Engineering Yarrowia lipolytica to Simultaneously Produce Lipase and Single Cell Protein from Agro-industrial Wastes for Feed

Jinyong Yan,Liangcheng Jiao,Catherine Madzak,Yunjun Yan,Li Xu,Dujie Pan,Yaofeng Wang,Guilong Wang,Xiaohua Gui,Genhan Zha,Bingnan Han

doi:10.1038/s41598-018-19238-9

Abstract

Lipases are scarcely exploited as feed enzymes in hydrolysis of lipids for increasing energy supply and improving nutrient use efficiency. In this work, we performed homologous overexpression, in vitro characterization and in vivo assessment of a lipase from the yeast Yarrowia lipolytica for feed purpose. Simultaneously, a large amount of yeast cell biomass was produced, for use as single cell protein, a potential protein-rich feed resource. Three kinds of low cost agro-industrial wastes were tested as substrates for simultaneous production of lipase and single cell protein (SCP) as feed additives: sugarcane molasses, waste cooking oil and crude glycerol from biodiesel production. Sugarcane molasses appeared as the most effective cheap medium, allowing production of 16420 U/ml of lipase and 151.2 g/L of single cell protein at 10 liter fermentation scale. In vitro characterization by mimicking a gastro-intestinal environment and determination of essential amino acids of the SCP, and in vivo oral feeding test on fish all revealed that lipase, SCP and their combination were excellent feed additives. Such simultaneous production of this lipase and SCP could address two main concerns of feed industry, poor utilization of lipid and shortage of protein resource at the same time.

Highlights

Lipases are well known as versatile biocatalysts for various industrial fields including oleochemical, textile, detergent, biodegradable polymers, food additive, biodiesel and so on[1,2,3]
Our results showed that pINA1297 based higher gene copy number integration led to an extracellular lipase activity of 2175 U/ml (Table 2), which represents a 1.4-fold increase compared to the pINA1317 based monocopy counterpart, and a 311-fold increase compared to wild type Y. lipolytica strain YLY
Waste cooking oil (WCO) was employed as a carbon source for lipase and single cell protein (SCP) production by engineered Y. lipolytica

Summary

Introduction

Lipases are well known as versatile biocatalysts for various industrial fields including oleochemical, textile, detergent, biodegradable polymers, food additive, biodiesel and so on[1,2,3]. We used Y. lipolytica as a host for homologous overexpression of an acidic and digestive resistant lipase in different cost-effective agro-industrial waste based media. Through in vitro assessment by mimicking a gastro-intestinal environment and characterization of SCP, our purpose is the potential use of this overproduced lipase as a fodder additive, while simultaneously utilizing the host yeast cell biomass as SCP for feed industry (Fig. 1). Such comprehensive utilization of enzymes and yeast biomass based on cheap feedstock for feed could be highly attractive from an industrial perspective. To the best of our knowledge, it is the first time that lipase and SCP were simultaneously produced from cost-effective agro-industrial waste media for feed purpose, especially in vivo fish oral feeding assessment

Methods

Results

Discussion

Conclusion