More than 500 marine algal strains in Vietnam were screened for their ability to produce high lipids. Among these, a Picochlorum species of Trebuxiophyceae emerged as the species that had the highest total lipid content with a value of 48.6% dry weight (DW), including 27.84% docosahexaenoic acid (DHA). The remaining lipid was mostly C16 and C18 fatty acids, which is appropriate for biofuel production. In addition, 20 different amino acids were identified and included a high ratio of essential amino acids. Subsequently, the effect of environmental conditions for growth, such as salinity, temperature, and media, on the oleogenic potential of this species was investigated. The alga grew better (μ = 0.25 divisions per day) at a salinity of 0.5 M NaCl in enriched seawater medium (MD1) and at high temperature, but the lipid production was higher at 2 M NaCl in artificial medium (MD2) and at low temperature. Consequently, a two‐phase culture system is recommended for obtaining high nutritional lipids and essential amino acids: MD1 can be used for biomass maximization at a high temperature (25°C), and cells can then be transferred into MD2 at a lower temperature (15°C) for oleogenesis.

The effect of nutrient starvation on lipid accumulation of Dunaliella salina A9 was studied. In nutrient starvation, cell colour changed from green to yellow (or orange) and cell growth reached stationary phase after 9 days of the culture. The study showed that under nutrient stress, decreased in cell growth is accompanied by carotenoid biosynthesis and lipid content of Dunaliella salina. The results of this study can be used to increase carotenoid and lipid production in microalgae for functional food and biofuel in the future.

Dunaliella salina A9 is unicellular green alga isolated from the saltern, Khanh Hoa province, Viet Nam.The effect of halostress and nutrient starvation was studied in this alga to estimate the growth, chlorophyll content and capacity of carotenoid and lipid accumulation. The results showed decrease in cell number and chlorophyll content as Dunaliella salina in response to a change from the optimal medium 1.5M NaCl to hypo-osmotic medium (0.5M NaCl) and hyper-osmotic medium (3.5M NaCl). We also observed decrease in cell count in nutrient starvation after 9 days of culture in MD4 medium. Salinity stress has more severe effect on the growth of Dunaliella salina A9 with greater decrease in cell number compared to nutrient starvation. The stress induced increasing carotenoid and lipid accumulation in cells. However the carotenoid and lipid accumulation in hypo-osmotic stress and the nutrient starvation were higher than in hyper-osmotic stress. The results suggested negative relationship between the growth rate, chlorophyll content and carotenoid, and lipid accumulation of Dunaliella salina under stress conditions.

Dunaliella strains were isolated from a key site for salt production in Vietnam (Vinh Hao, Binh Thuan province). The strains were identified based on Internal Transcribed Spacer (ITS) markers. The phylogenetic tree revealed these strains belong to the clades of Dunaliella salina and Dunaliella viridis. Results of this study confirm the ubiquitous nature of Dunaliella and suggest that strains of Dunaliella salina might be acquired locally worldwide for the production of beta-carotene. The identification of these species infers the presence of other Dunaliella species (Dunaliella tertiolecta, Dunaliella primolecta, Dunaliella parva), but further investigation would be required to confirm their presence in Vietnam. We anticipate the physiological and biochemical characteristics of these local species will be compared with imported strains in a future effort. This will facilitate selection of strains with the best potential for exploitation in the food, aquaculture and biofuel industries. The Dunaliella strains isolated and identified in this study are maintained at the Laboratory of Algal Biotechnology, International University and will be made available for research and educational institutions

Nowadays, the applications of automatic control systems have been developing very fast in many diversify of the industry fields. One of the most significant industry that is needed to care and focus to develop this automation technology in order to reduce the huge number of workers and increase the productivity is the seafood industries. Normally, the seafood industry has a lot of workers to carry out everything manually. There still remain many research topics relating to this field to help this industry to develop in the trend of 4.0 ages. The semi–automation shrimps Tempura frying production line is a system to make Tempura shrimps with high productivity. The workers simply put the shrimps into the serial of chain frying molds and the system will automatically do the whole production process to produce the completed Tempura shrimps. The whole process to produce Tempura shrimps includes the following steps: (1) Shaping shrimp and cover with powder solution by automatic powder solution spraying system; (2) Complete frying to make the shrimps to be cooked; (3) Oil draining system to remove the remain oil inside the shrimp and the powder cover. Then the finished products will be put into the frozen system to preserve. The whole production line will be separated into 3 main modules: Module 1: The shaping module (first time frying) and powder solution spraying module; Module 2: The deep fry module (second time frying); Module 3: The oil draining module. This paper introduces about the control system for each module and the controller of the whole system to make a complete semi-automation shrimp tempura frying production line. Some controller technology as On/Off, PID control algorithms are proposed to apply for the whole production line as: speed control of the stainless-steel chain conveyors, temperature control of the cooked tanks, quantitative control of the powder solution amount to be sprayed on the shrimps, the oil draining conveyor speed, the heat and air flow control of the oil draining module.