scholarly journals New Exopolysaccharides Produced by Bacillus licheniformis 24 Display Substrate-Dependent Content and Antioxidant Activity

2021 ◽  
Vol 9 (10) ◽  
pp. 2127
Author(s):  
Penka Petrova ◽  
Alexander Arsov ◽  
Ivan Ivanov ◽  
Lidia Tsigoriyna ◽  
Kaloyan Petrov
Keyword(s):  
Antioxidant Activity ◽  
Bacillus Licheniformis ◽  
Biological Activities ◽  
Batch Process ◽  
Industrial Applications ◽  
Batch Cultivation ◽  
Batch Processes ◽  
Exponential Growth Phase ◽  
Fed Batch ◽  
Platform Chemicals

Bacillus licheniformis is a soil bacterium with many industrial applications. In addition to enzymes, platform chemicals, antibiotics and phytohormones, the species produces exopolysaccharides (EPSs) of various biological activities. This study revealed that Bulgarian isolate B. licheniformis 24 produced EPSs consisting of galactose, glucose and mannose with substrate-dependent ratio. From glucose, B. licheniformis 24 secreted EPS1, consisting of 54% galactose, 39% glucose and 7% mannose. From fructose, the strain formed EPS2, containing 51% glucose, 30% mannose and 19% galactose. Batch cultivation in flasks yielded 2.2–2.6 g/L EPS1 and 1.90–2.11 g/L EPS2. Four to five times higher yields of EPS were obtained from both substrates during batch and fed-batch processes in a fermenter at 37.8 °C, pH 6.2 and aeration 3.68 vvm. The batch process with 200 g/L of starting substrates received 9.64 g/L EPS1 and 6.29 g/L EPS2, reaching maximum values at the 33rd and 24th h, respectively. Fed-batch fermentation resulted in the highest yields, 12.61 g/L EPS1 and 7.03 g/L EPS2. In all processes, EPSs were produced only in the exponential growth phase. Both EPSs exhibited antioxidant activity, but EPS2 was much more potent in this regard, reaching 811 μM Vitamin C Equivalent Antioxidant Capacity (versus 135 μM for EPS1). EPS1 displayed antibacterial activity against a non-O1 strain of Vibrio cholerae.

scholarly journals Optimization of Synthetic Media Composition for Kluyveromyces marxianus Fed-Batch Cultivation

Fermentation ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 62
Author(s):  
Konstantins Dubencovs ◽  
Janis Liepins ◽  
Arturs Suleiko ◽  
Anastasija Suleiko ◽  
Reinis Vangravs ◽  
...  
Keyword(s):  
Kluyveromyces Marxianus ◽  
Reaction Medium ◽  
Value Added ◽  
Batch Cultivation ◽  
Batch Processes ◽  
Biomass Growth ◽  
High Cell ◽  
Media Composition ◽  
Fed Batch ◽  
Fed Batch Cultivation

The Kluyveromyces marxianus yeast recently has gained considerable attention due to its applicability in high-value-added product manufacturing. In order to intensify the biosynthesis rate of a target product, reaching high biomass concentrations in the reaction medium is mandatory. Fed-batch processes are an attractive and efficient way how to achieve high cell densities. However, depending on the physiology of the particular microbial strain, an optimal media composition should be used to avoid by-product synthesis and, subsequently, a decrease in overall process effi-ciency. Thus, the aim of the present study was to optimise the synthetic growth medium and feeding solution compositions (in terms of carbon, nitrogen, phosphorous, magnesium, and calcium concentrations) for high cell density K. marxianus fed‑batch cultivations. Additionally, the biomass yields from the vitamin mixture and other macro/microelements were identified. A model predictive control algorithm was successfully applied for a fed-batch cultivation control. Biomass growth and substrate consumption kinetics were compared with the mathematical model predictions. Finally, 2‑phenylethanol biosynthesis was induced and its productivity was estimated. The determined optimal macronutrient ratio for K. marxianus biomass growth was identified as C:N:P = 1:0.07:0.011. The maximal attained yeast biomass concentration was close to 70 g·L-1 and the 2-PE biosynthesis rate was 0.372 g·L−1·h−1, with a yield of 74% from 2-phenylalanine.

scholarly journals Establishing a Fed‐Batch Process for Protease Expression with Bacillus licheniformis in Polymer‐Based Controlled‐Release Microtiter Plates

2019 ◽  
Vol 15 (2) ◽  
pp. 1900088 ◽  
Author(s):  
Tobias Habicher ◽  
Edward K. A. Rauls ◽  
Franziska Egidi ◽  
Timm Keil ◽  
Tobias Klein ◽  
...  
Keyword(s):  
Controlled Release ◽  
Bacillus Licheniformis ◽  
Batch Process ◽  
Fed Batch ◽  
Microtiter Plates ◽  
Protease Expression

scholarly journals Effect of feeding methods on the astaxanthin production by Phaffia rhodozyma in fed-batch process

