Journal Articles - UP - MSI
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- Growth, agar yield and quality of selected agarophyte species from the PhilippinesAraño, K. G.; Trono, G. C.; Montaño, N. E.; Hurtado, A. Q.; Villanueva, R. D. (Walter de Gruyter GmbH, 2000-01-30)Three local agarophyte species (Gracilaria firma, Gracilaria sp. and Gracilariopsis bailinae) were grown under controlled outdoor flow-through culture conditions. Growth rates and agar characteristics of the three species were determined. Gracilaria firma showed superior growth and agar quality among the three species. It exhibited the highest growth rate, highest agar gel strength and was observed to be highly resistant to epiphytes. Growth experiments under various light and ammonium combinations showed that the highest photon flux density level (900 μ mol m−2s−1) and moderate ammonium (150 μM NH4Cl) concentration gave the highest growth rates for all species. The single and interactive effects of light and ammonium enrichment on growth and agar characteristics of the three species were highly significant.
- In vitro carpospore release and germination in Kappaphycus alvarezii (Doty) Doty from Tawi-Tawi, PhilippinesAzanza, R. V.; Aliaza, T. T. (Walter de Gruyter GmbH, 1999-01-11)In vitro carpospore release and germination experiments in Kappaphycus alvarezii (Doty) Doty farmed in Tawi-Tawi, Philippines, were conducted to develop new mariculture techniques for this carrageenophyte traditionally farmed for many years using cuttings. Carpospore release was assessed over 40 d. Maximum production was attained after fertile branches were exposed to air for a period of 0.5 to 1 h at 240 μmol photons m−2 s−1 and subsequently immersed in seawater at 200 μmol photons m−2 s−1 and at 30 and 35 ppt salinities. Highest average carpospore output from days 1 to 5 was 279,000 carpospore/g wet weight of thallus. Nutrient enrichment (F/2 medium) seems to have little effect on spore release. Carpospore settlement occurred 3–5 days after release. The first branch formed after 26 d in diluted F/2 (F/20) media at 35 ppt salinity and 160 μmol photons m−2 s−1. Low irradiance (7 μmol photons m−2 s−1) and low or high salinities (25, 40 ppt) appeared to inhibit release and germling development. Higher levels of nutrients (F/2, F/20) enhanced growth of contaminants and reduced carpospore viability. Germling growth was highest in the more enriched medium (F/2) (10.57% growth d−1) when compared to F/20 medium (2.26 growth d−1).
- Acetic acid pretreatment in agar extraction of Philippine Gelidiella acerosa (Forsskaal) Feldmann et Hamel (Rhodophyta, Gelidiales)Roleda, M. Y.; Montaño, N. E.; Ganzon-Fortes, E. T.; Villanueva, R. D. (Walter de Gruyter GmbH, 1997)Application of different pre-extraction treatments and extraction methods were used to isolate agar from Gelidiella acerosa. Acetic acid pretreatment entailed soaking the sample in 0.5% acetic acid for 1 hour at 16-20 °C. Alkali pretreatment entailed treatment with l N NaOH at 90°C for 1 hour and eutralization in weak acid for another hour at 16-20 °C. Native agar was extracted directly from air dried samples. One hour extraction using steam pressure at 15-2PSI and boiling at 100 °C in a water bath were applied respectively. Comparative analysis showed that the acetic acid pretreated and autoclaved sample gave the highest agar yield (29.8 ± 2.41%) and gel strength (676 ± 4 g cm"2) among the extraction methods applied. Other physico-chemical properties of acid-modified agar were measured. Relative viscosity of a 1.0% solution at 65 °C ranged from 5-70 cps. A melting temperature of 90-98 °C is comparable to that of the agars from most Gelidiales, while a gelling temperature of 42-47 °C is relatively high which is suspected to be associated with a number of chemical variables masking or altering the basic structural unit of agar. Temperature hysteresis (difference between gelling and melting temperatures) at 48—50 °C was comparable to that of Difco Bacto agar tested at 50 °C.
