The microbiome of the black soldier fly larvae (BSFL) formed in real rearing substrates in close to industrial conditions was studied. The used substrates, dairy waste and feeding yeasts, differed in the sources of protein, which are available in commercial rearing of the black soldier fly (BSF). Amplicon 16S rRNA sequencing of the BSFL gut metagenome reveals high variability in the microbiome composition. The only bacteria genus found in all the studied developmental stages of BSFL was Enterococcus. We identified typical microorganisms for the initial and final stages of the experiment, as well as typical patterns in changes of the abundance of the main groups of microorganisms. It has been noted that many microorganisms previously believed to be members of the core microbiome of BSFL gut (such as Dysgonomonas) may be completely absent. It is important that the change of rearing conditions influences also the BSFL microbiome: opportunistic pathogen microorganisms, as well as unwanted histamine-poisoning bacteria can appear. Most of them belong to the families Enterobacteriaceae, Morganelliaceae, and Campylobacteriaceae. Other conditions prompt development of spore-forming bacilli, the presence of which may prevent successful heat sterilization of the final product (larva biomass). However, various modifications of substrate composition and the duration of the larva rearing lead to a reduction or complete elimination of unwanted microorganisms.

An aqueous extract from the larvae of black beetles Ulomoides dermestoides grown under controlled conditions was obtained and its proteomic analysis was performed based on one-dimensional electrophoretic separation of proteins, their trypsinolysis in a gel, and subsequent chromatography-mass spectrometry. Protein identification was performed using MaxQuant v.1.6.3.4 software. The Uniprot database was used to identify proteins by homology. Catalase activity was determined spectrophotometrically by a hydrogen peroxide concentration decrease. Antioxidant activity was evaluated by luminol chemiluminescence quenching. The extract contained proteins that can determine the biological activity of the extract: universal regulators of cellular processes calmodulin (6.2%), cytochrome c-2 (13.5%), nucleoside diphosphate kinase (11.1%), the enzymatic antioxidants superoxide dismutase, catalase, glutathione S-transferase, peroxiredoxin, and glutathione synthetase as well as thioredoxin, 70 kDa and 60 kDa heat shock proteins, and a chitinase complex (13.4% in total). The catalase activity was 45.9 ± 6.5 µmol H2O2/min/mg protein; the antioxidant activity of 1 mg protein per ml extract was equivalent to 2.1 ± 0.3 mM trolox. The prospects for the practical use of the extract as a natural antioxidant complex were noted.

An aqueous extract from the larvae of black beetles Ulomoides dermestoides grown under controlled conditions was obtained and its proteomic analysis based on one-dimensional electrophoretic separation of proteins, their trypsinolysis in a gel and subsequent chromatography-mass spectrometry was performed. Protein identification was performed using MaxQuant v.1.6.3.4 software. The Uniprot database was used to identify proteins by homology. Catalase activity was determined spectrophotometrically by hydrogen peroxide concentration decrease. Antioxidant activity was evaluated by luminol chemiluminescence quenching. The extract contained proteins that can determine the biological activity of the extract: universal regulators of cellular processes calmodulin (62%), cytochrome c-2 (13.5%), nucleoside diphosphate kinase (11.1%), the enzymatic antioxidants superoxide dismutase, catalase, glutathione S-transferase, peroxiredoxin, glutathione synthetase as well as thioredoxin, 70 and 60 kDa heat shock proteins, chitinase complex (13.4% in total). Catalase activity was 6.3 ± 1.1 µmol H2O2/min/mg protein; antioxidant activity of 1 mg protein per ml extract was equivalent to 1.36 ± 0.3 mM trolox. The prospects for practical use of the extract as a natural antioxidant complex were noted.

