Microfouling of Manganese-oxidizing microorganisms in Rameswaram Coastal Waters.

Manganese oxidizing marine microorganisms was studied from the coupons of PVC, Titanium, Brass, Copper and Stainless Steel were immersed one meter below water surface, using wooden rafts. The metal coupons, Brass, Titanium and Brass were exposed for a period of six months (October 2005 to March 2006). The PVC and SS were suspended in the sea for two months (February and March 2006). Sea water samples were also collected from the study area using water sampler to estimate the physiochemical and nutrients were analyzed. The population of HB and MHB on PVC was registered as 3.62 x 107 CFU/cm2 and 2.87 x 107 CFU/cm2, respectively while on Stainless Steel the population density of HB and MHB was recorded as 3.79 x 105 CFU/cm2 and 1.34 x 105 CFU/cm2. The PVC and titanium coupons were recorded relatively higher values comparing with other coupons, and it may be due to the non-toxic nature of the substratum. Brass also recorded higher bacterial population density compared to copper. The least population density observed in copper coupons could be due to it toxic nature. The generic composition of heterotrophic bacterial strains isolated from biofilm samples, both Gram-positive and Gram-negative groups were noted on all the materials studied. The notable thing was that Gram-positive group was fond to be dominant. The genera identified under Gram-positive were Bacillus sp., Staphylococcus sp. and Micrococcus sp. and the Gram-negative strains identified as Pseudomonas sp., Salmonella sp., Vibrio sp. and Proteus sp. Among the five types of coupons tested PVC exhibited highest Mn value of 5543 mg/g. Bacterial slim samples generated on the exposed coupons were scrapped and characterized by Bergey’s method.

&#xa

Effect of turmeric on shrimp (Penaeus semisulcatus) shelf life extension in chilled storage conditions

The present investigation aimed to evaluate the effect of turmeric on shelf life extension of shrimp Penaeus semisulcatus under chilled storage conditions by sensory (organoleptic parameters), pH, proximate and bacterial analysis. The experimental setup was grouped into six, head on (group I), head on coated with turmeric (group II), headless (group III), headless coated with turmeric (group IV), peeled (group V) and peeled and coated with turmeric (group VI) groups. Peeled shrimps coated with turmeric group retained their quality and their shelf life was extended up to 8 days of storage in ice (1:1). Significant differences (p<0.05) were found in the overall acceptability among the experimental groups of fresh and cooked shrimp. The level of pH, protein and carbohydrate varied (p<0.05) among the experimental groups. However no significant difference was found in the lipid and bacterial level in peeled shrimp coated with turmeric on the 8th day compared to other groups including the control. The sensory analysis, pH, protein, carbohydrate, lipid and bacteriological results of the present study proved that the application of turmeric in peeled shrimp stored in ice (1:1 ratio) extended its shelf-life up to 8 days

Assessment of the effect of green synthesized silver nanoparticles against aquatic pathogen Aeromonas hydrophila using Artemia nauplii

1831-1838Fish disease is a major threat affecting the long-term development of aquaculture industry leading to great economic loss annually. Aeromonas hydrophila bacterium may be a primary or secondary cause of ulcers, hemorrhagic septicemia, fin rot and tail rot in fishes. Excess and abandoned usage of antibiotic substances caused a substantial growth of antibiotic resistant pathogens. Now a days, enduring research has focused on improvement of nanomaterials for efficient antimicrobial therapies. Comparing to the synthesis of other metallic nanoparticles, silver nanoparticles (AgNPs) has gained much attention because of its unique antimicrobial properties. The present study was aimed to green synthesize AgNPs using the Annona squamosa leaf extract which acts as a non-toxic reducing agent. The synthesized AgNPs were evaluated for biocompatibility and antagonistic efficacy against A. hydrophila. The green synthesized AgNPs were bio-physically characterized by UV-Visible spectroscopy, X-ray powder diffraction, High Resolution Transmission Electron Microscope, Fourier-transform infrared spectroscopy and Zeta Potential analysis. The particles were almost spherical shaped and in the range of 15-25 nm. Green synthesized AgNPs exhibited significant DPPH radical scavenging activity (64.62 %). Synthesis of AgNPs using widely available plants can be promoted as a potential eco-friendly option to chemical methods used for nanosynthesis. In-vivo studies confirmed that the AgNPs exhibited good antagonistic against A. hydrophila and also proved its non-toxic effect to Artemia salina nauplii

