Optimization of Submerged Fermentation Parameters for Enhanced Lipase Production from Newly Isolated Lipolytic Yeasts using Agro Waste Substrates

Abstract

Fungi are currently recognized as the most preferred sources of lipase due to their ability to produce copious amount of extracellular lipase with lower production’s and extraction’s costs. Lipase production was carried out in agro wastes formulated-liquid fermentation media at 300C, at 130rpm, at initial pH of 7 for 96 hours using newly isolated LipA gene identified yeasts [Pichia kudriavzevii ENS1 [Accession No: OL546800], Candida orthopsilosis PMS3 [Accession No: OL546803] and Saccharomyces cerevisiae PMS8 [Accession No: OL546805] at inoculum size of 2%. Agrowastes such as Mango kernel and orange peel were used as alternative carbon sources; beans hull and groundnut shell as nitrogen sources while lipidic sources such as olive oil, soyabeans oil, palm oil, groundnut oil and coconut oil were used as inducers. Single factor optimization process was carried out to determine the effects of carbon sources, nitrogen sources, inducers, incubation time, inoculum size, pH and carbon: nitrogen ratio on lipase production and cell growth. Extraction by filtration, centrifugation and acetone precipitation; Quantitative lipase assay using titrimetric method and Cell growth by measuring optic density at 600nm were done. Proximate analysis of the agro-waste substrates showed higher percentage of carbohydrate and crude fat in mango kernel powder at 68.05±0.56% and 19.54±0.62% while groundnut shell recorded higher crude protein at 11.63±0.05%. Single factor optimization study showed optimum lipase production and cell growth at 50.83±1.18u/ml/min and 0.69±0.00[OD] with Candida orthopsilosis PMS3[Accession No: OL546803] using hot water treated mango kernel hydrolysate as carbon source. The results from this study showed that mango kernel would be an economical alternative carbon source for industrial-scale lipase production.