Production and Characterization of Biodiesel from Algae

Abstract

Algae oil is an intriguing supportable feedstock for biodiesel producing. Green algae have risen as a standout amongst the most encouraging hotspots for biodiesel creation. It can be construed that green growth developed in CO2-enhanced air can be changed over to sleek substances. This study was embraced to know the proper transesterification, measure of biodiesel production (ester) and characterization. Glycerol as a By-product which is used for many other products.

Keywords

Biodiesel, Ethanol, Algae, Transesterification

Introduction

Biodiesel

Bioenergy is a standout amongst the most imperative segments to alleviate nursery gas outflows and substitute of fossil powers. The need of energy is increasing persistently as a result of expansion in industrialization and population. The major disadvantage in using gasoline based fuels is atmosphere pollution and depletion of ozone layer. Biofuels are best example for renewable energy. Biodiesel will reduce the pollution by less CO₂ emissions and reduce the local pollution in terms of CO, CO₂, sulphur and fines particles. We can make use of various potentially energetic industrial and domestic wastes, as cooking oil and fats, as well as agricultural residues for production [1-10].

Algae

Microalgae can provide several different types of renewable biofuels. These include methane produced by anaerobic digestion of the algal biomass; biodiesel derived from micro algal oil photo biologically produced bio hydrogen [11-20]. Algae produce 7 to 31 time greater oil than palm oil. It is very simple to extract oil from algae. The best algae for biodiesel would be microalgae (Figure 1). Eg. Spirogyra plant.

Figure 1: Comparative study of biodiesel with different feed stock [20].

Discussion

Extraction of Oil from Algae

Green growth is dried it holds its oil content, which then can be "squeezed" out with an oil press. Since various strains of algae vary in their physical characteristics, different press designs (screw, expeller, cylinder, and so forth) work better for particular green growth sorts. Numerous business producers of vegetable oil utilize a blend of mechanical squeezing and chemical solvents in extricating oil [21-29].

Expeller presses can recover 75% of the oil from algae.

Production of Biodiesel

Transesterification Reaction: In Transesterification reaction oil or fat react with alcohol and produce ester with by products as glycerol. It is a reversible reaction [30-40] (Figure 2).

Figure 2: Transesterification reactions.

Process Flow Diagram

Figure 3 showing the process flow diagram of production. We can understand the whole process by analysing step by step.

Figure 3: Flow sheet of biodiesel production [41].

Procedure

Sample Collection: Production of Biodiesel starts with the sample collection. The amount of biodiesel we can extract is depends on the type of algae. We have chosen spirogyra as our sample to extract algae. Spirogyra is best option for biodiesel. Spirogyra species are available in normal water ponds. Testing of spirogyra can be done for confirmation of particular species [41-50].

Drying: Algae samples are dried in Hot Air Oven at 150°C to remove moisture content.

Algae Oil Extraction: We used ethyl alcohol as solvent for our experiment. Here using Ethyl alcohol as solvent we extracted Algal Oil. Then algal oil heated in Water Bath at 70°C (BP of Ethyl alcohol) to evaporate the remaining Ethyl alcohol in Oil. Finally we extracted 100 ml of Algae Oil [51-60] (Figure 4).

Figure 4: Algae Oil extracted from samples.

Base Catalysed Method

Transesterification: Initially the Algae oil was heated to 60°C in a flask. In another flask 7.5 ml of H2SO4 was added in 50 ml of ethanol. Then Algae oil was added to ethanol solution. Stirring was done for 15 min and then allowed it to settle. After 24 hours the settled ethyl esters was separated and send them to Transesterification reaction for recycling [61-72] (Figure 5).

Figure 5: Mixture after reaction.

Ethanol recovery: Ethanol is usually removed after the biodiesel and glycerine have been separated into two layers, preventing reaction reversal [73-80].

Biodiesel Refining: Once separated from the glycerine, the biodiesel goes through a purification process, removing all remaining alcohol and catalyst. It is then dried and stored [81-90,45] (Figure 6).

Figure 6: Separated biodiesel and glycerol from mixture.

Characterization of Biodiesel

27/3 test: Initially 27 ml of methanol was added to a test tube. Then 3 ml sample of biodiesel was added to the test tube. Test tube was closed by using stopper and shaken for 30 seconds. After settling for a while we have examine the bottom of the test tube. We have observed that methanol/biodiesel solution was crystal clear with a slight yellow tint which means that complete conversion of oil to biodiesel had occurred [91-98].

