Microorganisms - ENVIS Centre

The study of algae, called phycology or algology, encompasses large and diverse groups of simple organisms ranging from unicellular to multicellular forms. Many are useful product sources for medicinal and nutritional compounds. The largest algal seaweed forms are plant-like, but lack distinct organs found in higher plants, such as leaves, roots and vascular tissues. In Western countries seaweeds are harvested for their soluble fibre, non-digestable polysaccharides including agars, carrageenans and alginates (Kirkwood, 1974). Natural carrageenan biopolymers are now available as replacements for animal gelatins in the nutritional supplement industry for softgel encapsulation (Source-Omega product innovations). With broad utility as thickening agents for various industrial applications, seaweed polysaccharides have also long been used in toothpastes, soaps, shampoos, cosmetics, ice creams, processed foods and many other items of commercial value. Yet seaweeds are still only beginning to be used for their medicinal and chemical properties.

Though traditionally seaweeds are collected from natural wild stocks, certain ecosystem resources are becoming depleted or polluted, so cultivation techniques have been developed as either open run ponds or enclosed bioreactors. In general, culture harvests provide polysaccharides and dietary fibers (both soluble and insoluble) that may constitute 35-60% of dry weight, protein at 5-15% of dry weight and lipids at 1- 5% of dry weight, including fatty acids, carotenoids and vitamins. In oriental countries such as Japan, China, Korea and others, seaweeds are dietary superfood staples (Tab. 1). In Japan, Porphyra tenera “Nori” and Palmaria palmate“Dulse”, for instance, are richer in protein content (35 - 47% of dry weight) than even soybeans.

Table 1: Algae used for human consumption.

Types	Species
Microalgae	Spirulina spp. Odontella aurita Schizochytrium spp.
Green seaweeds	Ulva spp. Enteromorpha spp.
Brown seaweeds	Ascophyllum nodosum Fucus vesiculosus Himanthalia elongata Undaria pinnatifida
Red seaweeds	Gracilaria edulis Gracilaria verucosa Palmaria palmate Chondrus crispus Porphyra umilicans

All true algae have a nucleus enclosed within a membrane and have chloroplasts bound in one or more membranes, which distinguishes them from nonphotosynthetic protozoa. Like land plants, seaweeds have distinct photosystem pigments and use carbon di-oxide, trace nutrients and sunlight to make exclusive energy products de novo. Unlike land plants, however, and particularly important to human nutrition is the fact that essential long chain polyunsaturated fatty acids (PUFAs) are made by algal species only, not by plants.

Of the two classes of essential long chain polyunsaturated fatty acids (PUFA), called omega-6s and omega-3s, only microalgae (phytoplankton) and macroalgae (seaweeds) synthesize these polyunsaturated fatty acids needed by the human body. Fundamentally, omega-6s arachidonic acid (ARA) (C20:4 n-6) and docosapentaenoic acid (DPA) (C22:5 n-6), especially the omega-3s eicosapentaenoic acid (EPA) (C20:5 n-3) and docosahexaenoic acid (DHA) (C22:6 n-3) are vital to brain and organs through all stages of life. Since algae are the basis of food chain for most marine ecosystems, mankind also has the opportunity to utilize these source producers through mariculture technologies. In recent years, variety of algal species rich in PUFA have been screened using standard methodologies and validated for their efficiency.

DHA as a drug candidate

Currently, difficulties in obtaining sufficient dietary omega-3 docosahexaenoic acid (DHA) levels coupled with inefficiencies in human omega-3 metabolism prevents alpha-linolenic acid (ALA) precursor omega-3 bioconversion and subsequent docosahexaenoic acid (DHA) utilization at levels necessary for medical treatments. Unless docosahexaenoic acid is obtained directly from concentrated supplement sources, dietary sources are not sufficient to deliver a medicinal effect. Docosahexaenoic acid rich golden microalgae oil qualifies as a source of slow cognitive decline and onset of Alzheimer’s/dementia (Kalmijn et al., 1997; Lim et al., 2005).

For measurable benefits in cholesterol tests, high dose docosahexaenoic acid (DHA) treatments lower the high triglyceride levels upto 10-20% within 3 months. Other areas of importance include help in the diabetic dislipidemias and protection against arrhythmia, atherosclerosis, high blood pressure and other risk factors associated with cardiovascular diseases (Mori and Woodman, 2006).

Since docosahexaenoic acid (DHA) is 90% of the human body’s omega-3 content and 97% of the omega-3 content is in the brain, only edible algal oils can provide docosahexaenoic acid (DHA) at the medicinal concentrations needed to counter high fat dietary imbalances and omega-3 deficiencies. Worldwide measurements associated with modern dietary trends suggest that departure from traditional fresh diets can lead to metabolic decline and deficiency in docosahexaenoic acid (DHA) omega-3 levels. By harvesting selective algal species for docosahexaenoic acid (DHA) and for other food properties, the relatively untapped biodiversity of the marine algal kingdom can help provide sustainable medicinal omega-3 resources for our planet.

Bioinformatics can be used to probe the biodiversity of algal resources. The validation of drug likenesses using instructive in silico tools like Molinspiration (www.molinspiration.com) for screening candidate compounds against the Lipinski “Rule of 5” (Lipinski et al., 1997), qualified docosahexaenoic acid (DHA) omega-3 as a potential drug compound. The method demonstrates how predictive chemical criteria mirrors functionality, where docosahexaenoic acid’s (DHA’s) small molecule properties fit with its predefined clinical benefits, making it a candidate for future research and development. Notably, the medicinal and nutritional value of both arachidonic acid (ARA) and docosahexaenoic acid (DHA) are important for human welfare.

References:

Kalmijn, S., Launer, L. J., Ott, A., Witteman, J. C., Hofman, A. and Breteler, M. M. (1997) Dietary fat intake and the risk of incident dementia in the Rotterdam Study. Ann. Neurol. 42 (5), 776-82.

Lim, G., Calon, F., Morinara, T., Yang, F., Teter, B., Ubeda, O., Salem N. Jr., Ashe, K. H., Frautschy, S. A. and Cole, G. M. (2005) A diet enriched with the omega-3 fatty acid docosahexaenoic acid reduces amyloid burden in an aged Alzheimer mouse model. J. Neurosci. 25 (12), 3032-40.

Lipinski, C. A., Lombardo, F., Dominy B. W. and Feeney, P. J. (1997) Experimental and computational approaches to estimate solubility and permeability in drug discovery and development settings. Adv.Drug Deliv. Rev. 23, 4-25.

Mori, T. A. and Woodman, R. J. (2006) The independent effects of eicosapentaenoic acid and docosahexaenoic acid on cardiovascular risk factors in humans. Curr. Opin. Clin. Nutr. Metab. Care. 9, 95-104.

Salmonella typhimurium, a food poisoning bacteria sent into outer space for 12 days by researchers responded to the altered gravity (microgravity conditions) by becoming more virulent with changed expression of 167 different genes. The finding may be significant not only for those who travel in space, but also in terms of microbes astronauts are bringing back. Source: www.naturalnews.com