Factors favouring the accumulation of arabinitol in the yeast Debaryomyces hansenii

1985 ◽  
Vol 31 (5) ◽  
pp. 467-471 ◽  
Author(s):  
M. Fernanda Nobre ◽  
Milton S. da Costa

Culture conditions which lead to the intracellular accumulation of arabinitol were investigated in Debaryomyces hansenii. Arabinitol, detected in very low concentrations during the exponential phase of growth, accumulated during the stationary phase of growth in yeast extract – peptone – 1% (w/v) glucose medium. This polyol was retained intracellularly even after depletion of exogenous glucose, but was rapidly depleted during regrowth in fresh glucose medium. The accumulation of arabinitol was also favoured in media containing 1% (w/v) D-fructose, sucrose, L-arabinose, glycerol, and sodium acetate. High mannitol levels accumulated in stationary phase cells derived from growth in 1% (w/v) D-mannitol, and in these cultures only traces of arabinitol were detectable. Intracellular mannitol was also retained after the extracellular mannitol had been consumed, and was rapidly depleted during regrowth in glucose medium. Arabinitol did not accumulate in basal medium with no added carbon source, nor in media with nonmetabolizable carbon sources (D-arabinose or D-ribose). On the other hand, arabinitol accumulation was independent of the initial glucose concentration between 1% (w/v) and about 9% (w/v).

1985 ◽  
Vol 31 (11) ◽  
pp. 1061-1064 ◽  
Author(s):  
M. Fernanda Nobre ◽  
Milton S. da Costa

Growth of the yeast Debaryomyces hansenii in 1% (w/v) glucose medium containing NaCl or KCl resulted in the accumulation of glycerol during the exponential phase of growth and arabinitol during the stationary phase. Similar results were obtained during growth of the yeast in 12.5% (w/v) glucose, 25% glucose, 25% fructose, and 1% glucose plus 25% polyethylene glycol M.W.200 (PEG 200). The results indicate that the intracellular glycerol concentration increases concomitantly with the solute concentration of the growth medium, while the accumulation of arabinitol is less pronounced. Growth of the yeast in media containing meso-erythritol or D-mannitol as carbon sources without or with 1 M NaCl resulted in the pronounced inhibition of arabinitol accumulation because of the intracellular accumulation of the exogenous polyols. Mannitol accumulated primarily during the stationary phase, while erythritol accumulation occurred primarily during the exponential phase. The erythritol concentration attained very high levels during growth in media containing 1 M NaCl and effectively inhibited the accumulation of glycerol.


UNICIÊNCIAS ◽  
2019 ◽  
Vol 22 (3Esp) ◽  
pp. 25
Author(s):  
Daiane Felix Reis ◽  
Francisco Roberto da Silva Machado Junior ◽  
Joana Da Costa Ores ◽  
Ailton Cesar Lemes ◽  
Carlos Andre Veiga Burkert ◽  
...  

O crescimento celular da microalga de água doce Haematococcus pluvialis e a bioprodução de carotenoides são influenciados pelas diferentes condições de cultivo, como deficiência de nutrientes, iluminância, aeração, agitação, temperatura e pH, alterando sua morfologia celular e produzindo cistos avermelhados (carotenogênese). A aeração nos cultivos de microalgas está relacionada a alguns fatores que influenciam no crescimento celular. As microalgas absorvem e utilizam CO2 como a principal fonte de carbono no crescimento celular. Logo, a biossíntese de pigmentos pode ocorrer pela limitação do nitrogênio em presença de excesso de fontes de carbono. O objetivo desse trabalho foi investigar a influência do emprego de CO2 na aeração do cultivo da microalga Haematococcus pluvialis sob o crescimento celular e a bioprodução de carotenoides. No cultivo foi utilizado o meio mixotrófico BBM (Bold Basal Medium) e acetato de sódio, empregando 20% de inóculo em pH inicial de 7,0, aeração de 0,30 L.min-1, com 30% de injeção de CO2 uma vez ao dia durante 1 h, sob iluminância de 6 klux, à 25 ºC durante 22 dias. Nestas condições o crescimento celular alcançou o máximo de 1,13±0,39 g.L-1 (10 dias) e os carotenoides totais 2949,91±988,65 µg.g-1, onde foi observado que a suplementação de CO2 como fonte de carbono dissolvida no meio de cultivo pode influenciar o crescimento celular e os carotenoides totais. Palavras-chave: Microalga. Pigmento. Aeração. Cultivo. AbstractThe cellular growth of the freshwater microalgae Haematococcus pluvialis and the bioproduction of carotenoids are influenced by the different culture conditions, such as nutrient deficiency, illuminance, aeration, agitation, temperature and pH, altering its cellular morphology and producing reddish cysts (carotenogenesis). Aeration in microalgae cultures is related to some factors that influence cell growth. Microalgae absorb and utilize CO2 as the main source of carbon in cell growth. Therefore, the biosynthesis of pigments can occur by the limitation of nitrogen in the presence of excess carbon sources. The objective of this work was to investigate the influence of the use of CO2 on the aeration of the microalgae Haematococcus pluvialis under cell growth and bioproduction of carotenoids. In the culture, mixotrophic medium BBM (Bold Basal Medium) and sodium acetate were used, using 20% of inoculum at initial pH of 7.0, aeration of 0.30 L.min-1, with 30% of CO2 injection once a day for 1 h under 6 Klux illuminance at 25 ° C for 22 days. Under these conditions the cell growth reached a maximum of 1.13 ± 0.39 g. L-1 (10 days) and the total carotenoids 2949.91 ± 988.65 μg.g-1, where it was observed that CO2 supplementation as a source of carbon dissolved in the culture medium may influence cell growth and total carotenoids. Keywords: microalgae; pigment; aeration; cultivation. 


