2023

Pozhidaeva, E.A. | Popov, E.S. | Dymovskikh, Ya.A. | Grebennikova, M.S. | Durova, Yu.V.

Natural polysaccharides are waste products of probiotic microorganisms formed during biomass synthesis. They have good prospects as ingredients for sustainable and functional food production. Polysaccharides increase the adhesive activity of lacto- and bifidobacteria on the mucous surfaces of the gastrointestinal tract. In addition, they improve the anticarcinogenic, antiviral, and immunomodulatory properties of probiotic products. Conditions that are unfavorable for microbial biomass growth are known to stimulate the synthesis of moisture-binding metabolites by probiotic microorganisms. This research featured the activity of exopolysaccharide synthesis by a probiotic consortium, which involved Streptococcus thermophilus, Bifidobacterium bifidum, B. longum, B. adolescentis, B. breve, Lactobacillus acidophilus, L. plantarum, L. fermentum. The temperature modes combined stages of optimal and non-optimal conditions for microbial development at (47 ± 2) deg. C or (32 ± 2) deg. C, which intensified the synthesis of moisture-binding polysaccharide metabolites. The optimal concentration of probiotic microorganisms was 108 CFU/g: it resulted in an effective concentration of lactic acid, which ensured acid coagulation of proteins in the cultivated mix. The optical density was 632–643 A while the concentration of exopolysaccharides was 87.5–89.5 mcg/mL. The maximal synthesis of moisture-binding metabolites corresponded to a two-stage cultivation process at (32 ± 2) deg.C for 4–5 h and (40 ± 2) deg.C for 4–5 h, followed by cooling to (4 ± 2) deg. C. | В развитии пищевых технологий актуально расширение возможности применения естественных полисахаридов – продуктов жизнедеятельности пробиотических микроорганизмов, образующихся в процессе синтеза биомассы. Они повышают адгезионную активность лакто- и бифидобактерий на слизистых поверхностях желудочно-кишечного тракта и способствуют формированию антиканцерогенных, противовирусных и иммуномодулирующих свойств пробиотических продуктов. Cинтез влагосвязывающих метаболитов пробиотическими микроорганизмами активируется при неблагоприятных условиях для роста биомассы. Проведены экспериментальные исследования активности синтеза экзополисахаридов консорциумом пробиотических микроорганизмов на основе Streptococcus thermophilus, Bifidobacterium bifidum, B. longum, B. adolescentis, B. breve, Lactobacillus acidophilus, L. plantarum, L. fermentum. Изучены температурные режимы культивирования на основе комбинирования этапов оптимальных и неоптимальных условий для развития микроорганизмов, соответствующих варьированию температуры в диапазоне более высоких (47 ± 2) град. С или более низких значений (32 ± 2) град. С, с целью интенсификации синтеза влагосвязывающих метаболитов полисахаридной природы. Установлена возможность достижения концентрации молочной кислоты, достаточной для кислотной коагуляции белков культивируемой смеси, концентрации пробиотических микроорганизмов на уровне не менее 10E8 КОЕ/г. Приведены результаты исследований оптической плотности в диапазоне 632–643 А и концентрации экзополисахаридов для образцов биомасс консорциума лакто- и бифидобактерий в пределах и 87,5–89,5 мкг/мл (соответственно 273–277 А и 37,5–38,5 мкг/мл в контрольном образце). Максимальная активность синтеза влагосвязывающих метаболитов соответствует двухстадийному процессу культивирования при температурных воздействиях (32 ± 2) град. С (4–5 ч), (40 ± 2) град. С (4–5 ч) с последующим охлаждением до (4 ± 2) град. С.