Density Test: 100 ml sample of biodiesel was taken and its weight was measured by using weighing machine. It is weighted as 84.2 g [99,100].

Density of Biodiesel =0.842 g/ml

ASTM Specification for biodiesel density = 0.83-0.88 g/ml

By doing this test it has proven that there is no residual methanol present in biodiesel.

Conclusion

Biodiesel production from Alage will be the best resource for Future Generation. It is the eco-friendly process. It let all waste resource to useable form. The amount of algae oil will depends on the type of algae. Spirogyra is available freely in open ponds. The purpose of the transesterification process is to lower the viscosity of the oil or fat. Cost of biodiesel can be reduced by using Algae as feed stock. Water produced during the esterification process can reduce acid catalyst, and this can be eliminated by reaction mechanism. Ethanol is best option as catalyst because of its low cost and easy separation from biofuel.

Acknowledgement

We would like to express our gratitude to all the people behind the screen who helped us to transform an idea into a real application. We would also like to thank my external guide Mr. Veerendra Atla for their technical guidance and support. We would also like to thank Co-guide Mr. Vijay Kumar Mishra for his valuable explanation and encouragement.

References

1. Sankalp D and Savita D. Optimization and Fuel Properties of Water Degummed Linseed Biodiesel from Transesterification Process. Chem Sci J 2016; 7: 131.
2. Erinç Uludamar. Vibration Analysis of a Diesel Engine Fuelled with Sunflower and Canola Biodiesels. Adv Automob Eng 2016; 5: 137.
3. Dhan LF et al. Microbial Lipid Accumulation Capability of Activated Sludge Feeding on Short Chain Fatty Acids as Carbon Sources through Fed-Batch Cultivation. J Bioprocess Biotech 2016; 6: 275.
4. Sarpal AS et al. Investigation of Biodiesel Potential of Biomasses of Microalgaes Chlorella, Spirulina and Tetraselmis by NMR and GC-MS Techniques. J Biotechnol Biomater 2016; 6: 220.
5. Tse H, et al. Performances, Emissions and Soot Properties from a Diesel-Biodiesel- Ethanol Blend Fuelled Engine, Adv Automob Eng 2016; S1-005.
6. Hu Qunju et al. Evaluation of Five Nannocfhloropsis Sp. Strains for Biodiesel and Poly-Unsaturated Fatty Acids (PUFAs) Production. Curr Synthetic Sys Biol 2016; 4: 128.
7. Santos RRD, et al. Assessment of Triacylglycerol Content in Chlorella vulgaris Cultivated in a Two-Stage Process. J Biotechnol Biomater 2015; 5: 212.
8. Gautam K et al. A Method to Utilize Waste Nutrient Sources in Aqueous Extracts for Enhancement of Biomass and Lipid Content in Potential Green Algal Species for Biodiesel Production. J Bioprocess Biotech 2015; 5: 259.
9. Luisa WM et al. Culture-Independent Analysis of Bacterial Diversity during Bioremediation of Soil Contaminated with a Diesel-Biodiesel Blend (B10) J Bioremed Biodeg 2015; 6: 318.
10. Saborimanesh N and Mulligan CN. Effect of Sophorolipid Biosurfactant on Oil Biodegradation by the Natural Oil-Degrading Bacteria on the Weathered Biodiesel, Diesel and Light Crude Oil. J Bioremed Biodeg 2015; 6: 314.
11. Vrushali HJ. Cellulose Hydrolysis: An Unsolved Problem. Research & Reviews: Journal of Chemistry. 2015.
12. Sticklen M. Consolidating the Feedstock Crops Cellulosic Biodiesel with Cellulosic Bioethanol Technologies: A Biotechnology Approach. Adv Crop Sci Tech 2015; 3: e133.
13. Ang GT et al. Supercritical and Superheated Technologies: Future of Biodiesel Production. J Adv Chem Eng 2015; 5: e106.
14. Stephen S et al. Tracking Interfacial Adsorption/Desorption Phenomena in Polypropylene/Biofuel Media using Trace Cr3+/Cr6+ and As3+/As5+-A Study by Liquid Chromatography-plasma Mass Spectrometry. J Pet Environ Biotechnol 2015; 6: 239.
