4/2/2023 0 Comments Shapes of bacteria![]() ![]() Our results revealed a correlation between prokaryote colonization of the gill surfaces and the host lifestyle. Quantitative analysis of scanning electron microscopy images and the quantification of the bacterial 16S rRNA gene by qPCR revealed a higher specific abundance of prokaryote cells per gill surface area in the subtidal species than those living in the supratidal zone. The presence of replicating cells indicated that the prokaryote layer is actively growing on the gill surface. We consistently observed two distinct morphotypes (rod- and spherical-shaped), positioned horizontally and/or perpendicularly to the gill surface. Using electron microscopy techniques, we found a thick layer of prokaryotes over the gill surfaces of all of 12 crab species from the mangrove forests of Saudi Arabia, Kenya and South Africa. We hypothesize that similarly to other marine animals, the gills of tidal crabs are consistently colonized by prokaryotes that may quantitatively change along the environmental gradient driven by the tides. In these animals, the gill undergoes a high selective pressure, finely regulating multiple physiological functions during both animal submersion under and emersion from the periodical tidal events. We selected mangrove brachyuran crabs as a model group to investigate the prokaryotes associated with the gill of crabs dwelling at different tidal levels (subtidal, intertidal and supratidal). Microbial symbiosis is known to have played an important role in eukaryote evolution, favouring host adaptation under changing environmental conditions. Care should thus be taken to ensure that a method used to preserve stress adapted cells does not cause them to lose beneficial properties, nor revert to their pre-adaptation status.ĭue to the chemico-physical differences between air and water, the transition from aquatic life to the land poses several challenges for animal evolution, necessitating morphological, physiological and behavioural adaptations. Prolonged freezing compromised some functional properties of stress adapted cells and their stability under simulated GIT conditions. Under simulated GIT conditions, the viability of the stress adapted cells from the freezer diminished more than that of freshly adapted cells. plantarum B411 cells in foods was similar. The viability of freshly adapted and old adapted L. Long-term freezing negatively affected the morphology, auto-aggregation ability, BSH and antimicrobial activities of L. ![]() plantarum B411 cells in yoghurt and juices during storage and under simulated gastrointestinal (GIT) conditions was evaluated. Cell morphology was investigated using scanning electron microscopy, and then their selected functional (bile salt hydrolase (BSH) activity, surface hydrophobicity, auto-aggregative and antimicrobial) properties were evaluated. This study examined the impact of long-term freezing on structural and functional properties of multi-stress (acid, bile and heat) adapted Lactiplantibacillus plantarum B411. However, little is known about how long-term cold storage affects the properties of such preadapted probiotics. ![]() The preadaptation of probiotics to sub-lethal levels of multiple stress factors boosts their survival and stability. ![]()
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