Biology subjects

Yergaliyev, T.

Publications and source records attributed to Yergaliyev, T..

4 recordsLinked to original sources

bioRxiv2023

Novel taxonomic and functional diversity of bacteria from the upper digestive tract of chicken

Strategies to increase the production rate of chicken for human consumption alter the natural process of microbial colonisation and the nutritional performance of the animal. The lack of sufficient reference genomes limits the interpretation of sequencing data and restrain the study of complex functions. In this study, 43 strains obtained from crop, jejunum and ileum of chicken were isolated, characterised and genome analysed to observe their metabolic profiles, adaptive strategies and to serve as future references. Eight isolates represent new species that colonise the upper gut intestinal tract and present consistent adaptations that enable us to predict their ecological role, expanding our knowledge on the adaptive functions. Molecular characterisation confirmed the classification of Clostridium anaerovisceris sp. nov. (DSM 113860= LMG 32675), Clostridium butanolproducens (DSM 115076= LMG 32878), Ligilactobacillus hohenheimius sp. nov. (DSM 113870= LMG 32876), Limosilactobacillus gallus sp. nov. (DSM 113833 =LMG 32623), Limosilactobacillus avium sp. nov. (DSM 113849= LMG 32671), Limosilactobacillus pullum sp. nov. (DSM 115077 =LMG 32877), Limosilactobacillus digestus sp. nov. (DSM113835= LMG 32625) and Limosilactobacillus difficile sp. nov. (DSM 114195= LMG 32875). Strains of Limosilactobacillus were found to be more abundant in the crop, while Ligilactobacillus dominated the ileal digesta. Isolates from crop encode a high number of glycosidases specialized in complex polysaccharides compared to strains isolated from jejunum and ileum. These results represent the first approach for the isolation and detection of bacteria from the chickens upper digestive tract and describe the functional diversity of bacteria inhabiting these regions, improving the potential handling of chicken microbiota with biotechnological applications.

microbiology↗

bioRxiv2021

Teasing apart the host-related, nutrient-related and temperature-related effects shaping the phenology and microbiome of the tropical seagrass Halophila stipulacea

BackgroundHalophila stipulacea seagrass meadows are an ecologically important and threatened component of the ecosystem in the Gulf of Aqaba. Recent studies have demonstrated correlated geographic patterns for leaf endophytic community composition and leaf morphology, also coinciding with different levels of water turbidity and nutrient concentrations. Based on these observations, workers have suggested an environmental microbial fingerprint, which may reflect various environmental stress factors seagrasses have experienced, and may add a holobiont level of plasticity to seagrasses, assisting their acclimation to changing environments and through range expansion. However, it is difficult to tease apart environmental effects from host-diversity dependent effects, which have covaried in field studies, although this is required in order to establish that differences in microbial community compositions among sites are driven by environmental conditions rather than by features governed by the host. ResultsIn this study we carried out a mesocosm experiment, in which we studied the effects of warming and nutrient stress on the composition of epiphytic bacterial communities and on some phenological traits. We studied H. stipulacea collected from two different meadows in the Gulf of Aqaba, representing differences in the host and the environment alike. We found that the source site from which seagrasses were collected was the major factor governing seagrass phenology, although heat increased shoot mortality and nutrient loading delayed new shoot emergence. Bacterial diversity, however, mostly depended on the environmental conditions. The most prominent pattern was the increase in Rhodobacteraceae under nutrient stress without heat stress, along with an increase in Microtrichaceae. Together, the two taxa have the potential to maintain nitrate reduction followed by an anammox process, which can together buffer the increase in nutrient concentrations across the leaf surface. ConclusionsOur results thus corroborate the existence of environmental microbial fingerprints, which are independent from the host diversity, and support the notion of a holobiont level plasticity, both important to understand and monitor H. stipulacea ecology under the changing climate.

microbiology↗

bioRxiv2020

The bacterial community structure dynamics in Meloidogyne incognita infected roots and its role in worm-microbiome interactions

BackgroundPlant parasitic nematodes such as Meloidogyne incognita have a complex life cycle, occurring sequentially in various niches of the root and rhizosphere. They are known to form a range of interactions with bacteria and other microorganisms, that can affect their densities and virulence. High throughput sequencing can reveal these interactions in high temporal, and geographic resolutions, although thus far we have only scratched the surface. We have carried out a longitudinal sampling scheme, repeatedly collecting rhizosphere soil, roots, galls and second stage juveniles from 20 plants to provide a high resolution view of bacterial succession in these niches, using 16S rRNA metabarcoding. ResultsWe find that a structured community develops in the root, in which gall communities diverge from root segments lacking a gall, and that this structure is maintained throughout the crop season. We detail the successional process leading toward this structure, which is driven by interactions with the nematode and later by an increase in bacteria often found in hypoxic and anaerobic environments. We show evidence that this structure may play a role in the nematodes chemotaxis towards uninfected root segments. Finally, we describe the J2 epibiotic microenvironment as ecologically deterministic, in part, due to active bacterial attraction of second stage juveniles. ConclusionsHigh density sampling, both temporally and across adjacent microniches, coupled with the power and relative low cost of metabarcoding, has provided us with a high resolution description of our study system. Such an approach can advance our understanding of holobiont ecology. Meloidogyne spp., with their relatively low genetic diversity, large geographic range and the simplified agricultural ecosystems they occupy, can serve as a model organism. Additionally, the perspective this approach provides could promote the efforts toward biological control efficacy.

microbiology↗

bioRxiv2019

Dissecting the factors shaping fish skin microbiomes in a heterogenous inland water system

Fish skin microbiomes are rarely studied in inland water systems, in spite of their importance for fish health and ecology. This is mainly because fish species distribution often covaries with other biotic and abiotic factors, complicating the study-design. We tackled this issue in the northern part of the Jordan River system, in which a few fish species geographically overlap, across a steep gradients of water temperature and salinity. Using 16S rRNA metabarcoding, we studied the water properties that shape the skin bacterial communities, and their interaction with fish taxonomy. We found that considering the skin-community contamination by water microbial community is important, even when the water and skin communities are apparently different. With this in mind, we found alpha diversity of the skin-communities to be stable across sites, but higher in bentic loaches, compared to other fish. Beta diversity was found to be different among sites and to weakly covary with the dissolved oxygen, when treated skin-communities were considered. In contrast, water temperature and conductivity were strong factors explaining beta diversity in the untreated skin-communities. Beta diversity differences between co-occurring fish species emerged only for the treated skin-communities. Metagenomics predictions highlighted the microbiome functional implications of excluding the water-communities contamination from the fish skin-communities. Finally, we found that human induced eutrophication promotes dysbiosis of the fish skin-community, with signatures relating to fish health. This finding was in line with recent studies, showing that biofilms capture sporadic pollution events, undetectable by interspersed water monitoring.

microbiology↗