2005 ◽  
Vol 48 (3) ◽  
pp. 397-401 ◽  
Author(s):  
Danilo Gomes Moriel ◽  
Miriam Blumel Chociai ◽  
Iara Maria Pereira Machado ◽  
José Domingos Fontana ◽  
Tania Maria Bordin Bonfim
Keyword(s):  
Low Cost ◽  
Biomass Productivity ◽  
Batch Process ◽  
Phaffia Rhodozyma ◽  
Batch Processes ◽  
Fed Batch ◽  
Sugar Cane Juice ◽  
Astaxanthin Production ◽  
Feeding Methods ◽  
Effect Of Feeding

The effect of feeding methods on the production of astaxanthin by the yeast Phaffia rhodozyma ATCC 24202 was studied, using continuous and pulsed fed-batch processes and low cost materials as substrates (sugar cane juice and urea). In continuous fed-batch processes, a cellular astaxanthin concentration of 383.73 µg/g biomass was obtained. But in pulsed fed-batch processes a reduction in the cellular astaxanthin concentration (303.34 µg/g biomass) was observed. Thus the continuous fed-batch processes could be an alternative to industrial production of astaxanthin, allowing an increase in the biomass productivity without losses on astaxanthin production by the yeast.

Production of alkaline protease with Bacillus licheniformis in a controlled fed-batch process

1991 ◽  
Vol 35 (6) ◽  
Author(s):  
UlrichEberhard Giesecke ◽  
Gabriele Bierbaum ◽  
Heinz Rudde ◽  
Uwe Spohn ◽  
Christian Wandrey
Keyword(s):  
Bacillus Licheniformis ◽  
Alkaline Protease ◽  
Batch Process ◽  
Fed Batch

scholarly journals Production of Docosahexaenoic Acid, DHA using Different Modes of Cultivation by Aurantiochytrium sp. SW1

2021 ◽  
Vol 50 (7) ◽  
pp. 1947-1957
Author(s):  
Shariffah Nurhidayah Syed Abdul Rahman ◽  
Mohd Sahaid Kalil ◽  
Aidil Abdul Hamid
Keyword(s):  
Fatty Acids ◽  
Docosahexaenoic Acid ◽  
Batch Process ◽  
Industrial Applications ◽  
Batch Cultivation ◽  
Vital Role ◽  
Omega 3 ◽  
Working Volume ◽  
Repeated Batch ◽  
Promising Source

Thraustochytrids, such as members of the genus Aurantiochytrium, are rich in docosahexaenoic acid (DHA, C22:6n-3) and represent a promising source of omega-3 fatty acids which plays a vital role in the enhancement of human health, particularly for neurological and visual functions. Different modes of cultivation (batch, fed-batch and repeated-batch) by Aurantiochytrium sp. SW1 were studied for effective docosahexaenoic acid (DHA) production. In this study, three different modes of fermentation were carried out in 1 L shake flasks with a working volume of 500 mL, incubated at 30 ºC and 200 rpm. Batch cultivation significantly exceeds the rest of cultivation modes, achieving maximal lipid and DHA concentrations of 11.22 g/L and 5.87 g/L, respectively, and DHA productivity of 0.061 g/L/h. Lipid and DHA concentration of the repeated-batch process decreased through the cycles for all three different types of replacement ratio (80, 90 and 95%). The average decrease percentage of DHA concentration for cycle one and cycle two were 21.76 and 32.52%, respectively. However, the fatty acid composition of lipids obtained in the cycles remained consistent with 16:0 and DHA being the most abundant fatty acids indicating that this mode of fermentation is highly useable for industrial applications.

scholarly journals Predicting black soldier fly larvae biomass and methionine accumulation using a kinetic model for batch cultivation and improving system performance using semi-batch cultivation

2021 ◽  
Author(s):  
Lydia Palma Miner ◽  
Jesus Fernandez-Bayo ◽  
Ferisca Putri ◽  
Deb Niemeier ◽  
Heather Bischel ◽  
...  
Keyword(s):  
Specific Growth ◽  
Biomass Accumulation ◽  
Dry Weight ◽  
Batch Process ◽  
Batch Cultivation ◽  
Growth And Yield ◽  
Batch Processes ◽  
Model Parameters ◽  
Black Soldier Fly ◽  
Methionine Content

