Azaphilone pigments from a yellow mutant of the fungus Monascus kaoliang

Azaphilone pigments, monascusones A (1) and B (2), together with two known azaphilones, monascin (3) and FK17-P2b2 (4), were isolated from the CH2Cl2 extract of a yellow mutant of the fungus M. kaoliang grown on rice. Structures of the isolated compounds were elucidated by analyses of spectroscopic data. Monascusone A (1), the major metabolite of M. kaoliang, showed no antimalarial (against Plasmodium falciparum), antitubercular (against Mycobacterium tuberculosis H37Ra), and antifungal (toward Candida albicans) activities. Compound 1 exhibited no cytotoxicity against BC (breast cancer) and KB (human epidermoid carcinoma of cavity) cell lines.     

Production of Monascus pigments as extracellular crystals by cell suspension culture

Applied Microbiology and Biotechnology - It is generally accepted that Monascus pigments are predominantly cell-bound, including both intracellular and surface-bound pigments. This long-term...     

Male sterile mutant from somatic cell culture of rice

Summary Using MS medium supplemented with 6% sucrose and hormones, plantlets were regenerated from the expiants of mature seeds and young panicles of IR_s and IR₅₄. Out of 157 regenerated plants (R₁), three were found to be male sterile (ms): one from IR_s and two from IR₅₄, including a fertile and sterile chimaera. In the second generations (R₂) of IR₂₄ and IR₅₄, one line from each segregated into male sterile and fertile plants. These ms plants could be divided into two types with pollen failure: pollen free (without pollen) and pollen abortive. IR₂₄ was a semi-restorer for ms-plants of the pollen free type derived from the second generation of IR₅₄ somaclones. The segregation ratio of fertile: sterile in both R₂ of line 91 and the F₂ of ms-plant/IR₂₄ fitted the formula 15/161/16 quite well, showing that the male-sterile was controlled by two independent nuclear genes. Until now, as we know, male-sterile could be produced by hybridization or mutagenesis: sometimes it could be found in nature by spontaneous mutation. Recently the cytoplasmic male-sterile of tobacco was produced by protoplast fusion. This is the first paper to report male-steriles in regenerated plants and their offspring obtained from somatic cell culture.Some of the tissue culture and plant regeneration work in this study was conducted at IRRI, Manila     

以糙米为原料流加L-蛋氨酸的S-腺苷蛋氨酸发酵优化

研究了S-腺苷甲硫氨酸(SAM)高产菌啤酒酵母S-W55的廉价培养基及分批补料发酵过程优化.对啤酒酵母S-W55生长和SAM产量影响最为重要的糙米水解糖和酵母粉进行了响应面优化,得到了最优化的配方为糙米水解糖51.4g/L、酵母粉4.74g/L,此条件下啤酒酵母S-W55的SAM产量达2.61 g/L.不同分批补料发酵...     

New modified trichothecenes accumulated in solid culture by mutant strains of Fusarium sporotrichioides

Mutant strains of Fusarium sporotrichioides NRRL 3299 deficient in the ability to synthesize T-2 toxin were examined on solid rice medium. Five novel alicyclic trichothecenes were isolated: 11 alpha-hydroxytrichodiene; tricho-9-ene-2 alpha,3 alpha,11 alpha-triol; tricho-9-ene-2 alpha,3 alpha,8 alpha,11 alpha-tetraol; tricho-9-ene-2 alpha,3 alpha,8 beta,11 alpha-tetraol; and tricho-9-ene-2 alpha,3 alpha,11 alpha,16-tetraol.     

Effect of pH on citrinin and red pigments production by Monascus purpureus CCT3802

The production of red pigments and citrinin by Monascus purpureus CCT3802 was investigated in submerged batch cultures performed in two phases: in the first phase, cells were grown on glucose, at pH 4.5, 5.5 or 6.5; after glucose depletion, pH was adjusted, when necessary, to 4.5, 5.5, 6.5, 7.0, 8.0 or 8.5, for a production phase. The highest total red pigments absorbance of 11.3 U was 16 times greater than the lowest absorbance and was achieved with growth at pH 5.5, followed by production at pH 8.5, which causes an immediate reduction of the intra cellular red pigments from 75% to 17% of the total absorbance. The lowest citrinin concentration, 5.5 mg L⁻¹, was verified in the same culture while the highest concentration, 55 mg L⁻¹, was verified in cultures entirely carried out at pH 5.5. An alkaline medium, besides promoting intra cellular red pigments excretion, strongly represses citrinin synthesis.     

New modified trichothecenes accumulated in solid culture by mutant strains of Fusarium sporotrichioides.

