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1.
Mojeer Hasan Mohd Azhar Hina Nangia Prakash Chandra Bhatt 《Preparative biochemistry & biotechnology》2016,46(2):116-122
In this study astaxanthin production by Phaffia rhodozyma was enhanced by chemical mutation using ethyl methane sulfonate. The mutant produces a higher amount of astaxanthin than the wild yeast strain. In comparison to supercritical fluid technique, high-pressure homogenization is better for extracting astaxanthin from yeast cells. Ultrasonication of dimethyl sulfoxide, hexane, and acetone-treated cells yielded less astaxanthin than β-glucanase enzyme-treated cells. The combination of ultrasonication with β-glucanase enzyme is found to be the most efficient method of extraction among all the tested physical and chemical extraction methods. It gives a maximum yield of 435.71 ± 6.55 µg free astaxanthin per gram of yeast cell mass. 相似文献
2.
Effect of acetic acid on astaxanthin production by Phaffia rhodozyma 总被引:10,自引:0,他引:10
Summary Low concentrations of acetic acid decreased the growth rate of and astaxanthin production by Phaffia rhodozyma on glucose, with growth completely inhibited by 2 g acetic acid/l. Using H2SO4 for pH control after sugar depletion caused a decline in the biomass concentration, whereas using acetic acid as titrant resulted in an increase in the biomass with a high astaxanthin content of 1430 g/g cells. An extended culture with a continuous glucose feed failed to maintain a high astaxanthin content. 相似文献
3.
An insight into the mechanism of protein separation by colloidal gas aphrons (CGA) generated from ionic surfactants 总被引:1,自引:0,他引:1
Fuda E Jauregi P 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2006,843(2):317-326
Colloidal gas aphrons (CGA), which are surfactant stabilised microbubbles, have been previously applied for the recovery of proteins from model mixtures and a few studies have demonstrated the potential of these dispersions for the selective recovery of proteins from complex mixtures. However there is a lack of understanding of the mechanism of separation and forces governing the selectivity of the separation. In this paper a mechanistic study is carried out to determine the main factors and forces influencing the selectivity of separation of whey proteins with CGA generated from ionic surfactants. Two different separation strategies were followed: (i) separation of lactoferrin and lactoperoxidase by anionic CGA generated from a solution of sodium bis-(2-ethyl hexyl) sulfosuccinate (AOT); (ii) separation of beta-lactoglobulin by cationic CGA generated from a solution of cetyltrimethylammonium bromide (CTAB). Separation results indicate that electrostatic interactions are the main forces determining the selectivity however these could not completely explain the selectivities obtained following both strategies. Protein-surfactant interactions were studied by measuring the zeta potential changes on individual proteins upon addition of surfactant and at varying pH. Interestingly strongest electrostatic interactions were measured at those pH and surfactant to protein mass ratios which were optimum for protein separation. Effect of surfactant on protein conformation was determined by measuring the change in fluorescence intensity upon addition of surfactant at varying pH. Differences in the fluorescence patterns were detected among proteins which were correlated to differences in their conformational features which could in turn explain their different separation behaviour. The effect of conformation on selectivity was further proven by experiments in which conformational changes were induced by pre-treatment of whey (heating) and by storage at 4 degrees C. Overall it can be concluded that separation of proteins by ionic CGA is driven mainly by electrostatic interactions however conformational features will finally determine the selectivity of the separation with competitive adsorption having also an effect. 相似文献
4.
