Improved Productivity of Astaxanthin from Photosensitive Haematococcus pluvialis Using Phototaxis Technology

Haematococcus pluvialis is a microalgae actively studied for the production of natural astaxanthin, which is a powerful antioxidant for human application. However, it is economically disadvantageous for commercialization owing to the low productivity of astaxanthin. This study reports an effective screening strategy using the negative phototaxis of the H. pluvialis to attain the mutants having high astaxanthin production. A polydimethylsiloxane (PDMS)-based microfluidic device irradiated with a specific light was developed to efficiently figure out the phototactic response of H. pluvialis. The partial photosynthesis deficient (PP) mutant (negative control) showed a 0.78-fold decreased cellular response to blue light compared to the wild type, demonstrating the positive relationship between the photosynthetic efficiency and the phototaxis. Based on this relationship, the Haematococcus mutants showing photosensitivity to blue light were selected from the 10,000 random mutant libraries. The M1 strain attained from the phototaxis-based screening showed 1.17-fold improved growth rate and 1.26-fold increases in astaxanthin production (55.12 ± 4.12 mg g⁻¹) in the 100 L photo-bioreactor compared to the wild type. This study provides an effective selection tool for industrial application of the H. pluvialis with improved astaxanthin productivity.     

Genotype and virulence of Streptococcus iniae isolated from diseased olive flounder Paralichthys olivaceus in Korea

In the study, we characterized 29 Streptococcus iniae isolates from diseased olive flounder Paralichthys olivaceus in Korea from 2000 to 2005. Biochemical characteristics of 29 isolates using API 20 strep were identical. Through analysis of repetitive sequence-based PCR (rep-PCR) using BoxA primer and random amplified polymorphic DNA using p14 primer, 29 isolates of S. iniae were divided into two genotypes. The isolates were divided into two clusters by comparison of genetic distance using a sequence of the capsular polysaccharide D gene that was consistent with genotyping by the rep-PCR. The isolates belonging to genotype 1 in rep-PCR analysis showed a high virulence in the flounder, while the isolates belonging to genotype 2 were relatively low in virulence. Therefore, a correlation between the genotype and the virulence of S. iniae isolates has been identified.     

Genetic uniformity characterizes the invasive spread of Neofusicoccum parvum and Diplodia sapinea in the Western Balkans

In the past decade, trees and shrubs in the Western Balkans region have been damaged by canker and die‐back disease caused by Botryosphaeriaceae species. These pathogens include Neofusicoccum parvum and Diplodia sapinea. In this study, we determine genetic diversity and structure between populations of N. parvum and D. sapinea from Serbia and Montenegro (Western Balkans) using DNA sequence data of the internal transcribed spacer rDNA, translation elongation factor 1‐alpha, β‐tubulin‐2 and microsatellite markers. The relationship of both pathogens was compared for populations from the Continental (CR) and Mediterranean (MR) regions and for isolates of D. sapinea from Cedrus spp. and Pinus spp. Neofusicoccum parvum and D. sapinea were shown to have a low gene and genotypic diversity across the regions and hosts. All genotypes of D.  sapinea found on Pinus spp. were also present on Cedrus spp. The CR and MR populations of both species were found to be only slightly separated from one another by a geographical barrier. Low genetic diversity and dominance of N. parvum and D. sapinea on non‐native trees suggests that these species have most likely been introduced into Western Balkans, possibly through the movement of infected plants.     

Alleviating cancer drug toxicity by inhibiting a bacterial enzyme

The dose-limiting side effect of the common colon cancer chemotherapeutic CPT-11 is severe diarrhea caused by symbiotic bacterial β-glucuronidases that reactivate the drug in the gut. We sought to target these enzymes without killing the commensal bacteria essential for human health. Potent bacterial β-glucuronidase inhibitors were identified by high-throughput screening and shown to have no effect on the orthologous mammalian enzyme. Crystal structures established that selectivity was based on a loop unique to bacterial β-glucuronidases. Inhibitors were highly effective against the enzyme target in living aerobic and anaerobic bacteria, but did not kill the bacteria or harm mammalian cells. Finally, oral administration of an inhibitor protected mice from CPT-11-induced toxicity. Thus, drugs may be designed to inhibit undesirable enzyme activities in essential microbial symbiotes to enhance chemotherapeutic efficacy.     

