Edible freshwater algae and species useful for agriculture

Edible freshwater algae and species useful for agriculture

DREVO Freshwater Algae Food & Agriculture System

Concept

Within the frameworkDREVO Living MountainsFreshwater microalgae and photosynthetic microorganisms can be used in five directions:

human nutrition;

feed additives;

growing live food for aquaculture;

production of biostimulants and biofertilizers;

extraction of nitrogen and phosphorus from agricultural wastewater.

But natural and productive functions must be separated.

Natural local communities develop in rivers, swamps and oxbow lakes.

Food and feed biomass are grown separately.

Biomass produced from wastewater is not used directly as food or feed.

Unfamiliar cultures are not released into natural bodies of water.

The main principle:

The natural pond creates biodiversity, and the controlled pool produces food, feed and fertilizer.

1. Arthrospira - commercial "spirulina"

Biological status

Commercial spirulina is usually of the genusArthrospira, first of all:

Arthrospira platensis;

Arthrospira maxima.

This is not a true green alga, but a filamentous cyanobacterium.

Human use

Spirulina is used as:

dried food biomass;

protein supplement;

ingredient in powders and tablets;

source of phycocyanin pigment;

food component.

The FAO describes spirulina as a food and protein source, and as a supplement for poultry and aquaculture.

Importance for agriculture

Possible directions:

supplement to fish diet;

poultry feed additive;

component of functional feeds;

production of biostimulating extracts;

use of substandard clean biomass as organic fertilizer.

Benefits of Growing

Arthrospira prefers an alkaline environment. This partially reduces the number of competing organisms, but does not completely eliminate the risk of contamination.

Restrictions

Spirulina for nutrition should be grown:

on proven water;

with food nutrients;

no contact with household wastewater;

with control of heavy metals;

with microbiology analysis;

with cyanotoxin control;

with confirmation of the purity of the culture.

You cannot collect unknown "spirulina" from a natural lake based solely on color and shape.

2. Chlorella

Main types

The most promising are:

Chlorella vulgaris;

Chlorella sorokiniana;

individual registered food strains of other species.

Human use

Chlorella is used in the form of:

powder;

tablets;

food ingredient;

protein-pigment additive.

Chlorella and Spirulina are among the most widely commercialized microalgae food products. Their legal status depends on the specific species, strain, production technology, and country of sale.

Feature of the cell wall

Some Chlorella strains have cell walls that hinder digestion. Therefore, food biomass may require:

mechanical destruction of cells;

controlled drying;

additional processing;

confirmation of digestibility.

Agricultural applications

Chlorella shows promise as:

germination biostimulator;

seed treatment component;

foliar supplement;

component of soil biofertilizer;

source of organic nitrogen and microelements;

culture for extracting nutrients from treated wastewater;

feed ingredient for fish and other animals.

Research and reviews show the potential of microalgae, including Chlorella, as biostimulants and biofertilizers, but the results depend on the crop, dosage, strain, and field conditions. They are not a guaranteed complete replacement for mineral nutrients.

3. Scenedesmus and Desmodesmus

Promising childbirth

Scenedesmus;

Desmodesmus.

These green microalgae grow rapidly and are well suited for industrial agricultural systems.

Main directions

purification of nutrient-rich water;

production of technical biomass;

feed research;

biogas;

composting;

biofertilizers;

biostimulating extracts;

production of pigments and lipids.

Nutritional status

They cannot be automatically considered approved for human consumption. Each specific species, strain, and product requires verification under food law.

Strong point

Scenedesmus and Desmodesmus are more rationally considered primarily as:

Working agricultural microalgae for water purification, nutrient recovery and production of fertilizer biomass.

4. Haematococcus pluvialis

It is a freshwater microalgae known for its ability to accumulate red pigment.astaxanthinunder stressful conditions.

Possible use

astaxanthin production;

feed additive for aquaculture;

feed pigmentation;

production of specialized ingredients.

Limitation

Haematococcus should not be considered a common edible herb for mass consumption. Standardized extracts or specially produced biomass are more commonly used.

Production requires:

pure culture;

two-stage cultivation;

lighting and power control;

cell wall destruction technologies;

standardization of astaxanthin content.

5. Euglena gracilis

Euglena gracilis— a freshwater unicellular organism that combines the characteristics of a photosynthetic organism and a heterotroph.

Potential products

protein biomass;

food ingredients;

feed additives;

polysaccharide paramylon;

biostimulating extracts.

Limitation

Only a specific, proven production strain is used. The product's legal status must be verified separately for Switzerland, the EU, and the country of sale.

6. Nostoc

Some species and forms of the genusNostochave historically been consumed as food in certain regions.