Effect of turmeric and Spatoglossum asperum on shelf life extension of marine finfish Sillago sihama in chilled storage condition

829-838The effect of turmeric and seaweed powder (Spatoglossum asperum) on shelf life extension of Sillago sihama in chilled storage condition was determined by sensory, pH, biochemical and bacteriological analysis. The experimental setup was divided into six groups, undeveined, deveined, undeveined coated with 5 % S. asperum powder, deveined coated with 5 % S. asperum powder, undeveined coated with 5 % turmeric and deveined coated with 5 % turmeric, all the group of fishes were stored in chilled conditions with 1:1 (fish:ice) ratio. Deveined S. sihama coated with 5 % turmeric demonstrated a longer shelf life of 14 days and between the groups significant differences (P &lt; 0.05) were found in the sensorial, pH, biochemical and bacteriological values. Nevertheless, the validity of group one and two were found to be acceptable up to 8 and 10 days, respectively. In conclusion, deveined S. sihama coated with 5 % turmeric and stored in chilled conditions retain the shelf-life up to 14 days

Breeding biology of Babylon snail Babylonia spirata (Linnaeus) (Mollusca: Neogastropoda: Buccinidae)

368-370Breeding biology of the buccinid gastropod B. spirata, has been studied as regards to sex ratio, maturity size, gonad index, laboratory spawning, egg capsules, hatching, fecundity and larvae. The sex ratio was found to be 1:1.34. Gonad index of both males and females was high in March 1993. Spawning was observed from February to May 1993. The B. spirata laid vasiform egg capsules in night hours from February to Map 1993 and the number of egg capsules per female, varied from 28 to 41. It took nearly 24 hours to liberate all the veliger larvae from capsule and the larvae showed positive phototactism and planktotrophism

Magneto bacteria from estuarine, mangrove and coral reef environs in Gulf of Mannar

332-334Totally 37 strains from the three biota were isolated with predominance of Bacillus spp. followed by Pseudomonas spp. Spirillium spp., and Vibrio spp. Based on the fatty acid profile, a few of the strains were identified as Pseudomonas mesophilico, Pseudomonas caryophylli and Bacillus cereus. Of the three biota studied, the coral reef harbours higher percentage of magnetotactic bacteria followed by the mangroves and estuaries. The strains were further studied for growth, salinity optimum, magnetotaxis and survival. The bacterial growth was observed as a ring form ion between 7 and 14 days of inoculation. The distance to the ring from the top surface of culture medium ranged from 0.5 to 4.6 cm. The ring was prominent in a salinity of 20 ppt. Regarding magnetotaxis, a 3 h exposure to the external magnetic field was required for 100% aggregation of bacterial cells. The magnetobacleria isolated from coral reef were able to survive for 5 to 6 months whereas those from mangroves and estuaries survived for 4 and 2 months respectively.</span

Bleaching and secondary threats on the corals of Palk Bay: A survey and Proactive conservation needs

19-26A survey on bleaching and the secondary threats on bleached corals in the selected sites of Palk-Bay were conducted during May and June 2010. Massive corals represented by the genera Porites, Goniopora, Favia were bleached extensively. Significant portion of the surface of live corals were found dead. Coral recovery after bleaching was at a great risk due to the algal overgrowth and sedimentation which would lead to their death and permanent loss. Destruction of the slow growing corals by natural and altered environmental conditions warrant the proactive conservation approach guided by scientific principles. Current conservation methods in India offers physical protection to corals by entry restriction and a ban on collection of corals under wild life act. This is inadequate as they could not prevent secondary stressors taking toll on corals during environmentally induced stress conditions