Expression of a thermostable xylanase gene from Bacillus coagulans ST-6 in Lactococcus lactis

AIMS: The aim of the study is to evaluate whether xylanase can be used as a potential reporter gene for cloning and expression studies in Lactococcus. METHODS AND RESULTS: The 750 bp xylanase gene was amplified and subcloned into the unique NheI restriction enzyme site of pMG36e and subsequently transformed into competent Escherichia coli XLI-blue MRF cells and Lactococcus lactis cells. Bacterial culture containing pMG36e-Xy has an enzyme activity of 390 microg xylose ml(-1) culture 30 min(-1), respectively, when compared with 40 microg xylose ml(-1) culture 30 min(-1) for the negative control (plasmidless strain). CONCLUSIONS: The thermostable xylanase gene was successfully expressed in both E. coli and L. lactis. The activity of xylanase can be easily detected by the formation of visible clearing zones around the transformed colonies on Remazol Brilliant Blue-Xylan (RBB-Xylan) agar media. However, there were some significant differences in the optimum growth temperature and plasmid stability in the new clones. SIGNIFICANCE AND IMPACT OF THE STUDY: The constructed reporter vector has the potential to be used as a reporter system for Lactococcus as well as E. coli, and it is an addition to the pool of lactococcal vector systems.     

Effect of spent cotton stalks on color removal and chemical oxygen demand lowering in olive oil mill wastewater by white rot fungi

Wastewater from olive oil mill was decolorized (and its chemical oxygen demand reduced in static cultivation) using the fungiCoriolus versicolor, Funalia trogii, Phanerochœte chrysosporium andPleurotus sajor-caju. The effect of cotton stalk on decolorizing and COD removing capability was demonstrated.P. chrysosporium (in 20% medium with cotton stalk) reduced the COD by 48% and color by 58%,F. trogii (in 30% medium with cotton stalk) by 51 and 55%, respectively.     

Mitochondrial DNA variation in Indo-Pacific populations of the giant tiger prawn,Penaeus monodon

Surveys of mitochondrial DNA (mtDNA) variation in the giant tiger prawn, Penaeus monodon, using restriction fragment length polymorphisms have provided the first clear evidence that the Indo-West Pacific region is a site of accumulation of genetic diversity rather than a site of origin of genetic diversity. No haplotyes were found in common between a group of five southeast African populations and a group of five Australian (including Western Australia) and three southeast Asian populations. The dominant haplotype was different in the Australian and southeast Asian population groups. Genetic diversity (pi) was greatest in Indonesia (pi averaged 0.05), less in the Philippines and Australia (pi averaged 0.01), and markedly less in the southeast African and the West Australian populations (pi averaged 0.003). The high diversity of the southeast Asian populations resulted from the occurrence in those populations of a set of haplotypes found only in southeast Asia but derived from the southeast African haplotypes. These genetic variants therefore evolved in the Indian Ocean and later migrated into the Indo-West Pacific region. Low genetic variation in the geographically marginal populations in southeast Africa and Western Australia is considered to be the result of bottlenecks, but mismatch distributions suggest that large population sizes have been maintained in Indonesian populations for long periods.     

Population structure of the Indonesian giant tiger shrimp Penaeus monodon: a window into evolutionary similarities between paralogous mitochondrial DNA sequences and their genomes

Here we used both microsatellites and mtCR (mitochondrial DNA control region) sequences as genetic markers to examine the genetic diversity and population structure of Penaeus monodon shrimp from six Indonesian regions. The microsatellite data showed that shrimp from the Indian and the Pacific Ocean were genetically distinct from each other. It has been reported previously that P. monodon mtCR sequences from the Indo‐Pacific group into two major paralogous clades of unclear origin. Here we show that the population structure inferred from mtCR sequences matches the microsatellite‐based population structure for one of these clades. This is consistent with the notion that this mtCR clade shares evolutionary history with nuclear DNA and may thus represent nuclear mitochondrial pseudogenes (Numts).     

