scholarly journals Poly-β-Hydroxybutyrate Production by Rhodopseudomonas sp. Grown in Semi-Continuous Mode in a 4 L Photobioreactor

Symmetry ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1609
Author(s):  
Eleftherios Touloupakis ◽  
Eleni G. Poloniataki ◽  
Martina Casciana ◽  
Demetrios F. Ghanotakis ◽  
Pietro Carlozzi
Keyword(s):  
Growth Phase ◽  
Sufficient Conditions ◽  
Dry Weight ◽  
Growth Strategy ◽  
Continuous Mode ◽  
Sulfur Concentration ◽  
Continuous Growth ◽  
Sulfur Bacteria ◽  
Single Carbon Source ◽  
Accumulation Phase

The synthesis of polyhydroxybutyrate (PHB) by photosynthetic non-sulfur bacteria is a potential approach for producing biodegradable plastics. In this work, acetate was used as a single carbon source to study the effect on PHB formation in Rhodopseudomonas sp. cultured in a cylindrical four-liter photobioreactor under semi-continuous mode. The cultivation process is divided into a symmetrical growth phase and a PHB accumulation phase separated temporally. The symmetrical growth phase (nutrient sufficient conditions) was followed by a sulfur-limited phase to promote PHB accumulation. The main novelty is the progressive lowering of the sulfur concentration into Rhodopseudomonas culture, which was obtained by two concomitant conditions: (1) sulfur consumption during the bacterial growth and (2) semi-continuous growth strategy. This caused a progressive lowering of the sulfur concentration into Rhodopseudomonas culturedue to the sulfur-free medium used to replace 2 L of culture (50% of the total) that was withdrawn from the photobioreactor at each dilution. The PHB content ranged from 9.26% to 15.24% of cell dry weight. At the steady state phase, the average cumulative PHB was >210 mg/L. Sulfur deficiency proved to be one of the most suitable conditions to obtain high cumulative PHB in Rhodopseudomonas culture.

Application of Potassium Fertilizer and Chicken Coop Fertilizer Against Growth and Production of Shallots (Allium ascalanicum L.)

Nabatia ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Andy Pradana ◽  
Al Machfudz WDP
Keyword(s):  
Growth Phase ◽  
Vegetative Growth ◽  
Growth Parameters ◽  
Block Design ◽  
Dry Weight ◽  
Chicken Manure ◽  
Fertilizer Treatment ◽  
Potassium Fertilizer ◽  
Wet Weight ◽  
Number Of Leaves

This study aims to determine the application of potassium fertilizer and chicken manure to the growth and production of shallots (Allium ascalanicum L.). The study used a randomized block design with 2 factors repeated 3 times. Factor 1: Potassium Fertilizer 40,60,80 kg/ha. Factor 2: Chicken Manure 5,10,15 tons/ha. The results showed that the application of potassium fertilizer and chicken manure did not interact with either the growth phase or the production phase of the plant on all observation variables, while the potassium fertilizer treatment showed significantly different results only on the plant vegetative growth parameters, namely the number of leaves at the age of 7 days after planting, namely ( 8,111 strands), while the vegetative phase had no significant effect on the number of tubers per clump, wet weight of tubers per clump, wet weight of tubers per plot, dry weight of sun-dried tubers per clump, and dry weight of sun-dried tubers per plot. While the treatment of chicken manure had a significant effect on the vegetative growth phase of plants, namely the length of plants at 28 DAP (30.278 cm) and 35 DAP (32.704 cm), on the number of leaves at 7 DAP (8,000 strands). While the generative phase (60 DAP) significantly affected the number of tubers per clump, namely (5,889 grams), wet weight of tubers per clump (38,333 grams), wet weight of tubers per plot (319,000 grams), dry weight of sun-dried tubers per clump. namely (23.074 grams), and the dry weight of sun-dried tubers per plot (191.889 grams).

scholarly journals Variation in ω-3 and ω-6 Polyunsaturated Fatty Acids Produced by Different Phytoplankton Taxa at Early and Late Growth Phase

Biomolecules ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 559 ◽  
Author(s):  
Sami Taipale ◽  
Elina Peltomaa ◽  
Pauliina Salmi
Keyword(s):  
Fatty Acids ◽  
Polyunsaturated Fatty Acids ◽  
Growth Phase ◽  
Essential Fatty Acids ◽  
Late Summer ◽  
Dry Weight ◽  
Stationary Growth Phase ◽  
Epa And Dha ◽  
Average Proportion ◽  
Aquatic Food

