Development of continuous cultivation process for oil production through bioconversion of minimally treated waste streams from second‐generation bioethanol production. Issue 10 (10th June 2018)

• Record Type: Journal Article
• Authors: Singh, Dilip; Mehta, Preeti; Saxena, Rohit; Barrow, Colin J; Puri, Munish; Tuli, Deepak K; Mathur, Anshu S
• Is Part Of: Journal of chemical technology & biotechnology. Volume 93:Issue 10(2018)
• Page Start: 3018
• Page End: 3027
• Publication Date: 2018-06-10
• Subjects: nondetoxified liquid hydrolysate -- continuous cultivation -- inhibitors -- biodiesel -- oleaginous yeast -- lipid production; Biotechnology -- Periodicals; Chemistry, Technical -- Periodicals; Chemical engineering -- Periodicals; Industries -- Environmental aspects -- Periodicals; 660
• DOI: 10.1002/jctb.5660
• Languages: English
• ISSNs: 0268-2575

Abstract

Abstract: BACKGROUND: Efficient conversion of inhibitor containing pentose rich stream into bioethanol or biogas is still challenging due to several technological challenges; however, this stream can be efficiently assimilated into lipids by oleaginous yeasts such as Rhodotorula . In this work, a continuous and nonsterile process was developed for bioconversion of waste streams into lipids for biodiesel using growth‐inhibitor‐tolerant oleaginous yeast. RESULTS: An inhibitor‐tolerating property of the strain was used to develop a cyclic and continuous near axenic cultivation process in a 2 L nonsterile bioreactor to enhance valorization of waste streams and to reduce energy requirements for media and vessel sterilization. After media optimization, continuous cultivation resulted in significant increase in biomass (14.90 g L −1 day −1 ) and lipid productivity (6.15 g L −1 day −1 ) as compared to flask (biomass ∼3 g L −1 day −1 and lipid productivity ∼0.6 g L −1 day −1 ) results. Palmitic acid (C16:0) and oleic acid (C18:1) were the major fatty acids, accounting for almost 80% of total lipids, thus making lipid produced in the process suitable for biodiesel production. CONCLUSION: Inhibitors present in waste streams successfully maintained near axenic conditions during the cultivation. Maximum dilution rate of 1 was achieved after media optimization, which resulted in complete valorization of nutrients into biomass and lipids with high productivity. © 2018 Society of Chemical Industry