15. Katiyar P. Modified Fractionation Process via Organic Solvents for Wheat Straw and Ground Nut Shells. J Fundam Renewable Energy Appl 2015; 5: 178.
16. Banapurmath NR et al. Effect of Combustion Chamber Shapes on the Performance of Mahua and Neem Biodiesel Operated Diesel Engines. J Pet Environ Biotechnol 2015; 6: 230.
17. Hattab MA and Ghaly A. Microalgae Oil Extraction Pretreatment Methods: Critical Review and Comparative Analysis. J Fundam Renewable Energy Appl 2015; 5: 172.
18. Rahman MS et al. Aerobic Conversion of Glycerol to 2,3-Butanediol by a Novel Klebsiella variicola SRP3 Strain. J Microb Biochem Technol 2015; 7: 299-304.
19. Sajith V and Mohamed JP. Development of Stable Cerium Zirconium Mixed Oxide Nanoparticle Additive for Emission Reduction in Biodiesel Blends. Research & Reviews: Journal of Engineering and Technology. 2015.
20. Bouaid A et al. Biodiesel Production from Babassu Oil: A Statistical Approach. J Chem Eng Process Technol 2015; 6: 232.
21. Rahman MS et al. Aerobic Conversion of Glycerol to 2,3-Butanediol by a Novel Klebsiella variicola SRP3 Strain. J Microb Biochem Technol 2015; 7: 299-304.
22. Yang J et al. The Optimization of Alkali-Catalyzed Biodiesel Production from Camelina sativa Oil Using a Response Surface Methodology. J Bioprocess Biotech 2015; 5: 235.
23. Praveen AH et al. Simarouba Biodiesel as an Alternative Fuel for CI Engine: Review. International Journal of Innovative Research in Science, Engineering and Technology. 2015.
24. Samsukumar R et al. Performance and Emission Analysis on C.I Engine with Palm Oil Biodiesel Blends at Different Fuel Injection Pressures. International Journal of Innovative Research in Science, Engineering and Technology. 2016.
25. Diamantopoulos N et al. Comprehensive Review on the Biodiesel Production using Solid Acid Heterogeneous Catalysts. J Thermodyn Catal 2015; 6: 143.
26. Saravanan P and VijayaGowri G. Efficiency Analysis of Grid Connected Hybrid Wind-Biodiesel Electric Power Generation System. International Journal of Innovative Research in Science, Engineering and Technology. 2016.
27. Rajendran R et al. A Method of Central Composite Design (CCD) for Optimizationof Biodiesel Production from Chlorella vulgaris. J Pet Environ Biotechnol 2015; 6: 219.
28. Elkady MF et al. Production of Biodiesel from Waste Vegetable Oil via KM Micro-mixer. J Pet Environ Biotechnol 2015; 6: 218.
29. Mahesh MP and Arakerimath RR. Analysis of Exhaust Emission, and Performance Characteristics of Single Cylinder CI Engine Fuelled With Palm Oil and CNG. International Journal of Innovative Research in Science, Engineering and Technology. 2016.
30. Hajare SR and Kore SS. An Experimental Investigation on the Effect of Cetane Improver with Biodiesel in CI Engine. International Journal of Innovative Research in Science, Engineering and Technology. 2016.
31. Mohammad Z and Dinesh Kumar G. Reduction of NOx Emissions Using Algal Oil as Fuel. International Journal of Innovative Research in Science, Engineering and Technology. 2016.
32. Velmurugan K and Sathiyagnanam AP. Extenuation of NOX Emissions from Mango Seed Methyl Ester Fuelled DI Diesel Engine Using Antioxidant Additive. International Journal of Innovative Research in Science, Engineering and Technology. 2016.
33. Dhaneshkumar A. Performance and Emission Characteristics of Jatropha Biodiesel and Dimethoxy Methane Fuel Blends with EGR in A CI Engine. International Journal of Innovative Research in Science, Engineering and Technology. 2016.