Phytoplankton synthesizes essential ω-3 and ω-6 polyunsaturated fatty acids (PUFA) for consumers in the aquatic food webs. Only certain phytoplankton taxa can synthesize eicosapentaenoic (EPA; 20:5ω3) and docosahexaenoic acid (DHA; 22:6ω3), whereas all phytoplankton taxa can synthesize shorter-chain ω-3 and ω-6 PUFA. Here, we experimentally studied how the proportion, concentration (per DW and cell-specific), and production (µg FA L−1 day−1) of ω-3 and ω-6 PUFA varied among six different phytoplankton main groups (16 freshwater strains) and between exponential and stationary growth phase. EPA and DHA concentrations, as dry weight, were similar among cryptophytes and diatoms. However, Cryptomonas erosa had two–27 times higher EPA and DHA content per cell than the other tested cryptophytes, diatoms, or golden algae. The growth was fastest with diatoms, green algae, and cyanobacteria, resulting in high production of medium chain ω-3 and ω-6 PUFA. Even though the dinoflagellate Peridinium cinctum grew slowly, the content of EPA and DHA per cell was high, resulting in a three- and 40-times higher production rate of EPA and DHA than in cryptophytes or diatoms. However, the production of EPA and DHA was 40 and three times higher in cryptophytes and diatoms than in golden algae (chrysophytes and synyrophytes), respectively. Our results show that phytoplankton taxon explains 56–84% and growth phase explains ~1% of variation in the cell-specific concentration and production of ω-3 and ω-6 PUFA, supporting understanding that certain phytoplankton taxa play major roles in the synthesis of essential fatty acids. Based on the average proportion of PUFA of dry weight during growth, we extrapolated the seasonal availability of PUFA during phytoplankton succession in a clear water lake. This extrapolation demonstrated notable seasonal and interannual variation, the availability of EPA and DHA being prominent in early and late summer, when dinoflagellates or diatoms increased.

Effect of triglycerides on the production of lipids and lipase by Mucor hiemalis

1983 ◽  
Vol 29 (6) ◽  
pp. 664-669 ◽  
Author(s):  
M. Waheed Akhtar ◽  
A. Qayyum Mirza ◽  
M. Nadeem Nawazish ◽  
M. I. D. Chughtai
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Growth Phase ◽  
Lipase Activity ◽  
Dry Weight ◽  
Fermentation Medium ◽  
Lipase Production ◽  
Mucor Hiemalis ◽  
Sterol Esters ◽  
Ethanolamine Phosphatidyl

The effect of triglycerides on the growth of Mucor hiemalis and the production of lipase and mycelial lipids was studied. Addition of 1% triglycerides to the fermentation medium was best for the mycelial as well as the broth lipase production. The added triglycerides seemed to be utilized through the formation of free fatty acids, and towards the end of the growth phase most of the triglycerides and their hydrolysis products were utilized. The mycelial lipase activity was maximum (66 U/g dry mycelium) at the end of the growth phase, while the maximal broth lipase activity (204 U/100 mL) was achieved after the cell lysis had started. The lipids produced per gram mycelia were high initially (260 mg/g dry weight at 48 h), reducing gradually later. With increase in growth the maximum mycelial lipids per 100 mL of culture medium was obtained after 96 h (176 mg/100 mL). The various fractions detected in the mycelial lipid extracts were sterol esters, triglycerides, free fatty acids, diglycerides, sterols, monoglycerides, phosphatidyl ethanolamine, phosphatidyl choline, and small amounts of an unknown polar lipid at all the stages of fermentation studied. Proportion between total neutral and total polar lipids remained nearly constant throughout fermentation.

scholarly journals DETERMINATION OF OPTIMAL ALGAE CONCENTRATION FOR CONTINUOUS GROWTH OF Scenedesmus sp. IN CHU AND MODIFIED CHU MEDIA

2014 ◽  
Vol 13 (2) ◽  
pp. 52
Author(s):  
K. R. Santos ◽  
A. B. Mariano
Keyword(s):  
Cost Reduction ◽  
Research Approach ◽  
Continuous Mode ◽  
Continuous Growth ◽  
Dry Biomass ◽  
The Cost ◽  
Interesting Alternative ◽  
Number Of Cells ◽  
Made In

The high cost of production in the cultivation of microalgae in photobioreactors is a barrier to be overcome, therefore is necessary to search to reduce the cost of cultivation. The objectives of this work are to compare the growth of the microalgae Scenedesmus sp. being cultivated in CHU medium and in an alternative medium composed mainly of fertilizer and to establish guidelines for growth under continuous mode. The research approach consisted on growing the microalgae in Erlenmeyer type photobioreactors and producing thegrowth curves for both media. The comparisons between the two, were made based upon three parameters: dry biomass, absorbance, and total lipid quantity. The experiments were made in triplicates in order to quantify the uncertainty in the measurements. The comparison of the cultivation in both media suggest that the modification of the chemical nutrients by fertilizer did not produce significant changes in the number of cells, dry biomass and lipids. In spite of that, the modification resulted in 20% cost reduction in the growth medium. In this way, the substitution of conventional nutrients by fertilizers, constitute an interesting alternative for the production of biomass from microalgae leading to a cost reduction. The results are used to develop strategies for continuous growth.

scholarly journals The influence of gibberellic acid and kinetin on the growth of Scenedesmus quadricauda (Turp.) Breb.

