Diatoms and Nualgi - Paper published

A paper on Diatoms based on work by Mr M Thomas Kiran Chief Technology Office of Kadambari Consultants Pvt Ltd is published in Botanica Marina journal - 
http://www.degruyter.com/view/j/botm.ahead-of-print/bot-2011-0076/bot-2011-0076.xml?format=INT

Culture medium optimization and lipid profiling of Cylindrotheca, a lipid- and polyunsaturated fatty acid-rich pennate diatom and potential source of eicosapentaenoic acid

Suman, Keerthi ^1,a / Kiran, Thomas ^1,a / Devi, Uma Koduru ¹ / Sarma, Nittala S. ²

¹Department of Botany, Andhra University, Visakhapatnam 530003, Andhra Pradesh, India

²Department of Marine Chemistry, School of Chemistry, Andhra University, Visakhapatnam 530003, Andhra Pradesh, India

^aThe first two authors made equal contributions to the manuscript.

Corresponding author

Citation Information: Botanica Marina. Volume 0, Issue 0, Pages -–-, ISSN (Online) 1437-4323, ISSN (Print) 0006-8055, DOI: 10.1515/bot-2011-0076,

Publication History:

Received: 06/08/2011;

Accepted: 28/03/2012;

Published Online: 21/05/2012

Abstract

Cylindrotheca, an epipelic benthic pennate diatom, holds promise as a nutraceutical source and may be useful for aquaculture. Experiments were done on two Cylindrotheca species, Cylindrotheca fusiformis (UTEX 2084) andC. closterium, which was isolated from seawater collected offshore from Visakhapatnam, India. C. closteriumwas identified through microscopy and rDNA typing. Type and concentration of nutrient components in the culture medium that promoted best growth and highest lipid accumulation were identified. Lipid content was gravimetrically estimated. For relative comparison of the effects of different culture media on lipid content, we made estimations through rapid in situ screening method using Nile red staining and spectrofluorimetry. The fatty acid profile of lipid was obtained through gas chromatography-mass spectroscopy. Nualgi, a commercially available micronutrient ready-mix with elements adsorbed as nanoparticles on a modified silica sol, was found to significantly boost growth in bothCylindrotheca species when used in lieu of a conventional micronutrient mix prepared from eight compounds. Among the three nitrogen sources tested – sodium nitrate (NaNO₃), urea, and ammonium chloride (NH₄Cl) – best growth of C. fusiformis occurred on nitrate and urea, while NH₄Cl was best for C. closterium. Lipid productivity was much higher in cultures supplied with NH₄Cl for both Cylindrotheca species and compensated for lower biomass in C. fusiformis. Mixotrophy with glycerol or sodium acetate resulted in no significant increase in growth over photoautotrophy. Both Cylindrothecaspecies were lipid rich; lipid constituted 18–27% of dry biomass in the medium with NaNO₃. Among total fatty acids, polyunsaturated fatty acids constituted <40%, eicosapentaenoic acid 25%, and arachidonic acid ∼8% and ∼4% in C. fusiformis and C. closterium, respectively. NH₄Cl, phosphate, and Nualgi micronutrient ready-mix in concentrations optimal for each strain contribute to a good culture medium for Cylindrotheca.