AbstractGlobal demand for poultry and associated feed are projected to double over the next 30 years. Insect meal is a sustainable alternative to traditional feeds when produced on low-value high-volume agricultural byproducts. Black soldier fly (BSF) larvae (Hermetia illucens L.) are high in protein and contain methionine, an essential amino acid that is critical to poultry health. BSF larvae can be grown on many organic residues, however, larvae growth and quality vary based on feedstock and cultivation processes. Experiments were completed to monitor temporal changes in BSF larvae growth and composition using almond hulls as a growth substrate under batch and semi-batch processes and with varying substrate carbon to nitrogen ratio (C/N). A logistic kinetic growth model was developed to predict larval biomass and methionine accumulations during batch production. Estimated ranges of model parameters for larvae maximum specific growth rate and carrying capacity were 0.017–0.021 h−1 and 9.7–10.7 g larvae kg−1 hulls dry weight, respectively. Methionine content in larvae increased from 11.1 to 17.1 g kg−1 dry weight over a 30-day batch incubation period. Larvae-specific growth and yield increased by 168% and 268%, respectively, when cultivated in a semi-batch compared to a batch process. Increasing C/N ratio from 26 to 40 increased density of methionine content in larvae per unit feedstock by 25%. The findings demonstrate a logistic model can predict larvae biomass accumulation, harvest time can achieve specific methionine contents, and a semi-batch process is more favorable for larvae biomass accumulation compared to a batch process.

Improvement of cytoprotective and antioxidant activity of Rosa canina L. and Salix alba L. by controlled differential sieving process against H2O2-induced oxidative stress in mouse primary splenocytes

2017 ◽  
Vol 87 (3-4) ◽  
pp. 191-200 ◽  
Author(s):  
Nidhal Soualeh ◽  
Aliçia Stiévenard ◽  
Elie Baudelaire ◽  
Rachid Soulimani ◽  
Jaouad Bouayed
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Activities ◽  
Biological Activities ◽  
Good Alternative ◽  
Activity Levels ◽  
Salix Alba ◽  
Rosa Canina ◽  
Free Process ◽  
Plant Powders ◽  
Sieving Process

Abstract. In this study, cytoprotective and antioxidant activities of Rosa canina (RC) and Salix alba (SA), medicinal plants, were studied on mouse primary splenocytes by comparing Controlled Differential Sieving process (CDSp), which is a novel green solvent-free process, versus a conventional technique, employing hydroethanolic extraction (HEE). Thus, preventive antioxidant activity of three plant powders of homogeneous particle sizes, 50–100 µm, 100–180 µm and 180–315 µm, dissolved directly in the cellular buffer, were compared to those of hydroethanolic (HE) extract, at 2 concentrations (250 and 500 µg/mL) in H2O2-treated spleen cells. Overall, compared to HE extract, the superfine powders, i. e., fractions < 180 µm, at the lowest concentration, resulted in greater reactive oxygen species (ROS) elimination, increased glutathione peroxidase (GPx) activity and lower malondialdehyde (MDA) production. Better antioxidant and preventive effects in pre-treated cells were found with the superfine powders for SA (i. e., 50–100 µm and 100–180 µm, both p < 0.001), and with the intermediate powder for RC (i. e., 100–180 µm, p < 0.05) versus HE extract. The activity levels of catalase (CAT) and superoxide dismutase (SOD) in pretreated splenocytes exposed to H2O2, albeit reduced, were near to those in unexposed cells, suggesting that pretreatment with the fine powders has relatively restored the normal levels of antioxidant-related enzymes. These findings supported that CDSp improved the biological activities of plants, avoiding the use of organic solvents and thus it could be a good alternative to conventional extraction techniques.

Room Temperature Flow Electrochemistry as a Means of Retaining the “Memory of Chirality” via Hofer Moest Type Reaction

2020 ◽  
Author(s):  
Tomas Hardwick ◽  
Rossana Cicala ◽  
Nisar Ahmed
Keyword(s):  
Continuous Flow ◽  
Room Temperature ◽  
Biological Activities ◽  
Supporting Electrolyte ◽  
Enantiomeric Excess ◽  
Flow Chemistry ◽  
Batch Processes ◽  
Enabling Technology ◽  
Chiral Compounds ◽  
Memory Of Chirality

<p>Many chiral compounds have become of great interest to the pharmaceutical industry as they possess various biological activities. Concurrently, the concept of “memory of chirality” has been proven as a powerful tool in asymmetric synthesis, while flow chemistry has begun its rise as a new enabling technology to add to the ever increasing arsenal of techniques available to the modern day chemist. Here, we have employed a new simple electrochemical microreactor design to oxidise an L-proline derivative at room temperature in continuous flow. Flow performed in microreactors offers up a number of benefits allowing reactions to be performed in a more convenient and safer manner, and even allow electrochemical reactions to take place without a supporting electrolyte due to a very short interelectrode distance. By the comparison of electrochemical oxidations in batch and flow we have found that continuous flow is able to outperform its batch counterpart, producing a good yield (71%) and a better enantiomeric excess (64%) than batch with a 98% conversion. We have, therefore, provided evidence that continuous flow chemistry has the potential to act as a new enabling technology to replace some aspects of conventional batch processes. </p>

