No abstract

The objective of this study was to investigate the yield and characteristics of collagen protein extracted from the muscle of four different species of mantis shrimp: Miyakella nepa, Harpiosquilla harpax, Erugosquilla woodmasoni, and Odontodactylus cultrifer. Mantis shrimp muscle was extracted by using a pepsin-solubilization technique, with 0.5 M acetic acid and 5% pepsin enzyme. The highest collagen yield was from M. nepa muscle (0.478 ± 0.06%), which was significantly greater (p < 0.05) than that from H. harpax, O. cultrifer, and E. woodmasoni (0.313 ± 0.03%, 0.123 ± 0.02%, and 0.015 ± 0.00%, respectively). The freeze-dried collagen appeared as thin fibers, and formed an opaque film. The pepsin-soluble collagen (PSC) from four mantis shrimp species was analyzed by gel electrophoresis. The results showed that all species of mantis shrimp contained type I collagen, consisting of β, α1, and α2 subunits with average molecular weights of 250, 145, and 118 kDa, respectively. The study of the solubility of collagen showed that, for NaCl, collagen had the highest relative solubility in 2% NaCl (80.20 ± 4.95%). In contrast, the solubility decreased at higher NaCl concentrations. However, in terms of pH, collagen had the highest relative solubility at pH 3 (91.32 ± 5.14%), and its solubility decreased at higher pH. FT-IR spectroscopy was used to compare the collagen with a model compound. Five wavenumbers in the spectrum for model collagen were identified: Amide A (3,406-3,421 cm -1 ), amide B (2,916-2,940 cm -1 ), amide I (1,639-1,640 cm -1 ), amide II (1,539-1,570 cm -1 ), and amide III (1,234-1,250 cm -1 ).

The objective of this study was to identify Chaetoceros species using microscopic observations, sequence analysis of 18S rDNA, random amplified polymorphic DNA (RAPD) barcoding and nuclear magnetic resonance (NMR) spectroscopy. Chaetoceros were obtained from three different algae laboratories: Center of Excellence for Marine Biotechnology (CEMB), Chanthaburi Coastal Fisheries Research and Development (CHAN) and Institute of Marine Science, Burapha University (BIM). Genomic DNA for the RAPD analysis was extracted using the phenol-chloroform method, followed by 18S rDNA amplification. The 18S rDNA sequence analysis showed that Chaetoceros CEMB was most similar to C. gracilis (e-value = 0.0, identity = 98%), Chaetoceros CHAN was most similar to C. debilis (e-value = 0.0, identity = 99%) and Chaetoceros BIM was most similar to C. debilis (e-value = 0.0, identity = 98%). The RAPD results revealed differences in the three Chaetoceros isolates with polymorphisms between 30.43% and 60.00%, and Chaetoceros CEMB showed high polymorphic bands. Scanning electron microscopy revealed that Chaetoceros CEMB were larger and had larger setae compared with the other isolates (P < 0.05). The results of the NMR characterization of metabolites were consistent with the results of the sequence and morphological analyses. The concentrations of several metabolites, including chlorophyll c1, chlorophyll a, myo-inositol, fucoxanthin, astaxanthin, lutein and zeaxanthin, were lower in Chaetoceros CEMB than in Chaetoceros BIM and CHAN. However, high concentrations of fatty acids, such as oleic acid, linoleic acid, α-linolenic acid and arachidic acid, were observed in all isolates. Generally, the results of this study will aid future studies examining the diversity of Chaetoceros in various culture environments.

The objective of this study was to identify morphological and molecular comparison of three marine Chaetoceros species using microscopic observations, sequence analysis of 18S rDNA, random amplified polymorphic DNA (RAPD-PCR) barcoding and nuclear magnetic resonance (NMR) spectroscopy. Chaetoceros were obtained from three different algae laboratories: Center of Excellence for Marine Biotechnology (CEMB), Chanthaburi Coastal Fisheries Research and Development (CHAN) and Institute of Marine Science, Burapha University (BIM). Genomic DNA for the RAPD-PCR analysis was extracted using the phenol–chloroform method, followed by 18S rDNA amplification. The blast results of 18S rDNA sequence confirmed the significantly matched to C. gracilis for Chaetoceros BIM and CHAN and C. muelleri for Chaetoceros CEMB(e-value = 0.0, identity = 99%). The RAPD-PCR results revealed differences in the three Chaetoceros isolates with polymorphisms between 30.43% and 60.00%, and Chaetoceros CEMB showed high polymorphic bands. Scanning electron microscopy revealed that Chaetoceros CEMB were larger and had larger setae compared to the other isolates ( P < 0.05). The results of the NMR characterization of metabolites were consistent with the results of the sequence and morphological analyses. The concentrations of several metabolites, including chlorophyll c 1 , chlorophyll a, Myo-inositol, fucoxanthin, astaxanthin, lutein and zeaxanthin, were lower in Chaetoceros CEMB than in Chaetoceros BIM and CHAN. However, high concentrations of fatty acids, such as oleic acid, linoleic acid, α-linolenic acid and arachidic acid, were observed in all isolates. Generally, the results of this study will aid future studies examining the diversity of Chaetoceros in various cultural environments. Supplementary Information The online version contains supplementary material available at 10.1007/s00203-023-03525-9.