Mutant strains of Fusarium sporotrichioides NRRL 3299 deficient in the ability to synthesize T-2 toxin were examined on solid rice medium. Five novel alicyclic trichothecenes were isolated: 11 alpha-hydroxytrichodiene; tricho-9-ene-2 alpha,3 alpha,11 alpha-triol; tricho-9-ene-2 alpha,3 alpha,8 alpha,11 alpha-tetraol; tricho-9-ene-2 alpha,3 alpha,8 beta,11 alpha-tetraol; and tricho-9-ene-2 alpha,3 alpha,11 alpha,16-tetraol.     

黄酒中多糖的提取和分析

本文利用单因素和正交试验探究了黄酒中多糖提取工艺条件,并分析了黄酒多糖的化学组分。单因素实验结果表明,乙醇浓度在低于80%时,粗多糖的提取量随着乙醇浓度的增加而增加,高于80%时,粗多糖的量变化不大;醇沉时间到达第8 h时粗多糖的提取量基本达到稳定;在醇沉温度为10℃时粗多糖的量达到最大值。通过正交试验得到的黄酒多糖的最佳提取工艺为:乙醇浓度为80%,醇沉时间为6 h,醇沉温度为5℃。进一步分析纯化后多糖的化学组分为中性糖含量为89.6%、糖醛酸含量为0.48%、蛋白质含量为4%。     

金花菌黄色素的稳定性及其抗氧化活性研究

【目的】评价茯砖茶金花菌黄色素的稳定性和抗氧化性能。【方法】以色素保存率为指标, 研究温度、光照和pH对黄色素稳定性的影响。并对还原能力、DPPH·清除能力和H2O2诱导的红细胞溶血抑制能力进行测定, 考察黄色素的抗氧化性能。【结果】该色素在低温下保存7 d保存率高于98.88%, 温度升高, 保存率降低; 光照尤其是太阳光对其稳定性影响较大; 黄色素在pH 2?10较稳定, pH 12时色素保存率仅为46.22%。低浓度黄色素具有明显高于维生素E (VE)的还原能力、DPPH·清除率和溶血抑制率, 其中DPPH·的EC50低于50 mg/L。【结论】金花菌黄色素对热、酸和弱碱较稳定, 对强碱和太阳光极不稳定, 并有优良的抗氧化能力, 研究和开发前景良好。     

Cellulase production in a new mutant strain of Penicillium decumbens ML-017 by solid state fermentation with rice bran

To produce cellulolytic enzyme efficiently, Penicillium decumbens strain L-06 was used to prepare mutants with ethyl methane sulfonate (EMS) and UV-irradiation. A mutant strain ML-017 is shown to have a higher cellulase activity than others. Box-Behnken's design (BBD) and response surface methodology (RSM) were adopted to optimize the conditions of cellulase (filter paper activity, FPA) production in strain ML-017 by solid-state fermentation (SSF) with rice bran as the substrate. And the result shows that the initial pH, moisture content and culture temperature all have significant effect on the production of cellulase. The optimized condition shall be initial pH 5.7, moisture content 72% and culture temperature 30°C. The maximum cellulase (FPA) production was obtained under the optimized condition, which is 5.76 IU g(-1), increased by 44.12% to its original strain. It corresponded well with the calculated results (5.15 IU g(-1)) by model prediction. The result shows that both BBD and RSM are the cellulase optimization methods with good prospects.     

红曲米和红腐乳中红曲菌种的分类与鉴定

对我省红腐乳及红曲米中红曲菌的资源、多样性进行了调查,收集、分离和纯化得到20株红曲菌的纯培养。根据李钟庆等人的红曲菌属分类检索表,通过菌落形态和显微特征进行观察常规袁型鉴定,初步确定为以下七个种：红色红曲菌（FA01、FA11）;橙色红曲菌（FA02、FA05、FA06、FA15、FA16、FA17）、紫色红曲菌（FA03、FA09、FA13、FA19、FA20）、丛毛红曲菌（FA04）、发白红曲菌（FA07、FA18）、旱生红曲菌（R如8、FA10、FA12）和血红红曲菌（FA14）。运用FTIR分析图谱构建了20株红曲菌株的系统发育图,探讨耵IR分析运用于红曲菌资源或其它真菌的多样性、亲缘关系和分类鉴定中的可行性。研究结果显示FTIR分析在一定程度上可区分不同的红曲菌种,可以作为红曲菌菌种和疑难菌株鉴别的辅助手段。     

