酵母菌HL的批次发酵及发酵动力学初探

在摇瓶培养的基础上,对酵母菌Ｌｉｐｏｍｙｃｅｓ ｓｔａｒｋｅｙｉ ＨＬ进行了小型发酵罐的分批和分批补料发酵及其发酵动力学的初步研究。结果表明,通过后期补料既可明显地延长菌体脂类合成期,减缓油脂比合成速率的降低,又可增加菌液的细胞密度,最终提高了整个发酵罐的油脂产量和平均容量产率。发酵结果如下：发酵时间１２０ｈ;油脂产量１１.０ｇ／Ｌ;菌体生物量１９．４ｇ／Ｌ。油脂百分含量 ５６．５％,显然比分批培养８４ｈ所得的１１．２ｇ／Ｌ细胞生物量和 ６.１ｇ／Ｌ油脂产量分别增长了７３％和８０％。此外,通     

少动鞘脂单胞菌S1胞外多糖发酵工艺条件研究

研究了摇瓶培养条件下少动鞘脂单胞菌引的胞外多糖的发酵工艺。Ｓ１菌的发酵产胶可采用二步发酵法：第一阶段,培养基成分为：蔗糖１０ｇ,ＮＨ_４ＮＯ_３　０．５ｇ,ＫＨ_２ＯＰ_４　０．５ｇ,ＭｎＳＯ_４　０．３ｇ,ＭｇＳＯ_４　０．１ｇ,吐温８０ ０．０２ｇ溶于蒸馏水并定容至１０００ｍＬ,ｐＨ７．２±０．１,温度３３℃～３５℃,高溶氧。第二阶段,发酵 １０～１２ｈ后,补加蔗糖４０ｇ／Ｌ,温度     

活性干酵母SOD摇瓶发酵条件的研究

研究了营养与环境条件对耐高温酒精活性干酵母（ＴＨ－ＡＡＤＹ）ＳＯＤ摇瓶发酵的影响。实验结果表明,初糖浓度,金属离子、ＰＨ值、通气量（装液量）和培养时间等均对ＡＡＤＹ摇瓶发酵的生物量和ＳＯＤ含量有较大的影响。在实步优化的发酵条件下,细胞生物量为３９．６ｇ／Ｌ,菌体ＳＯＤ含量为１９４８Ｕ／ｇ,发酵液产酶能力为７．７万Ｕ／Ｌ。     

细菌产木聚糖酶发酵条件的研究*

研究了碳源、氮源以及其他因子对木聚糖酶高产菌ＷＬＵＮ０２４（Ｐｓｅｕｄｏｍｏｎａｓ ｓｐ．）产酶的影响,结果表明在麸皮６ｇ／Ｌ、（ＮＨ４）２ＳＯ４ ０．８ｇ／Ｌ、Ｋ２ＨＰＯ４ ０．４ｇ／Ｌ、接种量５％－１０％的条件下,３７℃培养３６ｈ,其木聚糖酶活力可达６００ＩＵ／ｍＬ。同时研究了在较优条件下该菌的摇瓶产酶曲线。     

利用葡萄糖发酵生产聚-β-羟基丁酸菌株的选育及其摇瓶发酵条件的研究

通过紫外线诱变筛选出能利用葡萄糖高积累ＰＨＢ的突变侏－真养产碱杆菌９２０。研究了碳源和氮源对该菌株发酵积累ＰＨＢ的影响。结果表明,在分批摇瓶发酵中碳源和氮源的最佳浓度分别为５％和０．３３％。经过３６ｈ的发酵菌体干重、ＰＨＢ含量、ＰＨＢ浓度和ＰＨＢ的产率分别为１９．３ｇ／Ｌ、５６．３％、１０．８６ｇ／Ｌ和０．２２。     

真养产碱杆菌突变株65－7产羟基丁酸与羟基戊酸共聚物的研究

研究了真养产碱杆菌突变株６５－７,以葡萄糖为主原料,添加丙酸或戊酸,采用二步发酵积累共聚物聚β－羟基丁酸－β－羟基戊酸（ＰＨＢＶ）。摇瓶总发酵时间为５０ｈ,细胞干重达７－１１ｇ／Ｌ,共聚物含量占细胞干重的７０％以上,其中β－羟基戊酸（３ＨＶ）含量占ＰＨＢＶ的１０－７２％,主要取决于不同碳源的组成,丙酸和戊酸对ＨＶ的转化率分别为０．４１－０．６３ｇＨＶ／ｇ丙酸和０．４０－０．７４ｇＨＶ／ｇ戊酸,制得的ＰＨＢＶ产品纯度９９％以上,分子量６．９×１０^{５相似文献}   