Decline in Diatoms in Oceans

http://www.ipsnews.net/news.asp?idnews=107711 UXBRIDGE, Canada, May 8, 2012 (IPS) - Without major reductions in the use of fossil fuels, sunlight is to kill an unknown number of ocean phytoplankton, the planet's most important organism, a new study reports this week. Not only are phytoplankton, also known as marine algae, a vital component in the ocean's food chain, they generate at least half of the oxygen we breathe. In the not so distant future, sunlight, the very source of life for phytoplankton, will likely begin to kill them because of the ocean's increasing acidity, researchers from China and Germany have learned. "There's a synergistic effect between increased ocean acidity and natural light," says Ulf Riebesell of the Helmholtz Centre for Ocean Research in Kiel, Germany. Riebesell added that it was also possible "phytoplankton could adapt". Researchers were surprised to discover that diatoms, one of the most important and abundant types of phytoplankton, fared very badly during shipboard experiments conducted by co-author Kunshan Gao, from the State Key Laboratory of Marine Environmental Science at Xiamen University, Xiamen China. Previous experiments in labs like Riebesell's found that diatoms actually did better in high-acid seawater, unlike most other shell- forming plankton. Burning fossil fuels has made the oceans about 30 percent more acidic researchers discovered less than 10 years ago. Oceans absorb one third of the carbon dioxide (CO2) emitted from using fossil fuels. The good news is this has slowed the rate of global warming. The bad news is oceans are now more acidic and it will get worse as more CO2 is emitted. This is basic, well-understood ocean chemistry. Gao and his team made several trips into the South China Sea taking samples from surface waters where phytoplankton are found. While still on the research vessel, those samples were made as acidic as the oceans are likely to be in 2100 without major emissions reductions (800-1000 parts per million compared to current 392 ppm). As expected under these conditions, certain types of plankton like coccolithophores did not do well but surprisingly, diatom productivity also declined. One possible reason was the much brighter natural light on the ship versus that in science labs, Riebsell and Gao suspected. Followup lab experiments with lights mimicking the intensity of natural light in the subtropical zone of the South China Sea confirmed that the combination of high-acid sea water and light intensity was more than diatoms could handle. Riebsell speculates that diatoms stressed by high-acid conditions can't cope with the energy they receive from sunlight at the same time. Their study was published May 6 in Nature Climate Change. "We don't know at what point the combination of a certain level of ocean acidity and sunlight leads to the decline of diatoms," he said. This is just one of many recent studies finding negative impacts as the oceans become more and more acidic. By 2040, most of the Arctic Ocean will be too acidic for shell- forming species including most plankton. Significant areas of the Antarctic Ocean will be similarly affected, oceanographer Carol Turley from Plymouth Marine Laboratory in the UK previously told IPS. The cold waters of the polar regions allow more CO2 to be absorbed faster, turning the oceans more acidic sooner. The oceans haven't seen a rapid change like this in 60 million years, said Turley. She warned that global warming is also raising water temperatures and reducing the amount of oxygen in seawater in some regions. This is another potentially dangerous combination. "Our research suggests the impact of oceanic acidification upon marine plankton could be more serious than previously thought," said John Beardall from the School of Biological Sciences at Monash University. Beardall and colleagues from several research centres calculate that without major reductions in CO2 emissions, ocean acidity will have a significant impact on phytoplankton before 2100. Their findings were also recently published in Nature Climate Change. It's not just plankton. The large and continuing decline of oysters, both wild and farmed, in the Pacific Northwest have now been linked to increased ocean acidity. Scientists have shown that oyster larvae have difficulty building shells in corrosive waters, according to a study in the journal Limnology and Oceanography published last month. "For the oceans, the Pacific Oyster larvae are the canaries in the coal mines for ocean acidification," said Richard Feely, a co-author of the study and senior scientist at the National Oceanic and Atmospheric Administration. Fish and other species are showing changes in their growth, behaviour and reproduction, according to other research. Not only are the oceans big, covering 70 percent of the planet, they are complex. Recent work by the Scripps Institution of Oceanography at San Diego reveals there is huge variability in ocean acidity levels. That makes "global predictions of the impacts of ocean acidification a big challenge," said Jennifer Smith, a marine biologist with Scripps. The only prediction Riebesell is willing to make is about the high likelihood of a major decline in the ocean's biodiversity (number and types of living things) if rates of fossil fuel emissions continue. Roughly 80 percent of all life is found in the oceans. "Changes in the oceans are happening too fast for most species to cope," he said. "It's clear we are conducting a giant experiment on the planet and we don't know what we are doing."

Sustainable Aquaculture - Scottish Marine Institute

http://www.smi.ac.uk/adam-hughes/dr-adam-hughes/?searchterm=Dr%20Adam%20Hughes

"Turning waste into a useful product is the basic premise of integrated multi-trophic aquaculture (IMTA). By using waste products from fin-fish aquaculture as food and nutrients for other organisms then we can reap the dual benefits of reduced pollution and increased productivity. The principle is simple, the practice however is complex,: ongoing research at the Scottish Marine Institute aims to overcome some of these complexities and bridge the gap between theoretical concept and industrial application."

