Role of VimF in Gingipain Maturation in Porphyromonas gingivalis

Gingipain activity in Porphyromonas gingivalis, the major etiological agent in adult periodontitis, is post-translationally regulated by unique Vim proteins including VimF, a putative glycosyltransferase. To ascertain the VimF mediated phenotype we first inactivated the vimF gene in P. gingivalis ATCC 33277 (FLL476), a less virulent fimbriated strain. We observed that the vimF-defective mutant (FLL476) showed a phenotype similar to that of the vimF-defective mutant (FLL95) in the P. gingivalis W83 background. While hemagglutination was not detected and autoaggregationn was reduced, biofilm formation was increased in FLL476. Also, invasive capacity decreased for this mutant. Furthermore, fimbrial structures were missing in FLL476, suggesting the role of VimF in fimbrial processing. We were able to restore the wildtype phenotype by complementing the defect. Secondly, we cloned, expressed and purified the vimF gene and demonstrated its ability to glycosylate gingipains. In vitro glycosyltransferase activity for rVimF was observed using UDP-galactose and N-acetylglucosamine as donor and acceptor substrates, respectively. Further, in the presence of rVimF and UDP-galactose, a 60 kDa protein from the extracellular fraction of FLL95 which was identified my mass spectrometry as Rgp gingipain, immunoreacted with the glycan specific mAb IB5 antibody. Finally, the polyclonal antibody raised against rVimF that did not react well with native VimF from P. gingilvalis, reacted with a 47 kDa protein when the fractions were first deglycosylated before probing with the antibody. Galactose is vital for growing glycan chain leading to maturation/activation of gingipains. Taken together, these results suggest that VimF glycoprotein is a galactosyltransferase that may be specific for gingipain glycosylation

Reproductive biology of the commercial sea cucumber Holothuria spinifera (Echinodermata: Holothuroidea) from Tuticorin, Tamil Nadu, India

The annual reproductive cycle of the commercial sea cucumber Holothuria spinifera was studied in Tuticorin, Tamil Nadu, India, from September 2000 to October 2001, by macroscopic and microscopic examination of gonad tubule, gonad index and histology of gametogenic stages, to determine the spawning pattern. The gonad consists of long tubules with uniform development. It does not confirm the progressive tubule recruitment model described for other holothurians. The maximum percentage of mature animals, gonad and fecundity indices, tubule length and diameter, with the observations on gonad histology, ascertained that H. spinifera had the peak gametogenic activity during September and October 2001 followed by a prolonged spawning period from November 2000–March 2001

Growth of the hatchery-produced juveniles of commercial sea cucumber Holothuria (Theelothuria) spinifera Theel

The present study was conducted to develop the hatchery technology for seed production of the widely exploited commercial sea cucumber Holothuria spinifera Theel 1886, to facilitate an e¡ective stock enhancement programme. Broodstock collected by skin divers were used for spawning trials. The embryonic and larval stages were similar to other aspidochirotes. The larval survival rate was 43.5% on day 9, which decreased to 18.3% nearing metamorphosis on day 13, the growth rate was 48 mmday_1and the settlement ratewas 3.5%. Algamacs used to induce settlement also served as the food source for the early settled juveniles, followed by Sargassum spp. extract (o40 mm) for the ¢rst month. Sargassum spp. powder along with ¢ne sand (1:1)was givento juveniles420mm. Addition of Spirulina spp. along with Sargassum spp. powder and ¢ne sand (0.5:1:2) enhanced the growth rate of the juveniles. In the hatchery, the juveniles attained an average size of 1, 30 and 48 on 20, 80 and 120 days respectivel

Effects of temperature, salinity and pH on larval growth, survival and development of the sea cucumber Holothuria spinifera Theel