真养产碱菌利用甜菜糖蜜发酵产聚β－羟基丁酸的研究

探讨了以廉价原料甜菜糖蜜培养真养产碱菌（Ａｌｃａｌｉｇｅｎｅｓｅｕｔｒｏｐｈｕｓ）Ｈ１６生产聚β－羟基丁酸（ＰＨＢ）的可行性。对培养基优化试验表明,菌体产量可达２０ｇ／Ｌ,ＰＨＢ产量达９．８ｇ／Ｌ,糖转化率为２７．５％。用２升自控发酵罐进行验证,在良好的供氧条件和特定的ｐＨ值自控条件下发酵周期从４８小时缩短到４０－４２小时,菌体和ＰＨＢ量都有提高。菌体最高产量２６ｇ／Ｌ,ＰＨＢ最高产量１３ｇ／Ｌ,糖转化率为２０．４％。ＰＨＢ占细胞的含量,摇瓶和罐上结果都在５０％左右。     

温度适应范围大的谷氨酸生产菌GMH—908选育,发酵及应用效果

以谷氨酸生产菌天津短杆菌（Ｂｒｅｖｉｂａｃｔｅｒｉｕｍｔｉｅｎｔｓｉｎｅｎｓ）Ｔ６－１３为出发菌株,经菌体或原生质体紫外线（ＵＶ）、氯化锂、香豆素等多因子诱变和高温驯化,选育出琥珀酸、生物素营养缺陷型,耐高糖、耐高谷氨酸又不利用谷氨酸,且温度适应范围大（既可在常温３２－３８℃发酵,又可在高温３６－４２℃发酵）的突变株ＧＭＨ－９０８。以淀粉糖为碳源,生物素亚适量,摇瓶常温发酵产酸９５ｇ／Ｌ以上,高温发酵产酸７４．９ｇ／Ｌ,比出发菌株Ｔ６－１３分别提高２６．６７％和２２．９９％;工业生产常温发酵月平均产酸８５－８８ｇ／Ｌ,转化率５２－５４ｇ％,单罐最高产酸１０８ｇ／Ｌ,转化率５８％;高温发酵产酸达７６．５ｇ／Ｌ,转化率４９．５％。     

温特曲霉转富马酸为L—苹果酸的初步研究

从大量霉菌在选育到一株具有较高富马酸酶活性的温特曲霉（Ａｓｐｅｒｇｉｌｌｕｓ ｗｅｎｔｉｉ）Ａ５－６１。在摇瓶培养条件下,３２℃ ９６小时,产Ｌ－苹果酸达１０．４９ｇ／１００ｍｌ,对富马酸的转化率达９０．８０％。利用菌体细胞,进行酶转化试验,结果表明：１．６ｇ湿菌体接入２５ｍｌ含富马酸１０．０％（用ＮａＯＨ中和至ｐＨ７．０）的转化液中,３５℃１６－２４小时,连续转化三次,分别产生Ｌ－苹果酸９．６１     

数理统计方法优化单细胞蛋白发酵培养基研究

采用正交试验和中心组合设计相结合的数理统计方法,在２Ｌ发酵罐中对紫云英汁液培养单细胞蛋白发酵培养基进行筛选、优化,试验结果表明较优培养基为：初糖２．３％,酵母粉０．１６％,ＫＨ_２ＰＯ_４０．２％,ＭｇＳＯ_４０．０５％。酵母浓度最高达１０．４６ｇ／Ｌ,基质生长得率为０．５５ｇ菌体／ｇ基质,基质转化率为８３％。研究结果同时说明采用数理统计方法设计实验,工作量小,效率高,结果准确。     

Conversion of sewage sludge into lipids by Lipomyces starkeyi for biodiesel production

The potential of accumulation of lipids by Lipomyces starkeyi when grown on sewage sludge was assessed. On a synthetic medium, accumulation of lipids strongly depended on the C/N ratio. The highest content of lipids was measured at a C/N-ratio of 150 with 68% lipids of the dry matter while at a C/N-ratio of 60 only 40% were accumulated. Within a pH range from 5.0 to 7.5 the highest lipid accumulation was found at pH 5.0 while the highest yield per litre was pH 6.5. Although sewage sludge had no inhibitory effects on growth or accumulation on L. starkeyi when added to synthetic medium, there was no significant growth on untreated sewage sludge. However, pretreatment of sludge by alkaline or acid hydrolysis, thermal or ultrasonic treatment lead to accumulation of lipids by L. starkeyi with highest values of 1 g L(-1) obtained with ultrasound pre-treatment. Based on the content of free fatty acids and phosphorus, lipids accumulated from sewage sludge could serve as a substrate for the production of biodiesel.     

