scholarly journals Optimization of β-galactosidase Production by Batch Cultures of Lactobacillus leichmannii 313 (ATCC 7830™)

Fermentation ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 27
Author(s):  
Yongjin Deng ◽  
Min Xu ◽  
Dawei Ji ◽  
Dominic Agyei

The endoenzyme β-galactosidase (β-d-galactoside galactohydrolase; EC 3.2.1.23) has been used at industrial scales for the preparation of lactose-free milk and for the conversion of lactose to galacto-oligosaccharides (GOS) prebiotics. In this study, using Plackett–Burman (PB) design and the response surface methodology (RSM), the batch growth conditions for the production of β-galactosidase in DeMan-Rogosa-Sharpe (MRS) media have been studied and optimized for Lactobacillus leichmannii 313 (ATCC 7830™) for the first time. The incubation temperature (30  <  T  <  55 °C), starting pH (5.5  <  pH  <  7.5), and carbon source (glucose, lactose, galactose, fructose, and sucrose) were selected as the significant variables for optimization. The maximum crude β-galactosidase production (measured by specific activity) was 4.5 U/mg proteins and was obtained after 12 h of fermentation. The results of the PB design and further optimization by RSM showed that the initial pH of 7.0 and 15.29 g/L of lactose were the levels that gave the optimum observed and predicted β-galactosidase activities of 23.13 U/mg and 23.40 U/mg, respectively. Through RSM optimization, β-galactosidase production increased significantly (over five-fold) in optimized medium (23.13 U/mg), compared with unoptimized medium (4.5 U/mg). Moreover, the crude enzyme obtained was able to hydrolyze lactose and also produce galacto-oligosaccharides. Because its ability to produce β-galactosidase was significantly improved through optimization by RSM, L. leichmannii 313 can serve as a potential source of β-galactosidase for food applications at an industrial scale.

2021 ◽  
Author(s):  
Atika Sajid ◽  
Saira Yahya

Abstract Background: Contamination of natural niches with pharmaceutical residues has emerged out as a serious concern. Disposal of untreated effluents from the pharmaceutical, hospital, and domestic settings has been identified as a significant source of such a massive spread of antibiotics. The unnecessary persistence of pharmaceutical residues including antibiotics has been related to the increased risk of resistance selection among pathogenic and non-pathogenic microorganisms. To date, several methods have been devised to eliminate such pollutants from wastewater, but their implication on larger scales is not feasible due to complexities and high costs of the processes, especially in developing and underdeveloped countries. This study aimed to isolate and characterize bacterial strains from domestic and pharmaceutical effluents having biotransformation potential towards most persistent antibiotics. Results: Antibiotic resistance screening and MIC determination experiments indicated highest resistivity of three bacterial isolates against two antibiotics Erythromycin and Sulfamethoxazole-trimethoprim, evincing extensive usage of these antibiotics in our healthcare settings. These isolates were identified as Comamonas jiangduensis, Aeromonas caviae and Aeromonas hydrophila by 16S rDNA sequencing. Growth conditions including incubation temperature, initial pH and inoculum size were optimized for these strains. Successful biotransformation of Erythromycin and Sulfamethoxazole-trimethoprim was achieved within 92 h under optimum growth conditions. Conclusions: Aeromonas and Comononas species were found to be potent degraders of antibiotics tested, presenting these strains as potential candidates to be utilized in the remediation processes.


2019 ◽  
Vol 5 (2) ◽  
pp. 115-123
Author(s):  
Haya Allawi ◽  
Amjad Al Tarawneh ◽  
Haitham Qaralleh ◽  
Muhamad Al-limoun ◽  
Khalid Alsharafa

Brevibacterium spp.that was already isolated from wastewater treatment plant of Petra City, Jordan. While 1 and 2 mM of 3,4-dichloro benzoic acid (3,4-DCBA) were used, the biodegradation rate was 14.5 and 21.25 µM/h, respectively, and the remaining was 58% for both. The remaining ratio to the quantity of 3,4-DCBA used was taken in consideration, as a result, 1 mM concentration of 3,4-DCBA substrate was applied for the rest of experiments because of the remaining amount is 0.58 mM 3,4-DCBA while 1.15 mM remained from 2mM concentration used. Thereafter, Brevibacterium spp was grown in batch cultures using M9 minimal media plus 1 mM concentrations of 3,4-DCBA as carbon and energy source. 3,4-DCBA degradation was optimally achieved at a 37 oC incubation temperature, a pH of 7.0 and an agitation rate of 150 rpm. During carbon starvation, the increased biodegradation potential of Brevibacterium spp. was accompanied by a lessening in the acclimatization period besides enhancement of the biodegradation completion of 3,4-DCBA. The adaptation to 3,4-DCBA not only increased the degradation rate but also managed to reduce the time required for complete 3,4-DCBA degradation from 80 to nearly 40 hours. In conclusion, the acclimatized period, and carbon starvation and other optimal conditions were key factors for the enhancement of the degradation ability of 3,4-DCBA by Brevibacterium spp.


