Conclusion

The Cladosporium tenuissimum CS4 fungal strain extracted lipase has proven characteristics to be a low-cost biocatalyst over con- ventional acid catalysts for microalgal biodiesel production with assured environmentally friendly bioproducts. Cladosporium sp. extracted lipase being used as a biocatalyst for optimizing micro- algal biodiesel production is reported for the first time in this study. Biochemical and enzyme characterization of such thermotolerant enzyme could aid as an industrially important enzyme serving diverse interdisciplinary applications. The extracted and purified enzyme is effective in catalyzing the conversion of microalgal oil into biodiesel with higher efficiency (87.2 ± 0.47%) compared to the conventional acid catalyst (83.02 ± 0.35%). Future studies on pro- tein characterization, sequencing and enzyme immobilization us- ing different solid substrate sources or chemical methods are expected to improve the enzyme viability and reuse.

Data and accessibility

Data used in the analyses are compiled from the field. Data is anlysed and organized in the form of table, which are presented in the manuscript. Also, synthesized data are archived at http://wgbis.ces.iisc.ernet.in/energy/paper/researchpaper. html#bio.

http://wgbis.ces.iisc.ernet.in/biodiversity/

Funding

The authors acknowledge the financial support from ISRO e IISc space technology cell [ISTC/BES/TVR/389] and Gajanana and Mad- havi Hegde [CES/TVR/GJH001] endowment for biofuel research.

Research ethics

The publication is based on the original research and has not been submitted elsewhere for publication or web hosting.

Animal ethics

The research does not involve either humans, animals or tissues.

Permission to carry out fieldwork

Ecological research carried by us in the Western Ghats is commissioned by the Ministry of Environment, Forests and Climate Change (ENVIS Division), Government of India and hence no further permission is required as the field work was carried out in the non- restricted areas/protected areas.

Declaration of competing interest

On behalf of all authors, the corresponding author states that there is no conflict of interest.

CRediT authorship contribution statement

G. Saranya: Data curation, Writing - original draft. T.V. Ram- achandra: Formal analysis, Writing - review & editing.

Acknowledgements

The authors acknowledge the financial support from ISRO e IISc space technology cell [ISTC/BES/TVR/389] and Gajanana and Mad- havi Hegde [CES/TVR/GJH001] endowment for biofuel research. We are grateful to the researchers at Prof. D. N Rao’s lab, Department of Biochemistry, Indian Institute of Science for providing the infra- structure support, guidance and useful inputs for enzyme charac- terization and purification. We thank central facilities of IISc e Society for Innovation and Development for Mass spectroscopy (GC-MS) analysis, Advanced Facility for Microscopy and

Microanalysis for SEM imaging and Micro Nano characterization Facility (MNCF) for FT-IR analysis.