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Central Scientific Agricultural Library - Russian Federation

2023

Javal, Marion | Terblanche, John S. | Benoit, Laure | Conlong, Desmond | Lloyd, James R. | Smit, Chantelle | Chapuis, Marie-Pierre

Biotic interactions can modulate the responses of organisms to environmental stresses, including diet changes. Gut microbes have substantial effects on diverse ecological and evolutionary traits of their hosts, and microbial communities can be highly dynamic within and between individuals in space and time. Modulations of the gut microbiome composition and their potential role in the success of a species to maintain itself in a new environment have been poorly studied to date. Here we examine this question in a large wood-boring beetle Cacosceles newmannii (Cerambycidae), that was recently found thriving on a newly colonized host plant. Using 16S metabarcoding, we assessed the gut bacterial community composition of larvae collected in an infested field and in “common garden” conditions, fed under laboratory-controlled conditions on four either suspected or known hosts (sugarcane, tea tree, wattle, and eucalyptus). We analysed microbiome variation (i.e. diversity and differentiation), measured fitness-related larval growth, and studied host plant lignin and cellulose contents, since their degradation is especially challenging for wood-boring insects. We show that sugarcane seems to be a much more favourable host for larval growth. Bacterial diversity level was the highest in field-collected larvae, whereas lab-reared larvae fed on sugarcane showed a relatively low level of diversity but very specific bacterial variants. Bacterial communities were mainly dominated by Proteobacteria, but were significantly different between sugarcane-fed lab-reared larvae and any other hosts or field-collected larvae. We identified changes in the gut microbiome associated with different hosts over a short time frame, which support the hypothesis of a role of the microbiome in host switches.

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Centre de coopération internationale en recherche agronomique pour le développement - France

2023

Abre, Marina | Kouakou-Kouamé, Clémentine Amenan | N'Guessan, Florent Kouadio | Teyssier, Corinne | Montet, Didier

Adjuevan is an Ivorian traditional fermented fish used as a condiment. However, the fermentation process and storage conditions may lead to the production of biogenic amines (BA) which can induce severe human toxicological effects. Thus, this study aimed to reveal the bacterial community diversity and the BA contents during the storage. Samples of adjuevan from the fish species Chloroscombrus chrysurus, Galeoides decadactylus, and Thunnus thynnus were collected from local producers, stored at ambient temperature (28–30 °C) and in a refrigerator (4 °C) over a period of 8 weeks. At 2-week intervals, BA were determined by HPLC and the bacterial communities analyzed using high-throughput sequencing (NGS) of the V3-V4 region of the 16S rRNA gene. Results showed that histamine, cadaverine, putrescine, and tyramine were the major compounds. In adjuevan from T. thynnus, the level of histamine was over the maximum level of 200 mg/kg determined by Codex Alimentarius. For the other amines, no safety concerns are related. In total, 21 bacterial genera with a relative abundance ≥ 1% and belonging to 14 families and 5 phyla were detected. The Bacillaceae family was the most found at ambient temperature while Staphylococcaceae and Enterococcaceae were the most abundant in a refrigerator. The analysis of correlation showed that the increase of Lentibacillus leads to a decrease of the major BA at ambient temperature. On the contrary, the increase of Staphylococcus, Lactobacillus, Psychrobacter, Peptostreptococcus, and Fusobacterium leads to an increase of these biogenic compounds. Thus, Lentibacillus acted as BA-oxidizing bacteria while the others were found as BA–producing bacteria during adjuevan storage.

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Centre de coopération internationale en recherche agronomique pour le développement - France

2023

Chernega, O.P. | Kazimirchenko, O.V. | Kostenko, A.A.

