maltophilia, isolated from soil. Different components of the defined media responsible for influencing chitinase secretion by the bacterial isolate were screened using Plackett-Burman experimental design and were further optimized by Box-Behnken factorial design of response surface methodology in liquid culture. Maximum chitinase production was predicted in medium containing 4.94 g/l chitin, 5.56 g/l maltose, 0.62 g/l yeast extract, 1.33 g/l $KH_2PO_4$, and 0.65 g/l $MgSO_4{\cdot}7H_2O$ using response surface plots and the point prediction tool of the DESIGN EXPERT 7.1.6 (Stat-Ease, USA) software.

• Journal of Microbiology and Biotechnology
• /
• 제18권4호
• /
• pp.695-703
• /
• 2008

A locally isolated thermophile, Geobacillus sp. SAB-40, producing thermostable extracellular amylase constitutively and an induced intracellular ${\beta}$-galactosidase was characterized and identified based on 16S rRNA sequencing. A phylogenetic analysis then revealed its closeness to Geobacillus stearothermophilus. To evaluate the effect of the culture conditions on the coproduction of both enzymes by G stearothermophilus SAB-40, a Plackett-Burman fractional factorial design was applied to determine the impact of twenty variables. Among the tested variables, $CaCI_2$, the incubation time, $MgSO_4{\cdot}7H_2O$, and tryptone were found to be the most significant for encouraging amylase production. Lactose was found to promote ${\beta}$-galactosidase production, whereas starch had a significantly negative effect on lactase production. Based on a statistical analysis, a preoptimized medium attained the maximum production of amylase and ${\beta}$-galactosidase at 23.29 U/ml/ min and 12,958 U/mg biomass, respectively, which was 3-and 2-fold higher than the yield of amylase and lactase obtained with the basal medium, respectively.

• 한국미생물·생명공학회지
• /
• 제51권1호
• /
• pp.69-82
• /
• 2023

Nitrilases are a hydrolase group of enzymes that catalyzes nitrile compounds and produce industrially important organic acids. The current objective is to optimize nitrilase production using statistical methods assisted with artificial intelligence (AI) tool from novel nitrile degrading isolate. A nitrile hydrolyzing bacteria Bacillus subtilis AGAB-2 (GenBank Ascension number- MW857547) was isolated from industrial effluent waste through an enrichment culture technique. The culture conditions were optimized by creating an orthogonal design with 7 variables to investigate the effect of the significant factors on nitrilase activity. On the basis of obtained data, an AI-driven support vector machine was used for the fitted regression, which yielded new sets of predicted responses with zero mean error and reduced root mean square error. The results of the above global optimization were regarded as the theoretical optimal function conditions. Nitrilase activity of 9832 ± 15.3 U/ml was obtained under optimized conditions, which is a 5.3-fold increase in compared to unoptimized (1822 ± 18.42 U/ml). The statistical optimization method involving Plackett Burman Design and Response surface methodology in combination with an AI tool created a better response prediction model with a significant improvement in enzyme production.

• Journal of Microbiology and Biotechnology
• /
• 제24권10호
• /
• pp.1319-1326
• /
• 2014

Rapamycin, produced by the soil bacterium Streptomyces hygroscopicus, has the ability to suppress the immune system and is used as an antifungal, anti-inflammatory, antitumor, and immunosuppressive agent. In an attempt to increase the productivity of rapamycin, mutagenesis of wild-type Streptomyces hygroscopicus was performed using ultraviolet radiation, and the medium composition was optimized using glycerol (which is one of the cheapest starting substrates) by applying Plackett-Burman design and response surface methodology. Plackett-Burman design was used to analyze 14 medium constituents: M100 (maltodextrin), glycerol, soybean meal, soytone, yeast extract, $(NH_4)_2SO_4$, $\small{L}$-lysine, $KH_2PO_4$, $K_2HPO_4$, NaCl, $FeSO_4{cdot}7H_2O$, $CaCO_3$, 2-(N-morpholino) ethanesulfonic acid, and the initial pH level. Glycerol, soytone, yeast extract, and $CaCO_3$ were analyzed to evaluate their effect on rapamycin production. The individual and interaction effects of the four selected variables were determined by Box-Behnken design, suggesting $CaCO_3$, soytone, and yeast extract have negative effects, but glycerol was a positive factor to determine rapamycin productivity. Medium optimization using statistical design resulted in a 45% ($220.7{\pm}5.7mg/l$) increase in rapamycin production for the Streptomyces hygroscopicus mutant, compared with the unoptimized production medium ($151.9{\pm}22.6mg/l$), and nearly 588% compared with wild-type Streptomyces hygroscopicus ($37.5{\pm}2.8mg/l$). The change in pH showed that $CaCO_3$ is a critical and negative factor for rapamycin production.

