红曲霉原生质体的制备、再生及其遗传转化系统

原生质体是研究和建立真菌遗传转化系统的重要工具。为了建立原生质体介导的红曲霉遗传转化系统,考察了各种细胞壁裂解酶和渗透压稳定剂等对红曲霉原生质体形成和再生的影响。将红曲霉分生孢子在铺有玻璃纸的平板上30℃培养30~40 h收获的菌丝体最有利于原生质体的形成和释放。红曲霉菌丝体形成和释放原生质体最适裂解酶和酶解时间分别为：0.3 % lysing enzyme、0.1 % cellulase和1 % snailase的酶组合,30℃作用2.5 h;最适渗透压稳定剂是：1mol /L MgSO4。最适合原生质体再生的培养基为含0.6 mol/L蔗糖的CM培养基。原生质体液涂布单层再生培养基的方法,再生率最高,菌株M34和N18分别为8.5 %和36.4 %。在PEG和CaCl2存在下,以潮霉素B为抗生素选择标记,用质粒pBC-Hygro和pNL1共转化菌株M34原生质体,每微克DNA克获得100个稳定转化子。     

红曲霉T-DNA插入转化库中桔霉素突变子的筛选

以农杆菌介导法建立的红曲霉T—DNA转化库为实验材料,采用抑菌圈法从5,000多个转化子中筛选出200株桔霉素突变子的候选菌株,用高效液相色谱法进一步筛选得到53株与出发菌株相比产桔霉素能力发生显著变化的突变子,其红曲中桔霉素含量介于0．04～154．57μg／g之间。进一步分析了突变子的红曲色价,发现突变子产桔霉素能力与产色素能力之间有一定的相关性。这些研究结果为进一步从分子水平上探讨红曲霉产桔霉素和色素等次生代谢产物之间的关系提供了材料和基础。     

红曲霉桔霉素的检测方法及红曲霉产桔霉素的判别方法*

建立了红曲霉真菌毒素桔霉素的HPLC检测方法。用谷氨酸和葡萄糖为唯一氮、碳源的培养基(MSG)液态摇瓶培养及红曲米固态培养,对30多株红曲霉产桔霉素的情况进行了普查,发现大多数红曲霉菌种可产生桔霉素。红曲霉的培养状态及条件对桔霉素的产生有重大影响。红曲霉菌种是否产桔霉素,可根据MSG培养基摇瓶发酵液中是否含有桔霉素来初步定性判断,为准确判断红曲霉菌是否产桔霉素,可采用多种培养法综合判断。     

电击法锈导的欧白英原生质体转化和转化植株再生

本研究使用电击法成功地将带有标记基因ＮＰＴⅡ的质粒ｐＣａＭＶＮＥＯ转入欧白英的原生质体,并获得了再生转化植株。通过用ｐＤＷ２质粒进行的ＣＡＴ基因短暂表达研究,确定了欧白英原生质体转化的电击条件为：电容３０ｎＦ、电场强度１５００Ｖ／ｃｍ、时间衰变常数５９．４微秒;质粒ＤＮＡ浓度为２０μｇ／２×１０＾６原生质体。在以上条件下,欧白英原生质体的相对转化率为１２．４％,绝对转化率为２．４×１０－４。在大多     

红曲霉发酵液中桔霉素快速检测方法的优化

研究确立了一种高效液相色谱法,能有效地对红曲霉代谢产物中的桔霉素分离和定量分析。色谱柱:Shimadzu VP-ODS C18(5μm,250 mm×4.6 mm),流动相组成为V(乙腈):V(甲醇):V(水)=70:10:20,pH≤2.8。荧光检测器:λex=331 nm,λem=500 nm。在优化的色谱条件下绘制标准曲线,当桔霉素质量浓度为0.1 mg.L-1~1 mg.L-1时线性关系良好,R2=0.9992。对桔霉素标品的最低检测质量浓度为0.01 mg.L-1,在红曲霉发酵样品中的定量回收率达到了0.9187722~1.029138。     

红曲霉T-DNA插入转化库中桔霉素突变子的筛选*

以农杆菌介导法建立的红曲霉T-DNA转化库为实验材料,采用抑菌圈法从5,000多个转化子中筛选出200株桔霉素突变子的候选菌株,用高效液相色谱法进一步筛选得到53株与出发菌株相比产桔霉素能力发生显著变化的突变子,其红曲中桔霉素含量介于0·04~154·57μg/g之间。进一步分析了突变子的红曲色价,发现突变子产桔霉素能力与产色素能力之间有一定的相关性。这些研究结果为进一步从分子水平上探讨红曲霉产桔霉素和色素等次生代谢产物之间的关系提供了材料和基础。     

