Extraction, structural and physical characterization of type I collagen from the outer skin of Sepiella inermis (Orbigny, 1848)

The acid soluble collagen (ASC) and pepsin soluble collagen (PSC) were extracted from the outer skin of Sepiella inermis and further characterized partially. The yield of ASC was low (0.58% on dry weight basis); whereas the yield of PSC was comparatively more (16.23% on dry weight basis). The protein content in ASC and PSC was calculated as 20.24 and 69.56%, respectively (on dry weight basis). The sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) gel profile showed two bands for ASC and PSC with corresponding molecular weight of 86 and 67 kDa and 86, 63 and 58 kDa respectively. The differential scanning calorimetry (DSC) results showed that ASC withstand up to 75.93°C whereas the PSC withstand up to 75.05°C. The fourier transform infrared spectroscopy (FT-IR) spectrum of both ASC and PSC recorded 11 and 13 peaks, respectively. The fine structure of both ASC and PSC was also studied using scanning electron microscopy (SEM).Key words: Sepiella inermis, acid soluble collagen (ASC), pepsin soluble collagen (PSC), differential scanning calorimetry (DSC), fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM)

Isolation and partial characterization of collagen from outer skin of Sepia pharaonis (Ehrenberg, 1831) from Puducherry coast

Type I collagen from outer skin of Sepia pharaonis was extracted and partially characterized. Yield of Acid Soluble Collagen (ASC) and Pepsin Soluble Collagen (PSC) were calculated as 1.66% and 3.93% and the total protein content of ASC and PSC were found as 18.4% and 48.6%. FT-IR spectrum of ASC and PSC recorded 12 and 14 peaks, respectively. 1H NMR spectrum of ASC showed singlets at 1.23 ppm, 3.1 ppm, 3.55 ppm and 3.7 ppm and PSC at 1.23 ppm and 2.08 ppm. The molecular weight for ASC was calculated as 102 kDa and for PSC as 110, 108 and 102 kDa through SDS-PAGE. Differential Scanning Calorimetry (DSC) results supported that PSC withstand high thermal stability (82.85 °C) than ASC (73.13 °C). Higher denaturation temperature with high molecular weight well support the property of type I collagen from skin of S. pharaonis and it could be used as another potent source for the extraction of collagen

Short-term in situ shading effectively mitigates linear progression of coral-killing sponge Terpios hoshinota.

The coral-killing sponge, Terpios hoshinota is a global invasive species that has conquered coral patches within a short span of time, which has led to a significant decline in living coral cover at various geographical locations. In this study, we surveyed the linear progression and impact of the Terpios invasion on live coral patches along Palk Bay, Indian Ocean, from August 2013 to August 2015. The field inventory revealed an extensive fatality rate of 76% as a result of Terpios outbreak. Experimental findings showed that symbiotic cyanobacteria act as a nutritional factory for the aggressive growth of Terpios. Shading hypothetically impairs the nutritional symbiont of the invasive species: the effect of sunlight on cyanobacterial biomass and its influence on Terpios progression over live coral patches was tested through in situ shading experiments. This study showed that artificial shading with cotton fabric could effectively mitigate sponge growth on live coral without affecting coral homeostasis

Correction: Short-term in situ shading effectively mitigates linear progression of coral-killing sponge Terpios hoshinota.

[This corrects the article DOI: 10.1371/journal.pone.0182365.]

Linear progression of <i>Terpios</i> over live corals.

<p>Images <i>a</i>, <i>b</i> and <i>c</i> show <i>Terpios</i> progression over live coral <i>Platygyra</i> colony. Note the progression of <i>Terpios</i> over the tag. Images <i>d</i> and <i>e</i> show <i>Terpios</i> covered <i>Acropora</i> and coralline algae, respectively.</p

(a) Mean chlorophyll <i>a</i> content, (b) Progression rate difference between control and experimentally shaded coral colonies.

<p>(a) Mean chlorophyll <i>a</i> content, (b) Progression rate difference between control and experimentally shaded coral colonies.</p

Short-term <i>in situ</i> shading effectively mitigates linear progression of coral-killing sponge <i>Terpios hoshinota</i>

<div><p>The coral-killing sponge, <i>Terpios hoshinota</i> is a global invasive species that has conquered coral patches within a short span of time, which has led to a significant decline in living coral cover at various geographical locations. In this study, we surveyed the linear progression and impact of the <i>Terpios</i> invasion on live coral patches along Palk Bay, Indian Ocean, from August 2013 to August 2015. The field inventory revealed an extensive fatality rate of 76% as a result of <i>Terpios</i> outbreak. Experimental findings showed that symbiotic cyanobacteria act as a nutritional factory for the aggressive growth of <i>Terpios</i>. Shading hypothetically impairs the nutritional symbiont of the invasive species: the effect of sunlight on cyanobacterial biomass and its influence on <i>Terpios</i> progression over live coral patches was tested through <i>in situ</i> shading experiments. This study showed that artificial shading with cotton fabric could effectively mitigate sponge growth on live coral without affecting coral homeostasis.</p></div