沼泽生红冬孢酵母生长及产类胡萝卜素培养条件的研究

通过单因素实验和正交实验对沼泽生红冬孢酵母生长和产类胡萝卜素的培养条件进行研究,最适培养条件为葡萄糖40 g/L,牛肉膏10 g/L,酵母膏10 g/L,NaCl 10 g/L,MgSO4.7H2O 0.1 g/L,K2HPO4 2 g/L,KH2PO4 2 g/L,初始pH 6.3,装液量为50 mL/250 mL,摇床转速170 r/min,培养温度为28℃,接种量为10%。在此发酵条件下,培养72 h后,沼泽生红冬孢酵母生物量和类胡萝卜素产量分别达到11.72 g/L和3.55 mg/L。     

粘红酵母发酵生产类胡萝卜素培养条件的优化

目的是通过测定不同条件下类胡萝卜素的产量找出粘红酵母发酵生产类胡萝卜素的最优条件。探讨了不同碳源、氮源对粘红酵母菌体生长和色素形成的影响,并通过正交实验确定了最佳条件组合。实验结果表明,最适发酵培养条件为：蔗糖40g/L、酵母粉20g/L、转速150r/min、装液量30mL/500mL、发酵时间84h。在此条件下,粘红酵母摇瓶发酵的生物量、类胡萝卜素含量及产量分别达15.17g/L、718.6μg/g、10.9mg/L,依次比初始发酵提高了1倍、7.4倍和15.8倍。发酵过程动态分析表明,84h色素产量达最高峰。     

红酵母类胡萝卜素高产菌株的筛选及其发酵生理学条件研究

从数株红酵母中选出了1株产类胡萝卜素能力较强的红酵母RY－98（生物量,类胡萝卜素含量和产量分别为19．9g/L,334.8ug/g和6．7mg/L);研究了该菌株产类胡萝卜素的最适营养与环境条件,获得了最佳的发酵生理学条件;葡萄糖40g/L,(NH4)2SO4 10g/L,酵母膏3g/L,蕃茄汁2mL/L,花生油0.5mL/L,接种量30mLL初始pH6.0和通气量（培养基装置040ml/250mL:,在此初步优化的培养条件下,红酵母RY－98经72小时摇瓶发酵其生物量,类胡萝卜素含量和产量分别可达26．8g/L,386.9ug/g和10．4mg/L,依次比初筛中提高了34．7％,15．6％,和55．2％。     

海洋红酵母Y2发酵产类胡萝卜素条件的研究

目的 对海洋红酵母Y2高产类胡萝卜素的发酵条件进行优化.方法 在摇瓶条件下,研究培养基成分和培养条件对海洋红酵母Y2生长和类胡萝卜素合成的影响,同时进行海洋红酵母Y2发酵过程的动态分析.结果 海洋红酵母Y2优化培养基组合为葡萄糖45 g/L,蔗糖15 g/L,酵母粉5 g/L,蛋白胨2.5 g/L,磷酸二氢钾1 g/L,磷酸二氢钠3 g/L,硫酸镁7.5 g/L,氯化钾3 g/L,氯化钠5 g/L.最适培养参数为:温度20℃,培养基初始pH为5,接种量为10％,250 mL摇瓶装液量为10～50 mL.类胡萝卜素的合成主要集中在对数生长期和稳定期.海洋红酵母Y2最适收获时间为72 h.种龄以36 h为宜.结论 利用优化培养基,在最适条件下培养海洋红酵母Y2,类胡萝卜素产量达到4.97 mg/L,比基础培养基提高了60.32％.     

红酵母类胡萝卜素形成的生理学研究

从数株红酵母中选出 1株产类胡萝卜素能力较强的红酵母RY 98(生物量、类胡萝卜素含量和产量分别为19.9g/L ,334 .8μg/ g和 6 .7mg/L) ;研究了该菌株产类胡萝卜素的最适营养与环境条件 ,获得了最佳的发酵生理学条件 :葡萄糖 40 g/L ,(NH4 ) 2 SO4 10 g/L ,酵母膏 3g/L ,蕃茄汁 2mL/L ,花生油 0 .5mL/L ,接种量 30mL/L ,初始pH 6 .0和通气量 (培养基装量 ) 4 0mL/ 2 5 0mL。在此初步优化的培养条件下 ,红酵母RY 98经 72h摇瓶发酵其生物量、类胡萝卜素含量和产量分别可达 2 6 .8g/L ,386 .9μg/ g和 10 .4mg/L ,依次比初筛中提高了 34 .7% ,15 .6 %和 5 5 .2 %。     

