Enhanced production of Scenedesmus spp. (green microalgae) using a new medium containing fermented swine wastewater.

Fermented swine urine (3%) (v/v) was added to a control medium (CT), named KEP I, and an aquatic microalgal culture (10% Bold's Basal Medium) for growing mixed Scenedesmus species. During a two-month period, the KEP I medium effected, the delayed onset of the stationary phase of cell division in a batch culture. After 31 days, of culturing, the growth rate (3-fold), dry weight (2.6-fold) and amino acid levels (2.7-fold), and secondary metabolites including chlorophyll a (2.1-fold), astaxanthin (2.8-fold), lutein (2.7-fold) and alpha (greater than 30-fold) and beta-carotene (greater than 5-fold) increased a greater degree in Scenedesmus grown in KEP I medium than in CT medium. Total lipids were much less in cells grown in KEP I than those grown in CT. An increased quantum yield of photosystem II of the aquatic microalgae. The KEP I medium should improve the cost efficiency of industrial mass batch cultures for CO(2) sequestration, bioremediation, phytonutrients, agricultural fertilizers, and microalgal stock for the species preservation of aquaculture strains for use in young fish feed. It may also serve to attenuate negative environmental impact via the recycling of animal wastewater.

Genome characterization of a Korean isolate of cymbidium mosaic virus.

The complete nucleotide sequence of the genomic RNA of a Korean isolate of cymbidium mosaic virus (CymMV-K2) was determined. The genomic RNA is 6227 nucleotides in length, excluding the poly(A) tail. It contains a 5'-noncoding region (NCR) of 73 nucleotides, five open reading frames (ORFs 1 to 5) which encode proteins with M(r) 160 kDa RNA-dependent RNA polymerase (ORF1), 26 kDa movement protein 1 (ORF2), 13 kDa movement protein 2 (ORF3), 10 kDa movement protein 3 (ORF4), 24 kDa coat protein (OFR5), and a 3' NCR of 76 nucleotides. The 5'-end of the CymMV-K2 genome initiates with GGAAAA which contrasts to GAAAA at the 5'-ends of other potexviruses, including a Singapore isolate of CymMV (CymMV-S2). When compared with CymMV-S2, 171 base substitutions were observed in the CymMV-K2 genome. Substitutions in the overlapping ORFs (ORFs 2 to 4) occurred more frequently than those in 5' NCR, ORF1, and 3' NCR. In addition to substitutions, two single-base deletions, one in the intercistronic region between ORF1 and ORF2 and the other in the ORF2, were found on the CymMV-K2 genome. The deletion in the ORF2 induced a frameshift which altered the C-terminal domain of movement protein 1. ORF3 and ORF4 of the CymMV-K2 genome are partially different from those of another Singapore CymMV genome (CymMV-S1) which has four frameshifts due to nucleotide deletions within these ORFs. Interestingly, the frameshifts resulted in no change in the conserved sequences of the movement proteins but reconstructed their transmembrane domains.

Coat protein gene and 3'-noncoding region of a new Korean isolate of cymbidium mosaic virus.

A new Korean isolate of cymbidium mosaic virus (denoted as CymMV-K2), a member of potexviruses, was identified and isolated from a Korean cultivar of Cymbidium species When the nucleotide sequence of the 3'-terminal region of the viral RNA was compared with those of the corresponding regions of two Singaporean isolates (denoted as CymMV-S1 and CymMV-S2) and a Korean isolate (denoted as CymMV-K1), the nucleotide sequence of the coat protein gene of CymMV-K2 was highly homologous to other cymbidium mozaic viruses (92.9%-96.7% homology). The coat protein of CymMV-K2 and CymMV-S2 consists of 223 amino acids, while the coat protein of CymMV-K1 and CymMV-S1 consists of 220 amino acids. This difference was caused by deletions of 5 nucleotides in the coat protein open reading frame (ORF) of CymMV-S1 and CymMV-K1, when compared with CymMV-K2 and CymMV-S2. These deletions result in changes of the deduced amino acid sequence and the length of the coat protein. The 3'-noncoding region of the CymMV-K2, which contains sequences involved in the replication and polyadenylation of viral RNA, was compared with those of other cymbidium mosaic viruses. No canonical polyadenylation signal was found in the 3'-noncoding region of CymMV-K2, whereas in other CymMVs AAUAAA boxes, are present at the end of RNA with their AAA portions as the first A residue of the poly(A) tail.

Identification of one of the major viruses infecting garlic plants, garlic virus X.

A partial cDNA clone for garlic virus X (GVX) was isolated. GVX was identified immunologically with an antibody raised against the recombinant coat protein (CP) and demonstrated to be one of the major viruses infecting garlic plants showing mosaic or streak symptoms. GVX belongs to an unassigned group of ShVX and GarV-type viruses rather than to carlaviruses or potexviruses. The recombinant CP of GVX was purified by Ni(2+)-NTA affinity chromatography. Anti-GVX CP antibody was raised against the purified recombinant CP. GVX particle is flexuous, rod-shaped, and about 750 nm long as determined by immunoelectron microscopy. The extent of infection by GVX of garlic plants was analyzed by Northern or immunoblot analyses of individual garlic plants cultivated in different regions. These results showed that almost all of the garlic plants tested from 40 different regions including America, China, Japan, and Korea are infected with GVX.