- Influence of light, water motion, and stocking density on the growth and pigment content of Halymenia durvillei (Rhodophyceae) under laboratory conditionsRula, Najeen Arabelle M.; Ganzon-Fortes, Edna T.; Pante, Ma. Josefa R.; Trono, Gavino C. (Springer, 2021-05-17)The tropical red seaweed Halymenia durvillei Bory de Saint Vincent is a potential source of the high-value pigments, r-phycoerythrin (RPE) and r-phycocyanin (RPC). The unique properties of these pigments find many applications—from food to cosmetics, pharmaceuticals, and biomedical research. This study aimed to improve the land-based culture technology of H. durvillei by determining the appropriate combination of light, water motion, and stocking density that would result in high growth performance and high RPE and RPC content. Combinations of two light levels (full light, 100% and reduced light, 67%), two water motion levels (low and moderate), and three stocking densities (50, 100, and 200 g) were studied using 64.5-L glass tanks with flow-through seawater and aeration systems at the outdoor land-based seaweed nursery in Bolinao, Pangasinan, Philippines. After 6 weeks of culture, growth performance (growth rate and productivity) of H. durvillei and phycobiliprotein content were best under a combination of full light (100%), moderate water motion, and 50-g stocking density. The generally low light regime during the experimental period, which coincided with the cold, dry season characterized by shorter days and overcast skies, may have influenced H. durvillei to maximize the use of available resources such as light and possible increased nutrient availability from water motion to promote growth and phycobiliprotein synthesis. Treatments with low stocking densities generally showed satisfactory growth and phycobiliprotein content. This study provides groundwork for future research into mechanisms by which these and other factors affect the growth and physiology of H. durvillei in culture.
- Summer heatwave impacts on the European kelp Saccharina latissima across its latitudinal distribution gradientDiehl, Nora; Roleda, Michael Y.; Bartsch, Inka; Karsten, Ulf; Bischof, Kai (Frontiers Media SA, 2021-10-11)Kelps are important foundation species in coastal ecosystems currently experiencing pronounced shifts in their distribution patterns caused by ocean warming. While some populations found at species’ warm distribution edges have been recently observed to decline, expansions of some species have been recorded at their cold distribution edges. Reduced population resilience can contribute to kelp habitat loss, hence, understanding intraspecific variations in physiological responses across a species’ latitudinal distribution is crucial for its conservation. To investigate potential local responses of the broadly distributed kelp Saccharina latissima to marine heatwaves in summer, we collected sporophytes from five locations in Europe (Spitsbergen, Bodø, Bergen, Helgoland, Locmariaquer), including populations exposed to the coldest and warmest local temperature regimes. Meristematic tissue from sporophytes was subjected to increasing temperatures of Δ+2, Δ+4 and Δ+6°C above the respective mean summer temperatures (control, Δ±0°C) characteristic for each site. Survival and corresponding physiological and biochemical traits were analyzed. Vitality (optimum quantum yield, Fv/Fm) and growth were monitored over time and biochemical responses were measured at the end of the experiment. Growth was highest in northern and lowest in southern populations. Overall, northern populations from Spitsbergen, Bodø and Bergen were largely unaffected by increasing summer temperatures up to Δ+6°C. Conversely, sporophytes from Helgoland and Locmariaquer were markedly stressed at Δ+6°C: occurrence of tissue necrosis, reduced Fv/Fm, and a significantly elevated de-epoxidation state of the xanthophyll cycle (DPS). The variations in phlorotannins, mannitol and tissue C and N contents were independent of temperature treatments and latitudinal distribution pattern. Pronounced site-specific variability in response to increasing temperatures implies that exceeding a threshold above the mean summer temperature exclusively affect rear-edge (southernmost) populations.Abiotic temperature data used in this manuscript were produced with the Giovanni online data system, developed and maintained by the NASA GES DISC. Sampling in France was conducted in accordance with the French legislation on the Access to Genetic Resources and Benefit-Sharing. We also acknowledge the MODIS mission scientists and associated NASA personnel for the production of the data used in this research effort. This study has been conducted at the Alfred Wegener Institute for Polar and Marine Research (AWI), Bremerhaven and at the AWIPEV Research Station in Ny-Ålesund, Svalbard. We are grateful to the station staff of AWIPEV for support and logistics and to the scientific diving teams on Spitsbergen and Helgoland for sampling. We thank A. Wagner (AWI) for sampling support on Helgoland and his support in the setting up of the experiments, and also J. Müller (University of Rostock) for running the C:N analyzer. B. Meyer-Schlosser (University of Bremen) supported sampling and pigment analyses.