Regioselective Synthesis of Potent 4,5,6,7-Tetrahydroindazole Derivatives via Microwave-assisted Vilsmeier-Haack Reaction and their Antioxidant Activity Evaluation

2019 ◽  
Vol 16 (3) ◽  
pp. 194-201 ◽  
Author(s):  
Renu Bala ◽  
Vandana Devi ◽  
Pratibha Singh ◽  
Navjot Kaur ◽  
Pawandeep Kaur ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Microwave Irradiation ◽  
Biological Activities ◽  
Reaction Times ◽  
Conventional Heating ◽  
High Chemical ◽  
Microwave Assisted ◽  
Work Up ◽  
Active Methylene ◽  
By Products

Background: Tetrahydroindazole, a member of the fused-pyrazole system, is a least studied class of heterocyclic compounds owing to its scarcity in nature. However, a large number of synthetically prepared tetrahydroindazoles are known to show a variety of biological activities such as interleukin- 2 inducible T-Cell kinase inhibitors, AMPA receptor positive allosteric modulators, antitumor, antituberculosis, anti-inflammatory and antimicrobial activities. Vilsmeier-Haack reaction is one of the most important chemical reactions used for formylation of electron rich arenes. Even though Vilsmeier- Haack reaction was studied on a wide variety of hydrazones derived from active methylene compounds, literature lacks the examples of the use of 4-substituted cyclohexanones as a substrate for the synthesis of 4,5,6,7-tetrahydroindazoles. The study of the reaction of Vilsmeier-Haack reagent with hydrazones derived from cyclic keto compounds having active methylene has been considered the interested topic of investigation. In the present study, ethyl cyclohexanone-4-carboxylate was treated with one equivalent of various hydrazines for two hours and the resulted hydrazones were further treated with an OPC-VH reagent (Vilsmeier-Haack reagent isolated from phthaloyl dichloride and N,Ndimethylformamide) afforded 4,5,6,7-tetrahydroindazoles in excellent yields. The synthesized compounds 4a-f and 5a-f were screened for their antioxidant activities using the DPPH radical scavenging assay. The target compounds were synthesized regioselectively using 4+1 approach in excellent yields. A number of experiments using both conventional heating as well as microwave irradiation methods were tried and on comparison, microwave irradiation method was found excellent in terms of easy work up, high chemical yields, shortened reaction times, clean and, no by-products formation. Some of the synthesized compounds showed significant antioxidant activity. The microwave assisted synthesis of 4,5,6,7-tetrahydroindazoles from ethyl cyclohexanone-4-carboxylate has been reported under mild conditions in excellent yield. Easy work up, high chemical yield, shortened reaction times, clean and no by-products formation are the major advantages of this protocol. These advantages may make this method useful for chemists who are interested in developing novel 4,5,6,7-tetrahydroindazole based drugs.

Production of Rhamnolipid Biosurfactant from Fed Batch Culture by Pseudomonas aeruginosa using Multiple Substrates

2020 ◽  
Vol 16 (6) ◽  
pp. 928-933
Author(s):  
Jujjavarapu S. Eswari
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Batch Process ◽  
Time Interval ◽  
Fed Batch ◽  
Multiple Substrates ◽  
Surface Active Agents ◽  
Limiting Nutrients ◽  
Limiting Nutrient ◽  
Surface Active ◽  
Rhamnolipid Biosurfactant

Objective: Biosurfactants are the surface active agents which are used for the reduction of surface and interfacial tensions of liquids. Rhamnolipids are the surfactants produced by Pseudomonas aeruginosa. It requires minimum nutrition for its growth as it can also grow in distilled water. The rhamnolipids produced by Pseudomonas aeruginosa are extra-cellular glycolipids consisting of L-rhamnose and 3-hydroxyalkanoic acid. Methods: The fed-batch method for the rhamnolipid production is considered in this study to know the influence of the carbon, nitrogen, phosphorous substrates as growth-limiting nutrients. Pulse feeding is employed for limiting nutrient addition at particular time interval to obtain maximum rhamnolipid formation from Pseudomonas aeruginosa compared with the batch process. Results: Out of 3 fed batch strategies constant glucose fed batch strategy shows best and gave maximum rhamnolipid concentration of 0.134 g/l.

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