Cultivating epizoic diatoms provides insights into the evolution and ecology of both epibionts and hosts

11 pages, 3 figures, 1 table, supplementary information https://doi.org/10.1038/s41598-022-19064-0.-- Data availability: DNA sequence data generated for this study are published on the NCBI GenBank online sequence depository under the accession numbers listed in Table S1. Additional micrographs and cleaned voucher material from the sequenced cultures are available from lead author MPAOur understanding of the importance of microbiomes on large aquatic animals—such as whales, sea turtles and manatees—has advanced considerably in recent years. The latest observations indicate that epibiotic diatom communities constitute diverse, polyphyletic, and compositionally stable assemblages that include both putatively obligate epizoic and generalist species. Here, we outline a successful approach to culture putatively obligate epizoic diatoms without their hosts. That some taxa can be cultured independently from their epizoic habitat raises several questions about the nature of the interaction between these animals and their epibionts. This insight allows us to propose further applications and research avenues in this growing area of study. Analyzing the DNA sequences of these cultured strains, we found that several unique diatom taxa have evolved independently to occupy epibiotic habitats. We created a library of reference sequence data for use in metabarcoding surveys of sea turtle and manatee microbiomes that will further facilitate the use of environmental DNA for studying host specificity in epizoic diatoms and the utility of diatoms as indicators of host ecology and health. We encourage the interdisciplinary community working with marine megafauna to consider including diatom sampling and diatom analysis into their routine practicesFinancial support for sequencing and SEM comes from the Jane and the Roland Blumberg Centennial Professorship in Molecular Evolution at UT Austin and the US Department of Defense (grant number W911NF-17-2-0091). Sampling in South Africa was done with partial financial support from The Systematics Association (UK) through the Systematics Research Fund Award granted to RM (2017 and 2020). Work in the Adriatic Sea was supported by Croatian Science Foundation, project UIP-05-2017-5635 (TurtleBIOME). KF has been fully supported by the “Young researchers' career development project – training of doctoral students” of the CSF funded by the EU from the European Social Fund. NJR was funded by the Spanish government (AEI) through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S)Peer reviewe

Effectiveness of different methods of preparing seedlings of cereals under sterile conditions for investigations of nucleic acids using radioactive precursors

On seedlings grown from grain not sterilized in advance bacteria numbered more than 108 microorganisms per one gram of fresh weight. Washing of seedlings with cetyltrimethylammonium bromide or sodium lauryl sulphate solutions reduced the number of bacteria several times. Sterilization of grains prior to planting with sodium hypochlorite and germination on solid substratum (perlit) reduced the number of bacteria to below 104 microorganisms to one gram of fresh weight. If germination was, however, in water, bacteria on the seedlings were approximately as numerous as on seedlings from mon-sterilized grains. Of the three antibiotics tested (streptomycin, chloramphenicol, penicillin) the most effective against the bacteria of wheat seedlings was chloramphenicol coupled with streptomycin; of antibiotics used singly chloramphenicol was best

Fractions of nucleic acids in seedlings and leaves of winter wheat in the vegetative and generative development phases

The composition of nucleic acid preparations isolated from seedlings and leaves of plants grown from vernalized and nonvernalized winter wheat grain was chromatographically investigated on a methylated albumin kieselguhr column (MAK column). The intensity of synthesis of the particular nucleic acid fractions was compared by the 32P-incorporation technique and the nucleotide composition of the newly synthesized nucleic acid fractions was determined. It was observed that the rate of 32P incorporation into the sRNA, rRNA+mRNA and TB-RNA fractions of the leaves of vernalized plants was about two times higher as compared with that in the nonvernalized control

Applying of balance equation to selected physical issues which occur in heading in a mine

W artykule przedstawiono ogólne równanie bilansu analizowanych wielkości fizycznych, które po nadaniu im odpowiedniej interpretacji prowadzi do równań opisujących takie procesy, jak przewodzenie ciepła, filtracja czy dyfuzja gazów. Procesy te występują w zagadnieniach przewietrzania kopalń, wobec tego zamieszczono również przykłady obliczeniowe dotyczące procesów, jakie mogą wystąpić w wyrobiskach górniczych.In this article the general balance equation has been shown for analysing physical items. After having these physical items interpreted, it is possible to receive equation for such processes like: heat conduction, filtration or gas diffusion. Those processes take place in issues of mining ventilation, in that case there has been placed some examples of other calculations of processes which can appear in case of heading in a mine

Heat exchange between air and cooled water in a pipeline located in a dead-end heading

Wykorzystanie wodnej chłodnicy przeponowej do schładzania powietrza w ślepym wyrobisku górniczym wymaga doprowadzenia do niej rurociągiem zimnej wody. Wydajność cieplna takiej chłodnicy zależy od temperatury dostarczonej do niej zimnej wody. Zabudowa rurociągu wodnego w wyrobisku, w którym płynie ciepłe powietrze, powoduje, że temperatura wody płynącej rurociągiem wzrasta i na wlocie chłodnicy jest wyższa od odpowiadającej wlotowi rurociągu. W artykule podano równania bilansów entalpii powietrza w ślepym wyrobisku (dla warunków bez kondensacji pary wodnej na zewnętrznej powierzchni rurociągu) i zimnej wody płynącej zabudowanym w tym wyrobisku izolowanym rurociągiem do chłodnicy powietrza oraz równania opisujące przepływ ciepła przez ściankę rurociągu od powietrza do wody. Układ równań entalpii powietrza i wody rozwiązano analitycznie, podając rozkłady temperatur powietrza i wody wzdłuż wyrobiska, a następnie - wykorzystując zależności ujmujące przenikanie ciepła przez ściankę rurociągu - podano też rozkłady wzdłuż wyrobiska temperatur wewnętrznej i zewnętrznej ścianki rurociągu oraz rozkład jednostkowego strumienia ciepła wymienianego między powietrzem a wodą. Zamieszczono przykład liczbowy, którego rozwiązanie - rozkłady wymienionych wielkości wzdłuż ślepego wyrobiska - przedstawiono w postaci wykresów, podano też przyrost temperatury zimnej wody w rurociągu.If we want to use a water diaphragm cooler of air in a dead-end heading, cold water must be brought into it through a pipeline. Heat capacity of such a cooler depends on the temperature of water supplied to it. Locating a water pipeline in a heading, in which warm air flows, leads to an increase in the temperature of water in pipe and is higher at the inlet of a cooler than at the inlet of pipeline. This article presents equations of air enthalpy balance in the dead end heading (without water vapor condensation on the external surface of the pipe) and cold water flowing through an insulated pipeline to the cooler of air as well as equations describing heat flow through the side wall of a pipeline from air to water. A set of equations of air and water enthalpy was solved analytically, giving distributions of air and water temperatures along the heading and, later on, using the dependences describing heat transmission through the wall of a pipe. Both distributions of temperatures of internal and external sides of pipe in the heading and the distribution of elementary heat flow exchanged between air and water are given. A calculation example, whose solution - distributions of the values mentioned above along the heading are shown in the form of graphs, was presented. An increase in temperature of cold water in a pipeline was also presented