2015 ◽  
Vol 44 (3) ◽  
pp. 415-421 ◽  
Author(s):  
J. Buczek ◽  
G. Kubik-Dorosz ◽  
E. Tatkowska
Keyword(s):  
Gibberellic Acid ◽  
Growth Phase ◽  
Protein Level ◽  
Dry Weight ◽  
Cell Number ◽  
Scenedesmus Quadricauda ◽  
Phase Cell ◽  
Cell Multiplication ◽  
Initial Growth ◽  
Later Phase

The influence of gibberellic acid (GA<sub>3</sub>) and of kinetin (6-furfurylamino purine) on the increment of cell number increase in dry weight and upon protein level in <i>Scenedesmus quadricauda</i> (Turp.) Bréb. was studied. It was found that 10<sup>-7</sup> M GA<sub>3</sub> stimulates at the same time cell growth and dry weight increase of the algae. No influence of GA<sub>3</sub> upon the protein content was observed. Kinetin of 10<sup>-</sup> M concentration stimulates in the initial growth phase cell multiplication and increases the protein level. This substance promotes the increment in dry weight however in the later phase of growth. Furthermore kinetin prolongs the viability of algae, extending the growth phase.

On the physiology of a fungus symbiotic with orchids

1975 ◽  
Vol 53 (2) ◽  
pp. 144-155 ◽  
Author(s):  
Gaëtan Harvais ◽  
Ain Raitsakas
Keyword(s):  
Glutamic Acid ◽  
Aspartic Acid ◽  
Growth Phase ◽  
Culture Media ◽  
Dry Weight ◽  
Active Growth ◽  
Mycorrhizal Associations ◽  
The Media ◽  
Aeration Conditions ◽  
Ethanol Extracts

A fungus (Rs10) symbiotic with orchids was grown in axenic liquid-still culture on mineral–sugar media. Dextrose was limiting at 1% and 2%, with mycelium dry weights directly proportional to the amount of sugar in the medium, but not at 3%. Sucrose gave similar results and was converted into reducing sugars, in the medium, in excess of utilization. With 3% sugar growth was not much better than with 2%, and daily dry weight values were more variable after the active growth phase. With 1% and 2% dextrose in the media, and 10, 20, and 30 ml/flask, dry weight was not affected by the different aeration conditions. Inocula failed to grow on media with pH 3.0, but growth seemed normal with pH 4.5. Ninhydrin-positive substances were not released in the culture media but were found in ethanol extracts of the mycelium. They were more abundant during the active growth phase and on media with 1% vs. 2% dextrose; with less sugar, high levels were maintained for longer periods. They consisted mainly of glutamic acid, glutamine, and aspartic acid, with some fluctuations in concentration related to growth phase. Metabolism seemed different on media with ammonium + nitrate vs. nitrate alone as nitrogen source. The hyphal wall contained chitin.Protocorms of Dactylorhiza purpurella (an orchid with which Rs10 is symbiotic) were grown on eight nutrient media with one amino acid in each, until only the latter were depleted. The best results were with glutamic acid, ornithine, and arginine, followed by aspartic acid and glycine. Alanine, serine, and lysine were toxic. N-acetyl-D-glucosamine derived from chitin was drip-fed to other cultures. It was ineffective at low and toxic at high concentrations.Implications of the results relating to mycorrhizal associations are briefly discussed.

Steve & Barry's: To Save or Not To Save?

