Вестник МГТУ, 2024, Т. 27, № 3.

Вестник МГТУ. 2024. Т. 27, № 3. С. 294-301. DOI: https://doi.org/10.21443/1560-9278-2024-27-3-294-301 Introduction The fundamental "tool" in microbiology is culture media. They are used for research purposes, selection and research of isolated types of microorganisms, creation of new vaccines and medicines, for other purposes related to pharmaceuticals, biology, and medicine. Today on the market there is a very large number of liquid and powder media for microbiology from the world's largest manufacturers "Pronadisa" laboratorios Conda, S.A. (Spain), Merck (Germany), bioMerieux (BioMerieux, France), Neogen (America). They have the appropriate quality certificates, but their cost is quite high. In this regard, the development of technologies for the production of import-substituting culture media is urgent. The main component of most culture media are the products of protein hydrolysis of plant and animal origin. Until now, pancreatic hydrolysate of fish meal (State research center for applied biotechnology and microbiology, Russia, Obolensk), enzymatic hydrolysate of casein (Pronadisa Conda, Spain), casein and soy peptones (Merck, Germany), pancreatic hydrolysate of casein have been widely used as protein bases, papain hydrolysate of soybeans (BioMerrier, France), gelatinous peptone and meat extract (Neogen, America), etc. However, due to the cessation of fishmeal production as well as the introduction of sanctions on the import of imported raw materials, there is a shortage of this type of product. For the production of protein hydrolysate - a source of nitrogen in the composition of microbiological culture media - we used an alternative source of raw materials: recycle fish materials, namely, meat and bone waste from cutting pelagic fish. Fish waste is an important underestimated reserve of raw materials. Research into the use of protein from fish waste as a component of culture media has been carried out by the research team for a number of years since 2016. Waste from cutting pelagic fish species on fillets makes up 57-64 % on average of the mass of fish received for cutting, and the share of musculoskeletal waste accounts for up to 30-35 % (Derkach et al., 2017; Дровянинова и др., 2015а). At the same time, they contain a significant amount of complete animal protein. Analysis of information sources (Дровянинова и др., 20156; Касьянов, 2015; Максимюк и др., 2009) had showed that it was the rationality of the use of recycle materials and waste that would reduce the raw material shortage in the production of microbiological nutrient media. The involvement of this source of raw materials in processing is a promising direction for the development of the most important branch of modern agriculture (Ломовцева и др., 2019). Materials and methods The purpose of the work was to study the possibility of utilization a hydrolysate from fish waste as a protein component of microbiological media. To achieve this goal, the following tasks were solved: to optimize the previously developed algorithm for the fermentation of fish waste; to study the physicochemical and biochemical parameters of a prototype of fish protein hydrolysate; to evaluate the quality of culture media used for growing microorganisms prepared using a prototype hydrolysate. In the developed algorithm for obtaining a prototype fish protein hydrolysate, the objects of study were musculoskeletal waste of cod fillets (cod caught by the "Public Joint-Stock Company Murmansk Trailing Fleet" in the fishing areas of the Barents Sea), an enzyme preparation - protosubtilin G3X - a product of the activity of bacteria of the Bacillus subtilis strain (Sibbiopharm, Russia), an experimental sample of fish protein hydrolysate obtained in the process of enzymatic hydrolysis. Physical and chemical indicators such as content of water, fat, proteins, amine nitrogen and minerals were determined by standard methods GOST 7636-85 "Fish, marine mammals, marine invertebrates and products of their processing. Analysis methods"1. The protein content was determined by the Kjeldahl method using equipment consisting of two elements: BLOCK-DIGEST 12 for sample mineralization and an automatic distillation unit PRO-NITRO A (J.P. Selekta, Spain). The fat content was determined by the Soxhlet method using a Selecta DET-gras extractor (Spain). The degree of hydrolysis was defined by the calculation method as the ratio of the mass fraction of amine nitrogen to the mass fraction of total nitrogen in the hydrolysate (Производство..., 1990). For establishing the optimal parameters of enzymatic hydrolysis two factors rotatable compositional plan was used. Mathematical data processing was carried out using the DataFit program, version 9.1 (Решетников, 2000). The experiments were carried out in triplicate, the data obtained were subjected to one-way analysis of variance (ANOVA) using Origin Pro 8.0. Differences between the means were considered significant at p < 0.05. We prepared culture media using the obtained fish protein hydrolysate according to the formulation of the control culture medium. The pancreatic fishmeal hydrolysate was replaced with a prototype fish protein hydrolysate. As a control medium, we used "Nutrient agar for the cultivation of microorganisms GRM" (manufactured by State research center for applied biotechnology and microbiology, Russia, Obolensk). To control the efficiency of culture media, test microorganisms with stable characteristics were used. The work used microorganisms with stable characteristics, which are the causative agents of the most dangerous food poisoning. 1Information on regulations and GOSTs is presented in the Appendix. 295