Thursday, August 26, 2010

Quality analysis of commercial Chlorella products used as dietary supplement in human nutrition

Quality analysis of commercial Chlorella products used as dietary supplement in human nutrition: "

Abstract
Chlorella vulgaris is one of the best-studied phototrophic eukaryotes. From the 1950s on, C. vulgaris and some other algal species were cultivated in huge quantities to meet the growing demand for alternative protein sources.
After drying, algal biomass can be merchandised as tablets, capsules, extract or powder with specific biochemical qualities.
However, the products quality, e.g. the containing species, microbial contamination or content and quality of pigments varies
enormously. In this study, commercial Chlorella products, unprocessed Chlorella powders and several production strains were investigated. Molecular analysis of the 18S rDNA confirmed either the existence
of more than one species per product or only other green algae species in about half of the samples tested. Many of the examined
samples contained critical amounts of bacterial contaminations. Furthermore, cyanobacteria were detected in some of the samples.
The content of chlorophyll a varied greatly between the samples and pheophytin, a degradation product of chlorophyll, was detected in some samples in
large concentrations. These data indicate that quality control of microalgal products is an important issue that should be
addressed by the manufactures.


  • Content Type Journal Article
  • DOI 10.1007/s10811-009-9455-4
  • Authors

    • Manuela Görs, University of Rostock Institute of Biological Sciences, Applied Ecology Albert-Einstein-Strasse 3 18051 Rostock Germany
    • Rhena Schumann, University of Rostock Institute of Biological Sciences, Applied Ecology Albert-Einstein-Strasse 3 18051 Rostock Germany
    • Dominik Hepperle, SequentiX, Digital DNA Processing Dorfstrasse 20 18249 Klein Raden Germany
    • Ulf Karsten, University of Rostock Institute of Biological Sciences, Applied Ecology Albert-Einstein-Strasse 3 18051 Rostock Germany


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Biofuels, facts, fantasy, and feasibility

Biofuels, facts, fantasy, and feasibility: "

Abstract It is frequently claimed that green algae are intrinsically more productive, often by orders of magnitude, than higher plants
commonly grown as crops for food. There is no firm evidence for this belief. On the contrary, there is much experience which
shows that algae are not more but less productive. Under optimal conditions, all green organisms photosynthesize at the same
rate in low light and, whilst commonly cultivated ‘sun’ species show some differences in rate in full light, these do not
translate into widely different rates of accumulation of biomass. Accordingly, irrespective of crop, one acre of land, pond
or bioreactor, can annually yield about enough biomass to fuel one motor vehicle or meet the calorific requirement of several
people. This amount of biomass is not sufficient to make other than a very small contribution to our present road transport
requirements and yet contributes significantly to global food shortages and rising prices. Reliable evidence also suggests
that, if all of the inputs are taken into account, the net energy gain of liquid biofuels, derived either from algae or terrestrial
crops, is either very modest or non-existent and will therefore bring about little or no sparing of carbon dioxide emissions.


  • Content Type Journal Article
  • DOI 10.1007/s10811-009-9446-5
  • Authors

    • David Alan Walker, University of Sheffield Sheffield UK


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Utilization of immobilized benthic algal species for N and P removal

Utilization of immobilized benthic algal species for N and P removal: "

Abstract Laboratory experiments were performed to study the growth rate and phosphorus (P) and nitrogen (N) uptakes of eight benthic
microalgae species isolated from different sources of pig manure. Cells immobilized in calcium alginate beads were cultured
with three replicates for each species. P removal rates obtained for the unicellular self-aggregating benthic species (Palmellopsis gelatinosa, Chlorosarcinopsis sp., and Macrochloris sp.) were markedly higher than those obtained in previous published experiments. N removal rates were highest for Macrochloris sp., Chlorosarcinopsis sp., and Euglena sp. 2 and comparable to the maximum rates obtained by other authors. Our results show an excellent efficiency of autochthonous
benthic species for nutrient removal, especially for P, and call attention to their use for wastewater treatment.


  • Content Type Journal Article
  • DOI 10.1007/s10811-009-9456-3
  • Authors

    • Carmen Pérez-Martínez, University of Granada Institute of Water Research Ramón y Cajal 4 18071 Granada Spain
    • Pedro Sánchez-Castillo, University of Granada Department of Plant Biology, Faculty of Sciences 18071 Granada Spain
    • Maria Valle Jiménez-Pérez, University of Granada Department of Plant Biology, Faculty of Sciences 18071 Granada Spain


"
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Heavy metals dynamics in seaweeds and seagrasses in Bahía Magdalena, B.C.S., México

Heavy metals dynamics in seaweeds and seagrasses in Bahía Magdalena, B.C.S., México: "

Abstract The process of metal bioaccumulation in marine food chains is poorly understood because very little data is available on metal
concentration at different trophic levels and their temporal or spatial variation. Because of that, we were interested to
(1) determine the concentration range of heavy metals in seaweed and seagrasses species in Magdalena Bay; (2) describe the
spatial and temporal variation of heavy metal concentrations in the seaweeds and seagrasses. Seasonal collections were done
at Estero Banderitas in November 2004, February, and April 2005 wherein we divided the estuary into three major areas (upper,
middle, and lower), and within each area, two sites were selected. Our results showed that iron, copper, and magnesium were
the most significant metals found in seagrasses, red, and green algae. We found significant more variation in temporal heavy
metal concentrations in relation to the maximum abundance in the samples and spatial variation in relation to the studied
taxa suggesting that hervibores have a differential intake of the metals. Also, our results suggest that heavy metals might
be incorporated regularly in the diet of many herbivorous animals with severe consequences to their health. Management strategies
for these species should consider monitoring the levels of metals.


