Pretreatment of Miscanthus giganteus with Lime and Oxidants for Biofuels

ACKNOWLEDEGMENTS The authors are grateful to the Energy Biosciences Institute, University of California, Berkeley, Berkeley, CA, for financial support, Dr. Stefan R. Bauer, Valerie D. Mitchell, and Ana Belen Ibanez Zamora for technical assistance, and Jason Cai for fruitful discussions. The authors thank the China Scholarship Council for financial assistance to Fuxin Yang during his stay at University of California, Berkeley.Peer reviewedPostprin

Chemical Components from the Light Petroleum Soluble Fraction of Uvaria cordata (Dunal) Alston

Chromatographic separation of the light petroleum extract from the stem bark of Uvaria cordata (Dunal) Alston led to the isolation of the triterpenoids glutinol and taraxerol in addition to the cyclohexene derivatives, pipoxide and its chlorohydrin. A small amount of benzyl benzoate was also isolated

Persistent Infection and Promiscuous Recombination of Multiple Genotypes of an RNA Virus within a Single Host Generate Extensive Diversity

Recombination and reassortment of viral genomes are major processes contributing to the creation of new, emerging viruses. These processes are especially significant in long-term persistent infections where multiple viral genotypes co-replicate in a single host, generating abundant genotypic variants, some of which may possess novel host-colonizing and pathogenicity traits. In some plants, successive vegetative propagation of infected tissues and introduction of new genotypes of a virus by vector transmission allows for viral populations to increase in complexity for hundreds of years allowing co-replication and subsequent recombination of the multiple viral genotypes. Using a resequencing microarray, we examined a persistent infection by a Citrus tristeza virus (CTV) complex in citrus, a vegetatively propagated, globally important fruit crop, and found that the complex comprised three major and a number of minor genotypes. Subsequent deep sequencing analysis of the viral population confirmed the presence of the three major CTV genotypes and, in addition, revealed that the minor genotypes consisted of an extraordinarily large number of genetic variants generated by promiscuous recombination between the major genotypes. Further analysis provided evidence that some of the recombinants underwent subsequent divergence, further increasing the genotypic complexity. These data demonstrate that persistent infection of multiple viral genotypes within a host organism is sufficient to drive the large-scale production of viral genetic variants that may evolve into new and emerging viruses

Delignification of miscanthus using ethylenediamine (EDA) with or without ammonia and subsequent enzymatic hydrolysis to sugars.

Pretreatment of miscanthus is essential for efficient enzymatic production of cellulosic ethanol. This study reports a possible pretreatment method for miscanthus using aqueous ethylenediamine (EDA) for 30 min at 180 °C with or without ammonia. The mass ratio of miscanthus to EDA was varied from 1:3, 1:1, and 1:0.5, keeping the mass ratio of miscanthus to liquid (EDA + Water) constant at 1:8. The ammonia-to-miscanthus ratio was 1:0.25. After pretreatment with a ratio of 1:3 miscanthus to EDA, about 75 % of the lignin was removed from the raw miscanthus with 90 % retention of cellulose and 50 % of hemicellulose in the recovered solid. Enzymatic hydrolysis of the recovered solid miscanthus gave 63 % glucose and 62 % xylose conversion after 72 h. EDA provides an effective pretreatment for miscanthus, achieving good delignification and enhanced sugar yield by enzyme hydrolysis. Results using aqueous EDA with or without ammonia are much better than those using hot water and compare favorably with those using aqueous ammonia. The delignification efficiency of EDA pretreatment is high compared to that for hot-water pretreatment and is nearly as efficient as that obtained for aqueous-ammonia pretreatment