一株法夫酵母虾青素高产菌株的生产性能

为了评价虾青素高产菌株-法夫酵母JMU-MVP14的生产性能及建立虾青素高产发酵技术,通过测定糖、生物量、虾青素产量、总类胡萝卜素产量等发酵参数,用摇瓶试验对比了法夫酵母JMU-MVP14和出发菌株的差异,用7 L罐试验对比了pH值调控方式及补料培养基成分对发酵的影响,用1 m3罐试验评估了法夫酵母JMU-MVP14高密度发酵虾青素的产量水平。摇瓶发酵结果表明,法夫酵母JMU-MVP14虾青素及总类胡萝卜素的细胞产率分别达到6.01 mg/g及10.38 mg/g;7 L罐分批发酵试验结果表明,自动流加调     

云南星云湖酵母菌多样性及产类胡萝卜素的评价

【背景】星云湖属云南高原湖泊,对其酵母菌的多样性研究和产类胡萝卜素菌株的筛选有助于开发利用星云湖酵母菌资源。【目的】研究云南星云湖酵母菌群落结构多样性,筛选和评价产类胡萝卜素活性菌株。【方法】采用膜过滤平置培养对星云湖水样进行酵母菌分离;应用26S rRNA D1/D2区域序列分析和形态特征及生理生化指标相结合,对分离获得的酵母菌进行鉴定;运用软件BIO-DAP分析酵母菌类群的多样性;采用酸热法提取类胡萝卜素,紫外分光光度计测定类胡萝卜素含量。【结果】从星云湖湖水中分离得到797株酵母菌,鉴定为18个属37个种。胶红酵母(Rhodotorula mucilaginosa)和Naganishia albida是优势种,分别占总菌株数的36.64%和28.86%;有28株酵母菌类胡萝卜素产量可达200μg/g细胞干重以上;有4株类胡萝卜素产量可达300μg/g细胞干重以上;粘红酵母(Rhodotorula glutinis) 2株、胶红酵母(Rhodotorula mucilaginosa)和Rhodosporidiobolus fluviale各1株。【结论】云南高原湖泊星云湖的酵母菌具有丰富的多样性,湖泊的营养化程度以及地理差异影响酵母菌群落的结构;红冬孢酵母属(Rhodosporidiobolus)和红酵母属(Rhodotorula)是星云湖类胡萝卜素产量可达300μg/g细胞干重以上的主要类群。有进一步开发研究的价值。     

法夫酵母高产虾青素的选育及发酵条件的优化

对法夫酵母原始菌株进行了紫外线－氯化锂复合诱变,获得了一株遗传性状稳定、在25℃条件下虾青素高产的菌株UL-40。其类胡萝卜素产量为7.10mg/L,经HPLC测定,其虾青素产量为643.97μg/g,比出发菌株提高了249.87%。利用SAS软件中的Plackett-Burman设计对发酵温度、初始pH值以及发酵培养基的八种组分进行优化组合,从中选出发酵温度、初始pH值和Corn steep liquor浓度为重要因素,通过响应面分析法建立了模型并从该模型中计算出在发酵温度为16.78℃、初始pH为4.73和CSL浓度为7.06mg/L时预测的最大响应值为3.9407mg/L,经实验证实此点的实测值为3.9261mg/L,证明模型是有效的并且存在极大值点。采用优化后的发酵条件及发酵培养基,法夫酵母生产虾青素的产量较原始发酵培养基提高了20.4%。     

逆境对红酵母发酵生产类胡萝卜素的促进作用

类胡萝卜素广泛存在于细菌、藻类、真菌和植物中,是一类具有重要的生理保健功能的呈黄色、橙红色或红色的多烯类化合物。考察了不同逆境条件,包括低温、低温处理时间、酸处理及高浓度盐处理对促进一株红酵母(Rhodotorulasp.)发酵生产类胡萝卜素的影响,并利用响应面分析方法研究了其交互作用。结果表明,低温,酸处理、高浓度盐的影响以及低温和酸处理、低温和高浓度盐以及低温处理时间和酸处理的交互作用对类胡萝卜素产量的影响均显著,在温度为15℃处理48 h,pH3.5,NaCl浓度为2 mol/L的条件下,类胡萝卜素最高产量达到31.04 mg/L,说明逆境对红酵母发酵生产类胡萝卜素具有促进作用。     