For large-scale seed production of sea cucumbers through a hatchery system, it is imperative to know the effects of environmental parameters on larval rearing. Auricularia larvae (48 h post-fertilization) were obtained from induced spawning of Holothuria spinifera and used in experiments to ascertain the effects of temperature, salinity and pH on the growth and survivorship of the larvae. The larvae were reared for 12 days at temperatures of 20, 25, 28 and 32 °C; salinities of 15, 20, 25, 30, 35 and 40 ppt; and pH of 6.5, 7.0, 7.5, 7.8, 8.0, 8.5 and 9.0. The highest survivorship and growth rate and fastest development of auricularia indicated that water temperature of 28–32 °C, salinity of 35 ppt and pH of 7.8 were the most suitable conditions for rearing larvae of H. spinifera

Drift gill net fishery along Mangalore-Malpe coast

Drift gill net is the major gear used in Mangalore- Malpe area to catch large pelagic fishes. Though the catch by drift-gill net forms only 1% of the toala marine fish catch, the value of the quality fishes it lands exceeds the value of other gears. this gear plays a pivotal roal in the economy of indigenious fisheries sector. the article deals with operation details of drift gill net, catch composition of major fishes and economic status of fishes due to this drift gill net

Preliminary Phytochemical Analysis of \u3cem\u3eDiospyros\u3c/em\u3e Species

Diospyros species are valuable traditional medicines of Chinese herbal medicine, Tibetan medicine, and Ayurvedic medicine. Extractive values and qualitative identification of phytochemicals constituents of 29 Diospyros species was carried out. The methanolic fruit extract yielded maximum percentage of Diospyros malabarica (5.61%), and minimum percentage of Diospyros foliosa (1.25%). Fruits of Diospyros species showed the presence of bioactive constituents of alkaloids (82%), flavonoids (68.97%), tannin (55.17%), terpenoids (100%), and essential oils (100%) were detected in 29 Diospyros species

Oyster farming

Large quantities of the edible oyster, Crassostrea madrasensis (Fig. 1) growing wildly in most of the tidal creeks and estuarine regions along the east coast of India, are allowed to perish un-exploring the great strides made in this venture by developed nations. The Central Marine Fisheries Research Institute focused its attention in developing systems for the culture of edible bivalves, identifying edible oyster farming and mussel farming as priority areas for Research and Development. Evaluation of the resources potential, identification of suitable water spread and areas for culture, evolving proper techniques to collect required seed for farming, introducing an appropriate method of farming and establishing a model farm formed the broad objectives of the project initiated in 1975 on edible oyster culture. By employing suitable method for spat collection and providing better growing conditions for the seed so collected it appeared distinctly possible to raise large number of oysters achieving faster growth rate and better meat yield. Weighing the pros and cons of the different systems of oyster culture followed in other countries and bearing in mind the local conditions, it was decided to experiment with the 'rack' system of culture

केंद्रीय समुद्री मात्स्यिकी अनुसंधान संस्थान का मंगलूर अनुसंधान केंद्र

केंद्रीय समुद्री मात्स्यिकी अनुसंधान संस्थान का मंगलूर अनुसंधान केंद्

Exploited seerfish fishery resources of India - A review

Seerfishes forming 1.7 % of the total marine Jish catch of the country are considered as one of the high value resources Andhra Pradesh (14.3%) and Tami Nadu (11.5%) on the east coast and Gujarat (22.8%). Maharashtra (16.9%) and Kerala (16.1%) on the west coast are the principal contributors of seerfish. They are caught mainly in gillnet (65.12%) and hook & line (6.96%) from 25-50 m depth zone and. in trawl (11.47%) operated from beyond 50 m depth. Of the five species available in Indian waters, the fishery is sustained by the king seer Scomberomorus commerson and the spotted seer S.guttatus. The stock assessment studies on the king seer revealed that the present yield in different regions of the country are closer to MSY. However there is scope for stepping up production by extending fishing operations to the deeper waters beyond 50 m depth. The paper reviews their fishery, biology and stock characteristics in Indian waters