一中国白酒酒曲中的丝状真菌菌群

采用6种不同的培养基,分别于25℃、32℃、42℃以及50℃培养分离从而对某一中国白酒酒曲中的丝状真菌菌群进行研究.从酒曲中共分离得到886株丝状真菌,分属于接合菌,子囊菌和无性型真菌的20属,45种.其中最为丰富的是无性型真菌(28种),其次是接合菌(10种)和子囊菌(7种).对发酵起主要作用的为那些嗜热和耐热的种属,包括:宛氏拟青霉,伞枝梨头霉,梳棉状嗜热丝孢菌,微小根毛霉,金孢霉属一种和红曲属的几个种.文中还对一些在发酵中起重要作用的丝状真菌的特性进行了探讨.     

一株高产Monacolin K紫红曲霉菌株筛选、鉴定及发酵条件优化

为从天然发酵红曲米中分离的30株红曲霉菌株中筛选高产MonacolinK的菌株,并对其产MonacolinK的发酵条件进行优化。实验采用高效液相色谱法(HPLC)筛选到9株具有产MonacolinK能力的红曲霉菌株,其中以编号ZX26的菌株产MonacolinK能力最高,发酵液中Monacolin K产量达到107.6mg/L,并且产MonacolinK能力具有良好的稳定性。微生物形态学结合ITS基因同源性分析结果表明,编号ZX26菌株为紫红曲霉。进一步采用单因素试验和正交试验法优化紫红曲霉ZX26产MonacolinK的发酵条件,结果表明在培养基组分为葡萄糖70g/L,牛肉膏15g/L,NaNO32g/L,MgSO4·7H2O0.5g/L,KH2PO41.5g/L时,其最优发酵条件为:发酵初始pH4.0,接种量为7%,培养温度30℃,发酵10天,在此条件下,紫红曲霉ZX26发酵液中MonacolinK产量达到271.36mg/L,相对于培养条件优化前MonacolinK产量提高152.19%,经验证此培养条件下MonacolinK产量最佳。     

农杆菌介导的红曲菌T-DNA插入突变库的构建及色素突变子的性质分析

以农杆菌EHA105为介导,将带有潮霉素抗性基因和gus基因的T-DNA片段转化到红色红曲菌(Monascusruber)中。通过转化条件的优化,成功构建了含有5132个转化子的T-DNA插入突变库。根据菌落颜色与色素分泌情况筛选到50株色素突变子,聚合酶链式反应(PCR)表明上述突变子均有T-DNA片段插入。经5代的继代培养后,94%的突变子具有稳定性(潮霉素抗性)。对突变子产色素和桔霉素能力的分析表明其分泌次生代谢产物的能力发生了较大变化。本方法的建立,为进一步深入研究红曲菌的代谢调节和基因功能奠定了基础。     

Life history variation in gametophyte populations of the moss Ceratodon purpureus (Ditrichaceae)

The life cycles of mosses and other bryophytes are unique among land plants in that the haploid gametophyte stage is free-living and the diploid sporophyte stage is ephemeral and completes its development attached to the maternal gametophyte. Despite predictions that populations of haploids might contain low levels of genetic variation, moss populations are characterized by substantial variation at isozyme loci. The extent to which this is indicative of ecologically important life history variation is, however, largely unknown. Gametophyte plants from two populations of the moss Ceratodon purpureus were grown from single-spore isolates in order to assess variation in growth rates, biomass accumulation, and reproductive output. The data were analyzed using a nested analysis of variance, with haploid sib families (gametophytes derived from the same sporophyte) nested within populations. High levels of life history variation were observed within both populations, and the populations differed significantly in both growth and reproductive characteristics. Overall gametophytic sex ratios did not depart significantly from 1:1 within either population, but there was significant variation among families in both populations for progeny sex ratio. Some families produced predominantly male gametophytes, while others yielded predominantly females. Because C. purpureus has a chromosomal mechanism of sex determination, these observations suggest differential (but unpredictable) germination of male and female spores. Life history observations showed that male and female gametophytes are dimorphic in size, maturation rates, and reproductive output.     

