Yeasts: From Nature to Bioprocesses

Sérgio Luiz Alves Júnior, Helen Treichel, Thiago Olitta Basso, Boris Ugarte Stambuk

• Éditeur: Bentham Science Publishers
• Année: 2022
• ISBN:
  9789815051063
• Sujet: Ciencias biológicas
• Sous-sujet: Biología

Since ancient times, yeasts have been used for brewing and breadmaking processes. They now represent a flagship organism for alcoholic fermentation processes. The ubiquity of some yeast species also offers microbiologists a heterologous gene-expression platform, making them a model organism for studying eukaryotes. Yeasts: from Nature to Bioprocesses brings together information about the origin and evolution of yeasts, their ecological relationships, and the main taxonomic groups into a single volume. The book initially explores six significant yeast genera in detailed chapters. The book then delves into the main biotechnological processes in which both prospected and engineered yeasts are successfully employed. Yeasts: from Nature to Bioprocesses, therefore, elucidates the leading role of these single-cell organisms for industrial microbiology in environmental, health, social, and economic terms. This book is a comprehensive, multidisciplinary resource for general readers as well as scholars of all levels who want to know all about yeast microbiology and their industrial applications.

Pichia: From Supporting Actors to the Leading Roles

Rosicler Colet¹, Guilherme Hassemer¹, Sérgio Luiz Alves Júnior², Natalia Paroul¹, Jamile Zeni¹, Geciane Toniazzo Backes¹, Eunice Valduga¹, Rogerio Luis Cansian^{1, *}

¹ Universidade Regional Integrada do Alto Uruguai e das Missões, Campus Erechim, Avenida Sete de Setembro, Erechim/RS, Brazil

² Laboratory of Biochemistry and Genetics, Federal University of Fronteira Sul, Chapecó/SC, Brazil

Abstract

Pichia pastoris are heterotrophic yeasts able to use many carbon sources such as glucose, glycerol, and methanol; they are unable, however, to metabolize lactose. Their methylotrophic properties, high yield, efficient post-translational modifications, and secretion of recombinant proteins, alongside a lack of hyperglycosylation, a post-translational process similar to that of mammals, and low maintenance costs for large-scale applications, make this yeast a promising alternative to produce recombinant proteins. The main recombinant products obtained from P. pastoris include vaccines and other biopharmaceuticals, enzymes, proteins, and pigments. Pichia spp. are also used in ethanol production and many other foods such as fermentation of coffee, cocoa, and olives, as well as alcoholic beverages. The use of Pichia yeasts in wastewater treatment and in fungal control of stored grains and fruit has also been reported. This chapter will discuss the environmental diversity of many species of Pichia, especially P. pastoris. Furthermore, the main uses of Pichia spp. in many bioprocesses will also be explored.

Keywords: Alcoholic beverages, Alcoholic beverages, Bioprocesses, Biocontrol systems, Carotenoids, Cocoa fermentation, Ethanol, Enzymes, Environmental diversity, Fermentation, Hyaluronic acid, Isobutanol, Pharmaceuticals, Pichia pastoris, Recombinant proteins, Ricinoleic acid, Vaccines, Wastewater treatment, Xylitol, Yeast.

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^* Corresponding author Rogerio Luis Cansian: Universidade Regional Integrada do Alto Uruguai e das Missões, Campus Erechim, Avenida Sete de Setembro, Erechim/RS, Brazil; Tel: [phone]; E-mail: [email protected]

INTRODUCTION

The methylotrophic yeast Pichia pastoris, also known as Komagataella pastoris, has been commercialized by the Phillips Petroleum Company as a source of single-cell protein (SCP) destined for animal feed. It grows using methanol as a carbon source, causing overexpression of alcohol oxidase enzyme (AOX1) [1]. However, the increase in oil prices around 1970 negatively affected the use of P. pastoris as SCP [2]. Later on, Phillips Petroleum contacted Salk Institute Biotechnology/Industrial Associates, Inc. (SIBIA) seeking to develop a Pichia strain that could be used as a host cell for recombinant protein production [3, 4]. Based on the success this strain has shown as host, many different companies and research groups refined the initial protein expression system seeking to improve the recombinant protein expression rate. Its potential applications now include synthetic biology and whole-cell biotransformation.

The first record of protein production through biological systems for human use was a protein-based smallpox vaccine developed by Edward Jenner in 1796. From 1990 onwards, the biotechnology industry has been using microbial fermentation techniques to obtain products to be used in many different areas, such as the production of cleaning agents, fabrics, medicines, plastics, and even nutrition supplements. With the advent of recombinant DNA, it is now possible to use cultures of yeast, mold, bacteria, mammal cells, and even bugs in recombinant protein production (RPP) [5].

Escherichia coli is one of the most commonly used microorganisms in recombinant protein research, mostly due to its quick duplication time, high cell density, fully mapped genome, and low cost. However, the use of E. coli also has disadvantages, such as the lack of post-translational processing (glycosylation), reduced yield of recombinant products, presence of inactive proteins, and potential production of cytotoxic compounds [6, 7]. Many proteins are not able to be expressed in E. coli strains, as they require exact levels of post-translational maturity and, as such, must be produced by methylotrophic yeasts [8].

In this regard, yeasts such as Pichia pastoris, Saccharomyces cerevisiae, Hansenula polymorpha, and Kluyveromyces lactis are the most prominent [9, 10]. These yeasts tend to be applied in the production of heterologous proteins, mostly due to their high yield, strain stability, rapid growth, high cell density, and post-translational processing similar to that of mammals [11]; however, their glycosylation pattern remains different from that of human cells [12, 13]. The use of non-conventional yeasts has become a promising alternative, merging microbial advantages and eukaryotic protein processing while displaying several

advantages over S. cerevisiae regarding pathway requirements, product profiles, and overall cell physiology [6, 14].

Regarding the protein expression system using recombinant DNA techniques, P. pastoris displays improved productivity rates, more efficient post-translational modifications, better secretion of recombinant proteins, lack of hyper-glycosylation, reduced costs for large-scale production and maintenance, as well the ability to grow under high cell density conditions (up to 130 g/L) when...