Cultivation of Efficient Marine Microalgae and Their Biochemical Composition and Its Antibacterial Activity against Human Pathogens

Abstract

The three marine microalgae (Chlorella vulgaris, Spirulina platensis and Nannochloropsis bacillaris) were collected from Vellar estuary, South east coast of India. These three microalgae were cultivated in respective media and estimated their biochemical composition and antibacterial activity. Simultaneously, these cultures were cultivated in flask containing 500 ml of respective media at lab condition for a period of one month and their growth, pH, biomass and CO 2 fixation and carbon content were determined. Based on the growth rate, the pH of three microalgae in media was observed at lab condition. During maximum growth and biomass, the pH was found to be ranged between 9 & 11 for Spirulina platensis, 7 & 9 for Chlorella vulgaris; 8 & 9 for Nannochloropsis bacillaris. Spirulina platensis and Chlorella vulgaris reached maximum growth rate whereas Chlorella vulgaris and Spirulina platensis showed maximum biomass produced. Chlorella vulgaris and Spirulina platensis attained maximum biomass in media at lab condition, also fixed highest level of carbon dioxide in media but they did not produce maximum biomass, though the growth of Nannochloropsis bacillaris were found high in media at lab condition. Among the three microalgae, Chlorella vulgaris and Spirulina platensis produced highest biochemical compounds. Hence Chlorella vulgaris and Spirulina platensis were selected as efficient microalgae for antibacterial activity against human pathogen. This study revealed that certain green algae and blue green microalgae having high growth, pH, CO 2 fixation, carbon content and biochemical composition paves the way for pharmaceutical activity. Antibacterial activity was evaluated for Chlorella and Spirulina with their potential health benefits.

Transesterification method of microalgae biomass to produce fatty acid methyl esters

“…In order to prevent contamination of the microalgae and media, the stock culture was prepared using an aseptic method under laminar flow according to the procedure described by Kumar 21 . An HV‐85 (Hirayama, Japan) autoclave was used to sterilize all of the media and flasks for 15 min at 121 °C, while the culture media were made with sterilized distilled water.…”

“…In order to prevent contamination of the microalgae and media, the stock culture was prepared using an aseptic method under laminar flow according to the procedure described by Kumar. 21 An HV-85 (Hirayama, Japan) autoclave was used to sterilize all of the media and flasks for 15 min at 121 °C, while the culture media were made with sterilized distilled water. After that, 5 mL of microalgal stock culture was seeded into a 2 L Schott bottle filled with 2 L of sterilized distilled water containing 20 mL of BBM I, 12 mL of BBM II and 2.5 mL of each of BBM III and BBM IV, at 25 °C, as presented in Table 1.…”