The plum fermentation process was studied in order to expand the range of long-term stored products of high nutritional value. As a result of microbiological analysis of fresh plums, it has been found that the basis of their microflora is coccal and rod-like lactic acid fermentation bacteria. There has been developed a plum fermentation technology carried out by spontaneous fermentation without adding brine and introducing starter cultures of microorganisms. Various methods of plum fermentation were compared: in a container under load or in vacuum bags with or without oxygen access. Quantitative and qualitative changes in the microflora during fermentation in various ways during 7 days are shown. It has been revealed that an oxygen-free environment promotes the reproduction of lactic acid streptococci and lactobacilli, as a result of which the pH value of the finished product has decreased to 3.18. This made it possible to obtain a safe product with a long shelf life and unusual organoleptic characteristics. Lactofermented plum has acquired a bright color, an individual and unique taste, and a special texture. The samples were characterized by storage resistance and microbiological stability in relation to sanitary-indicatory bacteria of the intestinal group and spoilage microbes. The following products were obtained on the basis of lactofermented plums: pulp, juice, powder from the peel of fruits. Their total bacterial contamination and microflora composition were investigated. The developed products can be used as snacks, side dishes for meat, poultry and fish, salad dressings, seafood sauce, and dessert ingredients. | Изучали процесс ферментации сливы в целях расширения ассортимента длительно хранящейся продукции высокой пищевой ценности. В результате микробиологического анализа свежих слив установлено, что основой их микрофлоры являются кокковые и палочковидные бактерии молочнокислого брожения. Разработана технология ферментации слив, осуществляемая самопроизвольным брожением без добавления рассола и внесения заквасочных культур микроорганизмов. Сравнивали различные способы ферментации слив: в емкости под грузом или в вакуумных пакетах с доступом кислорода или без него. Показаны количественные и качественные изменения микрофлоры в процессе ферментации различными способами в течение 7 сут. Выявлено, что бескислородная среда способствует размножению молочнокислых стрептококков и лактобацилл, вследствие чего значение рН готового продукта снизилось до 3,18. Это позволило получить безопасный продукт с длительным сроком хранения и необычными органолептическими показателями. Лактоферментированная слива приобрела яркий цвет, индивидуальный и неповторимый вкус, особую текстуру. Образцы отличались стойкостью при хранении и микробиологической стабильностью в отношении санитарно-показательных бактерий кишечной группы и микробов порчи. На основе лактоферментированной сливы были получены следующие продукты: мякоть, сок, порошок (пудра) из кожуры плодов. Исследована их общая бактериальная обсемененность и состав микрофлоры. Разработанные продукты могут применяться в качестве закуски, гарнира к мясу, птице и рыбе, приправы для салатов, соуса к морепродуктам, ингредиентов для десерта.

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Central Scientific Agricultural Library - Russian Federation

2022

Belkina, D.D. | Yurchenko, E.G. | Karpova, D.V. | Karaseva, Eh.V.

Представлены результаты исследования эндофитных сообществ проводящих органов винограда, возделываемого в ампелоценозах анапо-таманской зоны виноградарства. В процессе работы был проведён посев микробиоты однолетних и многолетних проводящих органов винограда сортов Молдова и Мерло, изучено разнообразие сообществ эндофитных бактерий, проанализирована их таксономическая структура, показана динамика фенотипического разнообразия эндофитов в зависимости от фенофазы винограда. По итогам работы сделан предварительный вывод о различиях в таксономической структуре сообществ эндофитных бактерий двух разных по генотипу сортов в двух отличающихся по свойствам субстратах проводящих органов винограда. Общее число изолированных эндофитных бактерий составило 93 штамма, бактериальные сообщества сорта Мерло показали большее таксономическое разнообразие, чем сообщества сорта Молдова. Большая часть выделенных штаммов входила в филумы Firmicutes (38 штаммов) и Actinobacteria (36 штаммов), в меньшем количестве были представлены штаммы, относящиеся к филуму Proteobacteria (12 штаммов). Идентифицировано 42 бактериальных штамма, в том числе Pantoea agglomerans, Bacillus sp., Kocuria sp., Paenibacillus sp., Dietzia sp., Pseudomonas sp., Rothia sp., Staphylococcus sp. Среди идентифицированных групп наибольшим разнообразием отличались представители рода Bacillus. Некоторые роды бактерий были отмечены только в определённых субстратах. Так, штаммы рода Acinetobacter выделены только из однолетней лозы обоих сортов, Dietzia и Paenibacillus – только из однолетней лозы Молдовы, Pseudomonas и Rothia – из многолетней древесины Мерло, Kocuria – из обоих сообществ сорта Мерло, но однолетние данные нуждаются в подтверждении в дальнейших исследованиях. | There are presented the results of a study of endophytic communities in the conductive organs of grapes, which is cultivated in the ampelocenoses of the Anapo-Taman viticulture zone. In the course of the work, the microbiota of annual and perennial conducting organs of Moldova and Merlot grape varieties was inoculated, the diversity of bacterial endophytic communities was studied, their taxonomic structure was analyzed, and the dynamics of their phenotypic diversity depending on grape phenophase was demonstrated. Based on the results of the work, a preliminary conclusion was made about the differences in the taxonomic structure of bacterial endophytic communities from 2 varieties genotypically different and from 2 substrates of grape conducting organs differing in properties. The total number of isolated endophytic bacteria was 93 strains. The bacterial communities of the Merlot variety showed greater taxonomic diversity than the bacterial communities of the Moldova variety. Most of the isolated strains belonged to phyla Firmicutes (38 strains) and Actinobacteria (36 strains). Phylum Proteobacteria (12 strains) was represented in a smaller number. There were identified 42 bacterial strains, including Pantoea agglomerans, Bacillus sp., Kocuria sp., Paenibacillus sp., Dietzia sp., Pseudomonas sp., Rothia sp., Staphylococcus sp. Among the identified groups, strains of the genus Bacillus were the most diverse. Some genera of bacteria have been observed only in specific substrates. Thus, strains of the genus Acinetobacter were isolated only from annual vines of both varieties, Dietzia and Paenibacillus – only from annual vines of Moldova, Pseudomonas and Rothia – from perennial Merlot wood, Kocuria – from both communities of Merlot varieties, but one-year data need to be confirmed in further studies.