‘Hidden hunger’ occurs in humans and livestock and stems from deficiencies in microelements, essential amino acids, and vitamins. Triggered by insufficient intake of micronutrients in food and feed, even when macronutrients are abundant, hidden hunger can result in the development of serious diseases and pathological conditions. Finding sufficient micronutrients is often challenging because they are either obtained from limited external natural sources or synthesised de novo . Soil-dwelling saprophages comprise one of the largest proportions of zoomasses on Earth but remain surprisingly overlooked as a potential micronutrient source. To assess their nutritional content concerning micronutrients, we selected 31 invertebrate species obtained from natural ecosystems of European Russia or widely cultivated species originating mainly from tropical regions. They belong to major soil saprophage taxa: cockroaches (Blattodea), beetle (Coleoptera) larvae and imagoes, springtails (Collembola), millipedes (Diplopoda), fly (Diptera) larvae, earthworms (Haplotaxida), woodlice (Isopoda), crickets (Orthoptera). We assessed their proteinogenic amino acid, microelement, and vitamin composition. Taxonomic differences in the composition and ratio of micronutrients were determined and we identified specific taxa naturally enriched with micronutrients for future consideration as potential candidates for incorporation into food and feed supplements to alleviate hidden hunger in livestock and humans.

Using the method of scanning electron microscopy, a comparative study of the particle surface morphology and the elemental composition of the cuticle of Hermetia illucens pupa before and after the application of the culture liquid (CL) of the probiotic strain Lactobacillus acidophilus B 2707 was carried out. At the same time, under the influence of CL, destruction of relatively large particles of the powder of the chitin-protein complex of the cuticle (average particle diameter D 845.3 ± 109.1 μm) and the formation of small fragments (average D 63.4 ± 13.9 μm), including nanoparticles (average D 54 ± 18 nm). A biofilm of lactobacilli enriched with calcium, magnesium and phosphorus was obtained on a sorbent consisting of microparticles of the cuticle of insect pupae and including nanoparticles, which provided the probiotic preparation with high biological efficiency.

Using the method of scanning electron microscopy, a comparative study of the morphology of the particle surface and the elemental composition of the cuticle of Hermetia illucens pupa before and after the application of a liquid culture (LC) of the probiotic strain Lactobacillus acidophilus B 2707 was carried out. At the same time, under the influence of the LC, destruction of relatively large particles of the powder of the chitin–protein complex of the cuticle (average particle diameter D 845.3 ± 109.1 μm) and the formation of small fragments (average D 63.4 ± 13.9 μm) occurred, including nanoparticles (average D 54 ± 18 nm). A biofilm of lactobacilli enriched with calcium, magnesium, and phosphorus was obtained on a sorbent consisting of microparticles of the cuticle of insect pupae and including nanoparticles, which provided the probiotic preparation with high biological efficiency.

Extracts of larvae and beetle Ulomoides dermestoides with high antioxidant activity were obtained: 1 mg/ml of larval extract protein is equivalent in antioxidant activity to 1.36 mM Trolox. The extract contains peptides of thioredoxin and glutathione redox systems, superoxide dismutase, catalase, heat shock proteins 70 kDa. Animals that received 400 micrograms/kg of extract for 1 month with food showed better cognitive abilities than the control ones.

An aqueous extract was obtained from the biomass of Hermetia illucens larvae using the electro-pulse plasma-dynamic method. The extract was highly effective in quenching the chemiluminescence of luminol in the presence of hemoglobin and hydrogen peroxide. It contained the dark pigment melanin with a concentration of paramagnetic centers of 8.3 × 10 16 spin/g of dry matter and antioxidant activity. The antiradical properties of the extract were confirmed on the model of oxidative stress of the nematode Caenorhabditis elegans in the presence of 40 mmol of paraquat: the introduction of the extract increased the median lifespan of the nematode by 25%. The antioxidant effect identified is associated with the presence of a complex of antioxidants in the extract and, possibly, antioxidant enzymes that destroy hydroperoxides.

