NON-TRADITIONAL RAW MATERIALS FOR BIOTECHNOLOGICAL INDUSTRIES AND SOME ENVIRONMENTAL ASPECTS OF THEIR DISPOSAL

The work proves how rational it is to use non-traditional, annually renewable wastes of plant raw materials (cuttings of fruit trees, hop stems, and castor bean stems) for further biotechnological processing in order to obtain a valuable protein feed supplement. It has been confirmed that burning these plant wastes adversely affects soil microbiota. The technological properties, chemical and biopolymer composition of the plant waste have been studied. It has been established that the optimum particle sizes for all the three types of the waste under study are 20-35 mm (along the fibres). This degree of grinding provides the best diffusion of the hydrolysing agent in the raw material particles and the extraction of monosaccharides into the solution. Non-traditional plant refuse is high in polysaccharides. The total yield of saccharides in the course of hydrolysis was 52.78-59.11%, depending on the raw material analysed. All types of the plant waste analysed had a high content of polysaccharides and extractive substances. This allows using them as potential raw materials for growth media to cultivate microorganisms in biotechnological industries. Acid degradation of biopolymers of the raw materials analysed has been carried out in the laboratory and confirmed in a production environment. Hydrolysate-based growth media have been obtained in a laboratory environment, and their biological purity has been studied. Yeast strains of the Candida genus have been selected, as they are able to grow actively on the hydrolysates of fruit tree cuttings and stems of hop and castor bean. Cultivation of these strains have been carried out in the periodic mode. The negative effect of plant waste incineration on the microbiological status of soil has been investigated. Samples of the soil were taken from the experimental plot before and after burning the plant waste. Microbiological analysis have been done of the total number of mesophilic aerobic, facultative anaerobic, and nitrogen-fixing microorganisms, since they are the only living organisms capable of absorbing molecular nitrogen from the air and incorporating it into the cycle of nitrogenous substances. The total number of microbes is reduced by 45%, and the number of nitrogen-fixing bacteria is halved. The process of their regeneration is rather slow, which will significantly affect the fertility of soil, and its podzolising (ashing) can lead to changes of crops capable of producing high yields on this soil, and will require scientifically based crop rotations.