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Central Scientific Agricultural Library - Russian Federation

2022

Tyurin, V.G. | Mysova, G.A. | Potemkina, N.N. | Sakharov, A.Yu. | Kochish, O.I. | Biryukov, K.N.

The results of a veterinary and sanitary assessment of biotechnological methods for organic animal waste processing based on active solid-phase fermentation and vermicomposting are presented. The dynamics of changes in the microbiological parameters of manure in the course of processing is shown. In the initial period of composting, pathogenic microorganisms such as bacteria of the Escherichia coli group (serovariants O141, O142) and staphylococci were isolated. The number of microorganisms in manure during its active composting depends on the temperature of the compost mixture, the duration of fermentation, and the number of thermophilic microorganisms. At the initial stage of active composting, the number of thermophilic microorganisms in manure is insignificant, after 4 days of biofermentation there is an increase in the number of active thermophilic cultures up to 1.5+0.1x10E8 CFU/g. The total microbial number decreases to 15.0+0.1x10E6, the number of Escherichia coli group and staphylococci decreases to 2.0+0.2x10E3 and 2.5+0.1x10E2, respectively; the number of thermophilic microorganisms remains high. After 5 days of manure biofermentation, pathogenic serovariants O141 and O142 were not isolated, and staphylococci were not detected on the 7th day of aerobic active manure fermentation. It is shown that the processed manure in the form of composts has a moisture content of 45.5%, which is 1.7 times less than the moisture content of manure on a straw bedding. When studying the nature of changes in chemicals in the biotechnological process of manure processing using vermiculture, it was established that biohumus contains in a well-balanced and easily digestible form all nutrients necessary for plants. When studying the nature of changes in toxic substances and their concentration in manure processed products, it was found that when organic waste is disposed of by vermicomposting, there is no significant decrease in the concentration of lead and cadmium, but the concentration of zinc and copper is significantly reduced. Methods for organic animal waste processing based on aerobic solid-phase fermentation and the use of vermiculture provide valuable and safe organic fertilizers that meet sanitary, hygienic and environmental requirements. | Представлены результаты ветеринарно-санитарной оценки биотехнологических способов переработки органических отходов животноводства на основе активной твердофазной ферментации и вермикомпостирования. Показана динамика изменения микробиологических показателей навоза в процессе переработки. В начальный период компостирования были выделены патогенные микроорганизмы из группы бактерий группы кишечной палочки (БГКП, сероварианты О141, О142) и стафилококки. На начальном этапе активного компостирования количество термофильных микроорганизмов в навозе незначительно, но после 4-х сут биоферментации происходит увеличение численности активных термофильных культур до 1,5+0,1х10E8 КОЕ/г. Общее микробное число (ОМЧ) снижается до 15,0+0,1х10E6, количество БГКП и стафилококков уменьшается до 2,0+0,2х10E3 и 2,5+0,1х10E2 соответственно при высокой численности термофильных микроорганизмов. После 5-ти сут биоферментации навоза патогенные сероварианты О141 и О142 не были выделены, а стафилококки не обнаруживались на 7-е сут аэробной активной ферментации навоза. Показано, что переработанный навоз в виде компостов имеет влажность 45,5%, что в 1,7 раза меньше, чем влажность навоза на соломенной подстилке. При изучении характера изменений химических веществ в биотехнологическом процессе переработки навоза с помощью вермикультуры установлено, что биогумус содержит в хорошо сбалансированной и легкоусвояемой форме все необходимые для растений питательные вещества. При утилизации органических отходов методом вермикомпостирования не происходит достоверного снижения концентрации свинца и кадмия, но достоверно снижается концентрация цинка и меди. Способы переработки органических отходов животноводства на основе аэробной твердофазной ферментации и использование вермикультуры обеспечивают получение ценных и безопасных органических удобрений, отвечающих санитарно-гигиеническим и экологическим требованиям.

