Isolation and Characterization of Microalgae from Diverse Pakistani Habitats: Exploring Third-Generation Biofuel Potential

Abstract

Production of microalgae as feedstock for biofuels must deal with a number of challenges including constraints imposed by local conditions. One solution is to use indigenous strains adapted to local climatic conditions. The present report describes the isolation, identification, and characterization of 32 microalgal strains from different ecological habitats: desert freshwater channels, northern region, and saline regions of Pakistan. The effects of temperature on algal growth rates, biomass productivity, and lipid content were determined through growth at 12, 20, and 35 °C for 15 days under 2% CO2 Responses to temperature varied among species with 20 °C being the optimum temperature in general, although, exceptionally, the best overall growth rate was found for strain S29 (0.311 d−1) at 12 °C. In some cases high biomass productivity was observed at 35 °C, and, depending upon the strain, the maximum lipid content was obtained at different temperatures, including 12 °C. Fatty acid methyl ester (FAME) analysis showed that the major fatty acids present were palmitic, stearic, oleic, linoleic, and linolenic. Oleic acid (C18:1) was the predominant fatty acid, with the specific FAME profile varying with strain. Thus, there is a rich diversity of microalgal strains native to Pakistan, some of which, characterized here, could be suitable for biodiesel production or other biotechnological applications.

Morphological characterization, growth appraisal, and probing biofuels potential of newly isolated Scenedesmus sp. from desert Cholistan

“…Microalgae are considered as a preeminent substitute for the production of various bio‐products including biofuels (Kishore et al, ). Still, inclusive research is required to promote green biomass‐based energy to minimize environmental adulteration and energy crises (Alam et al, ; Shah et al, ). The current research, by using native strain, is a step toward promoting green bioenergy.…”

“…For LM living cells were harvested, washed twice with sterile distilled water and were observed under Nikon Eclipse 80i microscope equipped with a Nikon Digital Sight DS‐U1 camera (Nikon, Japan) as described by Alam et al (). For SEM, a protocol of Jaffer, Ashraf, and Shaheen () was followed.…”

“…The photoperiod of 16:8 hr dark/light was continued for PT and MT cultures while 24 hr dark cycle for HT culture. The growth was measured on a daily basis at 630 nm OD using a Shimadzu UV–VIS Spectrophotometer (EL800; BioTek) throughout the cultivation period (14 days) (Alam et al, ; Leite et al, ).…”

“…Similarly, glycerol, a by‐product yield through biodiesel production, was found to perform well by enhancing the biomass, lipid contents, and thus helping in drop biofuel cost (Paranjape, Leite, & Hallenbeck, ; Zhang et al, ). It is attention grabbing to investigate the magnitude of HT and MT cultivation (using glycerol) on growth rate, biomass, and lipid content upon wild isolated native species collected from Cholistan desert as this could potentially be used as a strategy to increase biofuel productivity in an energy deficient zone (Alam et al, ; Zheng et al, ).…”

“…SEM plays a significant role in comparative analysis and identification of new microalgal taxa (Khan et al, ). Undoubtedly, Pakistani algal flora is highly diverse, but unfortunately, this important group of organisms has received very meager attention (Alam et al, ). Therefore, local algal flora becomes more attractive to be explored and deeply revise, to pick potentially vital species for biotechnology applications (Ali, Shinwari, & Leghari, ).…”