• 한국식품저장유통학회지
• /
• 제30권1호
• /
• pp.132-145
• /
• 2023

본 연구에서는 식품 원료로 이용이 허가된 Acetobacter pasteurianus SRCM101388을 사용하여 바이오매스 고농도배양을 위한 최적화 연구를 실시하였다. SRCM101388의 최적 배양온도와 pH 조건은 각각 28℃와 pH 6.0으로 나타났다. 배지조건을 확립하기 위하여 Plackett-Burman design을 실시한 결과, glucose, sucrose, yeast extract가 biomass 증가에 가장 높은 효과를 보였다. Glucose, sucrose, yeast extract의 최적농도를 알아보기 위하여 central composite design을 실시하였으며, 최적농도는 glucose 10.73 g/L, sucrose 3.98 g/L, yeast extract 18.73 g/L로 나타났다. Plackett-Burman design에서 biomass 증가에 영향이 있는 기타 미량원소에 대한 최적농도를 조사한 결과, ammonium sulfate 1 g/L, magnesium sulfate 0.5 g/L, sodium phosphate monobasic 2 g/L, sodium phosphate dibasic 2 g/L로 나타났으며, 최종 최적화된 배지 제조 시 pH는 6.10으로 최적 pH 조건과도 일치하였다. 최적화된 배지 3.5 L를 함유한 5 L jar fermenter에서의 배양결과, SRCM101388은 DO가 낮은 rpm에서 DO 감소가 더 빠르게 나타났다. 최대 생균수는 150 rpm, 0.5 vvm, pH 6.0, 28℃ 조건에서 18시간 배양 시 2.53± 0.12×10⁹ CFU/mL로 나타났다.

• Journal of Microbiology and Biotechnology
• /
• 제23권2호
• /
• pp.211-217
• /
• 2013

Corynebacterium glutamicum is one of the well-studied industrial strain that is used for the production of nucleotides and amino acids. Recently, it has also been studied as a possible producer of organic acids such as succinic acid, based on its ability to produce organic acids under an oxygen deprivation condition. In this study, we conducted the optimization of medium components for improved succinate production from C. glutamicum under an oxygen deprivation condition by Plackett-Burman design and applied a response surface methodology. A Plackett-Burman design for ten factors such as glucose, ammonium sulfate, magnesium sulfate, potassium phosphate ($K_2HPO_4$ and $KH_2PO_4$), iron sulfate, manganese sulfate, biotin, thiamine, and sodium bicarbonate was applied to evaluate the effects on succinate production. Glucose, ammonium sulfate, magnesium sulfate, and dipotassium phosphate were found to have significant influence on succinate production, and the optimal concentrations of these four factors were sequentially investigated by the response surface methodology using a Box-Behnken design. The optimal medium components obtained for achieving maximum concentration of succinic acid were as follows: glucose 10 g/l, magnesium sulfate 0.5 g/l, dipotassium phosphate ($K_2HPO_4$) 0.75 g/l, potassium dihydrogen phosphate ($KH_2PO_4$) 0.5 g/l, iron sulfate 6 mg/l, manganese sulfate 4.2 mg/l, biotin 0.2 mg/l, thiamine 0.2 mg/l, and sodium bicarbonate 100 mM. The parameters that differed from a normal BT medium were glucose changed from 40 g/l to 10 g/l, dipotassium phosphate ($K_2HPO_4$) 0.5 g/l changed to 0.75 g/l, and ammonium sulfate ($(NH_4)_2SO_4$) 7 g/l changed to 0 g/l. Under these conditions, the final succinic acid concentration was 16.3 mM, which is about 1.46 fold higher than the original medium (11.1 mM) at 24 h. This work showed the improvement of succinate production by a simple change of media components deduced from sequential optimization.