The objective of this study was screening of ommochromes from the compound eyes of insects and comparison of their antioxidant properties. Ommochromes were isolated in preparative quantities from insects of five different families: Stratiomyidae, Sphingidae, Blaberidae, Acrididae, and Tenebrionidae. The yield of ommochromes (dry pigment weight) was 0.9-5.4% of tissue wet weight depending on the insect species. Isolated pigments were analyzed by high-performance liquid chromatography and represented a mixture of several ommochromes of the ommatin series. The isolated ommochromes displayed a pronounced fluorescence with the emission maxima at 435-450 nm and 520-535 nm; furthermore, the emission intensity increased significantly upon ommochrome oxidation with hydrogen peroxide. The ommochromes produced a stable EPR signal consisting of a singlet line with g = 2.0045-2.0048, width of 1.20-1.27 mT, and high concentration of paramagnetic centers (> 10(17) spin/g dry weight). All the investigated ommochromes demonstrated high antiradical activity measured from the degree of chemiluminescence quenching in a model system containing luminol, hemoglobin, and hydrogen peroxide. The ommochromes strongly inhibited peroxidation of the photoreceptor cell outer segments induced by visible light in the presence of lipofuscin granules from the human retinal pigment epithelium, as well as suppressed iron/ascorbate-mediated lipid peroxidation. The obtained results are important for understanding the biological functions of ommochromes in invertebrates and identifying invertebrate species that could be used as efficient sources of ommochromes for pharmacological preparations to prevent and treat pathologies associated with the oxidative stress development.

A technique for the isolation and purification of ommochromes (pigments of the complex eye of the adult Hermetia illucens fly) has been developed. Isolated ommochromes showed fluorescence with emission maxima at 460–470 nm and 525–535 nm, the intensity of which increased abruptly during their oxidation with hydrogen peroxide. The method of chemiluminescence quenching of luminol was used to determine the antiradical activity of ommochromes; the constant value was (1.2 ± 0.5) × 104 M–1. A finely dispersed mixture of ommochromes in 0.1 M potassium phosphate buffer (pH 7.4) containing bovine serum albumin (2.0 mg/mL) showed antimicrobial activity against B. subtilis ATCC 6633, Candida albicans ATCC 2091, and Aspergillus niger INA 00760. The H. illucens imago was concluded to be a promising renewable source of natural pigments with good antioxidant characteristics and antibacterial properties.

This article discusses work on assessing the digestibility of a concentrate of Hermetia illucens larvae in fish with gastrointestinal digestion (rainbow trout Oncorhynchus mykiss, Russian sturgeon Acipenser gueldenstaedtii, red tilapia Oreochromis mosambicus × O. niloticus). It was found that this digestibility index of the larvae concentrate was 67–74%. At the same time, fish species consumed larvae protein at 91–97%, the digestibility of residual fat was 90–94%, and easily hydrolyzed carbohydrates amounted to 52–68%. Сhitin of H. illucens was digested 25–35% and did not adversely affect the digestion of protein and fat in the fish species studied. The digestion rates of the H. illucens larvae concentrate, protein, and easily digestible carbohydrates in O. mosambicus × O. niloticus are statistically significantly higher than in Onc. mykiss, while in A. gueldenstaedtii they were intermediate in comparison with tilapia and trout. This corresponded to the duration of food passage through the intestinal tract, which in O. mosambicus × O. niloticus, Ac. gueldenstaedtii, and O. mykiss came to 7.8, 9.6, and 15.7 hours, respectively. Fat and chitin were digested by red trout significantly more efficiently than other fish species. This corresponded to the duration of food passage through the intestinal tract, which for tilapia, sturgeon, and trout came to 7.8, 9.6, and 15.7 hours, respectively. The degree of digestibility of fat and chitin by trout was significantly higher than that of other fish species.

