石油酵母菌的分类鉴定

从工厂与研究单位送检的３０株石油发酵酵母菌，经鉴定分别属于３个属６个种：其中７株为皱格假丝酵母（Ｃａｎｄｉｄａｒｕｇｏｓａ），６株为热带假丝酵母（Ｃａｎｄｉｄａｔｒｏｐｉｃａｌｉｓ），７株为解脂假丝酵母（Ｃａｎｄｉｄａｌｉｐｏｌｙｔｉｃａ），７株为季也蒙假丝酵母（Ｃａｎｄｉｄａｇｕｉｌｔｉｅｒｍｏｎｄｉｉ），２株为脱蜡球拟酵母（Ｔｏｒｕｌｏｐｓｉｓｄｉｐｏｒａｆｆｉｎ），１株为皮状丝抱酵母（Ｔｉｒｃｈｏｓｐｏｒｏｎｃｕｆａｎｅｕｎ）；其中２７株属假丝酵母属，２株为球拟酵母属，１株为丝抱酵母属。     

紫外线诱变筛选抗双乙酰和低H_2S合成能力啤酒酵母的研究

利用紫外线分别对龙轻16和QB_1两种啤酒酵母进行诱变,并通过双乙酰和醋酸铅的酵母CM培养基进行筛选,选出了抗双乙酰和低H_zS合成能力的菌株,这样的菌株用于生产可以改变啤酒的口味,也可做为己标记的菌株,用做原生质体融合的出发菌株,进一步进行高种研究。     

酵母嗜杀质粒融合转移──Ⅰ．融合转移系统的建立

以嗜杀酵母ＥＲＲ１和啤酒生产酵母ＡＳ２４２０出发菌株，建立了供体菌ＭＫ２－３：Ｋ＋Ｒ＋Ｌｅｕ－ρ＋（ｎ）和受体菌ＡＳ２４２０－１：Ｋ－Ｒ－ｌｅｕ＋ρ°（２ｎ）．对原生质体制备再生条件的研究结果表明两株菌的原生质体制备条件不尽相同；同一菌株原生质体形成与再生的最佳条件也不相同．有利于融合再生的原生质体制备条件是ＭＫ２－３：菌龄３０ｈ，蜗牛酶解量３０ｇ／Ｌ酶解时间３０ｍｉｎ，此时原生质体形成率为８０％，而再生率达１７．１％，这些条件对嗜杀活性无影响，再生菌落的嗜杀活性率达１００％；而ＡＳ２４２０－１；菌龄２４ｈ，蜗牛酶量２０ｇ／Ｌ，酶解时间３０ｍｉｎ，原生质体形成率为８１％，再生率为１８．１％．对四种渗透压稳定剂的再生效果实验表明甘露醇效果最佳，氯化钾次之，考虑到廉价，氯化钾是很好的代用品，在３０％ＰＥＧ６０００及Ｃａ２＋条件下进行原生质体融合，融合率可达８．９×１０－６，对其中的融合子ＭＡＲ４的遗传性状及嗜杀活性的稳定性检测，ＤＮＡ含量及细胞大小测定，ｄｓＲＮＡ质粒的提取及电泳结果分析和发酵性能测定，结果表明融合子ＭＡＲ４具有较高的嗜杀活性并可以稳定遗传，有与供体菌ＭＫ２－３嗜杀质粒ｄｓＲＮＡ相同的电泳行为，     

Cloning， expression and characterization of a nucleoside diphosphate kinase (NDPK) gene from tobacco

Nucleoside diphosphate kinase (NDPK) is a housekeeping enzyme that maintains the intracellular levels of all (d)NTPs used in biosynthesis except ATP.Here we report that a full-length cDNA encoding nucleoside diphosphate kinase (NDPK) was cloned us- ing yeast two-hybrid approach.A tobacco NDPK gene was obtained and designated as NtNDPK1.NtNDPK1 is 704 bp in length and en- codes a putative 16.2 kD protein of 148 amino acids.Phylogenic analysis showed that NtNDPK1 is highly homologous to other plant NDPK genes and identified as type I (NDPK1).RNA-gel blot analysis showed that there was no significant difference of NtNDPK1 ex- pression in roots,stems,leaves and buds.And expression of NtNDPK1 was induced by ABA and PEG and repressed by NaCl,but not significantly affected by Paraquat,wounding and low temperature (4℃) treatments,indicating that NtNDPK1 may play a certain role in response to abiotic stress.In vitro phosphorylation assay demonstrated that NtNDPK1 had autophosphoryLation activity.     

Cloning and characterization of a new actin gene from Oryza sativa L.

Using Rho family member osRACD as bait, a new member of actin gene family -Act was isolated from Oryza sativa by yeast two-hybrid system. The full-length cDNA was cloned with 5' RACE technology, which contains an open reading frame of 1134 bp with a predicted protein of 377 amino acids. Sequence alignment revealed 96% to 81.8% identities with some known actin proteins in plants. The method of bioinformatics was used to analyze the protein modification sites, structure and evolution of the gene. Southern blot analysis showed that Act is a single-copy gene in the genome. The result of RT-PCR showed it is ubiquitously expressed in root, shoot, callus and panicle in a temporal fashion. The relationship between Rho family and actin family in evolution and function was also studied.     

细胞不对称分裂机制--芽殖酵母接合型不对称转换

芽列酵母的母细胞与子细胞呈不对称接合型转换，其原因是只有母细胞可表达编码核酸内切酶的基因HO，使相反接合型的缄默基因转位到活动位点取代了原来的接合型基因。HO的不对称表达是因在细胞分裂的末期至G1早期，子细胞核中存在有Ashlp转录抑制因子。Ashlp的不对称分布是由其mRNA的定向转运而实现的：ASH1 mRNA在有丝分裂期被转录出之后，通过接头蛋白She2p和She3p与肌球蛋白Myo4p结合成核糖核蛋白颗粒，经肌动蛋白纤维转运到子细胞远端皮层而锚定并翻译。     

酒曲根霉糖化性质的研究

研究了Rhizopus34产生糖化酶、液化酶、蛋白酶的最佳培养条件，利用Rhizopus34制曲的最佳培养时间为3～4d；在制曲过程中添加5％～10％的玉米粉能显著提高3种酶的活性；制曲和糖化过程中产生3种酶的最佳pH为5．8；3种酶的最佳作用pH值范围为4．6—5．2。     

hTERT主要HLA-A2.1相关基因的表达

为了研究hTERT的表达特性及意义。根据hTERT基因中与HLA-A2.1分子相关性较强的几个9mer肽段合成引物，通过RT-PCR技术分别对14例RCC组织和2例肿瘤细胞株进行了扩增，扩增片段大小为306bp(小片段）和1002bp(大片段），结果有13例癌肿组织表达hTERT基因小片段，1例组织不表达hTERT基因；Hela细胞和786-0肾腺癌细胞株均表达hTERT；对大片段进行克隆，酵母表达，构建了pPICZαA-hTERT重组表达载体和Pichia pastorisX33/hTERT酵母工程菌；SDS-PAGE电泳显示毕赤酵母能分泌表达39kD的目标蛋白。得出，大部分RCC肿瘤组织和细胞表达hTERTmRNA，而正常组织则不表达，提示hTERT可作为通用的抗肿瘤治疗尤其是免疫治疗的靶点。