Agrology (Feb 2021)
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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