Hendrik Schewe Andrea Kreutzer Isabell Schmidt Christian Schubert Jens Schrader 《Biotechnology and Bioprocess Engineering》2017,22(3):319-326
Astaxanthin additions to animal diets predominantly serve as colorization aid to satisfy consumer expectations and desire for a consistent product with familiar coloration, e.g. the characteristic pink colorization of the flesh of species being produced by aquaculture. The heterobasidiomycetous yeast Phaffia rhodozyma (Xanthophyllomyces dendrorhous) can be used as natural feed source of astaxanthin. However, currently, the majority of astaxanthin used for the feed market is produced by chemical synthesis. We present a further step in direction of a competitive production of natural astaxanthin in an optimized bioprocess with non-genetically modified Phaffia rhodozyma. After medium optimization AXJ-20, a mutant strain of P. rhodozyma wild-type strain ATCC 96594, was able to grow to a cell dry weight concentration of over 114 g per kg of culture broth in a fed-batch process. In this bioprocess, where pH was lowered from 5.5 to 3.5 during the maturation phase, AXJ-20 produced the highest value reported for astaxanthin production with P. rhodozyma up to now: 0.7 g astaxanthin per kg of culture broth with a space-time-yield of 3.3 mg astaxanthin per kg of culture broth per hour. Lowering the pH during the bioprocess and increasing trace element and vitamin concentrations prevented loss of cell dry weight concentration in the maturation phase and proved to be critical for astaxanthin concentration and purity. 相似文献
5.
L. Rubinstein A. Altamirano L. Ducrey Santopietro M. Baigorí L. I. C. de Figueroa 《Folia microbiologica》1998,43(6):626-630
Mutagenic treatment with N-methyl-N′-nitro-N-nitrosoguanidine (MNNG) inPhaffia rhodozyma generated 15 mutants with a wide diversity of color variants ranging from white to dark red. Characterization of the mutants
by absorption spectra, TLC and HPLC was performed. Two categories could be distinguished: astaxanthin hyperproducing and astaxanthin
hypoproducing mutants. Hyperproducing mutants exhibited considerable increases in astaxanthin content whereas hypoproducing
mutants showed higher β-carotene contents than the wild-type strain. The characterization of carotenoid mutants inP. rhodozyma could contribute to the knowledge of the biosynthetic pathway of astaxanthin production of this microorganism. 相似文献
6.
Temperature and pH had only a slight effect on the astaxanthin content of a Phaffia rhodozyma mutant, but influenced the maximum specific growth rate and cell yield profoundly. The optimum conditions for astaxanthin production were 22°C at pH 5.0 with a low concentration of carbon source. Astaxanthin production was growth-associated, and the volumetric astaxanthin concentration gradually decreased after depletion of the carbon source. The biomass concentration decreased rapidly during the stationary growth phase with a concomitant increase in the cellular content of astaxanthin. Sucrose hydrolysis exceeded the assimilation rates of D-glucose and D-fructose and these sugars accumulated during batch cultivation. D-Glucose initially delayed D-fructose uptake, but D-fructose utilization commenced before glucose depletion. In continuous culture, the highest astaxanthin content was obtained at the lowest dilution rate of 0.043 h–1. The cell yield reached a maximum of 0.48 g cells·g–1 glucose utilized between dilution rates of 0.05 h–1 and 0.07 h–1 and decreased markedly at higher dilution rates.
Correspondence to: J. C. Du Preez 相似文献
7.
Schmidt I Schewe H Gassel S Jin C Buckingham J Hümbelin M Sandmann G Schrader J 《Applied microbiology and biotechnology》2011,89(3):555-571
The oxygenated β-carotene derivative astaxanthin exhibits outstanding colouring, antioxidative and health-promoting properties
and is mainly found in the marine environment. To satisfy the growing demand for this ketocarotenoid in the feed, food and
cosmetics industries, there are strong efforts to develop economically viable bioprocesses alternative to the current chemical
synthesis. However, up to now, natural astaxanthin from Haematococcus pluvialis, Phaffia rhodozyma or Paracoccus carotinifaciens has not been cost competitive with chemically synthesized astaxanthin, thus only serving niche applications. This review
illuminates recent advances made in elucidating astaxanthin biosynthesis in P. rhodozyma. It intensely focuses on strategies to increase astaxanthin titers in the heterobasidiomycetous yeast by genetic engineering
of the astaxanthin pathway, random mutagenesis and optimization of fermentation processes. This review emphasizes the potential
of P. rhodozyma for the biotechnological production of astaxanthin in comparison to other natural sources such as the microalga H. pluvialis, other fungi and transgenic plants and to chemical synthesis. 相似文献
8.