红曲霉胞外脂酶催化己酸乙酯合成研究

己酸乙酯是浓香型曲渣的主体香昧成分,也是曲酒优质品率低的主要限制因素。60年代Iwai⑴发现在适当条件下脂酶可直接催化酸和醇合成酯。Langrand⑵比较了各种脂酶合成短碳链羧酸酯的能力。我们在对酒窖生香微生物的研究中发现红曲霉、根霉具有较强的己酸己酯合成能力,属首次报道⑶。本文主要报道利用红曲霉的脂酶合成己酸乙酯条件试验的结果。     

农杆菌介导红江橙遗传转化的研究初报

用红江橙实生苗的上胚轴为材料 ,初步研究以根癌农杆菌介导的 GUS基因转化。结果表明 :以卡那霉素作为选择试剂进行选择培养时 ,Km浓度为 5 0 mg/L;外植体以平放为好 ;抑菌剂选择头孢霉素较好。GUS基因瞬时表达检测 ,70 .4%的外植体呈阳性反应 ;GUS基因稳定表达检测 ,在获得的 1 2株抗性植株中 ,GUS反应呈阳性所占比例为 1 6.7%。     

红曲霉菌丝形态与产色素关系的研究

从培养基成分、培养温度、培养时间等方面对发酵条件与红曲霉菌丝形态、产色效果之间的关系进行了研究。实验结果表明:用4%玉米粉,2%豆饼粉作培养基,28℃,培养72h,红曲霉形成的菌丝球为250个/mL左右,直径为1.0~1.2mm,大小均匀,且产色效果最好。     

红曲霉AS 3.3491葡萄糖淀粉酶形成的研究

对红曲霉AS3．3491供给易利用碳源,葡萄糖淀粉酶的形成受咀遏,cAMP可使之解阻遏。易利用碳源的迅速利用使培养液pH显著下降,实验发现各种提高培养液pH值的方法都能促进葡萄糖淀粉酶的形成。同时发现该菌株的五种类型的葡萄糖淀粉酶是随培养液pH的逐渐回升陆续形成的,且各型酶的出现都与培养液的一定pH值相关联。文中讨论了该菌株中葡萄糖淀粉酶形成的调控机制。     

REMI介导电转化产甘油假丝酵母

为了分离耐高渗和甘油代谢相关基因,以Zeocin为选择标记,利用REMI技术电转化产甘油假丝酵母Candida glycerinogenes。考察了7种限制性内切酶对转化的影响,选择HindIII进一步优化了转化的几个条件。结果表明,在OD600≈1.3时收集细胞,在1.5kV电压下,感受态细胞浓度为2.0×109个细胞/mL,100U Hind III时,能获得129个转化子/μgDNA的较高转化率,58%的转化子稳定,表明REMI技术适合于产甘油假丝酵母的转化。     

野生鸡枞菌种长期保存方法比较

野生鸡枞菌种质资源的有效保存是对野生鸡枞加以保护和利用的前提。以自行分离的5个野生鸡枞菌株作为研究对象,采用蒸馏水保藏法和-80°C冻结保藏法对野生鸡枞菌种长期保存的方法进行了实验研究,蒸馏水法分别保存于室温和4°C,-80°C冻结保藏同时采用程控降温法和泡沫盒降温法,保存20个月后对4种不同方法保存的5个菌株的保存效果进行比较。实验结果表明:蒸馏水室温保存法菌种存活率为100%,萌发期较短,为4-10 d,是一种简便、实用、有效而成本低廉的长期保存方法;-80°C冻结保藏法的存活率为56%-76%,萌发期7-16 d,泡沫盒降温法可以很好地控制降温速度,是一种简便有效的控温方法。     

噬菌体浓缩方法的比较

目的：对不同噬菌体浓缩方法进行比较。方法：采用PEG沉淀、PEG反透析、阴阳离子结合树脂、超滤等5种方法对T4、T7、N4等3类噬菌体进行浓缩对比试验;在此基础上,用浓缩效果较好的方法对土壤和河道污水样本中的噬菌体进行浓缩,观察浓缩效果。结果：上述5种方法对3类噬菌体均有浓缩效果;超滤的浓缩效果最好,其次是PEG反透析,PEG沉淀没有很好的浓缩效果;河水样本中噬菌体的回收率比土壤样本高。结论：可通过PEG反透析、超滤或两者相结合的方法,得到高浓度的有活性的噬菌体。     