2014 ◽  
Vol 64 (Pt_3) ◽  
pp. 781-786 ◽  
Author(s):  
Maximo Sánchez ◽  
Martha-Helena Ramírez-Bahena ◽  
Alvaro Peix ◽  
María J. Lorite ◽  
Juan Sanjuán ◽  
...  

Strain S658T was isolated from a Lotus corniculatus nodule in a soil sample obtained in Uruguay. Phylogenetic analysis of the 16S rRNA gene and atpD gene showed that this strain clustered within the genus Phyllobacterium . The closest related species was, in both cases, Phyllobacterium trifolii PETP02T with 99.8 % sequence similarity in the 16S rRNA gene and 96.1 % in the atpD gene. The 16S rRNA gene contains an insert at the beginning of the sequence that has no similarities with other inserts present in the same gene in described rhizobial species. Ubiquinone Q-10 was the only quinone detected. Strain S658T differed from its closest relatives through its growth in diverse culture conditions and in the assimilation of several carbon sources. It was not able to reproduce nodules in Lotus corniculatus. The results of DNA–DNA hybridization, phenotypic tests and fatty acid analyses confirmed that this strain should be classified as a representative of a novel species of the genus Phyllobacterium , for which the name Phyllobacterium loti sp. nov. is proposed. The type strain is S658T( = LMG 27289T = CECT 8230T).


Homeopathy ◽  
2018 ◽  
Vol 108 (01) ◽  
pp. 043-053 ◽  
Author(s):  
José Mazón-Suástegui ◽  
Joan Salas-Leiva ◽  
Andressa Teles ◽  
Dariel Tovar-Ramírez

Background This research aimed to observe the effect of homeopathic treatments prepared from Vibrio parahaemolyticus and V. alginolyticus (H1) and commercial homeopathic medication Phosphoricum acidum and Silicea terra (H2) on the immune and antioxidant response in Seriola rivoliana juveniles under usual culture conditions and challenged with V. parahaemolyticus. Materials and Methods Quantitative polymerase chain reaction analysis was used to study changes in the expression of key genes related to immune response, cytokines (interleukin-1β [IL-1β]), adapter protein for cytokine release (MyD88) and piscidin and spectrophotometric techniques to analyze the activity of antioxidant superoxide dismutase (SOD) and catalase (CAT) enzymes in Seriola rivoliana juveniles at 30 (weaning stage [WS]) and 60 (early juveniles [EJ]) days post-hatching. Results The H1 treatment led to over-expression of the IL-1β and MyD88 genes in fish at WS and EJ with respect to control, contrary to the H2 treatment that led to under-expression of the IL-1β, MyD88 and piscidin genes at the EJ stage. In fish challenged with V. parahaemolyticus, both H1 and H2 led to over-expression of IL-1β and MyD88; H2 caused an over-expression of piscidin. The SOD activity was higher in H1 with respect to H2 and the control group. CAT remained relatively stable with both H1 and H2 treatments. Conclusions The results suggest that the overall effect of H1 was due to the presence of unknown antigens in low concentrations, while the response to H2—specifically during challenge—may have been due to a stimulating effect of nano-structures, prevailing from mother tincture after sequential dilution/succussion, in a pathway similar to that attributed to nano-vaccines.