The resistance to killing by free radicals of two mutants ofPhaffia rhodozyma was determined. Mutant 5–7 did not produce astaxanthin but produced β-carotene, while mutant 3–4 did not produce any carotenoid
pigments. The resistance of mutant 5–7 was the same as that of the wild type but mutant 3–4 was rapidly killed. Carotenoid
pigments increased the resistance to killing by free radicals. We investigated the effects of free radicals, generated by
H2O2 and Fe2+ added to the medium, on wild-type cells and mutants ofP. rhodozyma. Unpigmented mutants of basidiomycetous yeasts (Rhodotorula spp. and others) are more susceptible to killing by UV-irradiation than the pigmented, wild-type strains. Therefore, we investigated
the effect of free radicals on a similar basidiomycetous yeast,P. rhodozyma, a species of economic importance, in the biological production of astaxanthin. 相似文献
9.
Colloidal gas aphrons: A novel approach to protein recovery 总被引:3,自引:0,他引:3
Sebba (1987) defined colloidal gas aphrons (CGA) as microbubbles stabilized by surfactant layers, which are created by stirring surfactant solutions at speeds greater than a critical value. A high shear impeller is used for stirring and critical values for the impeller speed must be exceeded to create these stable gas liquid dispersions (typically >5000 rpm). Although there have been no previous reports of direct protein recovery using CGA, it is likely that, with appropriate choice of surfactant, proteins should adsorb to these surfactant bubbles by means of electrostatic and/or hydrophobic interactions. This is the basis of this study, in which the use of CGA for protein recovery from aqueous solution is considered. A surfactant which has been characterized previously for generation of CGA was chosen (Jauregi et al., 1997), i.e., the anionic surfactant sodium bis-(2-ethyl hexyl) sulfosuccinate (AOT). Lysozyme, a well-characterized protein, was chosen as the protein to be recovered. Lysozyme was recovered successfully from aqueous solution using CGA generated from AOT. At optimum conditions, lysozyme recovery, enrichment ratio, and separation ratio were 95%, 19 and 302 respectively, with enzyme activity maintained. These results indicate the exciting potential of this technique. A wide range of process conditions including initial concentration of protein and surfactant, surfactant/protein molar ratio, pH, and ionic strength were considered. High recoveries and enrichments were generally obtained at protein concentrations =0.41 mg/mL, and surfactant concentrations >0.11 mg/mL. However, at high ionic strength (0.29M) poor separation and recoveries were obtained at low protein concentrations (counter-ions diminishing electrostatic interactions between protein and aphrons at this condition). In general, (ns/np)a was determined to be between 10 and 16 for experiments in which high levels of recovery/separation parameters were found. For most conditions, protein precipitation was observed; however, this precipitate could be resolubilized without loss of enzyme activity. 相似文献
10.
Nanjundaswamy Ananda Praveen V. Vadlani 《Journal of industrial microbiology & biotechnology》2010,37(11):1183-1192
Whole stillage—a co-product of grain-based ethanol—is used as an animal feed in the form of dried distiller’s grain with solubles
(DDGS). Since animals cannot synthesize carotenoids and animal feed is generally poor in carotenoids, about 30–120 ppm of
total carotenoids are added to animal feed to improve animal health, enhance meat color and quality, and increase vitamin
A levels in milk and meat. The main objective of this study was to produce carotenoid (astaxanthin and β-carotene)-enriched
DDGS by submerged fermentation of whole stillage. Mono- and mixed cultures of red yeasts, Phaffia rhodozyma (ATCC 24202) and Sporobolomyces roseus (ATCC 28988), were used to produce astaxanthin and β-carotene. Media optimization was carried out in shake flasks using response
surface methodology (RSM). Macro ingredients, namely whole stillage, corn steep liquor and glycerol, were fitted to a second-degree
polynomial in RSM. Under optimized conditions, astaxanthin and β-carotene yields in mixed culture and P. rhodozyma monoculture were 5 and 278, 97, and 275 μg/g, respectively, while S. roseus produced 278 μg/g of β-carotene. Since the carotenoid yields are almost twice the quantity used in animal feed, the carotenoid-enriched
DDGS has potential application as “value-added animal feed or feed blends.” 相似文献
11.
