Exploring indigenously produced celite-immobilized Rhizopus oryzae NRRL 3562-lipase for biodiesel production

• Published in: Energy (Oxford) Vol. 222; p. 119950
• Main Authors: Dash, Archana, Banerjee, Rintu
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.05.2021; Elsevier BV
• Subjects: Biodiesel; Biodiesel fuels; Biofuels; Chlorella minutissima; Diatomaceous earth; Diesel; Fatty acids; Fermentation; Fuel properties; Fungi; Hexanes; Iodine; Lipase; Lipids; Microorganisms; Phyco-myco co-culture; Rhizopus oryzae; Solid state fermentation; Substrates; Transesterification; Tricalcium aluminate; Rhizopus oryzae; Phyco-myco co-culture; Chlorella minutissima; Transesterification; Lipase; Biodiesel; Fuel properties
• ISSN: 0360-5442; 1873-6785
• DOI: 10.1016/j.energy.2021.119950

Lipase-mediated transesterification is a greener method for renewable biodiesel production, which can maintain high-level purity of the end products compared to the chemical transesterification methods. Hence, in this study, lipase was produced indigenously using Solid State Fermentation (SSF) from Rhizopus oryzae NRRL 3562, which was further immobilized on activated celite for transesterification. The evaluation of various transesterification attributes and stepwise optimizations were carried out for two different feedstock lipids, viz., a unialgal culture of Chlorella minutissima MCC 27, and a phyco-myco co-culture of C. minutissima MCC 27 and Aspergillus awamori. The optimal conditions, viz., 1:3–1:4 oil:methanol (molar ratio), 15 U lipase, 35 °-40 °C reaction temperature, 1% initial water loading, 1:0.4–1:0.6 substrate:hexane (w/v), 200–250 rpm agitation speed, and 30 h reaction duration ensued 91.52–93.25% fatty acid methyl ester (FAME) conversions in the selected microbial strains. The spent lipase showed potential for cyclic use and was found to have upheld almost 90% residual activity at the end of the 5th cycle. The two resultant biodiesels showed comparable fuel properties except a marginal alleviation in density, viscosity, and iodine value in case of C. minutissima MCC 27 and A. awamori co-culture biodiesel compared to C. minutissima biodiesel. [Display omitted] •Fungal lipase was manufactured via SSF and immobilized on celite in laboratory.•Transesterifiation method was optimized for monoalgal and phyco-myco co-culture.•Potential reusability of spent lipase was found up to 5 cycles.•Optimized transesterification method recovered about 91–93% FAMEs.•Phyco-myco co-culture showed relatively improved fuel properties.