- Linking thallus morphology with P-I curves of 50 macrobenthic algae from Bolinao, Pangasinan, PhilippinesSaco, Jayvee; Ganzon-Fortes, Edna (Science and Technology Information Institute, 2022-08-04)This study demonstrated that thallus morphology could affect a species' capacity to utilize light for photosynthesis and, hence, will affect its productivity. Fifty (50) macroalgal species collected from an intertidal habitat in Bolinao, Pangasinan, Philippines were grouped into five "functional-forms" based on their inferred productivity: functional-form group (FFG) A: very thin tubes/sheets/strips, FFG B: thin sheets/delicately branched, FFG C: medium-thick blade/coarsely branched with dense ramuli, FFG D: heavily thick branches/segments or with moderate calcification, and FFG E: heavily calcified. Their photosynthesis-irradiance (P-I) curves were determined through the measurement of oxygen evolved in a closed system after 1-h incubation under six different light treatments. P-I curve parameters such as P n max , I k , I c , α, and R d were assessed to determine the groups' physiological responses to light. The thickness of thallus blades, coarseness of branches, complex branching, and calcification appeared to lessen photosynthetic capacity, as shown by the significantly decreasing trend of P n max from FFGs A-E. FFG A also showed the steepest slope (highest mean α value) compared with the rest of the functional-form groups, indicating their efficiency to utilize low light for photosynthesis. Light saturation and compensation values were less distinct in differentiating the functional form groups, probably because the seaweeds examined were all collected from the same shallow intertidal zone, suggesting their acclimation to similar photon flux densities. Results from this study fit the prediction of the function form hypothesis for seaweeds quite well.Appreciation is extended to: [1] the Philippine Council for Aquatic, Agricultural, and Natural Resources Research and Development of the Department of Science and Technology as thesis grant to the first author; [2] the UP-CS-MSI research grant to the second author; [3] the Commission on Higher Education for the financial support; and [4] the staff of the Bolinao Marine Laboratory, UP-MSI, and the Batangas State University for their assistance. Helpful critics and recommendations from Dr. Rhodora Azanza and Dr. Wilfredo Uy are acknowledged, most especially to the late Dr. Ronald Villanueva, to whom this paper is wholeheartedly dedicated. Also, deep appreciation is extended to the reviewers for greatly improving the manuscript of this paper.
- Variability and potential of seaweeds as ingredients of ruminant diets: An in vitro studyde la Moneda, Ana; Carro, Maria Dolores; Weisbjerg, Martin R.; Roleda, Michael Y.; Lind, Vibeke; Novoa-Garrido, Margarita; Molina-Alcaide, Eduarda (MDPI AG, 2019-10-22)This study was designed to analyze the chemical composition and in vitro rumen fermentation of eight seaweed species (Brown: Alaria esculenta, Laminaria digitata, Pelvetia canaliculata, Saccharina latissima; Red: Mastocarpus stellatus, Palmaria palmata and Porphyra sp.; Green: Cladophora rupestris) collected in Norway during spring and autumn. Moreover, the in vitro ruminal fermentation of seventeen diets composed of 1:1 oat hay: concentrate, without (control diet) or including seaweeds was studied. The ash and N contents were greater (p < 0.001) in seaweeds collected during spring than in autumn, but autumn-seaweeds had greater total extractable polyphenols. Nitrogen in red and green seaweeds was greater than 2.20 and in brown seaweeds, it was lower than 1.92 g/kg DM. Degradability after 24 h of fermentation was greater in spring seaweeds than in autumn, with Palmaria palmata showing the greatest value and Pelvetia canaliculata the lowest. Seaweeds differed in their fermentation pattern, and autumn Alaria esculenta, Laminaria digitata, Saccharina latissima and Palmaria palmata were similar to high-starch feeds. The inclusion of seaweeds in the concentrate of a diet up to 200 g/kg concentrate produced only subtle effects on in vitro ruminal fermentation.