2017 ◽  
pp. 1-14
Author(s):  
Michael Mazzeo ◽  
Ariel Shwayder ◽  
Sachin Waikar
Keyword(s):  
Business Model ◽  
Growth Phase ◽  
Business Strategy ◽  
Private Equity ◽  
Growth Strategy ◽  
Economic Conditions ◽  
Product Positioning ◽  
University Campuses ◽  
Before And After ◽  
A Chain

Steve & Barry's grew rapidly in the mid-2000s, transitioning from a chain of small stores selling inexpensive collegiate-branded merchandise near university campuses into a $1 billion mall-based giant selling a wide variety of low-priced, celebrity-endorsed apparel. While the company had a wide following, elements of its growth strategy—potentially exacerbated by economic conditions—contributed to its quick downfall. By 2008 Steve & Barry's had declared bankruptcy, and various private equity firms were investigating whether some or all of the company should be saved. This requires analyzing the underlying business strategy pursued by Steve & Barry's before and after its growth phase and specifically diagnosing the explanations for its failure.This case presents an initially successful firm whose product positioning, marketing, financial, organizational, and operations strategies are highly complementary. In analyzing the case, students will identify how the complementarities broke down during the firm's growth phase, ultimately precipitating its downfall. The diagnosis may reveal elements of the firm's strategy that are worth saving, or suggest related opportunities for profitability using a similar business model and approach.

Antibiotic production, accumulation of intracellular carbon reserves, and sporulation in Micromonospora echinospora (ATCC 15837)

2001 ◽  
Vol 47 (2) ◽  
pp. 148-152 ◽  
Author(s):  
Paul A Hoskisson ◽  
Glyn Hobbs ◽  
George P Sharples
Keyword(s):  
Growth Phase ◽  
Exponential Growth ◽  
Antibiotic Production ◽  
Cell Mass ◽  
Significant Proportion ◽  
Dry Weight ◽  
Exponential Growth Phase ◽  
Lipid Levels ◽  
Micromonospora Echinospora ◽  
Sporulation Phase

The physiology of the actinomycete Micromonospora echinospora was examined during growth. Biphasic accumulation of glycogen occurred, initially during the early exponential growth phase, and again following the onset of sporulation at 120 h. Lipid levels increased during growth eventually representing 25% of the cell mass. A significant proportion of the lipid was found to be in the form of triacylglycerols, which were found to accumulate markedly during the sporulation phase. The disaccharide trehalose was also found to accumulate during growth with levels rising to 5% of the dry weight during the mycelial production phase, then remaining constant during sporulation. Antibiotic was produced transiently by the cultures over the period preceding sporulation.Key words: Micromonospora, glycogen, trehalose, lipids, triacylglycerol.

scholarly journals Accumulation of 10 Fluoroquinolones by Wild-Type or Efflux Mutant Streptococcus pneumoniae

2002 ◽  
Vol 46 (3) ◽  
pp. 813-820 ◽  
Author(s):  
Laura J. V. Piddock ◽  
M. M. Johnson
Keyword(s):  
Molecular Weight ◽  
Streptococcus Pneumoniae ◽  
Growth Phase ◽  
Dry Weight ◽  
The Other ◽  
Free Form ◽  
Wild Type ◽  
Significant Difference ◽  
Carbonyl Cyanide ◽  
Presence And Absence

ABSTRACT A method for measuring fluoroquinolone accumulation by Streptococcus pneumoniae was rigorously examined. The accumulation of ciprofloxacin, clinafloxacin, gatifloxacin, grepafloxacin, levofloxacin, moxifloxacin, norfloxacin, ofloxacin, sitafloxacin, and trovafloxacin in the presence and absence of either carbonyl cyanide m-chlorophenyl-hydrazone (CCCP) or reserpine was determined for two wild-type fluoroquinolone-susceptible capsulated S. pneumoniae strains (M3 and M4) and the noncapsulated strain R6. Two efflux mutants, R6N (which overexpresses PmrA) and a mutant of M4, M22 (no expression of PmrA), were also examined. Essentially, the fluoroquinolones fell into two groups. (i) One group consisting of ciprofloxacin, grepafloxacin, and norfloxacin accumulated to 72 to 92 ng/mg (dry weight) of cells in all strains. (ii) The remainder of the agents accumulated to 3 to 30 ng/mg (dry weight) of cells. With a decrease in hydrophobicity, there was a decrease in the concentration accumulated. With an increase in the molecular weight of the free form of each agent, there was also a decrease in the concentration accumulated. The strains differed in their responses to reserpine and CCCP. For the three fluoroquinolone-susceptible strains, only reserpine had a significant effect upon accumulation of moxifloxacin and clinafloxacin by M3 and showed no effect for the other agents and strains. For M3 and M4, CCCP enhanced the concentration of ciprofloxacin and norfloxacin accumulated, whereas for R6, the effect was only statistically significant for ofloxacin. Efflux mutant M22 accumulated less ciprofloxacin, gatifloxacin, and ofloxacin than M4 did. M22 accumulated more norfloxacin than M4 did. Reserpine and CCCP had variable effects as for the other strains. Differences in the accumulation of fluoroquinolones by R6 and R6N were highly dependent upon growth phase, and only for norfloxacin was there a significant difference between two strains.

Sign in / Sign up

Export Citation Format

Share Document