ПИТАТЕЛЬНЫЕ СВОЙСТВА ЛИЧИНОКHermetia illucens L. -НОВОГО КОРМОВОГО ПРОДУКТА ДЛЯ МОЛОДНЯКА СВИНЕЙ (Sus scrofa domesticus Erxleben) * Р.В.НЕКРАСОВ 1 , М.Г.ЧАБАЕВ 1 , А.А.ЗЕЛЕНЧЕНКОВА 1 , А.И.БАСТРАКОВ 2 , Н.А.УШАКОВА 2 Выращивание личинок мухи черная львинка (Hermetia illucens L.) -экономичный способ превращения органических остатков в ценный источник биомолекул (белков, липидов и хитина).Доказана перспективность промышленного разведения личинок черной львинки на различных органических субстратах, в связи с чем целесообразно изучить их питательные свойства и эффективность применения в кормлении сельскохозяйственных животных.Целью нашей работы была оценка питательных характеристик личинок H. illucens, выращенных на различных кормовых субстратах, и изучение возможности введения их в рацион сельскохозяйственных животных на примере молодняка свиней.Личинок получали в лабораторных условиях (ИПЭЭ РАН) при использовании различных кормовых субстратов: послеспиртовой барды, фуражного зерна пшеницы, пшеничных отрубей, дробленой кукурузы, фруктово-зерново-овощных смесей, птичьей пометной подстилки.Физиологический опыт на гибридных боровках (F 1 крупная белая ½ ландрас, 6 гол.) проводили в условиях физиологического двора Федерального научного центра животноводства -ВИЖ им.академика Л.К.Эрнста.По принципу аналогов (происхождение, возраст, живая масса) были сформированы две группы животных по 3 гол.в каждой.Животным I группы (контроль) скармливали полнорационный стартовый комбикорм (СК-4) с содержанием 5 % отрубей и добавлением 5,0 % рыбной муки.Аналогам из II группы давали СК-4 с 7,0 % сухих личинок H. illucens, выращенных на дробленой кукурузе, и 3 % пшеничных отрубей.Опыт проводили в двух повторностях.Биоконверсия субстратов личинками составляла от 41 % (птичья пометная подстилка) до 77 % (дробленая кукуруза).Биомасса личинок варьировала от 54 г/кг (птичья пометная подстилка) до 240 г/кг (зерново-фруктово-овощные смеси).Наиболее предпочтительными субстратами для выращивания биомассы личинок оказались зерновые и зерново-фруктовоовощные смеси.Питательная ценность личинок мухи менялась в зависимости от субстрата.Количество обменной энергии находится в пределах 15,32-21,41 МДж/кг, количество белка колеблется в пределах 35,5-48,3 %, жира -20,6-45,5 %.Протеин личинок содержит полный набор аминокислот, характерный для белка животного происхождения, и по составу также зависит от используемого субстрата.Существенное влияние на биохимический состав личинок оказывал их возраст.У личинок последнего возраста (предкуколки) повышалось количество протеина и уменьшалась массовая доля жира: в сухих личинках, выращенных на фуражном зерне пшеницы, содержалось 37,6 % протеина и 38,3 % жира, в то время как в предкуколках эти показатели составляли соответственно 42,8 и 31,9 %.Замена рыбной муки сухими личинками мухи H. illucens способствовала лучшему использованию и отложению азота и, как следствие, более высокому приросту живой массы у поросят из опытной группы (504,95±17,94 против 475,92±22,93 г, р > 0,05).Включение в рацион личинок черной львинки не оказывало статистически значимого отрицательного воздействия на использование животными кальция и фосфора.Таким образом, личинки мухи Hermetia illucens можно рассматривать в качестве рациональной альтернативы традиционным высокопротеиновым кормам, удовлетворяющим потребности интенсивно растущего молодняка свиней в питательных веществах.

A comparative study of melanin and ommochrome-containing samples, isolated from the black soldier fly (BSF) by enzymatic hydrolysis, alkaline and acid alcohol extraction or by acid hydrolysis, was carried out. Melanin was isolated both as a melanin-chitin complex and as a water-soluble melanin. Acid hydrolysis followed by delipidization yielded a more concentrated melanin sample, the electron spin resonance (ESR) signal of which was 2.6 × 1018 spin/g. The ommochromes were extracted from the BSF eyes with acid methanol. The antiradical activity of BSF melanins and ommochromes was determined by the method of quenching of luminol chemiluminescence. It has been shown that delipidization of water-soluble melanin increases its antioxidant properties. A comparison of the antioxidant activity of BSF melanins and ommochromes in relation to photoinduced lipid peroxidation was carried out. The ESR characteristics of native and oxidized melanins and ommochromes were studied. It is assumed that H. illucens adult flies can be a useful source of natural pigments with antioxidant properties.

