Tag Archives: low-cost substrate

370-400 I. Berzina, S. Raita, M. Kalnins, K. Spalvins and I. Kuzmika
In search of the best technological solutions for creating edible protein-rich mutants: a multi-criteria analysis approach
Abstract |
Full text PDF (703 KB)

In search of the best technological solutions for creating edible protein-rich mutants: a multi-criteria analysis approach

I. Berzina*, S. Raita, M. Kalnins, K. Spalvins and I. Kuzmika

Riga Technical University, Institute of Energy Systems and Environment, Azenes street 12/1, LV 1048, Riga, Latvia
*Correspondence: Indra.Berzina@rtu.lv

Abstract:

Single-cell protein (SCP) is a promising alternative for replacing plant and animal-derived dietary proteins. SCP contains essential nutrients and high levels of essential amino acids (AA). Given the versatility of microbial strains and waste substrates that can be used as feedstocks, many variations of production processes can be explored. Improving these microorganism strains by enhancing their properties and productivity is vital to increasing SCP competitiveness. One of the options to enhance microorganism strains would be by creating mutants with better AA profiles. By using mutagenesis and AA inhibitors it should be possible the create novel strains with improved AA-producing properties. The use of AA inhibitors to promote selective pressure on SCP-producing strains is a novel concept and is not a widely explored approach, therefore, the further development of this method should be explored. This paper used a multi-criteria decision analysis method to evaluate different technological factors vital for creating protein-rich mutants. These factors are microorganism strains, agro-industrial waste substrates used as process feedstocks, AA inhibitors, and mutagenesis methods. Microorganisms Candida utilis and Bacillus subtilis showed the highest potential for being used. Molasses was the ‘closest to the ideal’ substrate to be used as feedstock for SCP production. As the most promising mutagenesis method ethyl methane sulphonate was selected. Glufosinate ammonium and methionine sulfoximine for both bacteria and fungi were identified as the best inhibitors for SCP-rich mutant selection. Identified combinations of optimal solutions for microorganisms, substrates, inhibitors, and mutagenesis techniques should be further investigated and evaluated in laboratory settings. This could help to increase SCP’s competitiveness as a sustainable protein source.

Key words:

, , , , , , , , , , , , , , , ,



1285–1307 K. Spalvins, S. Raita, K. Valters and D. Blumberga
Improving single cell protein yields and amino acid profile via mutagenesis: review of applicable amino acid inhibitors for mutant selection
Abstract |
Full text PDF (735 KB)

Improving single cell protein yields and amino acid profile via mutagenesis: review of applicable amino acid inhibitors for mutant selection

K. Spalvins*, S. Raita, K. Valters and D. Blumberga

Riga Technical University, Institute of Energy Systems and Environment, Azenes street 12/1, LV 1048 Riga, Latvia
*Correspondence: kriss.spalvins@rtu.lv

Abstract:

Single cell protein (SCP) is a good alternative for substituting plant and animal derived dietary proteins, since SCP production is more environmentally friendly, consumes less water, requires smaller land areas and its effect on climate change is much less pronounced than it is in the case of agriculturally derived proteins. Another advantage of SCP is that it is possible to use a wide variety of biodegradable agro-industrial by-products for the cultivation of SCP producing microorganisms. However, to make single cell protein technology more widely available and improve its economic viability in such markets as animal and fish feed industries, it is necessary to improve the protein yields and amino acid profiles in microorganism strains capable of using agro-industrial by-products. One way to improve the strains used in the process is to create and select SCP-rich mutants. In this review authors propose a novel approach to create SCP-rich mutants with improved total protein content and essential amino acid profiles. In this approach amino acid inhibitors are used to create selective pressure on created mutants. It is expected that mutants with the most pronounced growth would either have higher total protein content, increased essential amino acid concentrations or both, when cultivated on selective plates containing one or multiple amino acid inhibitors. This paper reviews the most suitable groups of amino acid inhibitors that could be used for selection of new strains of SCP-producing microorganisms.

Key words:

, , , , , ,



833–849 K. Spalvins and D. Blumberga
Single cell oil production from waste biomass: review of applicable agricultural by-products
Abstract |
Full text PDF (679 KB)

Single cell oil production from waste biomass: review of applicable agricultural by-products

K. Spalvins* and D. Blumberga

Riga Technical University, Institute of Energy Systems and Environment, Azenes street 12/1, LV 1048 Riga, Latvia
*Correspondence: kriss.spalvins@rtu.lv

Abstract:

Single cell oil (SCO) is an attractive alternative source of oils, since it can be used as feedstock in biofuel production and also have been recognized as viable option in production of essential fatty acids suitable for either human nutrition or as supplementary in animal feeds. However, the usability of SCO is limited due to the high price of raw materials used in the fermentation process. This problem can be tackled by using low-cost agro-industrial residues which are applicable for SCO production. Use of these by-products as the main carbon source in fermentations not only significantly reduces the overall production costs of SCO, but also enables treatment of generated waste streams, thus reducing the negative impact on environment. Since various biodegradable agro-industrial by-products can be used in microbial fermentations, this review aims to categorize and compare applicable agricultural residues by their availability, necessary pre-fermentation treatments, SCO yields and current usability in other competing sectors.

Key words:

, , , , ,