An innovative approach to boost up agricultural productivity
Limited consumption of natural food stuff in the 21st century has led to deficiency of vitamins and other important minerals in the human body. Due to excess and repetitive use of chemical fertilizers, the crop productivity is declining day by day. Spirulina is multi-cellular and filamentous blue-green algae biomass, which belongs to the class of cyanobacteria discovered by non-referenced Mexicans in the 16th century, can be a viable solution of all these problems. In recent years, Spirulina has gained enormous attentions.
Spirulina exhibits anticancer, antidiabetic, anti-inflammatory, immunomodulatory and many other properties. Spirulina has the potential of reducing the negative impacts of wastewater discharge through bioremediation. Two major technologies are being considered for the cultivation of Spirulina: closed photobioreactors (PBR) and open raceway ponds. In developing countries like India where malnutrition is a renowned social challenge and it can be defeated by the supplementation of Spirulina products in the diet. The commercial cultivation of Spirulina and converting it to consumable forms (tablets or powder) can be a new way of agribusiness. Therefore, Spirulina is emerging as a cost-effective means of improving livestock and crop productivity in a sustainable manner to ensure food and nutritional security.
Spirulina called a superfood because of its nutrient profile is more potent than any other food, plant, grain or herb. These nutrients make Spirulina a whole food alternative to isolated vitamin supplements. The United Nations world at food conference declared that Spirulina as the best food for the future, and its popularity is increasing nowadays among the wide population. Spirulina is one of nature’ s near perfect foods. It helps to boost our immune system, and is a good immediate energy source.
It is a natural detoxifier as it helps detoxification of toxins and impurities present in our body. Due to the several health benefits, Spirulina is gaining more and more interest, especially in the sector of food supplements, where it is either used as a powder, or consumed in the form of capsules or tablets.
Therefore, the demand for this supplementary diet is picking up in many countries to suffice the nutritional requirements of its population. As a result, many healthcare industries produce Spirulina products.
1. Open Raceway Pond
A raceway pond is a shallow artificial pond utilized for the cultivation of algae. The cultivation of Spirulina can be done in open systems like ponds, lakes or lagoons or a closed system. The open ponds are utilized commercially to produce high value spirulina products, which may be shallow big ponds, circular ponds, tanks and raceway ponds.
The cultivation is usually carried out in two ways:
a) Concrete ponds
b) Pits lined with PVC or other plastic sheets. The agripreneur had constructed concrete ponds for its cultivation. The installation of single or multiple ponds can be arranged with each pond size of 50 m long, 2-3 m wide, and with 20 to 30 cm depth are ideal pond conditions but the length of the ponds can be of any length depending on the land availability (Karthikeyan et al., 2016).
With such infrastructures, Spirulina biomass yield of 35 tons/ hectare/year has been reported in a commercial open mass cultivation pond.
2.Photobioreactors
Photobioreactor refers to closed systems that have no direct exchange of gases as well as contaminants with the environment. It results in high productivity of algae. Photobioreactors facilitate better control of culture environments such as carbon dioxide supply, water supply, optimal temperature, efficient light intensity, culture density, pH levels, gas exchange, aeration and culture density. Algal culture systems can be illuminated by using artificial or natural light or by both. In order to deal with the problems with open ponds, much attention should be on the development of suitable closed systems such as flat-plate, tubular, vertical column and internally-illuminated photobioreactor.
Generally, laboratory-scale photobioreactors are illuminated artificially internally or externally by fluorescent lamps or other light sources. Some photobioreactors can be easily tempered. Large scale outdoor systems mainly tubular photobioreactors cannot be easily modified without high technical support. Efforts have been taken in designing temperature controlled photobioreactors, such as double-walled internally lighted photobioreactor with both heating as well as cooling water circuit.