ПИТАТЕЛЬНЫЕ СВОЙСТВА ЛИЧИНОКHermetia illucens L. -НОВОГО КОРМОВОГО ПРОДУКТА ДЛЯ МОЛОДНЯКА СВИНЕЙ (Sus scrofa domesticus Erxleben) * Р.В.НЕКРАСОВ 1 , М.Г.ЧАБАЕВ 1 , А.А.ЗЕЛЕНЧЕНКОВА 1 , А.И.БАСТРАКОВ 2 , Н.А.УШАКОВА 2 Выращивание личинок мухи черная львинка (Hermetia illucens L.) -экономичный способ превращения органических остатков в ценный источник биомолекул (белков, липидов и хитина).Доказана перспективность промышленного разведения личинок черной львинки на различных органических субстратах, в связи с чем целесообразно изучить их питательные свойства и эффективность применения в кормлении сельскохозяйственных животных.Целью нашей работы была оценка питательных характеристик личинок H. illucens, выращенных на различных кормовых субстратах, и изучение возможности введения их в рацион сельскохозяйственных животных на примере молодняка свиней.Личинок получали в лабораторных условиях (ИПЭЭ РАН) при использовании различных кормовых субстратов: послеспиртовой барды, фуражного зерна пшеницы, пшеничных отрубей, дробленой кукурузы, фруктово-зерново-овощных смесей, птичьей пометной подстилки.Физиологический опыт на гибридных боровках (F 1 крупная белая ½ ландрас, 6 гол.) проводили в условиях физиологического двора Федерального научного центра животноводства -ВИЖ им.академика Л.К.Эрнста.По принципу аналогов (происхождение, возраст, живая масса) были сформированы две группы животных по 3 гол.в каждой.Животным I группы (контроль) скармливали полнорационный стартовый комбикорм (СК-4) с содержанием 5 % отрубей и добавлением 5,0 % рыбной муки.Аналогам из II группы давали СК-4 с 7,0 % сухих личинок H. illucens, выращенных на дробленой кукурузе, и 3 % пшеничных отрубей.Опыт проводили в двух повторностях.Биоконверсия субстратов личинками составляла от 41 % (птичья пометная подстилка) до 77 % (дробленая кукуруза).Биомасса личинок варьировала от 54 г/кг (птичья пометная подстилка) до 240 г/кг (зерново-фруктово-овощные смеси).Наиболее предпочтительными субстратами для выращивания биомассы личинок оказались зерновые и зерново-фруктовоовощные смеси.Питательная ценность личинок мухи менялась в зависимости от субстрата.Количество обменной энергии находится в пределах 15,32-21,41 МДж/кг, количество белка колеблется в пределах 35,5-48,3 %, жира -20,6-45,5 %.Протеин личинок содержит полный набор аминокислот, характерный для белка животного происхождения, и по составу также зависит от используемого субстрата.Существенное влияние на биохимический состав личинок оказывал их возраст.У личинок последнего возраста (предкуколки) повышалось количество протеина и уменьшалась массовая доля жира: в сухих личинках, выращенных на фуражном зерне пшеницы, содержалось 37,6 % протеина и 38,3 % жира, в то время как в предкуколках эти показатели составляли соответственно 42,8 и 31,9 %.Замена рыбной муки сухими личинками мухи H. illucens способствовала лучшему использованию и отложению азота и, как следствие, более высокому приросту живой массы у поросят из опытной группы (504,95±17,94 против 475,92±22,93 г, р > 0,05).Включение в рацион личинок черной львинки не оказывало статистически значимого отрицательного воздействия на использование животными кальция и фосфора.Таким образом, личинки мухи Hermetia illucens можно рассматривать в качестве рациональной альтернативы традиционным высокопротеиновым кормам, удовлетворяющим потребности интенсивно растущего молодняка свиней в питательных веществах.