- Microscopic stages of North Atlantic Laminaria digitata (Phaeophyceae) exhibit trait-dependent thermal adaptation along latitudesSchimpf, Nele M.; Liesner, Daniel; Franke, Kiara; Roleda, Michael Y.; Bartsch, Inka (Frontiers Media SA, 2022-06-17)Kelp forests in the North Atlantic are at risk of decline at their warm temperature distribution margins due to anthropogenic temperature rise and more frequent marine heat waves. To investigate the thermal adaptation of the cold-temperate kelp Laminaria digitata, we sampled six populations, from the Arctic to Brittany (Spitsbergen, Tromsø, Bodø [all Norway], Helgoland [Germany], Roscoff and Quiberon [both France]), across the species’ entire distribution range, spanning 31.5° latitude and 12-13°C difference in mean summer sea surface temperature. We used pooled vegetative gametophytes derived from several sporophytes to approximate the genetic diversity of each location. Gametophytes were exposed to (sub-) lethal high (20-25°C) and (sub-) optimal low (0-15°C) temperature gradients in two full-factorial, common-garden experiments, subjecting subsets of populations from different origins to the same conditions. We assessed survival of gametophytes, their ability to develop microscopic sporophytes, and subsequent growth. We hypothesized that the thermal performance of gametophytes and microscopic sporophytes corresponds to their local long-term thermal history. Integrated gametophyte survival revealed a uniform upper survival temperature (UST) of 24°C among five tested populations (Tromsø to Quiberon). In contrast, following two weeks of thermal priming of gametophytes at 20-22°C, sporophyte formation at 15°C was significantly higher in southern populations (Quiberon and Roscoff) compared to the high-latitude population of Tromsø. Between 0-15°C, survival of the Arctic population (Spitsbergen) was negatively correlated with increasing temperatures, while the southern-most population (Quiberon) showed the opposite. Thus, responses of survival at low, and sporophyte formation at high temperatures, support the concept of local adaption. On the other hand, sporophyte formation between 0-15°C peaked at 6-9°C in the Quiberon and at 9-12°C in the Spitsbergen population. Sporophyte growth rates (GR) both in length and width were similar for Spitsbergen, Tromsø and Quiberon; all had maximum GRs at 12-15°C and low GRs at 0-6°C. Therefore, responses of sporophyte formation and growth at low temperatures do not reflect ecotypic adaptation. We conclude that L. digitata populations display trait-dependent adaptation, partly corresponding to their local temperature histories and partly manifesting uniform or unpredictable responses. This suggests differential selection pressures on the ontogenetic development of kelps such as L. digitata.We would like to thank A. Wagner for the sampling and clonal isolation of kelp material and technical assistance in the laboratory, C. Daniel for support with the image analysis, L. Foqueau for the SST data, C. Gauci for statistical advice and S. DeAmicis for supervision in this BSc Thesis.
- Expressed sequence tags (ESTs) from the marine red alga Gracilaria gracilisLluisma, Arturo O.; Ragan, Mark A. (Springer, 1997-06)Expressed sequence tags (ESTs) are partial sequences of cDNAs, and can be used to characterize gene expression in organisms or tissues. We have constructed a 200-sequence EST database from vegetative thalli of Gracilaria gracilis, the first ESTs reported from any alga. This database contains recognizable ESTs corresponding to genes of carbohydrate metabolism (seven), amino acid metabolism (three), photosynthesis (five), nucleic acid synthesis, repair and processing (three), protein synthesis (14), protein degradation (six), cellular maintenance and stress response (three), other identifiable protein-coding genes (13) and 146 sequences for which significant matches were not found in existing sequence databases. We have already used this EST database to recover genes of carbohydrate biosynthesis from G. gracilis.
- Seasonal variations in the yield, gelling properties, and chemical composition of agars from Gracilaria eucheumoides and Gelidiella acerosa (Rhodophyta) from the PhilippinesVillanueva, R. D.; Montaño, N. E.; Romero, J. B.; Aliganga, A. K. A.; Enriquez, E. P. (Walter de Gruyter GmbH, 1999-01-01)The yield, physical, and chemical properties of agars from two Philippine red seaweeds, Gracilaria eucheumoides and Gelidiella acerosa, were investigated on a bimonthly basis. The yield of agar from Gracilaria eucheumoides was at a maximum during the early rainy season (May, 29%) and at a minimum during the summer month of March (20%). In Gelidiella acerosa, a peak in agar yield was also recorded in May (21%), with generally higher yields recorded during the rainy than in the dry season. Agar gel strengths fluctuated from 225 to 430 g cm−2 and from 160 to 820 g cm−2 for Gracilaria eucheumoides and Gelidiella acerosa, respectively, and both agars exhibited strongest gels in July. Significant seasonal variations were observed in the gelling and melting temperatures of agar from Gracilaria eucheumoides, but not from Gelidiella acerosa. Sulphate content only varied slightly in agar samples from Gracilaria eucheumoides, while a higher sulphate content was found in Gelidiella acerosa agar during the dry season. Moreover, the sulphate content in G. acerosa agar fluctuated inversely with the 3,6-anhydrogalactose content. A FT-IR analysis showed a fairly constant spectrum for temporal Gracilaria eucheumoides agar while peaks attributed to S–O vibrations intensified in Gelidiella acerosa samples which were recorded to contain high sulphate residues and possess low gel strengths. Diagnosis of the FT-IR spectra in the 1000–400 cm−1 frequency range was also conducted in comparison with agarose and Gracilaria chilensis agar.