Optimization of growth requirements of marine diatom Chaetoceros muelleri using Response Surface Methodology

• Published in: Aquaculture research Vol. 48; no. 4; pp. 1513 - 1524
• Main Authors: Kumaran, Jisha, Jose, Blessy, Joseph, Valsamma, Bright Singh, Isaac Sarojini
• Format: Journal Article
• Language: English
• Published: Oxford Hindawi Limited 01-04-2017
• Subjects: Bacillariophyceae; biomass production; Chaetoceros muelleri; Marine; microalgae; optimization; response surface methodology
• ISSN: 1355-557X; 1365-2109
• DOI: 10.1111/are.12987

The marine centric diatom Chaetoceros muelleri has been widely used as live feed in fish and shellfish aquaculture due to its excellent nutritional properties. The growth of microalgae is affected by various nutritional and environmental parameters, and species specific optimization of these parameters is essential for the development of cost‐effective biomass production process. In this study, the growth of C. muelleri, was optimized using response surface methodology (RSM). The variables nitrate, phosphate, silicate, temperature, pH, salinity and agitation speed were initially screened for biomass production in C. muelleri using Plackett–Burman experimental design, and it was found that nitrate, phosphate, silicate, temperature and pH significantly influenced the biomass production. These variables were further optimized by central composite design of RSM for biomass production and nutrient composition, and the medium was re‐constituted accordingly to have 180 mg L−1 nitrate, 7.5 mg L−1 phosphate, 30 mg L−1 silicate, with optimum growth conditions of temperature at 31°C and pH 6.46. At the end of 10 days culture period under the above conditions, biomass, protein, lipid and carbohydrate significantly increased from 0.360 ± 0.01 mg L−1, 9.41 ± 0.02%, 18.11 ± 0.01%, 0.6 ± 0.02% to 1.16 ± 0.01 mg L−1, 11.02 ± 0.01%, 19.58 ± 0.01% and 0.77 ± 0.01% respectively. The biomass production of C. muelleri could be increased 3.2‐fold with an improved nutrient profile by modifying the growth factors, the study thus offering an optimized process for biomass production of C. muelleri.