34. Thennarasu P et al. Combustion Characteristics of CI Engine Using Karanja Biodiesel Blends as Fuel. International Journal of Innovative Research in Science, Engineering and Technology. 2016.
35. Phate JM and Kulkarni AV. Experimental Investigation of the Suitability of Orange Peel Oil as a Blend with Cotton Seed Oil as Alternate Fuel for Diesel Engines: A Review. International Journal of Innovative Research in Science, Engineering and Technology. 2016.
36. Khandal SV et al. Effect of Turbo Charging on the Performance of Dual Fuel (DF) Engine Operated on Rice Bran Oil Methyl Ester (RBOME) and Coconut Shell Derived Producer Gas Induction. J Pet Environ Biotechnol 2015; 6: 216.
37. Khandal SV et al. Effect of Number of Injector Nozzle Holes on the Performance, Emission and Combustion Characteristics of Honge Oil Biodiesel (HOME) Operated DI Compression Ignition Engine. J Pet Environ Biotechnol 2015; 6: 215.
38. Katiyar P et al. A Current Scenario and Novel Approaches to Degrade the Lignocellulosic Biomass for the Production of Biodiesel. J Fundam Renewable Energy Appl 2015; 5: 161.
39. Kumar S et al. Production of Biodesiel from Animal Tallow via Enzymatic Transesterification using the Enzyme Catalyst Ns88001 with Methanol in a Solvent-Free System. J Fundam Renewable Energy Appl 2015; 5: 156.
40. Pathak RK and Nitin EP. Various Sources For Production Of Biodisel. Journal of Industrial Pollution Control. 2016.
41. Kulkarni AV and Bhopale SD. Performance Analysis and Investigation of Emissions of C.I. Diesel Engine Using Neem Oil as Blending Agent: Review. International Journal of Innovative Research in Science, Engineering and Technology. 2016.
42. Brown EK et al. Interaction of Selected Fuels with Water: Impact on Physical Properties and Microbial Growth. J Pet Environ Biotechnol 2015; 6: 204.
43. Sido-Pabyam M et al. Transesterification of Various Bio-oils: Application and Perspectives in Burkina Faso. J Pet Environ Biotechnol 2015; 6: 201.
44. Olalekan A. The Effect of Palm Kernel Oil (PKO) Biodiesel-Contaminated Soil on Morphological and Biochemical Properties of Zea mays. J Plant Biochem Physiol 2014; 2: 138.
45. Liu M et al. Bacterial Isolation from Palm Oil Plantation Soil for Biodiesel Production: Isolation and Molecular Identification as Inferred by 16s RNA. J Biotechnol Biomater 2014; 4: 165.
46. Gomez-Mares M et al. Comparative Study of the Effects of Diesel and Biodiesel Over POM, PPA and PPS Polymers Used in Automotive Industry. J Material Sci Eng 2014; 3: 142.
47. Alemán-Nava GS et al. Bioenergy Sources and Representative Case Studies in Mexico. J Pet Environ Biotechnol 2014; 5: 190.
48. Azad AK et al. Production of Microbial Lipids from Rice Straw Hydrolysates by Lipomyces starkeyi for Biodiesel Synthesis. J Microb Biochem Technol 2014; S8: 008.
49. Gautam G et al. A Cost Effective Strategy for Production of Bio-surfactant from Locally Isolated Penicillium chrysogenum SNP5 and Its Applications. J Bioprocess Biotech 2014; 4: 177.
50. Sahay S and Shyam M. Storage Conditions to Improve the Shelf Life of Jatropha curcas Seeds in Terms of Quality of Oil. J Fundam Renewable Energy Appl 2014; 4: 136.
51. Piechota G et al. Green Technologies in Polish Energy Sector - Overview. J Fundam Renewable Energy Appl 2014; 4: 133.
52. Swain KC. Biofuel Production in India: Potential, Prospectus and Technology. J Fundam Renewable Energy Appl 2014; 4: 129.
53. Saldivar RP et al. Algae Biofuels Production Processes, Carbon Dioxide Fixation and Biorefinery Concept. J Pet Environ Biotechnol 2014; 5: 185.
54. Nguyen LD and Seppala J. Bioconversion of Commercial and Waste Glycerol into Value-Added Polyhydroxyalkanoates by Bacterial Strains. J Microb Biochem Technol 2014; 6: 337-345.