Possible functions

fixation of atmospheric nitrogen;

formation of biological soil crusts;

participation in the restoration of poor soils;

research biomass production.

Why caution is required

Externally similar cyanobacteria are difficult to reliably identify without a laboratory examination. Possible variants include:

impurities of toxigenic species;

accumulation of heavy metals;

microbial contamination;

presence of unwanted metabolites.

Therefore, natural Nostoc colonies should not be collected for food without precise identification and sanitary control.

7. Nitrogen-fixing cyanobacteria for agriculture

In agriculture, representatives of the following groups are studied and used:

Nostoc;

Anabaenain the traditional sense;

Dolichospermum;

Calothrix;

Tolypothrix;

other native nitrogen-fixing cyanobacteria.

Possible functions

biological nitrogen fixation;

enrichment of rice fields;

stabilization of the soil surface;

release of polysaccharides;

retention of soil particles;

support of soil microbiota;

production of biostimulating substances.

Cyanobacteria and green microalgae are being studied as biofertilizers, biostimulants and components of circular agricultural systems.

Critical limitation

Some related cyanobacteria are capable of producing toxins.

Therefore it is impossible:

take material from a random pond;

to propagate an unknown blue-green mass;

introduce culture without identification;

release the production strain into natural water;

use biomass as feed without analysis.

For agriculture only the following are used:

identified non-toxigenic strains;

controlled inoculants;

cultures with confirmed absence of genes or production of significant toxins;

drugs permitted by local legislation.

8. Diatoms

Diatoms are especially valuable as a natural element:

streams;

channels;

fish farming systems;

biofilters;

live food growing pools.

Benefits for agriculture

nutrition of aquatic invertebrates;

support for fry;

formation of a natural food web;

bioindication of water quality;

development of periphytic feeding surfaces.

Limitation

Diatoms require available silicon for growth. However, the uncontrolled introduction of silicates into natural waters is not necessary. These conditions are created primarily through:

clean water;

stone-gravel substrate;

moderate light;

controlled flow;

absence of excess phosphorus.

9. Charophyta

Charophytes are an important object for the restoration of clean shallow water bodies.

Benefit

They:

create underwater meadows;

strengthen bottom sediments;

provide shelter for fry;

support aquatic invertebrates;

help maintain the water's clarity;

bind some of the nutrients in the biomass.

Agricultural function

Their main benefit is not mass production, but maintenance:

clean irrigation reservoirs;

biodiversity reservoirs;

spawning areas;

natural turbidity control.

Charal plants cannot be transferred between catchment areas without control.

10. The best types for human nutrition

For the DREVO start-up project, it is rational to limit ourselves to two main food crops:

Arthrospira;

Chlorella.

These are the most studied and commercially understandable directions.

11. Best crops for forage

For aquaculture

Promising:

Chlorella;

Scenedesmus;

Desmodesmus;

Arthrospira;

individual diatoms;

Haematococcus as a source of pigment;

other crops specially selected for larvae and fry.

Microalgae are used in aquaculture as a nutritional and functional component, but their composition varies greatly depending on the species and cultivation conditions.

For the bird

Arthrospira is best understood as a supplement to a complete diet.

Potential features:

additional protein;

pigments;

microelements;

functional components.

It should not replace balanced food on its own.

For ruminants and pigs

Possible use:

dehydrated microalgal biomass;

residues after extraction of valuable components;

small functional additives.

Before use, check:

amino acid composition;

digestibility;

salt content;

heavy metals;

microbiology;

toxins;

permitted dosage.

12. The best crops for biofertilizers

13. Forms of agricultural use

Living culture

Can be applied:

in rice systems;

in technical biofilters;

in experimental soil cultivation;

in closed hydroponic systems.

The risk of living culture is uncontrolled spread.

Dry biomass

Used as:

component of organic fertilizer;

feed additive;

raw material for extraction;

compost component.

Cell extract

Can be used as:

seed treatment;

root feeding;

foliar biostimulant;

anti-stress supplement.

Hydrolysate

After the cells are destroyed, nutrients and signaling substances become more available to plants.

Composted biomass

Allows:

stabilize the material;

mix it with plant waste;

reduce the risk of rapid decomposition in the field.

But composting does not guarantee the removal of all toxins and contaminants.

Biochar from algal biomass

Promising for technical processing, but requires analysis:

ash;

metals;

salts;

carbon stability;

safety of application.

14. Microalgae and agricultural wastewater treatment

This is one of the most promising areas.

Microalgae can extract from water:

ammonium;

nitrate;

phosphate;

carbon dioxide;

part of the microelements.

The USDA has been researching algae production from farm runoff nutrients as a way to manage pollution and produce useful biomass.