拉曼被孢霉F_5发酵生产γ—亚麻酸的研究

对拉曼被孢霉突变株F5发酵生产γ—亚麻酸的最适碳源、氮源、发酵时间及温度、无机盐离子添加、最适碳源浓度及补加碳源时间等发酵条件进行了研究探讨。最适发酵培养基组成为 (g/L) :葡萄糖 1 0 0 ,酵母浸出粉 4 ,蛋白胨 1 ,K2 HPO4 1 ,CaCl2 1× 1 0 - 2 ,MgSO4 5× 1 0 - 2 ,FeSO4 1× 1 0 - 2 ,ZnSO4 7.5× 1 0 - 3,CuSO4 0 .5× 1 0 - 3,MnSO4 2× 1 0 - 3,pH 6.0。培养温度为 2 5℃ ,1 4 0r/min振荡培养 1 0天 ,培养 8天后 (即收获前 2天 )补加 5 %葡萄糖。发酵结果为 :DC 2 4 .5 9g/L ,TL 1 0 .84g/L ,TL/DC 4 4.0 9% ,GLA/TL 1 0 .67% ,GLA产量为 1 1 5 6.63mg/L。GLA产量较初始结果提高 1 5 6.1 5 %。该菌株已达到工业化生产菌株要求     

恒化培养稀释率和碳氮比对圆红冬孢酵母油脂积累的影响

采用恒化培养的方法,考察了稀释率(D)和碳氮比(mol/mol)对圆红冬孢酵母Rhodosporidiumtoruloides AS 2.138 9积累油脂的影响。结果表明:稀释率增大,油脂含量和油脂得率降低。在D=0.02 h 1时油脂得率最大,为0.18 g油/g糖;D=0.14 h 1时油脂生成速率最大,为0.09 g/(L.h)。碳氮比增大,油脂含量略有增加。在C/N=92时油脂得率最大,为0.12 g油/g糖;C/N=32时油脂生成速率最大,为0.13 g/(L.h)。碳氮比对油脂的脂肪酸组成影响不明显,油脂的棕榈酸、硬脂酸和油酸总含量超过85%。     

The proteome analysis of oleaginous yeast Lipomyces starkeyi

Oleaginous yeast Lipomyces starkeyi, a species in the Saccharomycetales order, has the capability to accumulate over 70% of its cell biomass as lipid under defined culture conditions. In this study, analysis of L. starkeyi AS 2.1560 proteome samples from different culture stages during a typical lipid production process was performed using an online multidimensional μRPLC/MS/MS method. Data searching against the proteome database of the yeast Saccharomyces cerevisiae led to the identification of 289 protein hits. Further comparative and semi-quantitative analysis under more stringent criteria revealed 81 proteins with significant expression-level changes. Among them, 52 proteins were upregulated and 29 proteins were downregulated. Gene ontology annotation indicated that global responses occurred when cells were exposed to the nitrogen deficiency environment for lipid production. Protein hits were annotated and largely concerned metabolic processes for alternative nitrogen sources usage or lipid accumulation. Many of the downregulated proteins were related to glycolysis, whereas the majority of the upregulated proteins were involved in proteolysis and peptidolysis, carbohydrate metabolism and lipid metabolism. Insights were provided in terms of cellular responses to nutrient availability as well as the basic biochemistry of lipid accumulation. This work presented potentially valuable information for understanding the biochemical events related to microbial oleaginity and rational engineering of oleaginous yeasts.     

产油微藻自养培养条件调控

作为新兴生物燃料的生物柴油近年来发展迅速,以微藻为代表的第二代生物能源是解决能源危机的长远之计,但如何提高其产量仍是研究的热点问题。以提高产油自养微藻生物量和油脂含量为目的,在气升式光反应器中运用均匀设计实验方法进行了条件优化试验。分别得出了氮原子浓度、通气速率、二氧化碳体积浓度和光照强度4个因素对小球藻C2生物量积累和油脂含量影响的显著回归方程和反应器优化培养条件。以生物量为指标的优化培养条件是:氮原子浓度0.178 g/L,通气速率5 L/min,二氧化碳体积浓度3%(V/V),光照强度6000 lx。该优化条件下,生物量为2.11 g/L,即生产速率为0.352 g/(L.d),比测试实验中检测到的最高生物量[1.88 g/L,即生产速率为0.313 g/(L.d)]提高了12.2%;以油脂含量为指标的优化培养条件是:进气速率0.400 L/min,二氧化碳体积浓度1.94%(V/V),得到油脂含量为22.4%,比测试实验中检测到的最高油脂量(20.7%)提高7.7%。     

离子注入选育高产L-乳酸的米根霉突变株及其发酵特性研究

通过氮离子注入获得米根霉突变株RQ4012,其利用木糖的能力比出发菌株提高了1.6倍;通过多次传代,证明其具有良好的遗传稳定性。试验测定菌株RQ4012发酵木糖生产L-乳酸的最佳发酵条件:木糖10%,生理盐水浸泡孢子9 h,(NH4)2SO43 g/L,接种量4%,CaCO3添加量6%,装液量20%,温度37℃,转速200 r/min,在此条件下,乳酸产量达到79.51 g/L。对混合糖的发酵进行了探索,结果表明该菌能高效利用混合糖生产L-乳酸,在利用植物纤维素水解液生产L-乳酸上有良好的应用前景。     