Linkage analysis of a fertility restoring mutant generated from CMS rice

 DNA polymorphism between a cytoplasmic male-sterile rice line II-32A, the male-fertile maintainer counterpart II-32B, a fertile revertant (T24), as well as two commercial indica restorers, was analyzed with randomly amplified polymorphic DNA (RAPD). A very low degree of polymorphism was found between the revertant T24 and II-32A compared with that of indica rice varieties. This result, together with agronomic and genetic evidence, suggests the revertant to be a product of a nuclear mutation. An analysis of polymorphism between II-32A and the revertant T24 with 510 RAPD decamer primers identified the co-segregating markers OPB07₆₄₀ and OPB18₁₀₀₀ to be linked to a sterile allele of the restoring locus in the revertant T24, at a distance of 5.3 cM. RAPD analysis of a mapping population of Tesanai2/CB with primer OPB07 revealed linkage of OPB07₆₄₀ with RG374 (10.8 cM) and RG394 (8.8 cM) on chromosome 1. Thus the restorer gene, designated Rf ₅, was tentatively localized between RG374 and RG394 on chromosome 1 and appears to be independent of other mapped restorer genes in rice. Received: 11 November 1997 / Accepted: 17 December 1997     

无桔霉素红曲色素突变株FM5183对单谷氨酸钠(MSG)、组氨酸的代谢特性

经过复合诱变处理得到的产无桔霉素的红曲色素变异株,编号为FM5183,在摇瓶条件下分批深层培养,研究了菌株在碳源为葡萄糖条件下对单谷氨酸钠（MSG）,组氨酸的代谢特性,该菌株分别在含MSG和组氨酸情况下,对产生的中间产物苹果酸和乙醇的代谢特性进行了比较。结果表明：突变菌株FM5183产生的酒精量为2.5-2.7g/L,苹果酸浓度最大值为5.8g/L;另外,在含MSG和组氨酸的培养基上对产生的色素量进行测定,其色价分别为25.5和11.8,对试验所用的氮源等条件下,整个发酵过程未有桔霉素检出,突变菌株FM5183是一株较理想的无桔霉素红曲色素工业化生产菌株。     

Phenotypic rescue of mutant brown melanocytes by a retrovirus carrying a wild-type tyrosinase-related protein gene

A mouse cDNA for the developmentally controlled, melanocyte-specific protein, tyrosinase-related protein 1 (TRP-1), was previously cloned and reported to show genetic linkage with the coat-colour locus brown (b) on mouse chromosome 4. The cDNA has been inserted into a retroviral vector derived from Moloney murine leukaemia virus, under the control of the human histone H4 promoter. This vector was used to infect melanocytes of the immortal line melan-b, which are homozygous for the b mutation and which display light brown pigmentation in culture. Infected cultures containing between 0.2 and 2 copies of provirus per cell displayed an altered phenotype: 20-50% of cells now had the black to dark brown colour characteristic of cultured wild-type (Black, B/B) mouse melanocytes. Thus the TRP-1 gene complements the brown mutation. We conclude that TRP-1 is the product of the wild-type b-locus.     

Genetics and ultrastructure of a cytoplasmically inherited yellow mutant in soybeans

A chimeric plant was observed in the F₂ generation of a cross between a male-sterile line and a plant introduction homozygous for a chromosome interchange in soybeans [Glycine max (L.) Merr.]. F₃ progeny of this plant included one chimera, 36 yellow plants and 16 green plants. The yellow plants, which progressively turn green, were viable and fertile in field, greenhouse and growth-chamber environments. Reciprocal cross-pollinations were made between these yellow plants and four known nuclear yellow mutant plants, between these yellow plants and sibling green plants and between these yellow plants and unrelated green plants. Segregation data from F₁ and F₂ generations indicated cytoplasmic inheritance of the newly discovered yellow phenotype. Pollinations in which reciprocal F₁ hybrid plants were used as male or female parents were made with unrelated green plants. Observations in F₁ and F₂ generations substantiated the hypothesis of cytoplasmic inheritance. No interactions have been observed between this mutant and the various nuclear backgrounds. This is the first report of a cytoplasmically inherited mutant affecting plant color in soybeans. Exchange grafts were made between cytoplasmic yellow plants and sibling green plants and between cytoplasmic yellow plants and unrelated green plants. The phenotype was controlled by the scion, indicating that graft-transmissible agents were not involved. When grown in darkness, cytoplasmic yellow plants and normal green plants accumulated the same amount of protochlorophyllide. Cytoplasmic yellow plants grown in dim light accumulated slightly less chlorophyll than did their green siblings. Electron photomicrographs showed that the prolamellar body (a structure associated with synthesis of protochlorophyllide) and chloroplast ultrastructure were normal in the cytoplasmic yellow mutant. These observations led to the hypothesis that the synchrony involved in deposition of nuclear and cytoplasmic gene products during organelle development is impaired in this cytoplasmic mutant.