55. Nguyen PLT et al. In Situ Transesterification of Wet Activated Sludge under Subcritical Conditions. J Pet Environ Biotechnol 2014; 5: 182.
56. Dave D et al. Marine Oils as Potential Feedstock for Biodiesel Production: Physicochemical Characterization. J Bioprocess Biotech 2014; 4: 168.
57. Díaz L and Brito A. FFA Adsorption from Waste Oils or Non-Edible Oils onto an Anion-Exchange Resin as Alternative Method to Esterification Reaction Prior to Transesterification Reaction for Biodiesel Production. J Adv Chem Eng 2014; 4: 105.
58. Abd El Baky HH et al. Lipid Induction in Dunaliella salina Culture Aerated with Various Levels CO2 and Its Biodiesel Production. J Aquac Res Development 2014; 5: 223.
59. Jajesniak P et al. Carbon Dioxide Capture and Utilization using Biological Systems: Opportunities and Challenges. J Bioprocess Biotech 2014; 4: 155.
60. Lai EPC. Biodiesel: Environmental Friendly Alternative to Petrodiesel. J Pet Environ Biotechnol 2014; 5: e122.
61. Kumar S et al. Effectiveness of Enzymatic Transesterification of Beeftallow Using Experimental Enzyme Ns88001 with Methanol and Hexane. Enz Eng 2013; 2: 116.
62. Ghaly AE et al. Fish Processing Wastes as a Potential Source of Proteins, Amino Acids and Oils: A Critical Review. J Microb Biochem Technol 2013; 5: 107-129.
63. Martin MZ et al. Genetic Improvement, Sustainable Production and Scalable Small Microenterprise of Jatropha as a Biodiesel Feedstock. J Bioremed Biodeg 2013; S4: 002.
64. Ramakrishnan VV et al. Extraction of Oil from Mackerel Fish Processing Waste using Alcalase Enzyme. Enz Eng 2013; 2: 115.
65. Ragauskas AME and Ragauskas AJ. Re-defining the Future of FOG and Biodiesel. J Phylogenetics Evol Biol 2013; 4: e118.
66. Joshi CP and Nookaraju A. New Avenues of Bioenergy Production from Plants: Green Alternatives to Petroleum. J Phylogenetics Evol Biol 2012; 3: 134.
67. Mansourpoor M and Shariati A. Optimization of Biodiesel Production from Sunflower Oil Using Response Surface Methodology. J Chem Eng Process Technol 2012; 3: 141.
68. West TP. Crude Glycerol: A Feedstock for Organic Acid Production by Microbial Bioconversion. J Microbial Biochem Technol 2012; 4: e106.
69. Owolabi RU et al. Biodiesel from Household/Restaurant Waste Cooking Oil (WCO). J Chem Eng Process Technol 2011; 2: 112.
70. Li Q et al. Insect Fat, a Promising Resource for Biodiesel. J Phylogenetics Evol Biol 2011; S2: 001.
71. Meng L and Salihon J. Conversion of Palm Oil to Methyl and Ethyl Ester using Crude Enzymes. J Biotechnol Biomaterial 2011; 1: 110.
72. Montasser MS et al. A Novel Eco-friendly Method of Using Red Algae (Laurencia papillosa) to Synthesize Gold Nanoprisms. J Nanomed Nanotechnol 2016; 7: 383.
73. Kurup GM and Jose GM. In Vitro Antioxidant Properties of Edible Marine Algae Sargassum swartzii, Ulva fasciata and Chaetomorpha antennina of Kerala Coast. J Pharma Reports 2016; 1: 112.
74. Ammann AA. Hydroxyl Radical Production by Light Driven Iron Redox Cycling in Natural and Test Systems. J Environ Anal Chem 2016; 3: 182.
75. Eriksen NT. Research Trends in the Dominating Microalgal Pigments, β-carotene, Astaxanthin, and Phycocyanin Used in Feed, in Foods, and in Health Applications. J Nutr Food Sci 2016; 6: 507.
76. Garcia JS et al. Nutritional Potential of Four Seaweed Species Collected in the Barbate Estuary (Gulf of Cadiz, Spain). J Nutr Food Sci 2016; 6: 505.
77. Zhao Y et al. Identification of NaHCO3 Stress Responsive Proteins in Dunaliella salina HTBS using iTRAQ-based Analysis. J Proteomics Bioinform 2016; 9: 137-143.
78. Oramary SOM et al. Feeding Common Carp Fish (Cyprinus carpio) on Natural Foods (Algae, Phytoplankton, Zooplankton and Others) on Tigris River in Mosul Dam / Duhok, Kurdistan Region of Iraq. J Aquac Res Development. 2016; 7: 413.