Nualgi simplifies the use of animal waste to grow diatoms and since diatoms are good food for fin fish, they benefit from the natural feed.

The Silicon Cycle

http://www.awi.de/en/research/research_divisions/biosciences/marine_biogeosciences/research_themes/silicon_cycle/

The marine Silicon cycle

There is a close coupling of silicon and carbon in global biogeochemical cycling. About three quarters of the primary production in coastal and nutrient replete areas of the world oceans is carried out by diatoms, a phytoplankton group that essentially needs silicon (Si) for the build up of their opaline shells. In low nutrient areas diatoms still contribute to about one third of the marine primary production. Silicic acid, Si(OH)4 and its ions, is the biologically available form of Si in the marine environment and its surface water concentration can severely limit diatom biomass build up. Hence, efforts to understand the marine carbon cycle should also take into account the silicon nutrient cycle. Three stable isotopes of Si, 28Si, 29Si, and 30Si, exist with 28Si being the most abundant (92.2 % to 4.7 % to 3.1 %). Diatoms taking up silicic acid prefer the lighter isotope 28Si and, thus, progressively enrich the surface ocean silic acid in 29Si and 30Si relativ to 28Si.

Biodiesel from Diatoms

Diatoms grown in a tank using Urine as a the source of nutrients N and P and Nualgi as the micro nutrient input.

Nualgi Poster

Nualgi causes Diatom Algae to grow.

Diatoms consume Nutrients N and P, and CO2, and give Oxygen.

Aerobic bacteria consume Oxygen and give CO2.

Diatoms are consumed by Zooplankton and these by Fish, thus the food chain is completed.

Iron input and the export and burial of biogenic silica (opal produced from diatoms)

http://www.sciencedaily.com/releases/2012/03/120313140434.htm

Input of Iron Linked to Biological Productivity in Ancient Pacific
Ocean

"By closely examining the sedimentary record, Murray and his
colleagues have established a clear relationship between plant
plankton (diatoms) and the input of iron, exactly as Martin
predicted."

...

"By examining the paleo-oceanographic record of iron input and the
deposition of diatoms, Murray and his colleagues found that the
ancient system is highly consistent with what occurs in the oceans
today."

...

"The new publication provides an important sedimentary record from the
high-nutrient, low-chlorophyll region of the equatorial Pacific Ocean,
and shows strong links between iron input and the export and burial of
biogenic silica (opal produced from diatoms) over the past million
years."

The full paper is available at -

http://www.nature.com/ngeo/journal/v5/n4/full/ngeo1422.html

NATURE GEOSCIENCE | LETTER
Links between iron input and opal deposition in the Pleistocene equatorial Pacific Ocean

Richard W. Murray, Margaret Leinen & Christopher W. Knowlton
Nature Geoscience 5, 270–274 (2012) doi:10.1038/ngeo1422
Published online 11 March 2012

Increases in overall marine primary productivity and export production in high-nutrient, low-chlorophyll regions of the ocean have, particularly during dry and dusty glacial periods, been hypothesized to be linked to the enhanced delivery of iron1. In the modern ocean, iron availability limits production in high-nutrient, low-chlorophyll regions, and may be important in lower-nutrient settings as well2. Here, we assess the relationship between productivity and iron in sedimentary records from the high-nutrient, low-chlorophyll region of the equatorial Pacific Ocean over the past million years. We find strong links between iron input, the export and burial of biogenic silica (opal) and total export production. Our data demonstrate that iron accumulation was more closely tied to the accumulation of opal than any other biogenic component, with high iron input associated with substantially increased opal sedimentation. The strong links between iron and opal accumulation over the past one million years are in agreement with the modern biogeochemical behaviour of iron and silica, and the response of the diatom community to their mutual availablity3, 4. Our data support earlier suggestions1 of a biological response to iron delivery over geologic timescales.


This paper clearly mentions Diatoms as the phytoplankton that
sequester more carbon than other phytoplankton.