Diversity of algal species present in waste stabilisation ponds and different factors affecting its enrichment and phototaxis

ABSTRACT

Several algal species were found in the samples collected from a wastewater treatment plant located in Uttarakhand, India. Several media and their modifications were employed to understand the role of these elements and compounds in the species composition and proliferation. Euglena, Chlamydomonas-reinhardtii, Chlorella-sorokiniana, Chlorococcum, several diatoms and cyanobacteria were found in the wastewater samples. In stagnant and flowing municipal wastewater, Euglena, Chlorococcum, cyanobacteria and Volvox were predominant. In a bold basal medium, Scenedesmus and several diatom species were observed along with Chlorococcum. In the presence of acetate Selenastrum species were abundant. Metagenomic analysis of wastewater collected during winter revealed that Tetradesmus wisconsinensis (21.23%) and Actinastrum hantzchii (11.48%) were the dominant species. Some cyanobacterial species accumulated near the high-intensity light region. Hence, subsequent phototaxis experiments were performed. Under the white light, most species showed positive phototaxis. However, under the blue and red light, all the algal species present in the sample showed negative phototaxis. Under the green light, Chlorococcum and Chlamydomonas showed positive phototaxis and Euglena showed negative phototaxis. However, under the pink light, neither negative nor positive phototaxis was observed. Hence, the obtained results provided new insights into the effects of the studied parameters on the species’ diversity and proliferation.

KEYWORDS:

• Algae
• phototaxis
• different colours of light
• metagenome
• waste stabilisation pond
• eukaryotes

Acknowledgements

The first four authors of this manuscript received MHRD scholarships and Junior Research fellowships (Dept of Biotechnology) from the Government of India for carrying out the research. We are grateful to the two anonymous reviewers for their constructive and painstaking efforts to review the article for its significant improvement.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Dept of Science and Technology, Ministry of Science and Technology, Govt. of India [grant number DST-1589-CED]; Ministry of Human Resource Development, Govt. of India [grant number P G scholarship]; Department of Biotechnology, Ministry of Science and Technology, Govt of India [grant number DBT – 893 – CED].

Notes on contributors

Swati Dahiya

Swati Dahiya is a PhD candidate at the Dept of Civil Engineering, IITR. Her PhD research is on chemical hydrolysis of waste biomass and its uses for producing added value products through algal route.

Aparajita Shilpie

Aparajita Shilpie She was a junior research fellow working on the project (DBT –893 – CED). Her research interest includes genetics and microbiology.

Gowtham Balasundaram

Goutham Balasundaram is a graduate student who did his undergraduate in agricultural engineering.

Raja Chowdhury

Dr. Raja Chowdhury, is an Asst Professor at IITR. His research interest is on waste based algal biorefinery and its sustainability assessment.

Pradeep Kumar

Prof Pradeep Kumar is a Distinguish Professor at Sharda University. He is an expert on water quality management and water treatment.

Arun Kumar Mishra

Dr. Arun Kumar Mishra is a Professor of Botany at Banaras Hindu University, India.