scholarly journals A Study on L-Asparaginase ofNocardia levisMK-VL_113

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Alapati Kavitha ◽  
Muvva Vijayalakshmi

An enzyme-based drug, L-asparaginase, was produced byNocardia levisMK-VL_113 isolated from laterite soils of Guntur region. Cultural parameters affecting the production of L-asparaginase by the strain were optimized. Maximal yields of L-asparaginase were recorded from 3-day-old culture grown in modified asparagine-glycerol salts broth with initial pH 7.0 at temperature30∘C. Glycerol (2%) and yeast extract (1.5%) served as good carbon and nitrogen sources for L-asparaginase production, respectively. Cell-disrupting agents like EDTA slightly enhanced the productivity of L-asparaginase. Ours is the first paper on the production of L-asparaginase byN. levis.

2016 ◽  
Author(s):  
Wenfa Ng ◽  
Yen-Peng Ting

Microbes for environmental research should be cultured in growth media with characteristics (e.g., pH, ionic strength, and organic and ionic composition) as close to their original habitat as possible. Additionally, the medium should also enable high cell density to be obtained - needed for providing sufficient cells in subsequent experiments. This in-progress report describes the formulation of a medium with an environmentally-relevant composition (lack of complex organics), and that allows aerobic high cell density cultivation of Escherichia coli DH5α in shake flasks. The formulated medium comprises four components: a buffer system (K2HPO4: 12.54 g/L and KH2PO4: 2.31 g/L), vitamins (yeast extract: 12.0 g/L), salts (NaCl: 5.0 g/L and MgSO4: 0.24 g/L), and carbon and nitrogen sources (D-Glucose: 6.0 g/L and NH4Cl: 1.5 g/L). Notable characteristics of this medium were: high capacity phosphate buffer system (89 mM phosphate); 1:1 molar ratio between D-Glucose and NH4Cl; and yeast extract providing trace elements and a secondary carbon and nitrogen source. Growth experiments revealed that an OD600nm of 9 was attained after 24 hours of cultivation at 37 oC. Glucose and NH4Cl serve as primary carbon and nitrogen sources for this phase of growth. After 48 hours, the OD600nm reached 11, where carbohydrates, lipids and proteins in yeast extract provided the nutrients for biomass formation. Broth’s pH varied between 5.5 and 7.8 during cultivation, which was in the range conducive for E. coli growth. In comparison, the OD600nm of E. coli reached 1.4, 3.2, and 9.2 in three commonly used complex media; Nutrient Broth, LB Lennox, and Tryptic Soy Broth, respectively, over 48 hours under identical culture conditions. In addition, the formulated medium was able to maintain a large viable cell population for a longer period of time (three days) compared to Tryptic Soy Broth. Thus, preliminary data suggested that the formulated medium holds potential for use as a high cell density aerobic growth medium for Gram-negative bacteria.


2017 ◽  
Author(s):  
Wenfa Ng ◽  
Yen-Peng Ting

Microbes for environmental research should be cultured in growth media with characteristics (e.g., pH, ionic strength, and ionic composition) as close to their original habitat as possible. Additionally, the medium should also enable high cell density to be obtained, which is needed for providing sufficient cells in subsequent experiments. This in-progress report describes the formulation of a medium with an environmentally relevant composition (i.e., lack of complex organics), and that allows aerobic high cell density cultivation of Escherichia coli DH5α (ATCC 53868) in shake flasks. The formulated medium comprises four components: a buffer system (K2HPO4: 12.54 g/L and KH2PO4: 2.31 g/L), vitamins (yeast extract: 12.0 g/L), salts (NaCl: 5.0 g/L and MgSO4: 0.24 g/L), and carbon and nitrogen sources (D-Glucose: 6.0 g/L and NH4Cl: 1.5 g/L). Notable characteristics of this medium were: high capacity phosphate buffer system (89 mM phosphate); 1:1 molar ratio between D-Glucose and NH4Cl; and yeast extract providing trace elements and a secondary carbon and nitrogen source. Growth experiments revealed that an OD600nm of 9 was obtained after 24 hours of cultivation at 37 oC. Glucose and NH4Cl served as primary carbon and nitrogen sources for this growth phase. After 48 hours, the OD600nm reached 11, where carbohydrates, lipids and proteins in yeast extract provided the nutrients for biomass formation. Broth’s pH varied between 5.5 and 7.8 during cultivation, which is conducive for E. coli growth. In comparison, the OD600nm of E. coli reached 1.4, 3.2, and 9.2 in three commonly used complex media; Nutrient Broth, LB Lennox, and Tryptic Soy Broth, respectively, over 48 hours under identical culture conditions. In addition, the formulated medium was able to maintain a large viable cell population for a longer period of time (three days) compared to Tryptic Soy Broth. Thus, preliminary data suggested that the formulated medium holds potential for use as a high cell density aerobic growth medium for Gram-negative bacteria.