• Journal of Microbiology and Biotechnology
• /
• 제32권5호
• /
• pp.630-637
• /
• 2022

The objective of this study was to optimize industrial-grade media for improving the biomass production of Weissella cibaria JW15 (JW15) using a statistical approach. Eleven variables comprising three carbon sources (glucose, fructose, and sucrose), three nitrogen sources (protease peptone, yeast extract, and soy peptone), and five mineral sources (K₂HPO₄, potassium citrate, ⳑ-cysteine phosphate, MgSO₄, and MnSO₄) were screened by using the Plackett-Burman design. Consequently, glucose, sucrose, and soy peptone were used as significant variables in response surface methodology (RSM). The composition of the optimal medium (OM) was 22.35 g/l glucose, 15.57 g/l sucrose, and 10.05 g/l soy peptone, 2.0 g/l K₂HPO₄, 5.0 g/l sodium acetate, 0.1 g/l MgSO₄·7H₂O, 0.05 g/l MnSO₄·H₂O, and 1.0 g/l Tween 80. The OM significantly improved the biomass production of JW15 over an established commercial medium (MRS). After fermenting OM, the dry cell weight of JW15 was 4.89 g/l, which was comparable to the predicted value (4.77 g/l), and 1.67 times higher than that of the MRS medium (3.02 g/l). Correspondingly, JW15 showed a rapid and increased production of lactic and acetic acid in the OM. To perform a scale-up validation, batch fermentation was executed in a 5-l bioreactor at 37℃ with or without a pH control at 6.0 ± 0.1. The biomass production of JW15 significantly improved (1.98 times higher) under the pH control, and the cost of OM was reduced by two-thirds compared to that in the MRS medium. In conclusion, OM may be utilized for mass producing JW15 for industrial use.

• 한국미생물·생명공학회지
• /
• 제45권4호
• /
• pp.330-342
• /
• 2017

Statistical design of experiments was employed to optimize the media composition for the production of laccase from Bacillus sp. PK4. In order to find the key ingredients for the best yield of enzyme production from the selected eleven variables viz yeast extract, glucose, zinc sulphate, copper sulphate, potassium chloride, magnesium sulphate, calcium chloride, ferrous sulphate, sodium chloride, potassium dihydrogen phosphate ($KH_2PO_4$) and dipotassium hydrogen phosphate ($K_2HPO_4$), Plackett-Burman design was applied. The $MgSO_4$, $FeSO_4$, and $CuSO_4$ showed positive estimate, and their concentration optimized further. The steepest ascent method and Box-Behnken method revealed that 1.5 mM $MgSO_4$, 0.33 g/l $FeSO_4$ and 1.41 mM $CuSO_4$ were optimal for the laccase production by Bacillus sp. PK4. This optimization strategy leads to enhancement of laccase production from 2.13 U/ml to 40.79 U/ml. Agro-wastes residues replace the carbon source glucose in the optimized media namely sugarcane bagasse, wheat bran, rice husk, and groundnut shell, among these groundnut shells (117 U/ml) was found to enhance the laccase production significantly. The laccase produced by Bacillus sp. PK4 was found to have the potential to degrade persistent organic pollutant benzo[a]pyrene.

• Food Science and Biotechnology
• /
• 제15권6호
• /
• pp.825-832
• /
• 2006

The effect of alginate coating in combination with an anti-browning agent on increasing the post-cutting shelf life and improving the quality of minimally processed apple cubes was studied during storage at room temperature for 5 days. A simple coating technique involving the chemical cross-linkage of alginate by calcium was used. Statistical-based experimental designs were applied to improve the quality of the alginate-coated apple cubes (ACAC). Plackett-Burman design was first used to determine the main factors influencing the preservation of the original weight, color, and texture of ACAC. Among these variables, alginate concentration ($X_1$), dipping time ($X_2$), and dipping temperature ($X_3$) significantly influenced the ACAC weight and color (confidence levels above 90%). Subsequently, the effects of the 3 main factors were further investigated by a central composite design. The polynomial models developed by response surface methodology were adequate to describe the relationships between the studied factors and the responses. Overall optimization conducted by superimposing the curves of the responses enabled the determination of an optimal range of the independent variables in which the five responses were simultaneously optimized. The point chosen as representative of this optimal area corresponded to $X_1=2.98%$, $X_2=0.85\;min$, and $X_3=55^{\circ}C$ and under these conditions the model predicted weight loss=0.522%, relative hardness=1.517, ${\Delta}E=1.423$, browning inhibition=93.403%, and ${\Delta}L=0.158$.