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Central Scientific Agricultural Library - Russian Federation

2022

Hendrycks, Wouter | Delatte, Hélène | Moquet, Laura | Bourtzis, Kostas | Mullens, Nele | De Meyer, Marc | Backeljau, Thierry | Virgilio, Massimiliano

While contemporary changes in feeding preferences have been documented in phytophagous insects, the mechanisms behind these processes remain to be fully clarified. In this context, the insect gut microbiome plays a central role in adaptation to novel host plants. The cucurbit frugivorous fruit fly Zeugodacus cucurbitae (Diptera, Tephritidae) has occasionally been reported on “unconventional” host plants from different families, including Solanaceae. In this study, we focus on wild parental (F0) adults and semiwild first filial (F1) larvae of Z. cucurbitae from multiple sites in La Réunion and explore how the gut microbiome composition changes when this fly is feeding on a noncucurbit host (Solanum melongena). Our analyses show nonobvious gut microbiome responses following the F0–F1 host shift and the importance of not just diet but also local effects, which heavily affected the diversity and composition of microbiomes. We identified the main bacterial genera responsible for differences between treatments. These data further stress the importance of a careful approach when drawing general conclusions based on laboratory populations or inadequately replicated field samples.

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Centre de coopération internationale en recherche agronomique pour le développement - France

2022

Ravigné, Virginie | Becker, Nathalie | Massol, François | Guichoux, Erwan | Boury, Christophe | Mahe, Frédéric | Facon, Benoît

One promising avenue for reconciling the goals of crop production and ecosystem preservation consists in the manipulation of beneficial biotic interactions, such as between insects and microbes. Insect gut microbiota can affect host fitness by contributing to development, host immunity, nutrition, or behavior. However, the determinants of gut microbiota composition and structure, including host phylogeny and host ecology, remain poorly known. Here, we used a well-studied community of eight sympatric fruit fly species to test the contributions of fly phylogeny, fly specialization, and fly sampling environment on the composition and structure of bacterial gut microbiota. Comprising both specialists and generalists, these species belong to five genera from to two tribes of the Tephritidae family. For each fly species, one field and one laboratory samples were studied. Bacterial inventories to the genus level were produced using 16S metabarcoding with the Oxford Nanopore Technology. Sample bacterial compositions were analyzed with recent network-based clustering techniques. Whereas gut microbiota were dominated by the Enterobacteriaceae family in all samples, microbial profiles varied across samples, mainly in relation to fly identity and sampling environment. Alpha diversity varied across samples and was higher in the Dacinae tribe than in the Ceratitinae tribe. Network analyses allowed grouping samples according to their microbial profiles. The resulting groups were very congruent with fly phylogeny, with a significant modulation of sampling environment, and with a very low impact of fly specialization. Such a strong imprint of host phylogeny in sympatric fly species, some of which share much of their host plants, suggests important control of fruit flies on their gut microbiota through vertical transmission and/or intense filtering of environmental bacteria.