2021 ◽  
pp. 3476-3486
Author(s):  
Alaa. M. Hasan ◽  
Ekhlas. A.J. ElKaaby ◽  
Rakad. M.Kh. AL-Jumaily

    The leading purpose of this work is the development of efficient culture conditions to induce calli from cabbage (Brassica oleracea var. capitata L.) under in vitro conditions. The mature seeds were surface sterilized with combinations of different concentrations of ethanol and NaOCl in different time durations and  were germinated on MS basal medium. The results revealed that the best sterilization method of cabbage seeds was by using 70% ethanol for one minute, followed by 15 min in 2% (NaOCl). Seedlings were used as donor sources for hypocotyls, cotyledon leaves, true leaves, and shoot tip explants. These explants were cultured on different combinations of cytokinins (TDZ, BAP, Ad) and auxins (IAA, NAA, 2, 4-D) then implanted in Murashige and Skoog (MS) media. 4 weeks after culturing, a significant difference was found among the explants in response to plant hormones. The maximum percentage of callus induction (100%) was using the combinations of 1 BAP + 1 2, 4-D, 1 BAP + 1 NAA, and 1 BAP + 2 2,4-D mg. l-1. In addition, explants responses varied and the hypocotyls showed a superior result (85.71 %) as compared to other explants. For callus fresh weight, the combination of 0.22 TDZ + 79.9 Ad mg. l-1    had a significant effect, causing the highest fresh weight (0.2745g), while control treatment gave the lowest mean of 0.0066 g. Data showed that cotyledon explants were significantly superior in giving highest callus fresh weight with the mean of 0.1723 g. On the other hand, hypocotyl explants gave the lowest mean, reaching 0.1542 g.


AMB Express ◽  
2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Juliana Lebeau ◽  
Thomas Petit ◽  
Laurent Dufossé ◽  
Yanis Caro

AbstractFungal naphthoquinones, like red bikaverin, are of interest due to their growing applications in designing pharmaceutical products. Though considerable work has been done on the elucidation of bikaverin biosynthesis pathway in Fusarium fujikuroi, very few reports are available regarding its bioproduction in F. oxysporum. We are hereby proposing a putative metabolic pathway for bikaverin bioproduction in a wild F. oxysporum strain by cross-linking the pigment profiles we obtained under two different fermentation conditions with literature. Naphthoquinone pigments were extracted with a pressurized liquid extraction method, and characterized by HPLC–DAD and UHPLC-HRMS. The results led to the conclusions that the F. oxysporum LCP531 strain was able to produce bikaverin and its various intermediates, e.g., pre-bikaverin, oxo-pre-bikaverin, dinor-bikaverin, me-oxo-pre-bikaverin, and nor-bikaverin, in submerged cultures in various proportions. To our knowledge, this is the first report of the isolation of these five bikaverin intermediates from F. oxysporum cultures, providing us with steady clues for confirming a bikaverin metabolic pathway as well as some of its regulatory patterns in the F. oxysporum LCP531 strain, based on the previously reported model in F. fujikuroi. Interestingly, norbikaverin accumulated along with bikaverin in mycelial cells when the strain grew on simple carbon and nitrogen sources and additional cofactors. Along bikaverin production, we were able to describe the excretion of the toxin beauvericin as main extrolite exclusively in liquid medium containing complex nitrogen and carbon sources, as well as the isolation of ergosterol derivate in mycelial extracts, which have potential for pharmaceutical uses. Therefore, culture conditions were also concluded to trigger some specific biosynthetic route favoring various metabolites of interest. Such observation is of great significance for selective production of pigments and/or prevention of occurrence of others (aka mycotoxins).


2013 ◽  
Vol 2 (1) ◽  
pp. 158 ◽  
Author(s):  
Dolar Pak ◽  
Arunachalam Muthaiyan ◽  
Robert S. Story ◽  
Corliss A. O'Bryan ◽  
Sun-Ok Lee ◽  
...  

<p>A fermentation study of three probiotic <em>Lactobacillus</em> strains was conducted on individual carbohydrates including glucose (GLU) high methoxy pectin (HMP), sugar beet pectin (SBP), fructooligosaccharide (FOS), galactooligosaccharide (GOS), and inulin agave (IA) as the sole carbon sources. It was observed that <em>Lactobacillus bulgaricus </em>(LB), <em>Lactobacillus casei</em> (LC) and <em>Lactobacillus delbruckii</em> (LD) achieved the highest growth rates when they were grown in the presence of GLU, FOS, and IA, but LB had a slower growth rate in these substrates compared to LC and LD. Only LC had a statistically significantly higher growth rate in GOS than in the basal medium which contained no carbohydrate source. Exposure to bile caused a significant reduction of log colony forming units/ml of all 3 strains, with LD grown in HMP exhibiting the highest survival followed by LC and LD grown in GLU, and LD grown on IA. Although HMP was not fermented by the test organisms, results indicate that HMP may in fact help certain probiotic bacteria to survive exposure to bile. Exposure to simulated gastric juices indicated that the studied <em>Lactobacilli</em> are tolerant to simulated gastric juice.</p>