氮源种类及溶氧水平对锁掷酵母产类胡萝卜素组分的影响

在锁掷酵母（Sporidioboluspararoseus）发酵产类胡萝卜紊的过程中,发酵产物中类胡萝卜紊种类繁多,而且性质相似,加大了不同色素分离纯化的难度。为定向积累不同种类的类胡萝卜素,以本实验室保藏锁挪酵母JD-2为出发菌,研究了氮源种类和浓度及溶氧对锁掷酵母产类胡萝卜素的影响,并在7L发酵罐中进行了补料分批发酵试验。发现培养基中同时添加有机氮源和无机氮源且溶氧控制较低（5％）时有利于β-胡萝卜素的大量积累,最佳有机氮源和无机氮源分别为玉米浆（20g／L）、硫酸铵（5g／L）。补料分批发酵时β-胡萝卜素产量达到31．28mg／L,红酵母烯12．38mg／L。培养基中只添加有机氮源且相对溶氧控制相对较高（30％）时有利于红酵母烯的大量积累,最佳有机氮源为酵母膏（20g／L）。补料分批发酵时红酵母烯产量达到38．96mg／L,8．胡萝卜素12．36mg／L。     

红酵母RY—981类胡萝卜素发酵助剂的研究

通过探索几种促进剂和前体对红酵母RY－981类胡萝卜素发酵的影响,从中选出了番茄汁和花生油2种对红酵母生长及其类胡萝卜素合成具有显著促进作用的发酵助剂,并确定了适宜的用量。应用试验和发酵过程动态分析表明,这2种发酵助剂增产效果明显（当同时添加番茄汁2.6mL/L和花生油1ml/L时,菌体量、类胡萝卜素含量和产量可分别比对照组提高53．13％、20．29％和84．07％）,且对发酵过程菌体生长及生理代谢规律无不良影响。     

胶红酵母JB401降解脱色三苯甲烷类染料

从烟梗中分离筛选得到1株能够对三苯甲烷类染料高效脱色的微生物,经ITS-5.8S rDNA分析鉴定为胶红酵母,命名为Rhodotorula mucilaginosa JB401。全波长扫描实验结果证实染料的脱色由胶红酵母降解结晶紫引起。为了提高R.mucilaginosa JB401脱色结晶紫的能力,通过单因素试验对R.mucilaginosa JB401的培养条件进行了优化,得出菌体生长24 h后以2%接种量接入初始pH为5的脱色培养基并在37℃摇床培养,可以取得最优脱色效果,此时脱色50、100和200 mg/L的结晶紫达到90%去除率分别需要3、6和14 h。此外,胶红酵母对温度和pH良好的适应性使其具有应用于工业废水处理的潜力。     

Production of Egg Yolk Coloring Material by a Fermentation Process

Rhodotorula mucilaginosa was cultivated in a yeast propagator, for the production of biomass and carotenoids. A spray-dried preparation of the yeast was incorporated into the diets of laying chickens for the promotion of egg yolk color. Several aspects of the effect of media on growth and carotenogenesis of pigmented yeast were examined. Addition of 1 to 2% of Rhodotorula yeast to the feeding mixture considerably improved egg yolk color. The possibility of using carotenogenic yeasts as a feed supplement is suggested.     

<Emphasis Type="Italic">Rhodotorula mucilaginosa</Emphasis>, a carotenoid producing yeast strain from a patagonian high-altitude lake