Production of the secondary metabolites γ-aminobutyric acid and monacolin K by <Emphasis Type="Italic">Monascus</Emphasis>

γ-Aminobutyric acid (GABA), a hypotensive agent, and monacolin K, a cholesterol-lowering drug, can be produced by Monascus spp. Under optimal culture conditions, the products of fermentation using Monascus spp. may serve as a multi-functional dietary supplement and can prevent heart disease. In this study, Monascus purpureus CCRC 31615, the strain with the highest amount of monacolin K, was identified from 16 strains using solid fermentation. Its GABA productivity was particularly high. Addition of sodium nitrate during solid-state fermentation of M. purpureus CCRC 31615 improved the productivity of monacolin K and GABA to 378 mg/kg and 1,267.6 mg/kg, respectively. GABA productivity increased further to 1,493.6 mg/kg when dipotassium hydrophosphate was added to the medium. Electronic Publication     

Optimization of nutrient parameters for lovastatin production by <Emphasis Type="Italic">Monascus purpureus</Emphasis> MTCC 369 under submerged fermentation using response surface methodology

Lovastatin, an inhibitor of HMG-CoA reductase, was produced by submerged fermentation using Monascus purpureus MTCC 369. Five nutritional parameters screened using Plackett–Burman experimental design were optimized by Box–Behnken factorial design of response surface methodology for lovastatin production in shake flask cultures. Maximum lovastatin production of 351 mg/l were predicted in medium containing 29.59 g/l dextrose, 3.86 g/l NH₄Cl, 1.73 g/l KH₂PO₄, 0.86 g/l MgSO₄·7H₂O, and 0.19 g/l MnSO₄·H₂O using response surface plots and point prediction tool of DESIGN EXPERT 7.0 (Statease, USA) software.     

Large scale extraction of high quality moss DNA

For several years Physcomitrella patens Hedw. was the only land plant allowing targeted gene knockout via homologous recombination, which provides an efficient and elegant tool for the analysis of gene functions. The moss Ceratodon purpureus Hedw. was recently shown to have similar capabilities. However, extraction of high quality total DNA from both moss species — necessary for unambiguous proof of successful gene targeting events — is still a severe problem. Here, we report an improved DNA isolation protocol for moss filaments, which is fast, reliable, cheap, quick, and easy. It results in satisfying yields of DNA suitable for PCR and Southern blotting. The modified extraction procedure was additionally tested successfully for the alga Mougeotia scalaris Hass. as well as the higher plant Arabidopsis thaliana L. Published in Russian in Fiziologiya Rastenii, 2007, Vol. 54, No. 4, pp. 634–638. The text was submitted by the authors in English.     

1株高产多糖红曲霉菌株的分离鉴定及生物学特性研究

从市售红曲米和红腐乳中分离纯化得到56株红曲霉菌株,通过摇瓶发酵试验筛选出1株胞外多糖产量为4.73 g/L的红曲霉菌株M-6;依据形态特征、生理生化特征和ITS序列将菌株M-6鉴定为红色红曲霉（Monascus rubber）。并对其部分生物学特性进行了研究。     

Morphological variability and genetic identity in Rhinoestrus spp. causing horse nasal myiasis

Larvae of Rhinoestrus purpureus (Brauer) and Rhinoestrus usbekistanicus Gan (Diptera: Oestridae) cause nasal myiases of equids. During a recent epidemiological survey in southern Italy some morphological and taxonomical doubts arose concerning the identification of Rhinoestrus third stage larvae on the basis of the features of the posterior spiracles and the distribution of dorsal spines on the third segment. Four different morphotypes were retrieved: R. usbekistanicus-like, R. purpureus-like and two morphotypes with shared features. The genes encoding for the mitochondrial cytochrome oxidase I (COI) and for the ribosomal subunits 16S and 28S of the four morphotypes of Rhinoestrus were investigated to determine whether they belonged to a single taxon or they displayed genetic differences indicative of more than one species. The three genes showed a very low level of sequence variation (COI 0-0.43%, 16S 0-1.45%, 28S 0-0.23%) falling within the intraspecific ranges previously described for Oestridae species. Finally, the peritreme features and the spinulation of the third segment of the four morphotypes examined could not be used to differentiate the two species.     

The influence of tapioca on the growth,the activity of glucoamylase and pigment production of <Emphasis Type="Italic">Monascus purpureus</Emphasis> UKSW 40 in soybean-soaking wastewater

The present study evaluates the usefulness of tapioca starch as additional carbon source for the growth of Monascus purpureus in soybean-soaking wastewater (SSW). The result revealed that M. purpureus grown on 2.0% (w/v) tapioca starch in SSW produced significantly (P < 0.05) higher amounts of biomass and production of the pigments (OD₄₀₀ and OD₅₀₀) when compared to those grown on glucose-or maltose-containing media. However, the glucoamylase activity of M. purpureus grown on the tapioca-SSW medium was not significantly increased when compared to those from the glucose-containing medium.