Biorefinery approach for the utilization of dairy by-products and lignocellulosic biomass to lactic acid; Chapter 2
| Author | Affiliation | |
|---|---|---|
Juodeikienė, Gražina | ||
| Date |
|---|
2020-03-23 |
eISBN 978-3-11-053778-1. Taip pat galima rasti internete: Biomass and Biowaste ISBN 978-3-11-053778-9.
In Chapter 2, Juodeikiene et al., from Kaunas University of Technology and the University of Health Sciences in Lithuania, present the comprehensive use of agro-industrial wastes via biotechnological and chemical methodologies toward the production of lactic acid, giving a complete overview on green metrics (process efficiency, land use and costs). – Biorefinery Approach for the Utilization of Dairy By-products and Lignocellulosic Biomass to Lactic Acid. G. Juodeikiene, E. Bartkiene, D. Zadeike, D. Klupsaite.
Bioproduction of optically pure lactic acid (LA) has roused interest in the recent years due to its potential application in a wide range of fields, and there is a significant interest to further development of sustainable and cost-effective process. However, the efficient utilization of agro-industrial wastes for LA production still causes considerable challenges. The biotechnological LA production within the targeted cost still required the development of high-performance LA-producing microorganisms and the lowering of the costs of raw materials and fermentation process. Cheap biomass, such as starchy and cellulosic agricultural residues or by-producing from the food industry, has a potential for the cost-effective production of LA, but raw materials also should have a high production rate and yield without by-product formation and the ability to be fermented with low pretreatment [1]. However, the LA made by fermentation route refers optically active, consequently a suistable microorganism could selectively produce dextro (levo)-rotation enantiomers, and the greatest demand is for the L-LA isomer [2]. Targeted conversion of starchy substrates to LA can be performed using the amylolytic microorganisms [3]. Fungi species from Rhizopus, such as Rhizopus oryzae and Rhizopus arrhizus, excrete amylolytic activity that enables to convert starch directly into L-LA in the presence of oxygen [4]. However, LA-producing microorganisms, including the fungus R. oryzae, have low productivity depending on the low reaction rate caused by mass transfer limitation [5]. Most of the world's commercial L(+)-LA is produced by the fermentation of carbohydrates using homolactic microbes such as a variety of modified or developed strains of the genus Lactobacilli [6,7]. This can be considered to be an advantage, since the productivity of the industrial process may become independent of oxygen supple. [...].