2016 ◽  
Vol 51 (2) ◽  
Author(s):  
Katarzyna Sułkowska-Ziaja ◽  
Agnieszka Szewczyk ◽  
Joanna Gdula-Argasińska ◽  
Halina Ekiert ◽  
Jerzy Jaśkiewicz ◽  
...  

The effect of carbon and nitrogen sources and initial pH and temperature of the medium on the mycelial growth of <em>Sarcodon imbricatus</em> (L.) P. Karst. in axenic liquid culture was investigated. The optimal composition of the medium was found to be: 5% fructose, 1% hydrolysate of casein, 1% yeast extract, and 0.3% KH<span><sub>2</sub></span>PO<span><sub>4</sub></span> at pH = 6 and incubation temperature of 20°C. In this condition the maximum biomass growth was observed, yielding 10.2 g L<sup>−1</sup> of dry weight after 3-week of growth. The medium regarded as optimal for growth of <em>S. imbricatus</em> mycelium was used for the production of the biomass and further chemical analysis. The quantitative and qualitative composition of phenolic acids, fatty acids, and sterols were determined using chromatographic methods. The total content of phenolic acids was 1.86 mg × 100 g<sup>−1</sup> DW, with the largest amount of protocatechuic acid (1.27 mg × 100 g<sup>−1</sup> DW). Nineteen fatty acids were estimated, including five unsaturated fatty acids, e.g., oleic and α-linolenic acid. The analysis of sterols composition revealed the presence of ergosterol and ergosterol peroxide (197.7 and 200.47 mg × 100 g<sup>−1</sup> DW, respectively). These compounds were isolated and confirmed by <sup>1</sup>H-NMR. Presented study constitutes the first report on the accumulation of substances (phenolic acids, fatty acids, and sterols) with multidirectional biological activity in the mycelial axenic culture of <em>Sarcodon imbricatus</em>.


1990 ◽  
Vol 63 (02) ◽  
pp. 286-290 ◽  
Author(s):  
Christina Beurling-Harbury ◽  
Pehr B Harbury

SummaryActin is the major ATP and ADP binding protein in platelets, 0.9–1.3 nmol/108 cells, 50–70% in the unpolymerized state. The goal of these experiments was to develop a method for extracting all protein-bound ATP and ADP from undisturbed platelets in plasma. Extraction of actin-bound ADP is routine while extraction of actin-bound ATP from platelets in buffer has been unsuccessful. Prior to extraction the platelets were exposed to 14-C adenine, to label the metabolic and actin pools of ATP and ADP. The specific activity was determined from the actin-bound ADP in the 43% ethanol precipitate. Sequential ethanol and perchlorate extractions of platelet rich plasma, and the derived supernatants and precipitates were performed. ATP concentrations were determined with the luciferase assay, and radioactive nucleotides separated by TLC. A total of 1.18 nmol/108 cells of protein-bound ATP and ADP was recovered, 52% ATP (0.61 nmol). The recovery of protein-bound ADP was increased from 0.3 to 0.57 nmol/108 cells. This approach for the first time successfully recovered protein bound ATP and ADP from platelets in a concentration expected for actin.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Saleem Farooq ◽  
Ruqeya Nazir ◽  
Shabir Ahmad Ganai ◽  
Bashir Ahmad Ganai

AbstractAs an approach to the exploration of cold-active enzymes, in this study, we isolated a cold-active protease produced by psychrotrophic bacteria from glacial soils of Thajwas Glacier, Himalayas. The isolated strain BO1, identified as Bacillus pumilus, grew well within a temperature range of 4–30 °C. After its qualitative and quantitative screening, the cold-active protease (Apr-BO1) was purified. The Apr-BO1 had a molecular mass of 38 kDa and showed maximum (37.02 U/mg) specific activity at 20 °C, with casein as substrate. It was stable and active between the temperature range of 5–35 °C and pH 6.0–12.0, with an optimum temperature of 20 °C at pH 9.0. The Apr-BO1 had low Km value of 1.0 mg/ml and Vmax 10.0 µmol/ml/min. Moreover, it displayed better tolerance to organic solvents, surfactants, metal ions and reducing agents than most alkaline proteases. The results exhibited that it effectively removed the stains even in a cold wash and could be considered a decent detergent additive. Furthermore, through protein modelling, the structure of this protease was generated from template, subtilisin E of Bacillus subtilis (PDB ID: 3WHI), and different methods checked its quality. For the first time, this study reported the protein sequence for psychrotrophic Apr-BO1 and brought forth its novelty among other cold-active proteases.


2015 ◽  
Vol 26 (3) ◽  
pp. 495-505 ◽  
Author(s):  
Meredith O. Sweeney ◽  
Agnieszka Collins ◽  
Shae B. Padrick ◽  
Bruce L. Goode

Branched actin filament networks in cells are assembled through the combined activities of Arp2/3 complex and different WASP/WAVE proteins. Here we used TIRF and electron microscopy to directly compare for the first time the assembly kinetics and architectures of actin filament networks produced by Arp2/3 complex and dimerized VCA regions of WAVE1, WAVE2, or N-WASP. WAVE1 produced strikingly different networks from WAVE2 or N-WASP, which comprised unexpectedly short filaments. Further analysis showed that the WAVE1-specific activity stemmed from an inhibitory effect on filament elongation both in the presence and absence of Arp2/3 complex, which was observed even at low stoichiometries of WAVE1 to actin monomers, precluding an effect from monomer sequestration. Using a series of VCA chimeras, we mapped the elongation inhibitory effects of WAVE1 to its WH2 (“V”) domain. Further, mutating a single conserved lysine residue potently disrupted WAVE1's inhibitory effects. Taken together, our results show that WAVE1 has unique activities independent of Arp2/3 complex that can govern both the growth rates and architectures of actin filament networks. Such activities may underlie previously observed differences between the cellular functions of WAVE1 and WAVE2.