Summary Alfalfa residual juice (ARJ) supported good growth of the yeast Phaffia rhodozyma but formation of astaxanthin was inhibited. Supplementary nutrients did not reverse the inhibition, indicating that the the juice probably contained some inhibitor of astaxanthin biosynthesis. Six strains of P. rhodozyma were tested and found to be susceptible to the inhibitory effects of the juice. Concentrations of ARJ above 1.25% (v/v) were inhibitory to pigmentation of the yeast. Above approximately 3.7%, total inhibition of astaxanthin formation was observed but some chromogenic components of the juice were adsorbed on Phaffia cells and appeared as artefacts in astaxanthin analyses. Phaffia biomass produced in ARJ showed greater susceptibility to autolysis than that produced in a peptone-glucose-salts medium. Supplementation of ARJ with glucose enhanced yield of cell mass and minimised the autolytic phenomenon, and is potentially useful for producing Phaffia biomass for use as a source of single cell protein.Unsupplemented brewer's malt wort and molasses, separately and in a suitable combination, were compared with ARJ and were found suitable for growth and pigmentation of P. rhodozyma. 相似文献
12.
Domínguez-Bocanegra AR Ponce-Noyola T Torres-Muñoz JA 《Applied microbiology and biotechnology》2007,75(4):783-791
Phaffia rhodozyma (now Xanthophyllomyces dendrorhous) and Haematococcus pluvialis are known as the major prominent microorganisms able to synthesize astaxanthin natural pigment. Important research efforts
have been made to determine optimal conditions for astaxanthin synthesis. When the focus is on astaxanthin production, the
maximal reported value of 9.2 mg/g cell is obtained within H. pluvialis grown on BAR medium, under continuous illumination (345 μmol photon m−2 s−1) and without aeration. Whereas fermentation by mutated R1 yeast grown on coconut milk produced 1,850 μg/g yeast. However,
when looking at astaxanthin productivity, the picture is slightly different. The figures obtained with P. rhodozyma are rather similar to those of H. pluvialis. Maximal reported values are 170 μg/g yeast per day with a wild yeast strain and 370 μg/g yeast per day with mutated R1 yeast.
In the case of H. pluvialis, maximal values ranged from 290 to 428 μg/g cell per day depending on the media (BG-11 or BAR), light intensity (177 μmol
photon m−2 s−1), aeration, etc. The main aim of this work was to examine how astaxanthin synthesis, by P. rhodozyma and H. pluvialis, could be compared. The study is based on previous works by the authors where pigment productions have been reported. 相似文献
13.
Jagurti Jadhav Sruba Dutta Sandeep Kale 《Preparative biochemistry & biotechnology》2018,48(3):234-241
Glycolipids are one of the major classes of biosurfactants in which the rhamnolipids are best studied. The present work investigates the optimization of inoculum age and batch time for maximizing the yield of rhamnolipid from Pseudomonas aeruginosa (MTCC 2453). The yield and titer of rhamnolipids were maximum in the fermentation batch with an inoculum age of 24?hr. Batch time studies were performed on biomass production, rhamnolipid production, and sunflower oil utilization. The maximum yield of rhamnolipid was achieved at 96?hr when the culture cells were in the late exponential/early stationary phase. At optimum substrate concentration, maximum yield of 10.8?g/L was achieved. Further, downstream processing of crude rhamnolipid from broth using organic solvent extraction and subsequent purification using adsorption chromatography was done. In this study, chromatographic method was developed for purification of rhamnolipid by adsorption phenomena with more than 88.7% purity and 86.5% recovery. The present study provides new perspective on concepts involving separation by adsorption. Further antimicrobial properties and surfactant properties were studied for rhamnolipid production. 相似文献
14.
