ABSTRACT
Microalgae produce a wide range of compounds including pigments, protein, starch, and lipids, which havebeen extensively used for various applications. In the current scenario, microalgal lipids are considered as apromising source for the production of next-generation bioenergy, and a huge productivity is needed to meet thedemand. Thus, to increase the production of biomass and lipid content, physical conditions play an importantrole and necessary to be optimized. The present study made such an attempt to optimize the physical factors forthe growth and production of lipid from Nannochloropsis gaditana. The study aimed to determine the effect ofphysical parameters such as pH, temperature, light intensity, and salinity. The results showed that the maximumgrowth rate of the N. gaditana was noticed in the salinity of 25 ppt, pH of 8, temperature of 25°C, and 2,000 luxof light intensity. The highest lipid content of the N. gaditana was noticed in the salinity of 30 ppt, pH of 8, andtemperature of 30°C with 2,000 lux light intensity. After optimization, above 40% of lipid yield was obtained,and it can be effectively utilized in bioenergy production.
ABSTRACT
The effect of the co-inoculation of arbuscular mycorrhizal fungi (AMF) and Azospirillum on micro-propagated banana seedlings development during their adaptation phase was determined. At the time of transplanting, banana seedlings were inoculated with an indigenous mycorrhizal inoculum containing 10 spores/g at four doses: 0, 50, 100 and 200 g. Seventy days after fungal inoculation, 20 ml of Azospirillum in four concentrations (0, 106, 107 and 108 CFU/ml) were applied. Finally, after 98 days from the start of the experiment a second dose (40 ml) of Azospirillum in the concentrations mentioned above was inoculated. Plants were harvested 5 months after transplanting and the growth and nutritional parameters were evaluated. The analysis of the data showed that banana plants co-inoculated with 200 g of AMF and 1.5E8 CFU/ml of Azospirillum presented greater development, an increase of 7 times in height, 4 times in perimeter, 16 times in leaf area, 12 times in aerial biomass, and 8 times in root biomass relative to control plants. The results achieved were due to synergism between fungus-bacteria when inoculated at higher doses, with lower doses stimulating growth is minimal. The co-inoculation in high doses demonstrates adequate support and cooperative effect between HMA and Azospirillum crops. In addition, co-inoculation promotes optimal nutritional status because microorganisms allowed plants achieve greater absorption of phosphorus and nitrogen relative to those treated with single inoculation and the control.