1992 ◽  
Vol 285 ◽  
Author(s):  
S.H.H. Naqvi ◽  
M. Vickers ◽  
S. Tarling ◽  
P. Barnes ◽  
I.W. Boyd

ABSTRACTThe lead based superconductor Pb2Sr2Y0.5Ca0.5Cu3O8+δ is a most complex material. If any oxygen is present in the PbO-CuOδ-PbO sandwich layer (i.e. if δ>0) the superconductivity deteriorates. This is also a most difficult material to grow not only because of the large number of cation stoichiometries which have to be precisely balanced but also because of the tendency for multiple phases to form. Pulsed laser deposition (PLD) has been applied to prepare thin films of the 2213-phase on MgO (100) single crystal substrates at low temperature (300°C) in low oxidizing atmospheres. A basic set of ex-situ growth conditions has been determined which produce for the first time good quality films of this material as characterized by DC resistivity using the Van der Pauw method, as well as EDX and XRD. The layers are reasonably c-axis oriented and display a superconducting onset transition temperature of 79K and zero resistance at 65K after subsequent annealing in a nitrogen ambient.


Proceedings ◽  
2019 ◽  
Vol 40 (1) ◽  
pp. 23
Author(s):  
Zengin ◽  
Aygun ◽  
Aktumsek

Nowadays, knowledge of ancient botanical medicinal practices and application of modern phytochemical techniques have provided the excellent tools for the purification and structural elucidation of various phyto-compounds, which, in turn, has given insights into their mode of action on the human body. This study has been designed to investigate for the first time the antioxidant effects of the ethyl acetate, methanolic, and water extracts of Kitaibelia balansae. Different chemical methods were performed and the observed abilities depend on the solvent used. The best antioxidant ability was noted in water extract, followed by methanol and ethyl acetate extracts. The highest level of phenolic was also detected in water extract. The present findings suggest that K. balansae can be considered as a potential source of bioactive compounds for novel phytopharmaceuticals development


2018 ◽  
Vol 60 (4) ◽  
pp. 292-298
Author(s):  
Natalia A. Romanova ◽  
Alexander B. Zhirnov ◽  
Natalia A. Yust ◽  
Xu Fucheng

Abstract The problem of determining the dependence of the chainsaw on the density of wood, substantiation of effective options for the number of chainsaws in the assortment and whiplash method of logging is quite relevant. In the Far East of Russia, in particular, in the Amur region, the forest growth conditions are different from the western ones, and therefore, the properties of the wood differ from the generally accepted ones. The article describes forest growth conditions that influence the properties of the wood in areas of the Amur region. Using the method of density determination, the density of larch, pine and birch were studied for first time in the areas of the region. The dependence of the density on humidity, age, species, season of the year and the area of growth was found out. The results of the research showed that under humidity of 70%, the density of larch was 1088.99 kg/m3, it was 919.8 kg/m3 for pine and it was for birch 915.9 kg/m3.


2017 ◽  
Vol 13 (2) ◽  
pp. 191
Author(s):  
Anak Agung Istri Ratnadewi ◽  
Moch. Yoris Alidion ◽  
Agung Budi Santoso ◽  
Ika Oktavianawatia

<p>Endo-β-1,4-D-xylanase is a hydrolytic enzyme that breakdown the 1.4 chain of xylan polysaccharide. We have succes to transform the plasmid pET-Endo gene encoding endo-1,4-β-D-xylanase from Bacillus sp. originally from termites abdominal to E. coli BL21. The clone was ready for large scale of enzyme production. To reduce production cost, we look for subtitute media for the expensive Luria Berthani broth. Chicken guts broth is good alternative while rich of protein and very cheap. The content of N dissolved chicken guts broth reaches 87 % of LB broth. Growth of E. Coli BL21 in Chicken guts broth and LB broth (as control) was observed by Optical Density (OD) using spectrofotometer. Concentration of glucose added in broth and incubation temperature was varied. The result showed that optimal growth was in addition of 1.5 % glucose and incubated at  37 <sup>o</sup>C for 16 h. This optimal condition was used to grow E. coli BL21 pET-Endo for xylanase production. Enzyme purification was done by Ni-NTA affinity chromatography. Highest protein yield was 0.076 mg/mL obtained in 100 mM imidazole elucidation. The activity and specific activity of xylanase were estimated as 0.042 U/mL and 0.556 U/µg, respectively. The purification factor was 3.16 time and the molecular weight of enzyme was ± 30, 000 Dalton</p>


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