An-Feng Xiao Hui Ni Hui-Nong Cai Li-Jun Li Wen-Jin Su Qiu-Ming Yang 《World journal of microbiology & biotechnology》2009,25(11):2029-2034
Phaffia rhodozyma is one of the most important natural sources of the carotenoid astaxanthin, and the key process for extracting intracellular astaxanthin is disrption of the thick cell wall. In this work, an improved process for cell disruption and astaxanthin extraction from Phaffica rhodozyma was studied using an autoclave at low acid concentration. Under the optimum conditions (HCl 0.5 M and autoclave pressure 0.1 Mpa, 15 min), the relative residual astaxanthin and astaxanthin extractability reached 90.4 ± 3.5% and 84.8 ± 3.2%, respectively. The scanning electron microscopy pictures showed that all yeast cells shattered into fragments after autoclave treatment at low acid concentration condition, whereas cells were intact or partly broken after treatment by some other physical and chemical processes. This new method left no residual toxin and gavehigher extraction recovery, with good prospects for industrial use. 相似文献
15.
Lili Miao Yongxing Wang Shuang Chi Jiacong Yan Guohua Guan Bodi Hui Ying Li 《Journal of industrial microbiology & biotechnology》2010,37(6):595-602
A moderate-temperature mutant strain of the yeast Phaffia rhodozyma, termed MK19, was selected by 1-methyl-3-nitro-1-nitrosoguanidine (NTG) and Co60 mutagenesis. MK19 displayed fast cell growth
and elevated astaxanthin content at 25°C, whereas optimal temperature for growth and astaxanthin synthesis of wild-type P. rhodozyma was 17–21°C. Optimized astaxanthin yield for MK19 after 4 days culture in shaking flask at 25°C, determined by response surface
methodology, was 25.8 mg/l, which was 17-fold higher than that of the wild-type. MK19 was tolerant of high initial concentration
of glucose (>100 g/l) in optimized medium. Total fatty acid content of MK19 was much lower than that of the wild-type. Acetyl-CoA
is a common precursor of fatty acid and terpenoid biosynthesis, and it is possible that decreased fatty acid synthesis results
in transfer of acetyl-CoA to the carotenoid biosynthetic pathway. Our results indicate that astaxanthin content is negatively
correlated with fatty acid content in P. rhodozyma. Nutrient analysis showed that MK19 cells are enriched in lysine, vitamin E, and other rare nutrients, and have potential
application as fish food without nutritional supplementation. This moderate-temperature mutant strain is a promising candidate
for economical industrial-scale production. 相似文献
16.
Improvement of astaxanthin production by a newly isolated Phaffia rhodozyma mutant with low-energy ion beam implantation 总被引:1,自引:0,他引:1
Aims: Isolation, characterization and identification of Phaffia sp. ZJB 00010, and improvement of astaxanthin production with low‐energy ion beam implantation. Methods and Results: A strain of ZJB 00010, capable of producing astaxanthin, was isolated and identified as Phaffia rhodozyma, based on its physiological and biochemical characteristics as well as its internal transcribed spacer (ITS) rDNA gene sequence analysis. With low‐energy ion beam implantation, this wild‐type strain was bred for improving the yield of astaxanthin. After ion beam implantation, the best mutant, E5042, was obtained. The production of astaxanthin in E5042 was 2512 μg g?1 (dry cell weight, DCW), while the wild‐type strain was about 1114 μg g?1 (DCW), an increase of 125·5%. Moreover, the fermentation conditions of mutant E5042 for producing astaxanthin were optimized. The astaxanthin production under the optimized conditions was upscaled and studied in a 50‐l fermentor. Conclusions: A genetically stable mutant strain with high yield of astaxanthin was obtained using low‐energy ion beam implantation. This mutant may be a suitable candidate for the industrial‐scale production of astaxanthin. Significance and Impact of the Study: Astaxanthin production in Phaffia rhodozyma could be fficiently improved by low‐energy ion beam implantation, which is a new technology in the mutant breeding of micro‐organisms. The mutant obtained in this work could potentially be utilized in industrial production of astaxanthin. 相似文献
17.