农杆菌介导的紫色红曲霉遗传转化体系的建立和优化

通过优化各种转化因素,建立了根癌农杆菌(Agrobacterium tumefaciens)介导红曲霉(Monascus)的高效转化体系:红曲霉在PDA培养基培养21 d后收集孢子,制备红曲霉孢子悬浮液,浓度为106个/mL,根癌农杆菌浓度为OD600值0.5,诱导剂AS浓度为100μmol/L,农杆菌与红曲霉在25℃共培养3 d。采用此转化体系构建了含有530多个转化子的红曲霉T-DNA插入突变体库。随机选取50株转化子菌株进行分子验证和稳定性检测,证明T-DNA成功插入红曲霉基因组DNA中,并能稳定遗传。最后,通过形态观察筛选出8株变异较大的菌株,为以后的红曲霉基因功能研究奠定了一定的基础。     

Effect of nutrition of Monascus sp. on formation of red pigments

Summary A higher producer of ascospores and pigments, Monascus strain TTWMB 6042, was used to study regulation of pigment production by nutrients. An initial medium containing 4% glucose, 0.3% NH₄NO₃ (75 mm nitrogen) and inorganic salts was used. We found that the formation of red pigments in this strain, measured by optical density at 500 nm (OD₅₀₀) was strongly stimulated by monosodium glutamate (MSG) as the sole nitrogen source. The choice of carbon source and an initial pH of pH 5.5 were also important. High concentrations of phosphate and MgSO₄ were inhibitory to pigment production. A new chemically defined medium was devised containing 5% maltose, 75 mm MSG, phosphate and MgSO₄ at lower concentrations plus other mineral salts, which yielded a tenfold increase in OD₅₀₀ and a reversal of the pigment location from predominantly cell-bound, including both intracellular and surface-bound pigments, to mainly extracellular. Offsprint requests to: A. L. Demain     

红曲霉-金钗石斛双向发酵工艺优化

红曲霉(Monascus sp.)代谢产物具有很强的抗氧化性,是天然的抗氧化剂重要来源.金钗石斛是中国传统中药材,具有很多生物活性,结合红曲霉与中草药材双向发酵有望增强其抗氧化能力和改变代谢通路,为探究筛选最佳的金钗石斛-红曲霉发酵条件,提高双向发酵代谢产物的抗氧化活性,采用ABTS法、DPPH法和抗脂质过氧化法三种体...     

Pigment Production from Immobilized Monascus sp. Utilizing Polymeric Resin Adsorption

Pigment production by the fungus Monascus sp. was studied to determine why Monascus sp. provides more pigment in solid culture than in submerged culture. Adding a sterilized nonionic polymeric adsorbent resin directly to the growing submerged culture did not enhance the pigment production, thus indicating that pigment extraction is probably not a factor. Monascus cells immobilized in hydrogel were studied and exhibited decreased pigment production as a result of immobilization. This result is thought to be due to diffusional resistance of the pigment through the hydrogel beads. Addition of the adsorbent resin to the immobilized Monascus culture increased both the maximum pigment yield and the production rate above those of the free-cell fermentations. The provision of a support for the mycelium may explain enhanced pigment production by the solid-state culture. These results indicate that product diffusion from immobilized cell systems can be the limiting factor and that in situ extraction is one possible way to circumvent this problem.     

苯丙酮尿症常用筛查方法的比较

苯丙酮尿症是一种由于体内缺乏苯丙氨酸羟化酶所引起的遗传性代谢异常疾病,如果能够做到早诊断、早发现、早预防和早治疗,就可以避免患儿以后出现智能发育障碍,因此开展新生儿的筛查工作十分重要。简要介绍了苯丙酮尿症的基本情况以及目前应用于临床的常用筛查方法,如细菌抑制法、荧光法等,并从筛查原理、主要优缺点等方面进行了简单的比较。     

Comparison of Different Methods for Preparation of Human Milk Casein

Changes of the estradiol and lipid concentrations in hen serum, and those in the fatty acids of hen and cockerel livers were studied during the maturing period. The concentrations of estradiol and lipid in serum reached a maximum level a few days before the onset of laying, and then fell. A marked increase in oleate, and decreases in stearate and arachidonate were observed in both the liver and serum lipids of the hen when reaching laying. The fatty acid compositions of the serum and liver of the hen at 145 and 167 days of age were close to those of yolk lipid. In the cockerel, high contents of stearate and arachidonate and a low content of oleate were observed, and the fatty acid composition did not change appreciably with age. On estrogenization of the male chick, the fatty acid cmposition of the liver lipid was similar to that of the laying hen liver. The ratio of the unsaturated fatty acid/saturated fatty acid in the liver of hen increased when reaching laying, the value at 167 days old being close to that of yolk lipid. This ratio in the liver lipid of cockerel did not change significantly throughout the experimental period.