  • Content Type Journal Article
  • DOI 10.1007/s10811-009-9457-2
  • Authors

    • R. Riosmena-Rodríguez, Universidad Autónoma de Baja California Sur Programa de Investigación en Botánica Marina, Departamento de Biología Marina La Paz Baja California Sur 23080 Mexico
    • A. Talavera-Sáenz, Universidad Autónoma de Baja California Sur Programa de Investigación en Botánica Marina, Departamento de Biología Marina La Paz Baja California Sur 23080 Mexico
    • B. Acosta-Vargas, Centro de Investigaciones Biológicas del Noroeste S.C. (CIBNOR) Mar Bermejo #195, Col. Playa Palo de Santa Rita. A.P. 128 23090 La Paz Baja California Sur Mexico
    • S. C. Gardner, Centro de Investigaciones Biológicas del Noroeste S.C. (CIBNOR) Mar Bermejo #195, Col. Playa Palo de Santa Rita. A.P. 128 23090 La Paz Baja California Sur Mexico


"
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Development of a rapid and effective method for preparing delicate dinoflagellates for scanning electron microscopy

Development of a rapid and effective method for preparing delicate dinoflagellates for scanning electron microscopy: "

Abstract We developed a rapid and effective procedure for scanning electron microscopy of three delicate dinoflagellates, Karlodinium micrum, Akashiwo sanguinea, and Heterocapsa niei. Good results were obtained when the specimens were fixed with a modified Párducz’s fixative (2% osmium tetroxide:saturated
mercuric chloride = 5:1 v/v) for 10 min, washed in 0.05 M sodium cacodylate trihydrate buffer for 2 min, dehydrated in tert-butanol for 10 min and dried with hexamethyldisilazane in air for 3 min in a fume hood because reagents are very toxic. This
method could be completed in 25 min. Compared with other preparative techniques, the present protocol has significant advantages
for SEM observation by limiting distortion of delicate specimens and reducing the preparation time.


  • Content Type Journal Article
  • DOI 10.1007/s10811-009-9461-6
  • Authors

    • Seung Won Jung, Korea Ocean Research and Development Institute South Sea Institute Geoje 656-830 Republic of Korea
    • Hyoung Min Joo, Sangmyung University Department of Life Science Seoul 110-743 Republic of Korea
    • Joon Sang Park, Sangmyung University Department of Life Science Seoul 110-743 Republic of Korea
    • Jin Hwan Lee, Sangmyung University Department of Life Science Seoul 110-743 Republic of Korea


"
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M. E. Gershwin, A. Belay (eds). Spirulina in human nutrition and health

M. E. Gershwin, A. Belay (eds). Spirulina in human nutrition and health: "

M. E. Gershwin, A. Belay (eds). Spirulina in human nutrition and health


  • Content Type Journal Article
  • DOI 10.1007/s10811-009-9467-0
  • Authors

    • Michael A. Borowitzka, Murdoch University School of Biological Sciences & Biotechnology Perth WA 6150 Australia


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Epiphytism of Gracilaria cliftonii (Withell, Millar & Kraft) from Western Australia

Epiphytism of Gracilaria cliftonii (Withell, Millar & Kraft) from Western Australia: "

Abstract Epiphytism in Gracilaria is a common phenomena observed in natural populations and under culture conditions. Generally, epiphytes are attached superficially
to the surface of the host however, genera such as Polysiphonia spp. and Ceramium spp. can penetrate into the host tissue affecting its growth and hence productivity. The present paper aims to identify and
quantify epiphyte abundance and characterise their attachment and penetration on the natural populations of Gracilaria cliftonii collected from Shoalwater Marine Park, Perth, Western Australia. G. cliftonii samples were collected monthly for 1 year and their epiphytes were identified. Histological studies of G. cliftonii were also performed on epiphyte attachment sites. Twenty-four species of macroalgae epiphytes were recorded, 21 belonging
to Rhodophyta and 3 to Chlorophyta. Hypnea episcopalis and Polysiphonia forfex were the dominant (p < 0.05) species during the sampling period. The maximum epiphytic load was observed in October (40%), however, the maximum
diversity of epiphytes was recorded in September and February (n = 14). Light and scanning electron microscopy studies of the epiphyte attachment sites revealed that P. forfex and Ceramium isogonum penetrated into the cortex and outer medulla of G. cliftonii, while Bryopsis plumosa and Laurencia clavata altered the cellular structure of the cell wall of G. cliftonii.


  • Content Type Journal Article
  • DOI 10.1007/s10811-009-9469-y
  • Authors

    • Julieta Muñoz, Curtin University of Technology School of Agriculture and Environmental Sciences GPO Box U1987 Perth Western Australia Australia
    • Ravi Fotedar, Curtin University of Technology School of Agriculture and Environmental Sciences GPO Box U1987 Perth Western Australia Australia


"
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