Russian dandelion (<i>Taraxacum kok-saghyz</i> Rodin): rubber extraction methods and prospects for biotechnological methods application

Abstract

Natural rubber is a strategic natural raw material, which is used in the production of tires and military equipment, in medicine and other industries. An alternative to Hevea brasiliensis (Willd. ex A. Juss.) Müll. Arg. and the most promising rubber plant is the Russian dandelion (Taraxacum kok-saghyz Rodin). The rubber that accumulates in the roots of this dandelion is not inferior in quality to the natural rubber from H. brasiliensis, and its content reaches 27% of the dry weight of roots. The purpose of this paper is to describe the economically important components of T. kok-saghyz roots, the main methods for extracting natural rubber from the roots, as well as the approaches to micropropagation and genetic transformation of kok-saghyz and related species. In the middle of the 20th century, the industrial method of isolating rubber from Russian dandelion in the USSR was based on preliminary treatment of the roots with a 2% solution of alkali, which could negatively affect rubber quality. Therefore, it is important to develop new, rapid, but at the same time, inexpensive methods of rubber extraction from T. koksaghyz. Some of them are considered in this paper. The breeding of Russian dandelion should be aimed at both increasing the root size and the content of rubber. In this regard, the development of laboratory express methods for rubber extraction is also important. The authors have developed and optimized a method for extracting rubber from dry plant tissue using polar solvents (water and acetone), with the final extraction with a non‑polar solvent (hexane). The developed rubber extraction protocol showed results comparable to the literature data. In order to create more productive plant forms, experiments are also being conducted on T. kok-saghyz micropropagation and genetic transformation. However, the number of such works is still very small, probably due to the low regenerative abilities of this dandelion species.

TABLE OF CONTENTS AND LOCALIZATION OF RUBBER IN THE ROOTS OF KOK-SAGHYZ (Taraxacum kok-saghyz Rodin)

“…In a selective way, the rubber content in the root of kok-saghyz can be brought up to 25% [18]. It is assumed that when hybridizing with T.fficinale, which has large roots, you can get hybrids with a rubber content of 20%, theoretically, a rubber crop of up to 1800 kg / ha can be obtained [1,19].…”

“…Natural rubber (NR) is a strategically important material in the world industry. NR is used in rubber industry and in production of a wide range of goods: shoes, clothes, catheters, surgical gloves, tires for planes and cars as well as other goods [1,2]. Kok-saghyz rubber has great prospects as an additive to bioplastics for the manufacture of biopackages with improved strength [3,4].…”

Insight into Mechanical Extraction Mechanisms of Natural Rubber Extraction from Taraxacum kok-saghyz

“…For the NR extraction from TKS-root material, the following groups of extraction methods were previously used: Solvent extraction, , enzymatic pre-extraction of lignocellulose, − bacterial/fungal pre-extraction of lignocellulose, − latex extraction, − or a variation of different mechanical extraction methods. − For mechanical extraction, Eskew , developed a two-stage ball mill (pebble mill) extraction. The function of the first stage was to separate softened or degraded cells from rubber tubes, thus elevating the rubber content relative to dry mass in the ball mill and to exclude biomass so that a higher throughput was achieved in the extraction system .…”