The red yeast Rhodotorula mucilaginosa strain CRUB 0138 (previously identified as R. lactosa) was isolated from a high-altitude Patagonian Lake Toncek (1700 m a.s.l.), and assigned with mucilaginosa species. Its biochemical, physiological and molecular features were assessed and compared to R. mucilaginosa PYCC 5166 type strain using a polyphasic approach; in addition, biomass and carotenoid pigment production at different C/N ratios were determined in an incubator shaker. Phenetic characterization by means of 70 current physiological tests including assimilation of aldaric acids and aromatic compounds, and also the ability to grow with amino acids as sole carbon sources, was carried out. According to numerical taxonomy calculations, similarity indexes between R. mucilaginosa CRUB 0138 and PYCC 5166 type strain were 0.86 and 0.77, corresponding to a complete set of physiological tests and MSP-PCR (Mini/Micro Satellite Primed PCR; (GTG)5, M13 and (GAC)5 primers were employed) fingerprinting. Killer activity against 2 native strains, Rhodosporidium kratochvilovae and R. mucilaginosa was detected. Maximum biomass-glucose conversion efficiency (87%) and maximum carotenoid yield (2.32 mg/L) were obtained at C/N = 5 in culture medium containing 10 and 40 g/L glucose, respectively. Different C/N ratios did not influence carotenoid pigment production but low C/N enhanced biomass yield.     

Production of carotenoids by strains of Rhodotorula glutinis cultured in raw materials of agro-industrial origin

The production of carotenoids by strains of Rhodotorula glutinis on different raw materials of agro-industrial origin (grape must, glucose syrup, beet molasses, soybean flour extract, maize flour extract) was investigated. Maximum yield (5.95 mg/l of total carotenoids culture fluid, 630 μg/g dry cell weight) was obtained with a particular strain of Rhodotorula glutinis after a batch culture of 120 h in a substrate containing concentrated rectified grape must as the sole carbohydrate source. In all experiments, the major pigments forming carotenoids (β-carotene, torulene, torularhodin) were quantified.     

Production of biomass, carotenoid and other lipid metabolites by several red yeast strains cultivated on waste glycerol from biofuel production – a comparative screening study

This study was focused on a comparison of growth and production properties of seven red yeast strains of the genus Rhodotorula, Sporobolomyces and Cystofilobasidium cultivated on glycerol substrate. Production of enriched yeast biomas and specific yeast metabolites (carotenoids, ergosterol, lipids) was evaluated on medium with glucose, pure technical glycerol and/or waste glycerol from biofuel production (40 g/L) and mixture of glycerol and glucose (1:3, 1:1, 3:1; C/N ratio 57 in all cultivations). All tested strains were able to utilize glycerol as the only carbon source. Production of biomass on waste glycerol was in most strains higher than in control as well as in medium with pure technical glycerol and reached 15.97–21.76 g/L. Production of carotenoids and ergosterol was better in glucose medium than in medium with glycerol only. Nevertheless, using glycerol medium with addition of glucose, higher yields of total carotenoids, beta-carotene and ergosterol were obtained than in control. The highest yields of total pigments were reached by Sporobolomyces roseus (3.60 mg/g cell dry weight (CDW); glycerol:glucose 1:3), Sporobolomyces salmonicolor (2.85 mg/g CDW; glycerol:glucose 1:3) and Rhodotorula glutinis (2.80 mg/g CDW; glycerol:glucose 3:1) In glucose medium, most tested strains except Cystofilobasidium capitatum (22.6 %) produced neutral lipids in the range of 11–15 %. Production of triacylglycerols in all strains was in 10–30 % better in glycerol medium, in which Rhodotorula aurantiaca and Sporobolomyces shibatanus also reached intracellular triacylglycerol concentrations up to 20 % of biomass. This study has shown that oleaginous red yeasts could have great potential for converting crude glycerol to valuable lipids and carotenoids in respect of efficient bioresources utilization.     

Effect of aeration on the production of carotenoid pigments by Rhodotorula rubra-lactobacillus casei subsp. casei co-cultures in whey ultrafiltrate

Under intensive aeration (1.3 l/l min) the associated growth of Rhodotorula rubra GED2 and Lactobacillus casei subsp. casei in cheese whey ultrafiltrate (55 g lactose/l) proceeded effectively for both cultures with production of maximum carotenoids (12.4 mg/l culture fluid). For maximum amount of carotenoids synthesized in the cell, the yeast required more intensive aeration than the aeration needed for synthesis of maximum concentration of dry cells. Maximum concentration of carotenoids in the cell (0.49 mg/g dry cells) was registered with air flow rate at 1.3 l/l min, and of dry cells (27.0 g/l) at 1.0 l/l min. An important characteristic of carotenogenesis by Rhodotorula rubra GED2 + Lactobacillus casei subsp. casei was established--the intensive aeration (above 1.0 l/l min) stimulated beta-carotene synthesis (60% of total carotenoids).     