Insecticidal activities of crude extracts and phospholipids from Chenopodium ficifolium against melon and cotton aphid, Aphis gossypii

Several organic solvent extracts of Chenopodium ficifolium were tested for their insecticidal activity against melon and cotton aphid, Aphis gossypii, on cucumber plants. Both methanol and ethanol extracts, at 5000 μg ml⁻¹, were highly active giving over 80% control. The other crude extracts displayed moderate or weak insecticidal activity giving control in the range of 16–69%. Two phospholipids were isolated as insecticidal active substances from C. ficifolium. Their chemical structures were identified as 1-palmitoyl-2-(3-trans)-hexadecenoyl-sn-glycero-3-phosphoglycerol and 1-palmitoyl-2-linoleoyl-3-glycerophosphocholine by GC–MS, EDS, mass and NMR spectral analyses. Both compounds displayed a dose-dependent mortality of A. gossypii. Furthermore, the liquid formulation that was obtained by partitioning with n-hexane from the methanol extract of C. ficifolium controlled melon and cotton aphid on cucumber plants effectively. These results indicate that extracts of C. ficifolium have potential for development as botanical insecticides for controlling A. gossypii infesting cucumber plants.     

Antioxidant activity of Filipendula hexapetala flowers

The antioxidant activity of the methanol extract of Filipendula hexapetala flowers was assessed by the assay for ferric-reducing antioxidant power (FRAP), the assay for DPPH free radical scavenging ability (DPPH) and the assay for the influence of lipid peroxidation in liposomes, induced by Fe(2+)/ascorbate system and measured by the TBA test (LP). The activity of the investigated extract in all test-systems was found to be significant. The principal constituent responsible for the observed effects was isolated and identified as spiraeoside.     

Response of economically important aphids to components of Hemizygia petiolata essential oil

The essential oil of Hemizygia petiolata Ashby (Lamiaceae) contains high levels (>70%) of the sesquiterpene (E)-beta-farnesene, the alarm pheromone for many economically important aphid species. In order to test the suitability of H. petiolata oil as a source of (E)-beta-farnesene for use in new integrated aphid control strategies, behavioural responses of pest aphid species were studied in laboratory and field experiments. In alarm pheromone assays the peach-potato aphid, Myzus persicae Sulzer, and the pea aphid, Acyrthosiphon pisum (Harr), showed a lower level of response to the oil than expected given the high levels of (E)-beta-farnesene. It was shown that minor components in the oil, (+)-bicyclogermacrene and (-)-germacrene D, caused inhibition of the alarm response for M. persicae and A. pisum respectively. Nevertheless, in olfactometer studies the oil was directly repellent to A. pisum and the grain aphid, Sitobion avenae F. Sitobion avenae was not only repelled by (E)-beta-farnesene but also by (-)-germacrene D. Furthermore, although it was not directly repellent to M. persicae, the oil interfered with its attraction to host plant stimuli. In field plot experiments, numbers of A. pisum were significantly reduced in plots treated with a slow release formulation of the oil, when compared with control plots.     

Laparoscopic removal of gastric foreign bodies in dogs--comparison of manual suturing and stapling viscerosynthesis

This study was an attempt to evaluate the application of various laparoscopic techniques of removing foreign bodies from the stomach in dogs in comparison to conventional laparotomy. The research was conducted on two groups of 10 dogs each with clinically confirmed foreign bodies in the stomach. In case of all patients, a laparoscopic instrument, EndoBag, was used for the removal of the foreign body from the stomach and the abdominal cavity. Manual suturing with the use of Szabo-Berci suturing kit was used for the gastrotomy wound closure in group I. In group II, linear staplers were used for viscerosynthesis. All patients were subjected to radiological assessment of tightness of anastomosis. No significant differences between the quality of the performed stomach anastomosis were shown. Therefore, the competitiveness of an economical manual suturing in comparison with the very expensive mechanical suturing preferred in human surgery was confirmed. The described procedures of laparoscopic gastrotomy seem to be applicable for removing foreign bodies from the stomach in a clinical veterinary practice.     

The occurrence of hyena disease in young cattle]

Eight juvenile cattle with symptoms of hyena disease are described. This represents the first occurrence of the condition in the Republic of Poland. The growth of the affected animals was retarded, with a marked difference in longitudinal growth of the femoral, humeral, tibial and metatarsal bones. The animals showed altered nickel, manganese and inorganic phosphate concentrations, which may be related to the disease. The genetic studies did not reveal any aetiological factors.