2012 ◽  
Vol 554-556 ◽  
pp. 887-890
Author(s):  
Mei Lin Cui ◽  
Guo Qing He

To determine an optimal G. lucidum strain, we made the production of mycelia biomass, EPS, IPS, IT, ET as indicators, among the five tested strains, the American G. lucidum was screened, and the production of mycelia biomass, EPS, IPS, IT, ET could reach 2.013g/100 ml, 11.2988 mg/100ml, 23.7800 mg/10ml, 45.5412 mg/100ml, 11.1417 mg/100ml, respectively. On the other hand, according to the screening of carbon and nitrogen sources as well as their concentration, the suitable carbon and nitrogen was 3% malt powder, 1.5% yeast extract. So we can use the fermentation culture for the following research, which was as follows:3% malt powder, 1.5%yeast extract, 0.3% KH2PO4, 0.15% MgSO4, 0.005% VB1.


2018 ◽  
Vol 10 (1) ◽  
pp. 316 ◽  
Author(s):  
Adnina Fitra Azzahra ◽  
Dyah Karina Puspita Sukarna ◽  
Herman Suryadi

Objective: The objective of this study is to obtain the optimal fermentation conditions for Aspergillus oryzae by gradually optimizing the medium andfermentation conditions.Methods: Fermentation condition were optimized by varying carbon and nitrogen sources, pH medium, temperature, and aeration condition. Levelsof kojic acid were determined using thin-layer chromatography-densitometry with an ultraviolet detector at a wavelength of 318 nm.Results: A combination of sucrose and yeast extract was chosen as the best source of carbon and nitrogen, respectively, from nine medium variations,producing 1.5425 g/L kojic acid. The optimum acidity of the medium was at pH 4.5, producing 1.7127 g/L of kojic acid, compared with pH 3.5 and5.5. Compared with fermentation at room temperature, fermentation at 35°C yielded greater kojic acid production. The best aeration condition was100 mL medium in 250 mL flask that produced the most kojic acid (1.6472 g/L).Conclusion: The optimal medium for fermentation of kojic acid using A. oryzae uses sucrose and yeast extract as carbon and nitrogen sources,respectively, at pH 4.5. The optimal aeration and incubation conditions were used, a volume of 100 mL in a 250 mL conical flask, incubated at 35°C,obtaining the highest yield value of 0.0370 g/g.


2018 ◽  
Vol 10 (1) ◽  
pp. 279
Author(s):  
Herman Suryadi ◽  
Dyah Karina Puspita Sukarna

Objective: This study aimed to find the optimum kojic acid fermentation conditions using combination cultures of Aspergillus oryzae and Aspergillustamarii.Methods: Screening of the best mixed cultures was performed using yeast extract medium with 5% (w/v) glucose. Fermentation conditionswere optimized by varying carbon and nitrogen sources, pH of medium, inoculum ratio, and aeration. Aeration was varied using 50 and 100 mLof medium in 100 and 250 mL Erlenmeyer flasks, respectively. Kojic acid was analyzed using thin-layer chromatography-densitometry and UV-Visspectrophotometry.Results: Kojic acid produced from mixed cultures yielded 0.1396 gg−1, while sole cultures of A. oryzae and A. tamarii yielded 0.0329 gg−1 and0.1001 gg−1, respectively. Of the nine fermentation mediums, the best carbon and nitrogen sources were sucrose and yeast extract. From the threevariations of pH, pH 3.5 was the optimum pH value. From the three ratios of inoculum concentration, a ratio of 2:3 (A. oryzae:A. tamarii) was the bestratio. Aeration was varied using 50 and 100 mL of medium in 100 and 250 mL Erlenmeyer flasks, respectively. Aeration of 100 mL medium in 250 mLErlenmeyer flask was selected as the best aeration that produced 6.559 g/L kojic acid.Conclusion: The highest concentration of kojic acid was obtained by mixing cultures of A. oryzae and A. tamarii in a ratio of 2:3, using sucrose andyeast extract as the substrates at pH 3.5 and semiaerobic condition.