Screening of lipid high producing mutant from rhodotorula glutinis by low ion implantation and study on optimization of fermentation medium

In order to obtain lipid producing strain with high-yield, the wild type stain Rhodotorula glutinis was treated by low ion implantation, and optimization of fermentation medium for higher lipid yield was carried out using mutant strain. It was found that the strain had a higher positive mutation rate when the output power was 10 keV and the dose of N⁺ implantation was 80 × 2.6 × 10¹³ ions/cm². Then a high-yield mutant strain D30 was obtained through cid-heating coupling ultrasonic method and lipid yield was 3.10 g/L. Additionally, the surface response method was used to optimize fermentation medium. The three significant factors (glucose, peptone, KH₂PO₄) were optimized using response surface methodology (RSM), and the optimized parameters of fermentation medium were as follows: glucose 73.40 g/L, peptone 1.06 g/L and KH₂PO₄ 3.56 g/L. Finally the fermentation characteristic of high-yield mutation strain D30 was studied, when fermentation time was 10 days, which lipid yield increased to 7.81 g/L. Fatty acid composition of the lipid was determined by GC, and the most represented fatty acids of mutant D30 were C16:0 (11.4 %), C16:1 (5.66 %), C18:1 (49.3 %), and C18:2 (27.0 %).     

广谱碳源产油酵母菌的筛选

对10株酵母菌利用不同单糖为碳源条件下菌体内积累油脂的能力进行了初步考察,并对菌油进行了分离和脂肪酸组成分析。实验发现,以葡萄糖为唯一碳源时有9株菌油脂含量超过自身细胞干重的20%,可以界定为产油微生物。其中6#菌(T.cutaneumAS2.571)利用葡萄糖发酵菌体油脂含量达到65%(W/W)。所有实验菌株都能同化多种单糖,其中1#菌(L.starkeyiAS2.1390)、4#菌(R.toruloidesAS2.1389)和11#菌(L.starkeyiAS2.1608)表现出对碳源利用的广谱性,能转化五碳糖木糖和阿拉伯糖并在菌体内积累油脂,油脂含量最高达到26%。脂肪酸组成分析结果表明,菌油富含饱和及低度不饱和长链脂肪酸,其中棕榈酸、油酸和亚油酸三者之和占总脂肪酸组成的90%以上,脂肪酸组成分布类似于常见的植物油。这些结果对利用产油微生物转化木质纤维素水解混合糖获取油脂资源的研究具有重要意义。     

Mixed culture of oleaginous yeast Rhodotorula glutinis and microalga Chlorella vulgaris for lipid production from industrial wastes and its use as biodiesel feedstock

A mixed culture of oleaginous yeast Rhodotorula glutinis and microalga Chlorella vulgaris was performed to enhance lipid production from industrial wastes. These included effluent from seafood processing plant and molasses from sugar cane plant. In the mixed culture, the yeast grew faster and the lipid production was higher than that in the pure cultures. This could be because microalga acted as an oxygen generator for yeast, while yeast provided CO(2) to microalga and both carried out the production of lipids. The optimal conditions for lipid production by the mixed culture were as follows: ratio of yeast to microalga at 1:1; initial pH at 5.0; molasses concentration at 1%; shaking speed at 200 rpm; and light intensity at 5.0 klux under 16:8 hours light and dark cycles. Under these conditions, the highest biomass of 4.63±0.15 g/L and lipid production of 2.88±0.16 g/L were obtained after five days of cultivation. In addition, the plant oil-like fatty acid composition of yeast and microalgal lipids suggested their high potential for use as biodiesel feedstock.     

Toxicity of paraquat to microorganisms

The biochemical response of the microorganisms Lipomyces starkeyi (Lod & Rij), Escherichia coli K-12 W3110, Bacillus subtilis 168 (Marburg) and Pseudomonas sp. strain TTO1 to the presence of growth-inhibitory concentrations of paraquat was studied. Paraquat was added to each culture at a concentration previously determined to reduce the culture growth rate by up to 50%. The changes in activity of a number of enzymes previously shown to be associated with the defense of the mammalian system against the action of paraquat were studied. While the response of E. coli was in agreement with that found in other studies of this microorganism and supports a commonly accepted mechanism for paraquat toxicity, the results obtained with L. starkeyi, B. subtilis, and Pseudomonas sp. strain TTO1 suggest that other mechanisms exist for protection against the toxicity of paraquat.