Phaffia rhodozyma was isolated by Herman Phaff in the 1960s, during his pioneering studies of yeast ecology. Initially, the yeast was isolated from limited geographical regions, but isolates were subsequently obtained from Russia, Chile, Finland, and the United States. The biological diversity of the yeast is more extensive than originally envisioned by Phaff and his collaborators, and at least two species appear to exist, including the anamorph Phaffia rhodozyma and the teleomorph Xanthophyllomyces dendrorhous. The yeast has attracted considerable biotechnological interest because of its ability to synthesize the economically important carotenoid astaxanthin (3,3-dihydroxy-, -carotene-4,4-dione) as its major pigment. This property has stimulated research on the biology of the yeast as well as development of the yeast as an industrial microorganism for astaxanthin production by fermentation. Our laboratory has isolated several mutants of the yeast affected in carotenogenesis, giving colonies a vivid array of pigmentation. We have found that nutritional and environmental conditions regulate astaxanthin biosynthesis in the yeast, and have demonstrated that astaxanthin protects P. rhodozyma from damage by reactive oxygen species. We proposed in the 1970s that P. rhodozyma could serve as an economically important pigment source in animal diets including salmonids, lobsters, and the egg yolks of chickens and quail, in order to impart characteristic and desirable colors. Although P. rhodozyma/Xanthomyces dendrorhous has been studied by various researchers for nearly 30 years, it still attracts interest from yeast biologists and biotechnologists. There is a bright and colorful outlook for P. rhodozyma/X. dendrorhous from fundamental and applied research perspectives. 相似文献
18.
Yuichi Yamane Takashi Mikami Katsuya Higashida Toshihide Kakizono Naomichi Nishio 《Biotechnology Techniques》1996,10(7):529-534
Summary Near infrared reflectance spectroscopy (NIR) was employed to estimate the concentrations of cells, astaxanthin and glucose in the culture broth of Phaffia rhodozyma. The culture broth (119 samples) was directly subjected for NIR analysis without any pretreatment. When the data obtained by NIR were compared with those obtained by conventional methods, high correlation coefficients were obtained: 0.98 for cells, 0.99 for astaxanthin and 0.94 for glucose. These results suggest that NIR analysis, which is very simple and requires only 3 to 5 mm for a sample, is applicable to monitor P. rhodozyma cultures. 相似文献
19.
Sawai H Na K Sasaki N Mimitsuka T Minegishi S Henmi M Yamada K Shimizu S Yonehara T 《Bioscience, biotechnology, and biochemistry》2011,75(12):2326-2332
This report describes the production of highly optically pure D-lactic acid by the continuous fermentation of Sporolactobacillus laevolacticus and S. inulinus, using a membrane-integrated fermentation (MFR) system. The optical purity of D-lactic acid produced by the continuous fermentation system was greater than that produced by batch fermentation; the maximum value for the optical purity of D-lactic acid reached 99.8% enantiomeric excess by continuous fermentation when S. leavolacticus was used. The volumetric productivity of the optically pure D-lactic acid was about 12 g/L/h, this being approximately 11-fold higher than that obtained by batch fermentation. An enzymatic analysis indicated that both S. laevolacticus and S. inulinus could convert L-lactic acid to D-lactic acid by isomerization after the late-log phase. These results provide evidence for an effective bio-process to produce D-lactic acid of greater optical purity than has conventionally been achieved to date. 相似文献
20.
Extraction and quantitation of astaxanthin from Phaffia rhodozyma 总被引:32,自引:0,他引:32
Summary The rapid, quantitative release of astaxanthin and other carotenoids from the yeast Phaffia
rhodozyma is described. Hashed cells are ruptured with dimethylsulfoxide (DMSO) and carotenoids extracted into an organic solvent. Extraction and spectrophotometric quantitation of total carotenoids is rapid, reproducible and only small volumes (0.1–2 ml) of culture are required. HPLC analysis in normal phase silica gel column indicates that astaxanthin comprises 65–95% of the total pigmented carotenoids of P.
rhodozyma. 相似文献