2017 ◽  
Vol 22 (1) ◽  
pp. 31 ◽  
Author(s):  
Eris Septiana ◽  
Partomuan Simanjuntak

Antioxidant is an interesting topic due to their capability to inhibit free radical and prevent damage because of oxidative processes. Endophyt fungi is one of antioxidant compound resources in nature. The low yield to gain antioxidant compound from fungi challenges to look for the composition of media and optimalization of growth conditions. This research aimed to know the effect of medium condition in different carbon and nitrogen sources as well as initial pH towards antioxidant activity of endophyt fungi Bo.Ci.Cl.A3. Shaker fermentation was used on 120 rpm at room temperature for 14 days. The carbon sources were glucose, sucrose, and starch and nitrogen sources were NaNO3, NH4NO3, and yeast extract with initial pH at 5, 7, and 9. Ethyl acetate was used as extractor. The results showed that endophyt fungi can produce secondary metabolite as antioxidant at all variation of fermented media. The nitrogen source of yeast extract could increase antioxidant activity of endophyt fungi Bo.Ci.Cl.A3, while other sources such as nitrogen source, carbon sources, and different initial pH on the basal medium that were used did not give increasing antioxidant activity. The conclusion of this research was the substitution of nitrogen source with yeast extract (3 g/L) on the basal medium Czapek Dox’s Broth could increase antioxidant activity of endophyt fungi Bo.Ci.Cl.A3.


2017 ◽  
Author(s):  
Wenfa Ng ◽  
Yen-Peng Ting

Microbes for environmental research should be cultured in growth media with characteristics (e.g., pH, ionic strength, and ionic composition) as close to their original habitat as possible. Additionally, the medium should also enable high cell density to be obtained, which is needed for providing sufficient cells in subsequent experiments. This in-progress report describes the formulation of a medium with an environmentally relevant composition (i.e., lack of complex organics), and that allows aerobic high cell density cultivation of Escherichia coli DH5α (ATCC 53868) in shake flasks. The formulated medium comprises four components: a buffer system (K2HPO4: 12.54 g/L and KH2PO4: 2.31 g/L), vitamins (yeast extract: 12.0 g/L), salts (NaCl: 5.0 g/L and MgSO4: 0.24 g/L), and carbon and nitrogen sources (D-Glucose: 6.0 g/L and NH4Cl: 1.5 g/L). Notable characteristics of this medium were: high capacity phosphate buffer system (89 mM phosphate); 1:1 molar ratio between D-Glucose and NH4Cl; and yeast extract providing trace elements and a secondary carbon and nitrogen source. Growth experiments revealed that an OD600nm of 9 was obtained after 24 hours of cultivation at 37 oC. Glucose and NH4Cl served as primary carbon and nitrogen sources for this growth phase. After 48 hours, the OD600nm reached 11, where carbohydrates, lipids and proteins in yeast extract provided the nutrients for biomass formation. Broth’s pH varied between 5.5 and 7.8 during cultivation, which is conducive for E. coli growth. In comparison, the OD600nm of E. coli reached 1.4, 3.2, and 9.2 in three commonly used complex media; Nutrient Broth, LB Lennox, and Tryptic Soy Broth, respectively, over 48 hours under identical culture conditions. In addition, the formulated medium was able to maintain a large viable cell population for a longer period of time (three days) compared to Tryptic Soy Broth. Thus, preliminary data suggested that the formulated medium holds potential for use as a high cell density aerobic growth medium for Gram-negative bacteria.


2012 ◽  
Vol 518-523 ◽  
pp. 453-459
Author(s):  
Li Fan Liu

Bioflocculant MBF7 was produced by a novel bioflocculant-producing microorganism HHE-P7. In order to reduce the bioflocculant producing cost, culture experiments were conducted. The effects of medium components including carbon and nitrogen sources as well as culture conditions such as pH of molasses diluents, cultivating temperature, inoculum size were investigated. The results showed when the molasses waste was diluted at COD concentration of 2000 mg/L, the optimal culture conditions for MBF7 production by HHE-P7 were inoculum size 1% (v/v), initial pH 5, cultivating temperature 25°C at the rotation speed 150 r/min. Under such conditions, MBF7 had a flocculating activity of 83% for 5 g/L kaolin clay suspension. About 3.19 g crude bioflocculant could be recovered from 1.0 L of molasses fermentation broth.


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