Optimization of the Micromycete Cultivation Process � Basics of Growth Regulators and Biotesting Their Growth- Stimulating Activity Concerning to Miscanthus Giganteus

Abstract

Miscanthus × giganteus Greef et Deu. is a perennial herbaceous introduced energy hybrid plant whose biomass is used after processing to a solid or liquid biofuel. The plant is characterized by a relatively low level of absorption of pollutants from the soil by vegetative organs, as its well-developed root system acts as a buffer, helps to stabilize pollutants in the soil and prevents their further spread. Sustainable Miscanthus × giganteus Greef et Deu.(M. × giganteus) growth on contaminated with heavy metals and other хenobiotiсs soil depends on its adaptive performance, including establishment rate, resistance to stressors. The one way to address this issue is the use of plant growth regulators (PGRs), namely Stimpo and Regoplant with micromycete Cylindrocarpon obtusiusculum (Sacc.) U. Braun, whose metabolites are the active substance. The objective of this laboratory study was to evaluate possibility to cultivate Cylindrocarpon obtusiusculum on Chapek’s medium with replacing of hydrocarbon component glucose to chipper one – lactose or starch for further production of Stimpo and Regoplant and testing its growth stimulating activity on M. giganteus. The results showed that the most suitable for the growth and accumulation of biomass of C. obtusiusculum was the Chapek media, which includes starch. The mean growth rate of C. obtusiusculum was in 2.3-fold higher on 8th day of cultivation compared to growth on glucose medium and in 3.3-fold higher than growth on lactose medium. It was found that on the 6th day of growth the concentration of biomass accumulaed by the strain was higher on the medium with a single carbon source – starch with value of2.47 g/l, respectively. On the Chapek medium with glucose and lactose, the biomass concentration was twice as low. Obtained results indicated the possibility of replacing glucose – a valuable carbon sources of Chapek’s medium with starch as a cheaper ingredient for PGRs production. Cultivation of C. obtusiusculum with a change in carbohydrate source did not affect the morphological characteristics and development of spore-bearing cultures. On the medium with starch the growth acceleration and formation of mycelial fungal metabolites was observed, which were used further to obtain of the culture fluid and PGRs Stimpo and Regoplant. Their growth – sti- mulating activity against giant miscanthus was revealed, namely the positive influence on the indicators of Miscanthus establishment and growth rate. The statistical analysis conformed that source of сarbon and type of PGRs effect the length of roots and aerial part of Miscanthus sprouts(Radj2 = 0.91 and Radj2 = 0.87 respectively).

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“…The organic biological products under study are third-generation plant growth regulators with a broad spectrum of action and bioprotective effect. The mechanism of action of these preparations is based on the synergy of microbial fungi and aversectin, which has a positive effect on the physiological and biochemical parameters of plants and increases their resistance to stress (Medkov et al, 2021). This is confirmed by the findings of studies of the influence of these biostimulants on the formation of the photoassimilation apparatus of different varieties of legumes in the different climate zones of Ukraine (Pyda et al, 2021;Makogonenko et al, 2019).…”

Formation of the photoassimilation apparatus of pea (Pisum sativum L.) crops under biostimulants in arid conditions of the Southern Steppe of Ukraine

“…The organic biological products under study are third-generation plant growth regulators with a broad spectrum of action and bioprotective effect. The mechanism of action of these preparations is based on the synergy of microbial fungi and aversectin, which has a positive effect on the physiological and biochemical parameters of plants and increases their resistance to stress (Medkov et al, 2021). This is confirmed by the findings of studies of the influence of these biostimulants on the formation of the photoassimilation apparatus of different varieties of legumes in the different climate zones of Ukraine (Pyda et al, 2021;Makogonenko et al, 2019).…”

The quantitative composition of micromycetes under cereal crops in chernozem soils in the Left-Bank Forest Steppe of Ukraine

“…In particular, soil scientists have proven that the natural potential of soil fertility is significantly influenced by the qualitative and quantitative composition of its microflora (Medkov et al, 2021). The number, biomass and taxonomic structure of the soil microbial complex depend on many factors (Kolodiazhniy & Patyka, 2014).…”