Serum selenium and gluthathione-peroxidase activities and their interaction with toxic metals in dialysis and renal transplantation patients

Selenium, aluminum, cadmium, and magnesium concentrations and gluthathione-peroxidase activities in sera of 35 healthy individuals, 30 renal transplants, and 30 hemodialysis patients were measured. Serum selenium, aluminum, and cadmium concentrations in both groups of patients were higher than the controls (p<0.001), whereas the serum gluthathione-peroxidase levels were lower (p<0.001). According to our results, it can be concluded that the patients receiving hemodialysis are subjected to more toxic elements than the transplantation patients. These findings imply that dietary selenium supplement may be suggested in renal failure for the detoxification of elements, such as cadmium and mercury. The essential trace element selenium takes part not only in the direct protection of endothelial cells against the accumulation of aggressive oxygen species, but also in the preventions of the toxic effects of cadmium or in the modulation of the active calcium transport.     

Paralogous mitochondrial control region in the giant tiger shrimp, Penaeus monodon (F.) affects population genetics inference: A cautionary tale

The mitochondrial control region (mtCR) is a widely used genetic marker for phylogenetic, phylogeographic and population genetic inference. The analysis of mtCR in 115 Indonesian specimens of the giant tiger shrimp, Penaeus monodon, revealed 26 individuals yielding a second - apparently paralogous - sequence in addition to the putatively authentic mitochondrial haplotype. The paralogous haplotypes fell into two major haplogroups that are highly diverged with respect to the authentic mitochondrial haplotypes (average pairwise sequence divergence of 12.5% and 5.0%, respectively). A comparison with published mtCR sequences of P. monodon showed that the paralogous contaminant sequences were inadvertently included in a series of recent population genetic studies, leading to seriously compromised conclusions about genetic diversity and differentiation. The prevalence of the paralogous haplotypes throughout the sampled Indo-Pacific populations is highly skewed: From African and Indian individuals only paralogs have been sequenced, while they are completely absent from Australian individuals. This suggests that geographically unequally distributed allelic variants at binding sites of the primer pair ordinarily used to amplify mtCR in P. monodon suppressed the amplification of authentic mtCR in a wide range of samples.     

Ethnobotancal studies in the villages of the district of Ilica (province erzurum), Turkey

An ethnobotanical survey was made of the villages of the Ilica District, Erzurum Province, Turkey. The authors interviewed 130 people in 60 villages. The information so obtained was classified according to the use of plants for food, fuel, dye, and construction materials, as well as for miscellaneous uses. All in all, this study revealed 60 plant taxa that were useful to the villagers of this district.     

Short communication: Decolourization of Crystal Violet by fungi

Crystal Violet was decolourized by Coriolus versicolor, Funalia trogii, Laetiporus sulphureus and Phanerochaete chrysosporium ME446 by 92%, 82%, 86% and 62%, respectively, over 3 days.     

Histopathological and ultrastructural features of enlarged cells of humpback grouper Cromileptes altivelis challenged with Megalocytivirus (family Iridoviridae) after vaccination

The genus Megalocytivirus in the family Iridoviridae encompasses isolates of red sea bream iridovirus (RSIV) and grouper sleepy disease iridovirus (GSDIV). In the present study, humpback grouper Cromileptes altivelis juveniles were challenged with GSDIV after vaccination with a commercial RSIV vaccine. The unvaccinated group (in duplicate) showed higher mortalities (59.3 to 66.7%) than the vaccination group (0% mortalitiy, in duplicate). Surviving fish in the vaccinated group displayed masses of enlarged cells in the spleen. Electron microscopy revealed that they contained hemosiderin granules within the cytoplasm. In contrast, moribund fish from the unvaccinated group exhibited large numbers of inclusion body-bearing cells (IBCs) in the spleen, while surviving fish displayed masses of enlarged cells in which a small number of GSDIV virions were assembled.