The correct technological chain

Runoff → mechanical separation → sedimentation → algae pool → biomass collection → additional treatment → water control.

Important separation of streams

Food flow

clean water;

food reagents;

closed control;

separate equipment.

Feed flow

feed-grade water;

controlled raw materials;

security analysis.

Technical flow

agricultural runoff;

nutrient extraction;

biogas, compost, technical fertilizer or disposal after analysis.

These streams cannot be mixed.

15. Not algae, but important partners

Some very promising freshwater crops are mistakenly called algae.

Azolla

Azolla- a small aquatic fern, not an alga.

Nitrogen-fixing cyanobacteria live in its tissues.

Possible uses:

green manure for rice fields;

cover crop;

feed additive after analysis;

nutrient capture;

compost production.

Risk:

rapid spread;

closing the water surface;

displacement of native species;

anaerobic conditions after death.

Duckweed

Duckweed is a flowering plant, not an alga.

Possible uses:

forage biomass;

nutrient extraction;

aquaculture;

compost;

biogas.

It should be grown in controlled tanks.

Wolfia

Wolffia is a very small flowering plant.

Some species are edible, but the nutritional status and safety of a particular product must be confirmed.

It makes sense to include these cultures in a separate module:

DREVO Freshwater Protein Plants, and not mixed with microalgae.

16. Recommended production structure of DREVO

Line A — DREVO Spirulina Food

Purpose:

food powder;

paste;

flakes;

Phycocyanin.

Requirements:

separate drinking water;

alkaline pools or photobioreactors;

sanitary zone;

soft drying;

full laboratory control.

Line B — DREVO Chlorella Food

Purpose:

food biomass;

functional ingredients;

supplements.

Requirements:

pure culture;

controlled reactors;

destruction of the cell wall if necessary;

protection from foreign algae.

Line C - DREVO AquaFeed Algae

Cultures:

Chlorella;

Scenedesmus;

suitable diatoms;

Arthrospira;

Haematococcus.

Purpose:

aquaculture;

live food;

functional additives.

Line D — DREVO Algae Biofertilizer

Cultures:

Chlorella;

Scenedesmus;

Desmodesmus;

identified nitrogen-fixing cyanobacteria.

Products:

dry biomass;

extract;

hydrolysate;

soil inoculant;

compost additive.

Line E — DREVO Nutrient Recovery

Purpose:

farm wastewater treatment;

return of nitrogen and phosphorus;

production of technical biomass;

reducing the load on rivers and swamps.

17. Control of safety of food and feed biomass

The following are checked:

exact species and strain;

foreign cyanobacteria;

microcystins;

toxoids;

cylindrospermopsin;

heavy metals;

arsenic;

lead;

cadmium;

mercury;

pesticides;

petroleum products;

bacterial contamination;

mold;

humidity;

protein;

fats;

amino acids;

storage stability.

The high ability of Spirulina and Chlorella to bind substances from the environment makes water quality and production control critical.

18. What not to do

The following is not allowed:

collect green biomass from a random pond for food;

grow food-grade spirulina on manure sludge;

use biomass from treatment basins as feed without analysis;

mix food and technical production lines;

release production strains into natural floodplains;

propagate unknown cyanobacteria;

consider the absence of odor as proof of safety;

use water bloom as fertilizer without analysis;

feed animals with raw, uncontrolled biomass;

promise a complete replacement of fertilizers without field testing;

grow one species in a natural swamp;

sell a new species as food without checking the law.

19. Priorities for the first pilot

Food direction

Arthrospira platensis;

Chlorella vulgaris.

Feed direction

Arthrospira;

Chlorella;

Scenedesmus or Desmodesmus;

Haematococcus as a specialized supplement.

Fertilizer direction

Chlorella;

Scenedesmus;

Desmodesmus;

proven native nitrogen-fixing cyanobacteria;

mixed biomass of technical algae pool after analysis.

Water-ecological direction

local diatoms;

natural periphyton;

Char communities;

underwater plants;

zooplankton and local filter feeders.

20. Main conclusion

The most realistic for human nutrition are:

Arthrospira — spirulina;

Chlorella;

specialized products from Haematococcus and Euglena.

The most promising for agriculture are:

Chlorella;

Scenedesmus;

Desmodesmus;

Arthrospira;

identified nitrogen-fixing cyanobacteria;

Natural diatom and periphyton communities in aquaculture.

But their roles differ:

food crops produce clean biomass;

forage crops supplement the diet;

industrial crops extract nutrients;

biofertilizers return some of these substances to the soil;

Natural algae support the ecosystem.

The best system does not grow one “universal algae,” but separates food, feed, fertilizer, water purification, and natural community restoration into independent, controlled lines.