Rhodotorula Fungemia of an Intensive Care Unit Patient and Review of Published Cases

Rhodotorula species are commensal yeasts that have emerged as a cause of life-threatening fungemia in severely immunocompromised patients. A case of Rhodotorula mucilaginosa fungemia in a 48-year-old woman that had undergone consecutive abdominal surgeries due to ovarian cancer and bowel necrosis while she was receiving fluconazole prophylaxis is presented. Several risk factors were identified such as presence of central venous catheters, solid organ neoplasm, abdominal surgery and administration of antibiotics. Identification was performed using commercial systems. The yeast was resistant to fluconazole, posaconazole and voriconazole and to echinocandins, whereas MIC to amphotericin B was 1.5?mg/L. Furthermore, published cases of Rhodotorula spp fungemia during the last decade are reviewed. In conclusion, Rhodotorula spp must be considered a potential pathogen in patients with immunosupression and central venous catheters. Correct identification is mandatory for appropriate management, as Rhodotorula spp are resistant to antifungal agents, such as fluconazole and echinocandins.     

Formation of carotenoids by rhodotorula glutinis in whey ultrafiltrate

The growth and carotenoid biosynthesis of the yeast Rhodotorula glutinis was studied by cocultivation with Lactobacillus helveticus in cheese ultrafiltrate containing 3.9% and 7.1% lactose. By growing this mixed culture in a 15-L fermentor MBR AG (Switzerland) at an air flow rate of 0.5 L/L min and agitation at 220 rpm for 6 days, a total yield of carotenoids of 268 mug/g dry cells wasobtained. Carotenoids were formed almost parallel with the cell growth, anda maximum production was reached at an early stationary phase. A high-performance liquid chromatographic system (HPLC) permitting simultaneous determination of major carotenoid pigments was used. The three main pigments (torularhodin, beta-carotene, and torulene) were formed in Rhodotorula glutinis, and reached a maximum concentration as follows: 182.0, 43.9, 23.0 mug,g dry cells. (c) 1994 John Wiley & Sons, Inc.     

The role of carotenoids in preventing oxidative damage in the pigmented yeast, Rhodotorula mucilaginosa

Rhodotorula mucilaginosa is an obligate aerobic yeast which contains a high concentration of carotenoid pigment. To test whether carotenoids are able to protect R. mucilaginosa against oxidative injury, yeast cells in liquid culture were incubated with duroquinone (DQ) (100 microM), a redox-cycling quinone known to generate intracellular O2-. or were grown in a hyperoxic atmosphere (80% O2) under conditions where carotenoid concentrations were altered either intracellularly or extracellularly. Neither of these oxidative challenges affected cell growth unless carotenogenesis was blocked by the addition of diphenylamine (50 microM). In the diphenylamine-treated nonpigmented cells, growth was completely inhibited by DQ and by hyperoxia. In normoxia, however, diphenylamine alone reduced growth by only 30%. The growth inhibition observed in diphenylamine-treated cells exposed to hyperoxia was primarily mycocidal rather than mycostatic since plating of these cells onto solid media revealed that only 25% of the cells were viable after 50 h of incubation when compared to plated control cells. Addition of 10 microM beta-carotene to diphenylamine-treated cells completely prevented the growth inhibition caused by either hyperoxia or DQ. Carotenoids, therefore, are able to prevent oxidant-induced cytotoxicity in R. mucilaginosa. Analysis of the absorption spectra of chloroform extracts of beta-carotene-supplemented cells showed that beta-carotene, not the endogenous carotenoid, torularhodin, was the major carotenoid present in these cells. Superoxide dismutase (SOD) activity in R. mucilaginosa was compared with that of another yeast, Saccharomyces cerevisiae by two methods: (i) activity staining of proteins separated by gel electrophoresis and (ii) measurement of inhibition of ferricytochrome c reduction. By these techniques, the R. mucilaginosa SOD activity had the characteristics of Mn-SOD. No Cu/ZnSOD activity was detected. Thus, the apparent absence of Cu/ZnSOD may make the antioxidant capability of endogenous carotenoids even more critical in preventing oxidative damage in R. mucilaginosa.