## 4 Concurrent Development of Value-Added Products Beneficial to Human and Animal Health
### Emerging Products  
The metabolic potential of microalgae offers new opportunities to increase the range of products produced. Research is primarily directed towards the use of microalgae for the development of methods of expression and accumulation of recombinant proteins and biopolymer production. Microalgae have been used to express recombinant proteins (RPs), including industrial enzymes, immunotoxins, antibodies, and vaccine subunits. Although most research has concentrated on _Chlamydomonas reinhardtii_, _Chlorella_ and _Dunaliella_ species are also thought to be safe organisms that can be utilized for RP production. A big single-chain antibody against the glycoprotein of the herpes simplex virus was the first antibody to be expressed. Recently, the chloroplast of _Chlamydomonas_ has been shown to express single-chain mono- and bilateral immunotoxins, in addition to the complete human immunoglobulin G (IgG) antibody against anthrax. _Chlamydomonas reinhardtii_ recombinant proteins have been extracted and purified using a variety of processing techniques [2]. The global market for bioplastics, or renewable, biodegradable plastics, is projected to grow to USD 10 billion by 2020. Microalgae biomass and polymers or additives are combined to form the final form of bioplastics, which are then formed into objects, sheets, and films. Microalgae bioplastics, also known as hybrid plastics, cellulose-based plastics, polylactic acid, or biopolyethylene, are utilized in the packaging, catering, gardening, medical, and automotive industries. The production of bioplastics from spirulina and chlorella is frequently employed because of their small cells and the proteins they produce, which enable conversion to bioplastics without the need for prior treatment. Bioplastics are produced from microalgae biomass and their proteins via a series of steps that include denaturation, digestion, fermentation, lamination, mixing, and compatibility. The production of bioplastics from microalgae is comparatively simple, and unlike other common bioplastic raw materials like soybeans, the use of microalgae has less of an impact on the food industry. The functional characteristics of microalgae proteins should be enhanced, and techniques for eliminating volatile compounds that cause odors should be developed, in order to attain commercial viability [2]. The global bioplastics production market is expected to reach 9.2 million tonnes in 2021, from 1.7 million tonnes in 2014. Polylactic acid (PLA) plays a leading role in biodegradable biopolymers. The properties of polylactate are comparable to those of conventional polymers produced from fossil fuels, such as polypropylene or polystyrene, so it is applied to a wide range of products (from packaging materials to medical applications). For the production of PLA, starchy materials such as corn and potatoes are used as raw materials, but they are foods, and therefore incompatibility is created in nutritional needs [30]. In addition, starch combines the advantages of low cost, abundance, and biodegradation, making thermoplastic starch (TPS) a dynamic alternative to fossil fuel plastics. Microalgae, with their increased ability to adapt to changing environmental conditions, can accumulate biopolymers, such as polysaccharides and, especially, starch, when cultivated under stress. In particular, the lack of essential nutrients, such as nitrogen and phosphorus, as well as the macro-element sulfur, is a factor that induces the storage of biopolymers in microalgae cells during their growth. The direction of research on microalgae that produce increased amounts of starch is of strategic importance, as the produced starch, in addition to its plasticization, can also be a substrate for fermentation for the production of bioethanol [31]. In this study, the possibility of increased starch production among ten strains of microalgae was examined.