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Centre de coopération internationale en recherche agronomique pour le développement - France

2022

Ben Zineb, Ameni | Barkaoui, Karim | Karray, Fatma | Mhiri, Najla | Sayadi, Sami | Mliki, Ahmed | Gargouri, Mahmoud

Agroforestry (AF) is a promising land-use system to mitigate water deficiency, particularly in semi-arid areas. However, the belowground microbes associated with crops below trees remain seldom addressed. This study aimed at elucidating the effects of olive AF system intercropped with durum wheat (Dw), barely (Ba), chickpea (Cp), or faba bean (Fb) on crops biomass and their soil-rhizosphere microbial networks as compared to conventional full sun cropping (SC) under rainfed conditions. To test the hypothesis, we compared the prokaryotic and the fungal communities inhabiting the rhizosphere of two cereals and legumes grown either in AF or SC. We determined the most suitable annual crop species in AF under low-rainfed conditions. Moreover, to deepen our understanding of the rhizosphere network dynamics of annual crops under AF and SC systems, we characterized the microbial hubs that are most likely responsible for modifying the microbial community structure and the variability of crop biomass of each species. Herein, we found that cereals produced significantly more above-ground biomass than legumes following in descending order: Ba > Dw > Cp > Fb, suggesting that crop species play a significant role in improving soil water use and that cereals are well-suited to rainfed conditions within both types of agrosystems. The type of agrosystem shapes crop microbiomes with the only marginal influence of host selection. However, more relevant was to unveil those crops recruits specific bacterial and fungal taxa from the olive-belowground communities. Of the selected soil physicochemical properties, organic matter was the principal driver in shaping the soil microbial structure in the AF system. The co-occurrence network analyses indicated that the AF system generates higher ecological stability than the SC system under stressful climate conditions. Furthermore, legumes' rhizosphere microbiome possessed a higher resilient capacity than cereals. We also identified different fungal keystones involved in litter decomposition and drought tolerance within AF systems facing the water-scarce condition and promoting crop production within the SC system. Overall, we showed that AF reduces cereal and legume rhizosphere microbial diversity, enhances network complexity, and leads to more stable beneficial microbial communities, especially in severe drought, thus providing more accurate predictions to preserve soil diversity under unfavorable environmental conditions.

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Centre de coopération internationale en recherche agronomique pour le développement - France

2022

Ben Zineb, Ameni | Barkaoui, Karim | Karray, Fatma | Mhiri, Najla | Sayadi, Sami | Mliki, Ahmed | Gargouri, Mahmoud

Plant rhizosphere microbiomes are crucial for crops' health and productivity but the selection and specificity that govern crop microbiome assembly are not fully known. Herein, we examined bacterial communities of two cereals, durum (Triticum durum) and barley (Hordeum vulgare), and two legumes' species, chickpeas (Cicer arietinum) and bean (Faba been) under rainfed conditions and without fertilization practices. Our results demonstrate that microbiome composition and assembly are shaped predominantly by host species. Each species either cereals or legumes recruits a distinct rhizosphere microbiome, with the strongest host effect in Faba been. Moreover, crop microbiomes were dominated by a few dominant taxa belonging to Thaumarchaeota and Actinobacteria phyla, with Rhizobiales (Alphaproteobacteria) identified as the important biomarker taxa for both legumes. Our work provides comprehensive empirical evidence on host selection, potential sources, and enrichment processes for crop microbiome assembly, and has important implications for future crop management and manipulation of crop microbiome for sustainable agriculture.

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Centre de coopération internationale en recherche agronomique pour le développement - France