79. Sano Y et al. Microalgal Culture for Chlorella sp. using a Hollow Fiber Membrane Module. J Membra Sci Technol 2016; 6: 147.
80. Pérez L. Biofuels from Microalgae, A Promising Alternative. Pharm Anal Chem Open Access 2016; 2: e103.
81. Benmoussa M. Algomics for the Development of a Sustainable Microalgae Biorefinery. Single Cell Biol 2016; 5: 132.
82. Jana BB et al. Evidences of Manure Driven and C: N Regulated Enhanced Carbon Status and Microalgal Productivity in Managed Aquatic System under Simulated Green House Conditions. J Earth Sci Clim Change 2016; 7: 336.
83. Sarpal AS et al. Investigation of Biodiesel Potential of Biomasses of Microalgaes Chlorella, Spirulina and Tetraselmis by NMR and GC-MS Techniques. J Biotechnol Biomater 2016; 6: 220.
84. Hong JW et al. Mass Cultivation from a Korean Raceway Pond System of Indigenous Microalgae as Potential Biofuel Feedstock. Oil Gas Res 2016; 2: 108.
85. Rotermund LM et al. A Submersible Holographic Microscope for 4-D In-Situ Studies of Micro-Organisms in the Ocean with Intensity and Quantitative Phase Imaging. J Marine Sci Res Dev 2016; 6: 181.
86. Qunju H et al. Evaluation of Five Nannocfhloropsis Sp. Strains for Biodiesel and Poly-Unsaturated Fatty Acids (PUFAs) Production. Curr Synthetic Sys Biol 2016; 4: 128.
87. Taucher J et al. Cell Disruption and Pressurized Liquid Extraction of Carotenoids from Microalgae. J Thermodyn Catal 2016; 7: 158.
88. Ouma SO et al. Seasonal Variation of the Physicochemical and Bacteriological Quality of Water from Five Rural Catchment Areas of Lake Victoria Basin in Kenya. J Environ Anal Chem 2016; 3: 170.
89. Lin X and Peter P. Cool Water Off-flavor Algae and Water Quality in Four Arkansas Commercial Catfish Farms. J Fisheries Livest Prod 2016; 4: 158.
90. Alassali A et al. Methods for Upstream Extraction and Chemical Characterization of Secondary Metabolites from Algae Biomass. Adv Tech Biol Med 2016; 4: 163.
91. Fenta AD and Kidanemariam AA. Assessment of Cyanobactrial Blooms Associated with Water Quality Status of Lake Chamo, South Ethiopia. J Environ Anal Toxicol 2016; 6: 343.
92. Nadeem F et al. Red Sea Microbial Diversity for Antimicrobial and Anticancer Agents. J Mol Biomark Diagn 2015; 7: 267.
93. Hayase S et al. Consumption of Bone Mineral Density-Associated Nutrients, and Their Food Sources in Pre-school Japanese Children. Vitam Miner 2015; 4: 133.
94. Rajkumar R and Takriff MS. Prospects of Algae and their Environmental Applications in Malaysia: A Case Study. J Bioremed Biodeg 2016; 7: 321.
95. Karthik R et al. Attenuation of Negative Impacts by Micro Algae and Enriched Artemia Salina on Penaeus Monodon and Litopenaeus Vannamei Larval Culture. J Aquac Res Development 2015; 6: 365.
96. Iturriaga R. Photo Adaptation Response of Microalgae to Environmental Changes. Oceanography 2015; 3: e113.
97. Gautam K et al. A Method to Utilize Waste Nutrient Sources in Aqueous Extracts for Enhancement of Biomass and Lipid Content in Potential Green Algal Species for Biodiesel Production. J Bioprocess Biotech 2015; 5: 259.
98. Ghosh R and Mitra A. Suitability of Green Macroalgae Enteromorpha intestinalis as a Feed Form Macrobrachium rosenbergii. J Fisheries Livest Prod 2015; 3: 138.
99. El-Sharony TF et al. Effect of Foliar Application with Algae and Plant Extracts on Growth, Yield and Fruit Quality of Fruitful Mango Trees Cv. Fagri Kalan. J Horticulture 2015; 2: 162.
100. Stoyneva-Gärtner MP and Uzunov BA. An Ethnobiological Glance on Globalization Impact on the Traditional Use of Algae and Fungi as Food in Bulgaria. J Nutr Food Sci 2015; 5: 413.