1999 ◽  
Vol 65 (12) ◽  
pp. 5504-5509 ◽  
Author(s):  
M. Quirasco ◽  
A. López-Munguía ◽  
M. Remaud-Simeon ◽  
P. Monsan ◽  
A. Farrés

ABSTRACT Dextransucrase production by Leuconostoc mesenteroidesNRRL B-512F in media containing carbon sources other than sucrose is reported for the first time. Dextransucrases were analyzed by gel electrophoresis and by an in situ activity assay. Their polymers and acceptor reaction products were also compared by 13C nuclear magnetic resonance and high-performance liquid chromatography techniques, respectively. From these analyses, it was found that, independently of the carbon source, L. mesenteroides NRRL B-512F produced dextransucrases of the same size and product specificity. The 5′ ends of dextransucrase mRNAs isolated from cells grown under different culture conditions were identical. Based on this evidence, we conclude that dextransucrases obtained from cells grown on the various carbon sources result from the transcription of the same gene. The control of expression occurs at this level. The low dextransucrase yields from cultures in d-glucose ord-fructose and the enhancement of dextransucrase gene transcription in the presence of sucrose suggest that an activating phenomenon may be involved in the expression mechanism. Dextransucrase mRNA has a size of approximately 4.8 kb, indicating that the gene is located in a monocistronic operon. The transcription start point was localized 34 bp upstream from the ATG start codon. The −10 and −35 sequences found, TATAAT and TTTACA, were highly homologous to the only glycosyltransferase promoter sequence reported for lactic acid bacteria.


2017 ◽  
Vol 2017 ◽  
pp. 1-19 ◽  
Author(s):  
Iwona Gientka ◽  
Marek Kieliszek ◽  
Karolina Jermacz ◽  
Stanisław Błażejak

The search for efficient oleaginous microorganisms, which can be an alternative to fossil fuels and biofuels obtained from oilseed crops, has been going on for many years. The suitability of microorganisms in this regard is determined by their ability to biosynthesize lipids with preferred fatty acid profile along with the concurrent utilization of energy-rich industrial waste. In this study, we isolated, characterized, and identified kefir yeast strains using molecular biology techniques. The yeast isolates identified wereCandida inconspicua,Debaryomyces hansenii,Kluyveromyces marxianus,Kazachstania unispora, andZygotorulaspora florentina. We showed that deproteinated potato wastewater, a starch processing industry waste, supplemented with various carbon sources, including lactose and glycerol, is a suitable medium for the growth of yeast, which allows an accumulation of over 20% of lipid substances in its cells. Fatty acid composition primarily depended on the yeast strain and the carbon source used, and, based on our results, most of the strains met the criteria required for the production of biodiesel. In particular, this concerns a significant share of saturated fatty acids, such as C16:0 and C18:0, and unsaturated fatty acids, such as C18:1 and C18:2. The highest efficiency in lipid biosynthesis exceeded 6.3 g L−1.Kazachstania unisporawas able to accumulate the high amount of palmitoleic acid.


2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Gustavo Carvalho do Nascimento ◽  
Ryhára Dias Batista ◽  
Claudia Cristina Auler do Amaral Santos ◽  
Ezequiel Marcelino da Silva ◽  
Fabrício Coutinho de Paula ◽  
...  

β-fructofuranosidase (invertase) andβ-D-fructosyltransferase (FTase) are enzymes used in industrial processes to hydrolyze sucrose aiming to produce inverted sugar syrup or fructooligosaccharides. In this work, a blackAspergillussp. PC-4 was selected among six filamentous fungi isolated from canned peach syrup which were initially screened for invertase production. Cultivations with pure carbon sources showed that invertase and FTase were produced from glucose and sucrose, but high levels were also obtained from raffinose and inulin. Pineapple crown was the best complex carbon source for invertase (6.71 U/mL after 3 days of cultivation) and FTase production (14.60 U/mL after 5 days of cultivation). Yeast extract and ammonium chloride nitrogen sources provided higher production of invertase (6.80 U/mL and 6.30 U/mL, respectively), whereas ammonium nitrate and soybean protein were the best nitrogen sources for FTase production (24.00 U/mL and 24.90 U/mL, respectively). Fermentation parameters for invertase using yeast extract wereYP/S= 536.85 U/g andPP= 1.49 U/g/h. FTase production showed values ofYP/S= 2,627.93 U/g andPP= 4.4 U/h using soybean protein. The screening for best culture conditions showed an increase of invertase production values by 5.10-fold after 96 h cultivation compared to initial experiments (fungi bioprospection), while FTase production increased by 14.60-fold (44.40 U/mL) after 168 h cultivation.A. carbonariusPC-4 is a new promising strain for invertase and FTase production from low cost carbon sources, whose synthesized enzymes are suitable for the production of inverted sugar, fructose syrups, and fructooligosaccharides.


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