Scaling-Up and Semi-Continuous Cultivation of Locally Isolated Marine Microalgae Tetraselmis striata in the Subtropical Island of Gran Canaria (Canary Islands, Spain)

The goal of this study was to determine the feasibility of the large-scale cultivation of locally isolated Tetraselmis striata in different open ponds in Gran Canaria. The biomass productivities were 24.66 ± 0.53 kgDW in 32 days (28.9t/ha/year) for 8000 L indoors, 42.32 ± 0.81 kgDW in 43 days (38.8 t/ha/year) for an 8000 L pond outdoors, and 54.9 ± 0.58 kgDW in 28 days (19.6 t/ha/year) for a 45,000 L pond outdoors. The photosynthetic efficiencies were 1.45 ± 0.03% for an 8000 L pond indoors, 1.95 ± 0.04% for 8000 L outdoors. and 1.10 ± 0.01% for a 45,000 L pond outdoors. The selected strain was fast-growing (µ = 0.21 day−1) and could be rapidly scaled up to 45,000 L; it formed healthy cultures that maintained high photosynthetic activity during long-term cultivation and provided stable biomass productivities, able to grow on urea, which acted as a cheap and effective grazer control. The obtained biomass is a good source of proteins and has an FA profile with a high content of some nutritionally important fatty acids: oleic, α-linolenic (ALA) and EPA. The high ash content in the biomass (>35%) can be reduced by the implementation of additional washing steps after the centrifugation of the culture.

The Influence of Dissolved Organic Carbon on the Microbial Community Associated with Tetraselmis striata for Bio-Diesel Production

The green alga Tetraselmis striata is regarded as a suitable candidate microalga for bio-diesel production. Recently, T. striata was cultured near Yeonghueung Island, Korea, in a “marine culturing field”; however, its environmental impacts are not yet studied. We estimated the amount of dissolved organic carbon (DOC) released from T. striata cultivation in the marine culturing field, and we investigated the changes in bacterial composition. Then, we designed and installed a mesocosm for further understanding. From the mesocosm results, the DOC released from the cultivation of T. striata led to changes in bacterial communities, disturbance of the microbial food web structure, rapid depletion of nutrients, and a decrease in dissolved oxygen (DO) and pH. Our novel work demonstrates that large amounts of DOC secreted by large-scale microalgal cultures such as that of T. striata can potentially have a significant impact on the structure and function of the surrounding microbial ecosystem.

Biomass and Lipid Production Potential of an Indian Marine Algal Isolate Tetraselmis striata BBRR1

Four different strains of marine algae viz. Tetraselmis tetrathele, Tetraselmis striata, Tetraselmis chuii, and Tetraselmis gracilis were isolated from the saltpans in Kovelong, Chennai, Tamil Nadu, India. The systematic position of Tetraselmis striata BBRR1 was confirmed through molecular identification. Under laboratory conditions, T. striata Butcher BBRR1 grown in f/2-medium recorded highest biomass concentration of 0.58 ± 0.021 g L−1, volumetric productivity of 0.025 ± 0.004 g L−1 d−1, 19 ± 2.3% proteins, 17 ± 1.5% carbohydrates, and 15 ± 2.4% lipids. Volumetric biomass productivity of 0.063 ± 0.08 g L−1 d−1, specific growth rate of 0.45 day−1 and lipid content of 19.42 ± 0.98% were recorded for the alga T. striata Butcher BBRR1 cultivated in 10-m2 open raceway ponds using Modified CFTRI ABRR1 medium. The fatty acid profile of T. striata Butcher BBRR1 showed the presence of 33.14% palmitic acid, 22.64% 11-octadecenoic acid, and 21.94% heptadecanoic acid. This study confirms the feasibility of cultivating the marine alga T. striata in open raceway ponds to produce biomass, which can be used for the production of biofuels.

High-Quality Draft Genome Sequence of the Green Alga Tetraselmis striata (Chlorophyta) Generated from PacBio Sequencing

A high-quality draft genome sequence of the microalgal species Tetraselmis striata was generated using PacBio sequencing. The assembled genome is 228 Mb, derived from 3,613 polished contigs at 84× coverage depth. This genome contains an average GC content of 57.9% and 48,906 predicted genes.